Do the Pros of Brown Rice Outweigh the Cons of Arsenic?

Are there unique benefits to brown rice that would justify keeping it in our diet despite the arsenic content?

For years, warnings had been given about the arsenic levels in U.S. rice potentially increasing cancer risk, but it had never been put to the test until a study out of Harvard. The finding? “Long-term consumption of total rice, white rice or brown rice[,] was not associated with risk of developing cancer in US men and women.” This was heralded as good news. Indeed, no increased cancer risk found even among those eating five or more servings of rice per week. But, wait a second: Brown rice is a whole grain, a whole plant food. Shouldn’t brown rice be protective and not just neutral? I discuss this in my video Do the Pros of Brown Rice Outweigh the Cons of Arsenic?.

If you look at whole grains in general, there is “a significant inverse”—or protective—“association between total whole-grain intake and risk of mortality from total cancers,” that is, dying from cancer. My Daily Dozen recommendation of at least three servings of whole grains a day was associated with a 10 percent lower risk of dying from cancer, a 25 percent lower risk of dying from heart attacks or strokes, and a 17 percent lower risk of dying prematurely across the board, whereas rice consumption in general was not associated with mortality and was not found to be protective against heart disease or stroke. So, maybe this lack of protection means that the arsenic in rice is increasing disease risk, so much so that it’s cancelling out some of the benefits of whole-grain brown rice.

Consumer Reports suggested moderating one’s intake of even brown rice, but, given the arsenic problem, is there any reason we should go out of our way to retain any rice in our diet at all? With all of the other whole grain options out there, should we just skip the rice completely? Or, are there some unique benefits we can get from rice that would justify continuing to eat it, even though it has ten times more arsenic than other grains?

One study showed that “a brown rice based vegan diet” beat out the conventional Diabetes Association diet, even after adjusting for the extra belly fat lost by the subjects on the vegan diet, but that may have been due to the plant-based nature of their diet rather than just how brown rice-based it was.

Another study found a profound improvement in insulin levels after just five days eating brown rice compared to white rice, but was that just because the white rice made people worse? No, the brown rice improved things on its own, but the study was done with a South Indian population eating a lot of white rice to begin with, so this may have indeed been at least in part a substitution effect. And yet another study showed that instructing people to eat about a cup of brown rice a day “could significantly reduce weight, waist and hip circumference, BMI, Diastole blood pressure,” and inflammation—and not just because it was compared to white. However, a larger, longer study failed to see much more than a blood pressure benefit, which was almost as impressive in the white-rice group, so, overall, not too much to write home about.

Then, another study rolled around—probably the single most important study on the pro-rice sideshowing a significant improvement in artery function after eight weeks of eating about a daily cup of brown rice, but not white, as you can see at 3:18 in my video, and sometimes even acutely. If you give someone a meal with saturated fat and white rice, you can get a drop in artery function within an hour of consumption if you have some obesity-related metabolic derangements. But, if you give brown rice instead of white, artery function appears protected against the adverse effects of the meal. Okay, so brown rice does show benefits in interventional studies, but the question is whether it shows unique benefits. Instead, what about oatmeal or whole wheat?

Well, first, researchers needed to design an artery-crippling meal, high in saturated fat. They went with a Haagen Daaz, coconut cream, and egg milkshake given with a bowl of oatmeal or “a comparable bowl of whole rolled wheat.” What do you think happened? Do you think these whole grains blocked the artery-damaging effects like the brown rice did? The whole oats worked, but the whole wheat did not. So, one could argue that brown rice may have an edge over whole wheat. Do oats also have that beneficial long-term effect that brown rice did? The benefit was of a similar magnitude but did not reach statistical significance.

So, what’s the bottom line? Until we know more, my current thinking on the matter is that if you really like rice, you can moderate your risk by cutting down, choosing lower arsenic varieties, and cooking it in a way to lower exposure even further. But, if you like other whole grains just as much and don’t really care if you have rice versus quinoa or another grain, I’d choose the lower arsenic option.

Tada! Done with arsenic in the food supply—for now. Should the situation change, I’ll produce another video on the latest news. Make sure you’re subscribed so you don’t miss any updates.


Here are all 13 videos in the series, in case you missed any or want to go back and review:

And you may be interested in Benefits of Turmeric for Arsenic Exposure.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Cancer Risk from Arsenic in Rice and Seaweed

A daily half-cup of cooked rice may carry a hundred times the acceptable cancer risk of arsenic. What about seaweed from the coast of Maine?

“At one point during the reign of King Cotton, farmers in the south central United States controlled boll weevils with arsenic-based pesticides, and residual arsenic still contaminates the soil.” Different plants have different reactions to arsenic exposure. Tomatoes, for example, don’t seem to accumulate much arsenic, but rice plants are really good at sucking it out of the ground—so much so that rice can be used for “arsenic phytoremediation,” meaning you can plant rice on contaminated land as a way to clear arsenic from the soil. Of course, you’re then supposed to throw the rice—and the arsenic—away. But in the South, where 80 percent of U.S. rice is grown, we instead feed it to people.

As you can see at 0:52 in my video Cancer Risk from Arsenic in Rice and Seaweed, national surveys have shown that most arsenic exposure has been measured coming from the meat in our diet, rather than from grains, with most from fish and other seafood. Well, given that seafood is contributing 90 percent of our arsenic exposure from food, why are we even talking about the 4 percent from rice?

The arsenic compounds in seafood are mainly organic—used here as a chemistry term having nothing to do with pesticides. Because of the way our body can deal with organic arsenic compounds, “they have historically been viewed as harmless.” Recently, there have been some questions about that assumption, but there’s no question about the toxicity of inorganic arsenic, which you get more of from rice.

As you can see at 1:43 in my video, rice contains more of the toxic inorganic arsenic than does seafood, with one exception: Hijiki, an edible seaweed, is a hundred times more contaminated than rice, leading some researchers to refer to it as the “so-called edible hijiki seaweed.” Governments have started to agree. In 2001, the Canadian government advised the public not to eat hijiki, followed by the United Kingdom, the European Commission, Australia, and New Zealand. The Hong Kong Centre for Food Safety advised the public not to eat hijiki and banned imports and sales of it. Japan, where there is actually a hijiki industry, just advised moderation.

What about seaweed from the coast of Maine—domestic, commercially harvested seaweed from New England? Thankfully, only one type, a type of kelp, had significant levels of arsenic. But, it would take more than a teaspoon to exceed the provisional daily limit for arsenic, and, at that point, you’d be exceeding the upper daily limit for iodine by about 3,000 percent, which is ten times more than reported in a life-threatening case report attributed to a kelp supplement.

I recommend avoiding hijiki due to its excess arsenic content and avoiding kelp due to its excess iodine content, but all other seaweeds should be fine, as long as you don’t eat them with too much rice.

In the report mentioned earlier where we learned that rice has more of the toxic inorganic arsenic than fish, we can see that there are 88.7 micrograms of inorganic arsenic per kilogram of raw white rice. What does that mean? That’s only 88.7 parts per billion, which is like 88.7 drops of arsenic in an Olympic-size swimming pool of rice. How much cancer risk are we talking about? To put it into context, the “usual level of acceptable risk for carcinogens” is one extra cancer case per million. That’s how we typically regulate cancer-causing substances. If a chemical company wants to release a new chemical, we want them to show that it doesn’t cause more than one in a million excess cancer cases.

The problem with arsenic in rice is that the excess cancer risk associated with eating just about a half cup of cooked rice a day could be closer to one in ten thousand, not one in a million, as you can see at 4:07 in my video. That’s a hundred times the acceptable cancer risk. The FDA has calculated that one serving a day of the most common rice, long grain white, would cause not 1 in a million extra cancer cases, but 136 in a million.

And that’s just the cancer effects of arsenic. What about all the non-cancer effects? The FDA acknowledges that, in addition to cancer, the toxic arsenic found in rice “has been associated with many non-cancer effects, including ischemic heart disease, diabetes, skin lesions, renal [kidney] disease, hypertension, and stroke.” Why, then, did the FDA only calculate the cancer risks of arsenic? “Assessing all the risks associated with inorganic arsenic would take considerable time and resources and would delay taking any needed action to protect public health” from the risks of rice.

“Although physicians can help patients reduce their dietary arsenic exposure, regulatory agencies, food producers, and legislative bodies have the most important roles” in terms of public health-scale changes. “Arsenic content in U.S.-grown rice has been relatively constant throughout the last 30 years,” which is a bad thing.

“Where grain arsenic concentration is elevated due to ongoing contamination, the ideal scenario is to stop the contamination at the source.” Some toxic arsenic in foods is from natural contamination of the land, but soil contamination has also come from the dumping of arsenic-containing pesticides, as well as the use of arsenic-based drugs in poultry production and then the spreading of arsenic-laced chicken manure on the land. Regardless of why south central U.S. rice paddies are so contaminated, we shouldn’t be growing rice in arsenic-contaminated soil.

What does the rice industry have to say for itself? Well, it started a website called ArsenicFacts. Its main argument appears to be that arsenic is everywhere, we’re all exposed to it every day, and it’s in most foods. But shouldn’t we try to cut down on the most concentrated sources? Isn’t that like saying look, diesel exhaust is everywhere, so why not suck on a tailpipe? The industry website quotes a nutrition professor saying, “All foods contain arsenic. So, if you eliminate arsenic from your diet, you will decrease your risk…and you’ll die of starvation.” That’s like Philip Morris saying that the only way to completely avoid secondhand smoke is to never breathe—but then you’ll asphyxiate, so you might as well just start smoking yourself. If you can’t avoid it, you might as well consume the most toxic source you can find?!

That’s the same tack the poultry industry took. Arsenic and chicken? “No need to worry” because there’s a little arsenic everywhere. That’s why it’s okay the industry fed chickens arsenic-based drugs for 70 years. If you can’t beat ’em, join ’em.

How can the rice industry get away with selling a product containing a hundred times the acceptable cancer risk? I cover that and so much more in my other videos on arsenic and rice, which also include concrete recommendations on how to mediate your risk.


Check out:

Pesticides were not the only source of arsenic. Poultry poop, too, if you can believe it! I cover that story in Where Does the Arsenic in Chicken Come From? and Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?.

Chronic low-dose arsenic exposure is associated with more than just cancer. See The Effects of Too Much Arsenic in the Diet.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

The Effects of Too Much Arsenic in the Diet

Even at low-level exposure, arsenic is not just a class I carcinogen, but may also impair our immune function and increase our risk of cardiovascular disease and diabetes.

When people hear about arsenic, they think of it as an acute poison, and, indeed, a tiny amount—a hundred milligrams, about one-tenth the weight of a paperclip—could kill you in an hour. But, there is also chronic arsenic poisoning, where even a dose 10,000 times as small can be harmful if you’re exposed day-after-day for years at a time as I discuss in my video The Effects of Too Much Arsenic in the Diet. Chief among the concerns is cancer.

Arsenic is classified as a class I carcinogen, which is the highest level and includes things known to cause cancer in humans. Other class I carcinogens are asbestos, cigarette smoke, formaldehyde, plutonium, and processed meat (the consumption of bacon, ham, hot dogs, deli meat, and the like). So, arsenic is pretty bad, to say the least, implicated in tens of thousands—or even hundreds of thousands—of cancer cases worldwide every year.

Of course, cancer is our number-two killer. What about heart disease, our leading cause of death? “Long-term exposure to low to moderate arsenic levels was associated with cardiovascular disease incidence and mortality,” meaning heart attacks and strokes.

Arsenic is also considered an immunotoxicant, meaning it’s toxic to our immune system. How do we know that? There’s a virus called varicella, which is what causes chickenpox—the first time we get it. Our immune system is able to stamp it down but not stamp it out. The virus retreats into our nerve cells where it lies in wait for our immune function to dip. And, when it does, the virus re-emerges and causes a disease called shingles. We’ve all been exposed to the virus, but only about one in three of us will get shingles because our immune system is able to keep it at bay. However, the virus can slip its muzzle as we get older or immunosuppressed, for instance, if we’re given arsenic chemotherapy. Shingles is a common side effect, because the arsenic drugs not only kill the cancer but also some of our immune cells, too. That’s at high doses, though. Might even low doses of arsenic, like the kind we’re exposed to in our daily diet, impact our immune function? Researchers tested the levels of arsenic in the urine of thousands of Americans, along with their levels of anti-virus antibodies, and, indeed, they found that the more arsenic the subjects had flowing through their bodies, the lower their defenses.

And, if you’re pregnant, arsenic can pass to your baby, possibly increasing the risk of miscarriage or infant mortality, and “may affect an infant’s immune development and susceptibility to infections early in life.” Indeed, a study out of New Hampshire on infant infections in relation to prenatal arsenic exposure found that the more arsenic the mom was exposed to during pregnancy, the higher the baby’s risk of infection during infancy. However, “it’s unknown whether arsenic-induced epigenetic changes are transgenerational”—that is, whether changes in gene expression can impact the health of not only your own children but your grandchildren as well. Regardless, arsenic exposure isn’t good for mom’s own health, as it is associated with increasing blood pressure.

Hold on. If arsenic suppresses immune system function, then, as a silver lining, would we, for example, have fewer allergies, which is a kind of over-reaction of the immune system? Apparently not. Those with higher arsenic levels tend to have higher rates of food allergies, tend not to sleep as well, and tend not to feel as well. When people were asked how they would rate their health, those reporting “excellent” or “very good” tended to have lower levels of arsenic, compared to those who reported their general health condition as “good,” “fair,” or “poor,” who tended to have higher arsenic levels.

What about diabetes? You can see the results of two dozen population studies on arsenic exposure and confirmed diabetes at 4:07 in my video. Any result above one suggests increased risk for diabetes, and any result below one suggests lower risk. The findings? “Our results support an association between ingested arsenic and DM [diabetes] in humans.” Population studies can’t prove cause and effect, though. “While it would be nice to demonstrate a cause and effect relationship…is it necessary?”

We know arsenic is a carcinogen. We know it causes cancer. What more do we need to take steps to decrease our exposure?

Where is arsenic found in our diet? See my videos Where Does the Arsenic in Chicken Come From?  and Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?.


 Ready for a deep dive into the rice issue? Check out:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

 

 

 

What White Blood Cell Count Should We Shoot for?

At the start of my video What Does a Low White Blood Cell Count Mean?, you can see what it looks like when you take a drop of blood, smear it between two pieces of glass, and view at it under a microscope: a whole bunch of little, round, red blood cells and a few big, white blood cells. Red blood cells carry oxygen, while white blood cells are our immune system’s foot soldiers. We may churn out 50 billion new white blood cells a day. In response to inflammation or infection, that number can shoot up to a 100 billion or more. In fact, pus is largely composed of: millions and millions of white blood cells.

Testing to find out how many white blood cells we have at any given time is one of the most common laboratory tests doctors order. It’s ordered it hundreds of millions of times a year. If, for example, you end up in the emergency room with abdominal pain, having a white blood cell count above about 10 billion per quart of blood may be a sign you have appendicitis. Most Americans fall between 4.5 and 10, but most Americans are unhealthy. Just because 4.5 to 10 is typical doesn’t mean it’s ideal. It’s like having a “normal” cholesterol level in a society where it’s normal to die of heart disease, our number-one killer. The average American is overweight, so if your weight is “normal,” that’s actually a bad thing.

In fact, having excess fat itself causes inflammation within the body, so it’s no surprise that those who are obese walk around with two billion more white cells per quart of blood. Given that, perhaps obese individuals should have their own “normal” values. As you can see at 2:06 in my video, if someone with a 47-inch waist walks into the ER with a white blood cell count of 12, 13, or even 14, they may not have appendicitis or an infection. That may just be their normal baseline level, given all the inflammation they have in their body from the excess fat. So, normal levels are not necessarily healthy levels.

It’s like smoking. As you can see at 2:31 in my video, if you test identical twins and one smokes but the other doesn’t, the smoker is going to end up with a significantly higher white cell count. In Japan, for example, as smoking rates have steadily dropped, so has the normal white count range. In fact, it’s dropped such that about 8 percent of men who have never smoked would now be flagged as having abnormally low white counts if you used a cut-off of 4. But, when that cut-off of 4 was set, most people were smoking. So, maybe 3 would be a better lower limit. The inflammation caused by smoking may actually be one of the reasons cigarettes increase the risk of heart attacks, strokes, and other inflammatory diseases. So, do people who have lower white counts have less heart disease, cancer, and overall mortality? Yes, yes, and yes. People with lower white blood cell counts live longer. Even within the normal range, every one point drop may be associated with a 20 percent drop in the risk of premature death.

As you can see at 3:39 in my video, there is an exponential increase in risk in men as white count goes up, even within the so-called normal range, and the same is found for women. The white blood cell count is a “stable, well-standardized, widely available and inexpensive measure of systemic inflammation.” In one study, half of the women around 85 years of age who had started out with white counts under 5.6 were still alive, whereas 80 percent of those who started out over 7 were dead, as you can see at 4:05 in my video—and white blood cell counts of 7, 8, 9, or even 10 would be considered normal. Being at the high end of the normal range may place one at three times the risk of dying from heart disease compared to being at the lower end.

The same link has been found for African-American men and women, found for those in middle age, found at age 75, found at age 85, and found even in our 20s and 30s: a 17 percent increase in coronary artery disease incidence for each single point higher.

As you can see at 5:00 in my video, the higher your white count, the worse your arterial function may be and the stiffer your arteries may be, so it’s no wonder white blood cell count is a useful predictor of high blood pressure and artery disease in your heart, brain, legs, and neck. Even diabetes? Yes, even diabetes, based on a compilation of 20 different studies. In fact, it may be associated with everything from fatty liver disease to having an enlarged prostate. And, having a higher white blood cell count is also associated with an increased risk of dying from cancer. So, what would the ideal range be? I cover that in my video What Is the Ideal White Blood Cell Count?.

A higher white blood cell count may be an important predictor for cardiovascular disease incidence and mortality, decline in lung function, cancer mortality, all-cause mortality, heart attacks, strokes, and premature death in general. This is no surprise, as the number of white blood cells we have circulating in our bloodstreams are a marker of systemic inflammation. Our bodies produce more white blood cells day to day in response to inflammatory insults.

We’ve known about this link between higher white counts and heart attacks since the 1970s, when we found that higher heart attack risk was associated with higher white blood cell counts, higher cholesterol levels, and higher blood pressures, as you can see at 0:53 in my video What Is the Ideal White Blood Cell Count?. This has been found in nearly every study done since then. There are decades of studies involving hundreds of thousands of patients showing dramatically higher mortality rates in those with higher white counts. But why? Why does white blood cell count predict mortality? It may be because it’s a marker of inflammation and oxidation in the body. In fact, it may even be a biomarker for how fast we are aging. It may be more than just an indicator of inflammation—it may also be an active player, contributing directly to disease via a variety of mechanisms, including the actual obstruction of blood flow.

The average diameter of a white blood cell is about seven and a half micrometers, whereas our tiniest vessels are only about five micrometers wide, so the white blood cell has to squish down into a sausage shape in order to squeeze through. When there’s inflammation present, these cells can get sticky. As you can see at 2:20 in my video, a white blood cell may plug up a vessel as it exits a small artery and tries to squeeze into a capillary, slowing down or even momentarily stopping blood flow. And, if it gets stuck there, it can end up releasing all of its internal weaponry, which is normally reserved for microbial invaders, and damage our blood vessels. This may be why in the days leading up to a stroke or heart attack, you may find a spike in the white cell count.

Whether white count is just a marker of inflammation or an active participant, it’s better to be on the low side. How can we reduce the level of inflammation in our body? Staying away from even second-hand smoke can help drop your white count about half of a point. Those who exercise also appear to have an advantage, but you don’t know if it’s cause and effect unless you put it to the test. In one study, two months of Zumba classes—just one or two hours a week—led to about a point and a half drop in white count. In fact, that may be one of the reasons exercise is so protective. But is that just because they lost weight?

Fitness and fatness both appear to play a role. More than half of obese persons with low fitness—51.5 percent—have white counts above 6.6, but those who are more fit or who have less fat are less likely to have counts that high, as you can see at 3:47 in my video. Of course, that could just be because exercisers and leaner individuals are eating healthier, less inflammatory diets. How do we know excess body fat itself increases inflammation, increases the white count? You’d have to find some way to get people to lose weight without changing their diet or exercise habit. How’s that possible? Liposuction. If you suck about a quart of fat out of people, you can significantly drop their white count by about a point. Perhaps this should get us to rethink the so-called normal reference range for white blood cell counts. Indeed, maybe we should revise it downward, like we’ve done for cholesterol and triglycerides.

Until now, we’ve based normal values on people who might be harboring significant background inflammatory disease. But, if we restrict it to those with normal C-reactive protein, another indicator of inflammation, then instead of “normal” being 4.5 to 10, perhaps we should revise it closer to 3 to 9.

Where do the healthiest populations fall, those not suffering from the ravages of chronic inflammatory diseases, like heart disease and common cancers? Populations eating diets centered around whole plant foods average about 5, whereas it was closer to 7 or 8 in the United States at the time. How do we know it isn’t just genetic? As you can see at 5:38 in my video, if you take those living on traditional rural African diets, who have white blood cell counts down around 4 or 5, and move them to Britain, they end up closer to 6, 7, or even 8. Ironically, the researchers thought this was a good thing, referring to the lower white counts on the “uncivilized” diet as neutropenic, meaning having too few white blood cells. They noted that during an infection or pregnancy, when more white cells are needed, the white count came right up to wherever was necessary. So, the bone marrow of those eating traditional plant-based diets had the capacity to create as many white cells as needed but “suffers from understimulation.”

As you can see at 6:26 in my video, similar findings were reported in Western plant eaters, with an apparent stepwise drop in white count as diets got more and more plant based, but could there be non-dietary factors, such as lower smoking rates, in those eating more healthfully? What we need is an interventional trial to put it to the test, and we got one: Just 21 days of removing meat, eggs, dairy, alcohol, and junk affected a significant drop in white count, even in people who started out down at 5.7.

What about patients with rheumatoid arthritis who started out even higher, up around 7? As you can see at 7:03 in my video, there was no change in the control group who didn’t change their diet, but there was a 1.5 point drop within one month on whole food plant-based nutrition. That’s a 20 percent drop. That’s more than the drop-in inflammation one might get quitting a 28-year pack-a-day smoking habit. The most extraordinary drop I’ve seen was in a study of 35 asthmatics. After four months of a whole food plant-based diet, their average white count dropped nearly 60 percent, from around 12 down to 5, though there was no control group nor enough patients to achieve statistical significance.

If white blood cell count is such a clear predictor of mortality and is so inexpensive, reliable, and available, why isn’t it used more often for diagnosis and prognosis? Maybe it’s a little too inexpensive. The industry seems more interested in fancy new risk factors it can bill for.

I touch on the health of the rural Africans I discussed in How Not to Die from Heart Disease.


For more on fighting inflammation, see:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Garlic Powder to Lower Lead Levels

There are so-called chelation drugs that can be taken for acute, life-threatening lead poisoning—for instance if your two-year-old swallowed one of the little lead weights her grandma was using while sewing curtains and the doctor happened to miss it on x-ray, so it stayed lodged inside her until she died with a blood lead level of 283 mcg/dcl, a case I discuss in my video Best Foods for Lead Poisoning: Chlorella, Cilantro, Tomatoes, Moringa?.

However, for lower grade, chronic lead poisoning, such as at levels under 45 μg/dL, there were no clear guidance as to whether these chelation drugs were effective. When they were put to the test, the drugs failed to bring down lead levels long term. Even when they worked initially, in dose after dose, the lead apparently continued to seep from the patients’ bones, and, by the end of the year, they ended up with the same lead levels as the sugar pill placebo group, as you can see at 0:50 in my video. It was no surprise, then, that even though blood lead levels dipped at the beginning, researchers found no improvements in cognitive function or development.

Since much of lead poisoning is preventable and the drugs don’t seem to work in most cases, that just underscores the need “to protect children from exposure to lead in the first place.” Despite the medical profession’s “best intentions to do something to help these kids…drug therapy is not the answer.” Yes, we need to redouble efforts to prevent lead poisoning in the first place, but what can we do for the kids who’ve already been exposed?

The currently approved method, these chelating drugs that bind and remove lead from our tissues, “lack[s]…safety and efficacy when conventional chelating agents are used.” So, what about dietary approaches? Plants produce phytochelatins. All higher plants possess the capacity to synthesize compounds that bind up heavy metals to protect themselves from the harmful effects, so what if we ate the plants? “Unlike other forms of treatment (e.g., pharmacotherapy with drugs), nutritional strategies carry the promise of a natural form of therapy that would presumably be cheap and with few to no side effects.” Yes, but would it work when the drugs didn’t?

We had learned that a meal could considerably cut down on lead absorption, but “the particular components of food intake that so dramatically reduce lead absorption” were uncertain at the time. Although the calcium content of the meal appeared to be part of it, milk didn’t seem to help and even made things worse. What about calcium supplements? Some assert that calcium supplements may help in reducing lead absorption in children, but “recommendations…must be based on evidence rather than conviction.” What’s more, those assertions are based in part on studies on rodents, and differences in calcium absorption and balance between rats and humans make extrapolation tricky. What you have to do is put it to the test. Researchers found that even an extra whopping 1,800 mg of calcium per day had no effect on blood lead levels. Therefore, the evidence doesn’t support conclusions that calcium supplements help.

What about whole foods? Reviews of dietary strategies to treat lead toxicity say to eat lots of tomatoes, berries, onions, garlic, and grapes, as they are natural antagonists to lead toxicity and therefore should be consumed on a regular basis. Remember those phytochelatins? Perhaps eating plants might help detoxify the lead in our own bodies or the bodies of those we eat.

These natural phytochelatin compounds work so well that we can use them to clean up pollution. For example, the green algae chlorella can suck up lead and hold onto it, so what if we ate it? If it can clean up polluted bodies of water, might it clean up our own polluted bodies? We don’t know, because we only have studies on mice, not men and women.

So, when you hear how chlorella detoxifies, they’re talking about the detoxification of rat testicles. Yes, a little sprinkle of chlorella might help your pet rat, or perhaps you could give them some black cumin seeds or give them a sprig of cilantro, but when you hear how cilantro detoxifies against heavy metals, I presume you don’t expect the researchers to be talking about studies in rodents. If we’re interested in science protecting our children, not just their pets, we’re out of luck.

The same is true with moringa, tomatoes, flaxseed oil, and sesame seed oil, as well as black grapes, and black, white, green, and red tea. There are simply no human studies to guide us.

Dietary strategies for the treatment of lead toxicity are often based on rodent studies, but, for tofu, at least, there was a population study of people that showed lower lead levels in men and women who ate more tofu. The researchers controlled for a whole bunch of factors, so it’s not as if tofu lovers were protected just because they smoked less or ate less meat, but you can’t control for everything.

Ideally, we’d have a randomized, placebo-controlled study. Researchers would take a group of people exposed to lead, split them into two groups, with half given food and the other half given some kind of identical placebo food, and see what happens. It’s easy to do this with drugs because you just use look-alike sugar pills as placebos so people don’t know which group they’re in, but how do you make placebo food? One way to do disguised food interventions is to use foods that are so potent they can be stuffed into a pill—like garlic. There had been various studies measuring the effects of garlic in rats and looking at garlic as a potential antidote for lead intoxication distributed among different mouse organs, but who eats mouse organs? One animal study did have some direct human relevance, though, looking at the effect of garlic on lead content in chicken tissues. The purpose was to “explore the possible use of garlic to clean up lead contents in chickens which”—like all of us on planet Earth—“had been exposed to lead pollution and consequently help to minimize the hazard” of lead-polluted chicken meat.

And…it worked! As you can see at 1:59 in my video Best Food for Lead Poisoning: Garlic, feeding garlic to chickens reduced lead levels in the “edible mass of chicken” by up to 75 percent or more. Because we live in a polluted world, even if you don’t give the chickens lead and raise them on distilled water, they still end up with some lead in their meat and giblets. But, if you actively feed them lead for a week, the levels get really high. When you give them the same amount of lead with a little garlic added, however, much less lead accumulates in their bodies.

What’s even more astonishing is that when researchers gave them the same amount of lead—but this time waited a week before giving them the garlic—it worked even better. “The value of garlic in reducing lead concentrations…was more pronounced when garlic was given as a post-treatment following the cessation of lead administration”—that is, after the lead was stopped and had already built up in their tissues. We used to think that “the beneficial effect of garlic against lead toxicity was primarily due to a reaction between lead and sulfur compounds in garlic” that would glom on to lead in the intestinal tract and flush it out of the body. But, what the study showed is that garlic appears to contain compounds that can actually pull lead not only out of the intestinal contents, but also out of the tissues of the body. So, the “results indicate that garlic contain chelating compounds capable of enhancing elimination of lead,” and “garlic feeding can be exploited to safeguard human consumers by minimizing lead concentrations in meat….”

If garlic is so effective at pulling lead out of chickens’ bodies, why not more directly exploit “garlic feeding” by eating it ourselves? Well, there had never been a study on the ability of garlic to help lead-exposed humans until…2012? (Actually, I’m embarrassed to say I missed it when the study was first published. That was back when I was just getting NutritionFacts.org up and running. Now that we have staff and a whole research team, hopefully important studies like this won’t slip through the cracks in the future.)

The study was a head-to-head comparison of the therapeutic effects of garlic versus a chelation therapy drug called D-penicillamine. One hundred and seventeen workers exposed to lead in the car battery industry were randomly assigned into one of two groups and, three times a day for one month, either got the drug or an eighth of a teaspoon of garlic powder compressed into a tablet, which is about the equivalent of two cloves of fresh garlic a day. As expected, the chelation drug reduced blood lead levels by about 20 percent—but so did the garlic. The garlic worked just as well as the drug and, of course, had fewer side effects. “Thus, garlic seems safer clinically and as effective,” but saying something is as effective as chelation therapy isn’t saying much. Remember how chelation drugs can lower blood levels in chronic lead poisoning, but they don’t actually improve neurological function?

Well, after treatment with garlic, significant clinical improvements were seen, including less irritability, fewer headaches, and improvements in reflexes and blood pressure, but these improvements were not seen in the drug group. They weren’t seen after treatment with the chelation therapy drug. So, garlic was safer and more effective. “Therefore, garlic can be recommended for the treatment of mild-to-moderate lead poisoning.


 There are also some human studieson vitamin C. Check out Can Vitamin C Help with Lead Poisoning?.

For even more lead videos, see:

To learn more about chlorella, see:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Adult Exposure to Lead

“Children in approximately 4 million households in the United States are being exposed to high levels of lead.” As I discuss in my video The Effects of Low-Level Lead Exposure in Adults, “Despite the dramatic decline in children’s blood-lead concentrations over the decades, lead toxicity remains a major public health problem”—and not just for children. Yes, lead is “a devastating neurotoxin,” with learning disabilities and attention deficits in children beginning around blood lead levels of 10 mg/dL, which is when you start seeing high blood pressure and nerve damage in adults, as you can see at 0:41 in my video. But, the blood levels in American adults these days are down around 1 mg/dL, not 10 mg/dL, unless you work or play in an indoor firing range, where the lead levels in the air are so high that more than half of recreational target shooters have levels over 10 mg/dL or even 25 mg/dL.

In fact, even open-air outdoor ranges can be a problem. Spending just two days a month at such a range may quadruple blood lead levels and push them up into the danger zone. What if you don’t use firearms yourself but live in a house with someone who does? The lead levels can be so high that the Centers for Disease Control and Prevention advises those who go to shooting ranges to take “measures to prevent take-home exposure including showering and changing into clean clothes after shooting…, storing clean clothes in a separate bin from contaminated clothing, laundering of non disposable outer protective clothing…and leaving at the range shoes worn inside the firing range,” among other actions. Even if none of that applies and your blood levels are under 10 mg/dL, there is still some evidence of increased risk of hand tremors, high blood pressure, kidney damage, and other issues, as you can see at 1:44 in my video. But what if you’re down around a blood lead level of 1 mg/dL, like most people?

“Blood lead levels in the range currently considered acceptable are associated with increased prevalence of gout,” a painful arthritis. In fact, researchers found that blood levels as low as approximately 1.2 mg/dL, which is close to the current American average, can be associated with increased prevalence of gout. So, this means that “very low levels of lead may still be associated with health risks,” suggesting “there is no such thing as a ‘safe’ level of exposure to lead.”

Where is the lead even coming from? Lead only circulates in the body for about a month, so if you have lead in your bloodstream, it’s from some ongoing exposure. Most adults don’t eat peeling paint chips, though, and autos aren’t fueled by leaded gas anymore. There are specific foods, supplements, and cosmetics that are contaminated with lead (and I have videos on all those topics), but for most adults, the source of ongoing lead exposure is from our own skeleton. I just mentioned that lead only circulates in the body for about a month. Well, where does it go after that? It can get deposited in our bones. “More than 90% of the total body lead content resides in the bone, where the half-life is decades long,” not just a month. So, half or more of the lead in our blood represents lead from past exposures just now leaching out of our bones back into our bloodstream, and this “gradual release of lead from the bone serves as a persistent source of toxicity long after cessation of external exposure,” that is, long after leaded gasoline was removed from the pumps for those of us that who were around back before the 1980s.

So, the answer to where the lead comes from is like Pogo’s We’ve met the enemy and he is us or that classic horror movie scene where the call is coming from inside the house.

The amount of lead in our bones can actually be measured, and research shows higher levels are associated with some of our leading causes of death and disability, from tooth decay and miscarriages to cognitive decline and cataracts. “Much of the lead found in adults today was deposited decades ago. Thus, regulations enacted in the 1970s were too late” for many of us, but at least things are going in the right direction now. The “dramatic societal decreases” in blood lead in the United States since the 1970s have been associated with a four- to five-point increase in the average IQs of American adults. Given that, a “particularly provocative question is whether the whole country suffered brain damage prior to the 1980 decreases in blood lead. Was ‘the best generation’ really the brain damaged generation?”

I’m such a sucker for science documentaries, and my favorite episode of Cosmos: A Spacetime Odyssey was The Clean Room, which dealt with this very issue. Trivia: Carl Sagan was my next-door neighbor when I was at Cornell!

If you want to find out How the Leaded Gas Industry Got Away with It, check out that video. How the Lead Paint Industry Got Away with It is similarly scandalous. Lead in Drinking Water offers the modern-day tale of what happened in Flint, Michigan, and “Normal” Blood Lead Levels Can Be Toxic explores the impacts on childhood development.


I close out this extended video series on lead with information on what we can do about it:

Interested in learning more about lead being absorbed and released in our bones, and how calcium supplements may affect that process? See The Rise in Blood Lead Levels at Pregnancy and Menopause and Should Pregnant Women Take Calcium Supplements to Lower Lead Levels?.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

 

How to Lower Your Sodium-to-Potassium Ratio

The potassium content in greens is one of two ways they can improve artery function within minutes of consumption.

More than a thousand years ago, for the treatment of hypertension, an ancient Persian medical text advised lifestyle interventions, such as avoiding meat and pastries, and recommended eating spinach. A thousand years later, researchers discovered that a single meal containing spinach could indeed reduce blood pressure, thanks to its nitrate content. All green leafy vegetables are packed with nitrate, which our body can use to create nitric oxide that improves the flexibility and function of our arteries. This may be why eating our greens may be one of the most powerful things we can do to reduce our chronic disease risk.

As you can see at 0:54 in my video Lowering Our Sodium-to-Potassium Ratio to Reduce Stroke Risk, just switching from low-nitrate vegetables to high-nitrate vegetables for a week can lower blood pressure by about 4 points, and the higher the blood pressure people started out with, the greater benefit they got. Four points might not sound like a lot, but even a 2-point drop in blood pressure could prevent more than 10,000 fatal strokes every year in the United States.

Potassium-rich foods may also act via a similar mechanism. If we get even just the minimum recommended daily intake of potassium, we might prevent 150,000 strokes every year. Why? Potassium appears to increase the release of nitric oxide. One week of eating two bananas and a large baked potato every day significantly improved arterial function. Even a single high-potassium meal, containing the equivalent of two to three bananas’ worth of potassium, can improve the function of our arteries, whereas a high-sodium meal—that is, a meal with the amount of salt most people eat—can impair arterial function within 30 minutes. While potassium increases nitric oxide release, sodium reduces nitric oxide release. So, the health of our arteries may be determined by our sodium-to-potassium ratio.

As you can see at 2:30 in my video, after two bacon slices’ worth of sodium, our arteries take a significant hit within 30 minutes. However, if you add three bananas’ worth of potassium, you can counteract the effects of the sodium. As I show at 2:48 in my video, when we evolved, we were eating ten times more potassium than sodium. Now, the ratio is reversed, as we consume more sodium than potassium. These kinds of studies “provide additional evidence that increases in dietary potassium should be encouraged,” but what does that mean? We should eat more beans, sweet potatoes, and leafy greens, the latter of which is like giving you a double whammy, as they are high in potassium and nitrates. The recommendation from a thousand years ago to eat spinach is pretty impressive, though bloodletting and abstaining from sex were also encouraged, so we should probably take ancient wisdom with a grain of salt—but our meals should be added-salt free.

Why might abstaining from sex not be the best idea for cardiovascular health? Because the opposite may actually be true. See my video Do Men Who Have More Sex Live Longer?.


What else can we do about stroke risk? Check out:

For more on potassium, see in Potassium and Autoimmune Disease and 98% of American Diets Potassium-Deficient.

Interested in learning more about the dangers of sodium? See:

Sodium isn’t just bad for our arteries. Check out How to Treat Asthma with a Low-Salt Diet and Sodium and Autoimmune Disease: Rubbing Salt in the Wound?.

I further explore the wonders of nitrate-rich vegetables in:

Sweet potatoes are an excellent high-potassium, low-sodium choice, but what’s the best way to prepare them? Check out The Best Way to Cook Sweet Potatoes.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

 

What Exercise Authorities Don’t Tell You About Optimal Duration

Physical fitness authorities seem to have fallen into the same trap as the nutrition authorities, recommending what they think may be achievable, rather than simply informing us of what the science says and letting us make up our own minds.

Researchers who accept grants from The Coca-Cola Company may call physical inactivity “the biggest public health problem of the 21st century,” but, in actually, physical inactivity ranks down at number five in terms of risk factors for death in the United States and even lower in terms of risk factors for disability, as you can see at 0:17 in my video How Much Should You Exercise? What’s more, inactivity barely makes the top ten globally. As we’ve learned, diet is our greatest killer by far, followed by smoking.

Of course, that doesn’t mean you can just sit on the couch all day. Exercise can help with mental health, cognitive health, sleep quality, cancer prevention, immune function, high blood pressure, and life span extension, topics I cover in some of my other videos. If the U.S. population collectively exercised enough to shave just 1 percent off the national body mass index, 2 million cases of diabetes, one and a half million cases of heart disease and stroke, and 100,000 cases of cancer might be prevented.

Ideally, how much should we exercise? The latest official “Physical Activity Guidelines for Americans” recommends adults get at least 150 minutes a week of moderate aerobic exercise, which comes out to be a little more than 20 minutes a day. That is actually down from previous recommendations from the Surgeon General, as well as from the Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine, which jointly recommend at least 30 minutes each day. The exercise authorities seem to have fallen into the same trap as the nutrition authorities, recommending what they think may be achievable, rather than simply informing us what the science says and letting us make up our own minds. They already emphasize that “some” physical activity “is better than none,” so why not stop patronizing the public and just tell everyone the truth?

As you can see at 2:16 in my video, walking 150 minutes a week is better than walking 60 minutes a week, and following the current recommendations for 150 minutes appears to reduce your overall mortality rate by 7 percent compared with being sedentary. Walking for just 60 minutes a week only drops your mortality rate about 3 percent, but walking 300 minutes weekly lowers overall mortality by 14 percent. So, walking twice as long—40 minutes a day compared with the recommended 20 daily minutes—yields twice the benefit. And, an hour-long walk each day may reduce mortality by 24 percent. I use walking as an example because it’s an exercise nearly everyone can do, but the same applies to other moderate-intensity activities, such as gardening or cycling.

A meta-analysis of physical activity dose and longevity found that the equivalent of about an hour a day of brisk walking at four miles per hour was good, but 90 minutes was even better. What about more than 90 minutes? Unfortunately, so few people exercise that much every day that there weren’t enough studies to compile a higher category. If we know 90 minutes of exercise a day is better than 60 minutes, which is better than 30 minutes, why is the recommendation only 20 minutes? I understand that only about half of Americans even make the recommended 20 daily minutes, so the authorities are just hoping to nudge people in the right direction. It’s like the Dietary Guidelines for Americans advising us to “eat less…candy.” If only they’d just give it to us straight. That’s what I try to do with NutritionFacts.org.

Most of the content in my book How Not to Die came from my video research, but this particular video actually sprung from the book. I wanted to include exercise in my Daily Dozen list, but needed to do this research to see what was the best “serving size.”

I wish someone would start some kind of FitnessFacts.org website to review the exercise literature. I’ve got my brain full with the nutrition stuff—though there’s so much good information I don’t have time to review that there could be ten more sites just covering nutritional science!


For more on all that exercise can do for our bodies and minds, see

Some tips for maximizing the benefits:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

High Blood Pressure May Lead to Low Brain Volume

Having hypertension in midlife (ages 40 through 60) is associated with elevated risk of cognitive impairment and Alzheimer’s dementia later in life, even more so than having the so-called Alzheimer’s gene.

“It is clear that cerebral vascular disease”—that is, hardening of the arteries inside our brain—“and cognitive decline travel hand in hand,” something I’ve addressed before. “However, the independent association of AD [Alzheimer’s disease] with multiple AVD [atherosclerotic vascular disease] risk factors suggests that cholesterol is not the sole culprit in dementia.”

As I discuss in my video Higher Blood Pressure May Lead to Brain Shrinkage, one of the most consistent findings is that elevated levels of blood pressure in midlife, ages 40 through 60, is associated with elevated risk of cognitive impairment and Alzheimer’s dementia later in life—in fact, even more so than having the so-called Alzheimer’s gene.

“The normal arterial tree”—all the blood vessels in the brain—“is…designed as both a conduit and cushion.” But when the artery walls become stiffened, the pressure from the pulse every time our heart pumps blood up into our brain can damage small vessels in our brain. This can cause “microbleeds” in our brain, which are frequently found in people with high blood pressure, even if they were never diagnosed with a stroke.

These microbleeds may be “one of the important factors that cause cognitive impairments,” “perhaps not surprising[ly],” because on autopsy, “microbleeds may be associated with [brain] tissue necrosis,” meaning brain tissue death.

And speaking of tissue death, high blood pressure is also associated with so-called lacunar infarcts, from the Latin word lacuna, meaning hole. These holes in our brain appear when little arteries get clogged in the brain and result in the death of a little round region of the brain. Up to a quarter of the elderly have these little mini-strokes, and most don’t even know it, so-called silent infarcts. But “no black holes in the brain are benign.” As you can see at 2:12 in my video, it’s as though your brain has been hole-punched.

“Although silent infarcts, by definition, lack clinically overt stroke-like symptoms, they are associated with subtle deficits in physical and cognitive function that commonly go unnoticed.” What’s more, they can double the risk of dementia. That’s one of the ways high blood pressure is linked to dementia.

There’s so much damage that high blood pressure levels can “lead to brain volume reduction,” literally a shrinkage of our brain, “specifically in the hippocampus,” the memory center of the brain. This helps explain how high blood pressure can be involved in the development of Alzheimer’s disease.

As you can see at 3:02 in my video, we can actually visualize the little arteries in the back of our eyes using an ophthalmoscope, providing “a noninvasive window” to study the health of our intracranial arteries, the little vessels inside our head. Researchers “found a significant association” between visualized arterial disease and brain shrinkage on MRI. However, because that was a cross-sectional study, just a snapshot in time, you can’t prove cause and effect. What’s needed is a prospective study, following people over time. And that’s just what the researchers did. Over a ten-year period, those with visual signs of arterial disease were twice as likely to suffer a significant loss of brain tissue volume over time.


What can we do about high blood pressure? A lot! See, for example:

What else can we do to forestall cognitive decline or dementia? I referenced my video Alzheimer’s and Atherosclerosis of the Brain earlier, and here are other videos that offer information on treatment and prevention:

 

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Pill-Free Ways to improve Your Sex Life

“Sex is important to health,” according to the Harvard Health Letter. “Frequent sexual intercourse is associated with reduced heart attack risk.” But, as I discuss in my video Do Men Who Have More Sex Live Longer?, that seems to be the perfect case of reverse causation. They’re implying that more sex leads to healthier arteries, but isn’t the opposite more likely—that is, healthier arteries lead to more sex? Blood flow in the penis is so reflective of blood flow elsewhere that penile Doppler ultrasound can predict cardiovascular disease. However, low frequency of sexual activity may predict cardiovascular disease in men independently of erectile dysfunction. This suggests that sex may be more than “just fun” and may also be therapeutic, or at least so says an editor of the Journal of Sexual Medicine and colleagues in discussing whether or not “frequent sexual activity can be prescribed” to improve general health. In men, they suggest it’s because more sex means more testosterone.

When men have sex, they get a big spike in testosterone levels in their blood, but, interestingly, in contrast, they don’t get a testosterone boost when they masturbate, as you can see at 1:21 in my video. This may be because “testosterone increases with competitive success,” like if you win a sports game. While sex “is not usually regarded as a competitive event…one’s mental state following coitus could nevertheless be something like that of a winner,” as opposed to the mental state after masturbation.

As you can see at 2:00 in my video, the spike in sex hormones in the blood is so great that men’s beards actually grow faster on days they have sex. And, since low testosterone levels are associated with increased risk of mortality, this could help explain the health benefits of having sex.

So, do men who have more sex actually live longer? I searched Pubmed for sexual activity and longevity and found a study supported by the U.S. Department of Agriculture, titled “Sexual activity and longevity of the southern green stink bug”—clearly an example of our taxpayer dollars hard at work. I was less interested in whether or not screwworms live up to their namesake and more interested in a study on sex and death, in which the objective was “to examine the relation between frequency of orgasm and mortality.” The researchers found that men with “high orgasmic frequency” appeared to cut their risk of premature death in half and, apparently, the more, the better: There was an associated 36 percent drop in mortality odds for every additional 100 orgasms a year. “Conclusion: Sexual activity seems to have a protective effect on men’s health”—but, apparently, not if you cheat. “Unfaithfulness in men seems to be associated with a higher risk of major cardiovascular events,” like heart attacks and strokes. “Extramarital sex may be hazardous and stressful because the lover is often younger…[and] a secret sexual encounter” may be more stressful.

In a large autopsy series, the majority of cases of sudden death during sex occurred in men during extramarital intercourse. The absolute risk is low—“only one out of 580 men might be expected to suffer a sudden death attributable to sexual intercourse”—but for those at high risk, research shows that “[s]ex in familiar surroundings, in a comfortable room temperature, and with the usual partner adds less stress to the heart” and may be safer.

Speaking of safe sex, you thought drinking and driving was bad? “While it is generally assumed that sexual behavior happens in parked cars, there is little discussion…in the research literature of sexual activity in moving vehicles.” About one in five college students report engaging in sex while driving, nearly half while going more than 60 miles an hour. Researchers suggest maybe this is something students should be warned about in health class.

When done right, though, love may protect your lover’s life. Given the benefits of sexual activity, “intervention programmes could also be considered, perhaps based on the exciting ‘At least five a day’ campaign aimed at increasing fruit and vegetable consumption—although the numerical imperative may have to be adjusted.”

What are some pill-free ways to improve your sex life? Exercising, quitting smoking, not drinking too much alcohol, not weighing too much, and eating a healthy diet. But what does it mean to “eat a healthy diet”? As I discuss in my video Best Foods to Improve Sexual Function, heart-healthy lifestyle changes are sex-healthy lifestyle changes, which have been demonstrated in studies from around the world, including in women (for whom there is sadly a dearth of research about in the biomedical literature). “Sexual function in women is significantly affected” by coronary artery disease, atherosclerotic narrowing of blood flow through our arteries, including the arteries that supply our pelvis. So, high cholesterol may mean “lower arousal, orgasm, lubrication, and satisfaction,” and the same holds for high blood pressure.

Given this, putting women on a more plant-based diet may help with sexual functioning.   Researchers found that improvements in female sexual function index scores were related to an increased intake of fruits, vegetables, nuts, and beans, and a shift from animal to plant sources of fat. The same for men: a significant improvement in international Index of Erectile Function scores. In fact, the largest study on diet and erectile dysfunction found that each additional daily serving of fruits or vegetables may reduce the risk of ED by 10 percent. But why? It may be due to the anti-inflammatory effects. Two years on a healthier diet resulted in a significant reduction in systemic inflammation, as indicated by reduced levels of C-reactive protein. Fiber itself may play an anti-inflammatory role. Those who eat the most fiber tend to have significantly lower levels of inflammation in their bodies, as you can see at 2:06 in my video. The opposite was found for saturated fat, “associated with an increased likelihood of elevated CRP”, C-reactive protein levels.

We’re used to seeing changes in inflammatory markers over weeks, months, or years, but people don’t realize that the level of inflammation in our bodies can change after only a single meal. For example, there’s a pro-inflammatory signaling molecule in our bodies called interleukin 18, thought to play a role in destabilizing atherosclerotic plaque. As such, the level of interleukin 18 in the blood “ is a strong predictor” of cardiovascular death.

What would happen if you fed people one of three different types of meals: sausage-egg-butter-oil sandwiches, cheeseless pizza with white flour crust, or the same cheeseless pizza but with whole-wheat crust? Within hours of eating the sausage sandwich, interleukin 18 levels shot up about 20 percent, an effect not seen after eating the plant-based pizza. In contrast, those eating the whole food, plant-based pizza made with the whole-wheat crust had about a 20 percent drop in interleukin 18 levels within hours of consumption, reinforcing dietary recommendations to eat a diet high in fiber and starches, and low in saturated fat to prevent chronic diseases.

But the billions in profits are in pills, not plants, which is why the pharmacology of the female orgasm has been studied ever since 1972 when a researcher at Tulane University implanted tubes deep within the brain of a woman so he could inject drugs directly into her brain and was able to induce repetitive orgasms. A man who had electrodes placed into similar parts of his brain was given a device for a few hours that allowed him to press the button himself to stimulate the electrode. He pressed the button up to 1,500 times.


For more on male reproductive health, see:

Also check out my other men’s health videos, such as:

What effect might that inflammation directly following an unhealthy meal have on our artery function? Check out my three-part endotoxins series starting with The Leaky Gut Theory of Why Animal Products Cause Inflammation.

And why exactly is fiber anti-inflammatory? Watch my video Prebiotics: Tending Our Inner Garden.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Chia Seeds vs. Flaxseeds

 

What effect do chia seeds have on weight loss, blood sugar, cholesterol, blood pressure, and inflammation?

We’ve been eating chia seeds for more than 5,000 years. Historically, they are one of the main crops grown in the Western hemisphere. They are exceptionally high in fiber and omega-3 fatty acids, though, like flaxseeds, it’s better to grind them up. As you can see at 0:26 in my video Which Are Better: Chia Seeds or Flaxseeds?, eating two tablespoons of whole chia seeds every day for ten weeks led to no change in omega-3 levels, but consuming the same amount of ground chia seeds did lead to a significant increase in blood levels of both short-chain and long-chain omega 3s. “Ingestion of…milled chia seed compared to whole chia seed or placebo… appeared to have no influence on inflammation or disease risk factors,” though. As well, there was no change in body fat, blood sugar, cholesterol, blood pressure, C-reactive protein, or any of the other markers of inflammation, as you can see at 0:47 in my video.

An earlier study purported to show a significant reduction in C-reactive protein levels (an indicator of systemic inflammation), compared to control. However, if you look closely at the data, you see that was only because there was a significant worsening in the placebo group who had been given a couple of tablespoons of wheat bran a day instead of chia. So it’s not that the chia group got significantly better; the control group just got significantly worse, as you can see at 1:22 in my video.

Whenever researchers appear to be exaggerating their results, that’s a red flag to check their funding source. In this case, they didn’t disclose any conflicts of interest. Five years later, however, the truth came out. The study was indeed funded by a chia company. Furthermore, the lead investigator had filed a patent to use chia seeds to treat diseases. Why wasn’t any of this disclosed when the study was originally published? Because the journal’s “conflict-of-interest policy did not specifically require the disclosure of such information.”

Regardless, the “patent has since been abandoned,” likely because subsequent studies found no significant benefits for weight loss, blood sugar, cholesterol, blood pressure, or inflammation after eating a quarter cup of chia seeds a day for three months, as you can see at 2:16 in my video. The original study, however, did show a significant drop in blood pressure, which was replicated by other researchers.

More potent effects have been found with ground flaxseeds, though. The primary reason I prefer flaxseeds over chia seeds is their lignan content, which averages about 15 times more than other seeds, including sesame and chia. This is thought to explain the anti-cancer effects of flaxseeds for both prevention and survival.

Still, chia seeds are certainly better than eggs and oil. By mixing one part chia seeds and nine parts water and letting it sit, you can create a chia gel that can be used as an egg or oil replacer in baked goods.

Who grinds chia seeds? Were you as surprised by that as I was?

For an update about the potential of chia seeds for weight loss, check out Do Chia Seeds Help with Belly Fat?


You can learn more about flax seeds and cancer from my videos, including:

To find out more about what flax seeds can do, check out:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

What Meat and Eggs Do to Our Microbiome

As I’ve explored before, whether young or old, male or female, smoker or non-smoker, with high blood pressure or low blood pressure, high cholesterol or low, having high levels of a toxic compound called TMAO—trimethylamine oxide—in the bloodstream is associated with a significantly higher risk of having a heart attack, stroke, or dying over a three-year period. Where does TMAO come from? As I investigate in my video How to Develop a Healthy Gut Ecosystem, the choline in foods like eggs can be turned by gut bacteria into TMAO, which is then absorbed back into our system. And, the more eggs we eat, the higher the levels climb, as you can see at 0:41 in my video.

Given the similarity in structure between carnitine and choline, Cleveland Clinic researchers wondered if carnitine found in red meat, energy drinks, and supplements might also lead to TMAO production and put it to the test. As you can see at 1:00 in my video, if you feed omnivores, those who regularly eat meat, a steak, their TMAO levels shoot up. Those who eat strictly plant-based may start out with almost no TMAO in their system, presumably because they’re not eating any meat, eggs, or dairy. But, even if vegans eat a sirloin, still almost no TMAO is made. Why? Presumably, they don’t have steak-eating bacteria in their guts. Indeed, it was found that no TMAO is produced if you don’t have TMAO-producing bacteria in your gut. If you don’t regularly eat meat, then you’re not fostering the growth of the meat-eating microbes that produce TMAO.

This suggests that once we develop a plant-based gut ecosystem, our bacteria will not produce TMAO, even if we eat meat every once and awhile. However, we still don’t know how rapidly gut bacteria shift after a shift in our diet—but it does not appear to be all or nothing. If men eating the standard American diet are given two sausage, egg, and cheese biscuits before and after just five days of eating lots of similarly high-fat meals, their TMAO production boosts even higher, as you can see at 2:09 in my video. So, it’s not just whether we have the bad bugs or not. Apparently, we can breed more of them the more we feed them.

Meat-free diets, on the other hand, can also have been “demonstrated to have a profound influence on human metabolism.”Just by analyzing a urine sample, we can tell what kind of diet people eat, based on measurements like how low TMAO levels are in the urine of those eating egg-free vegetarian diets, as you can see at 2:26 in my video. At 2:43 in my video, you’ll see that we can even take the same people rotate them through three different diets, and determine who is on a high-meat diet, low-meat diet, or no-meat diet, based in part on the different compounds churned out by the different gut flora or different flora activity after just about two weeks on the different diets. It’s possible that some of the beneficial effects of whole plant foods may be mediated by the effects they have on our gut bacteria. At the same time, the standard American diet may increase the relative abundance of undesirables that produce toxic compounds including TMAO (as you can see at 3:07 in my video).

Strictly plant-based diets have gained acceptance as a dietary strategy for preventing and managing disease. Perhaps, in part, this is because of their rather unique gut flora, with less of the disease-causing bacteria and more of the protective species. So, all along, we thought the reason those eating plant-based had lower heart disease rates was because they were eating less saturated fat and cholesterol, but maybe their lower TMAO levels may also be contributing to their benefits, thanks to their reduced ingestion of carnitine and choline.

I talked about the egg industry response to the choline revelation in Egg Industry Response to Choline and TMAO. How has the carnitine supplement industry reacted? In response to the research implicating carnitine in TMAO production, the former vice president of AdvoCare—a multilevel marketing company that sells carnitine supplements like AdvoCare Slam while getting slammed with lawsuits finding them guilty of being “engaged in false, misleading or deceptive acts or practices” and forced to pay more than a million dollars—questioned whether there was a secret vegan conspiracy at the Cleveland Clinic. Restricting our intake of meat or carnitine supplements to prevent our gut bacteria from making TMAO, he argued, is like trying to prevent car accidents by restricting the sale of fuel.

Okay…but there are benefits to transportation. We’re talking about TMAO, which may be fueling our epidemic of heart disease, the number-one killer of men and women in this country. As far as I’m concerned, the more we can cut the fuel for that, the better.


For more background on TMAO, see Carnitine, Choline, Cancer, and Cholesterol: The TMAO Connection, then find out How to Reduce Your TMAO Levels.

Our gut flora are what we eat. Check out:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

The Benefits of Slow Breathing

There are all manner of purported hiccup “cures,” which include everything from chewing on a lemon, inhaling pepper, or, our dog’s favorite, eating a spoonful of peanut butter. In my video How to Strengthen the Mind-Body Connection, I talk about the technique I’m excited to try the next time I get hiccups: “supra-supramaximal inspiration,” where you take a very deep breath, hold for ten seconds, then, without exhaling, breathe in even more and hold for another five seconds, and then take one final, tiny breath in and hold for five last seconds to achieve “an immediate and permanent termination to hiccups…”

When I was a kid, I taught myself to control my own hiccups using slow-paced breathing, and, as an adult, was so excited to see there was finally a case report written up on it.

There’s a nerve—the vagus nerve—that goes directly from our brain, to our chest, and to our stomach, connecting our brain back and forth to our heart and our gut, and even to our immune system. The vagus nerve is like the “‘hard-wired’ connection” that allows our brain to turn down inflammation within our body. When you hear about the mind-body connection, that’s what the vagus nerve is and does. “There has been increasing interest in treating a wide range of disorders with implanted pacemaker-like devices for stimulating the vagal afferent [vagus nerve] pathways,” but certain Eastern traditions like Yoga, QiGong, and Zen figured a way to do it without having electrodes implanted into your body.  

“A healthy heart is not a metronome,” as a study titled exactly that explains. “Your heart rate goes up and down with your breathing. When you breathe in, your heart rate tends to go up. When you breathe out, your heart rate tends to go down.” Test this out on yourself right now by feeling your pulse change as you breathe in and out.

Isn’t that remarkable?

That heart-rate variability is a measure of vagal tone—the activity of your vagus nerve. Next time you’re bored, try to make your heart rate speed up and slow down as much as possible within each breath. This can be done because there’s an entirely other oscillating cycle going on at the same time, as you can see at 2:08 in my video, which is the speeding up and then slowing down of your heart rate, based on moment-to-moment changes in your blood pressure. And, as any physics student can tell you, “all oscillating feedback systems with a constant delay have the characteristic of resonance,” meaning you can boost the amplitude if you get the cycles in sync. It’s like pushing your kid on a swing: If you get the timing just right, you can boost them higher and higher. Similarly, if you breathe in and out at just the right frequency, you can force the cycles in sync and boost your heart rate variability, as you can see at 2:36 in my video.

And what’s the benefit again? According to the neurophysiologic model postulation it allows us to affect the function of our autonomic nervous system via vagal afferents to brainstem nuclei like the locus coeruleus, activating hypothalamic vigilance areas.

Huh?

In other words, it’s not just about curing hiccups. Practicing slow breathing a few minutes a day may have lasting beneficial effects on a number of medical and emotional disorders, including asthma, irritable bowel syndrome, fibromyalgia, and depression. In the United States, we’ve also put it to use to improve batting performance in baseball.

To date, most studies have lacked proper controls and have used fancy biofeedback machines to determine each person’s resonant frequency, but, for most people, it comes out to be about five and a half breaths per minute, which is a full breath in and out about every 11 seconds. You can see the graph at 3:34 in my video. When musicians were randomized into slow-breathing groups with or without biofeedback, slow breathing helped regardless. It’s the same with high blood pressure. As you can see at 3:52 in my video, you can use this technique to significantly drop your blood pressure within minutes. The hope is if you practice this a few minutes every day, you can have long-lasting effects the rest of the day breathing normally.

Practice what exactly? Slow breathing—taking five or six breaths per minute, split equally between breathing in and breathing out. So, that’s five seconds in, then five seconds out, all the while breathing “shallowly and naturally.” You don’t want to hyperventilate, so just take natural, shallow breaths, but be sure to simply breathe really slowly. Try it the next time you get hiccups. Works for me every time!


For more tips, watch my video on How to Stop Hiccups.

And, because slowing down our pulse in general may also have beneficial effects, I encourage you to check out:

Every time I’m amazed by ancient wisdom, I have to remind myself of the video I did on toxic heavy metals—Get the Lead Out. So, though traditional healing methods may offer a plethora of insights, they still need to be put to the test.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

What About the Sodium in Miso?

According to the second World Cancer Research Fund/American Institute for Cancer Research expert report, “[s]alt is a probable cause of stomach cancer,” one of the world’s leading cancer killers. If the report’s estimate of an 8 percent increase in risk for every extra gram of salt a day is correct, then in a country like the United Kingdom, nearly 1,700 cases of stomach cancer happen every year just because of excess salt intake, as you can see at 0:27 in my video Is Miso Healthy?, and, in a country like the United States, it would be thousands more annually.

The risk of stomach cancer associated with salt intake appears on par with smoking or heavy alcohol use, but may only be half as bad as opium use or increased total meat consumption, as you can see at 0:43 in my video. These findings were based on a study of more than a half million people, which may explain why those eating meatless diets appear to have nearly two-thirds lower risk.

We know dietary salt intake is directly associated with the risk of stomach cancer, and the higher the intake, the higher the risk. A meta-analysis went one step further and looked at specific salt-rich foods: pickled foods, salted fish, processed meat, and miso soup. Habitual consumption of pickled foods, salted fish, and processed meat were each associated with about a 25 percent greater risk of stomach cancer. The pickled foods may explain why Korea, where the pickled cabbage dish kimchi is a staple, appears to have the highest stomach cancer rates in the world, as you can see at 1:39 in my video. But researchers found there was no significant association with the consumption of miso soup. This may be because the carcinogenic effects of the salt in miso soup are counteracted by the anti-carcinogenic effects of the soy, effectively canceling out the risk. And, if we made garlicky soup with some scallions thrown in, our cancer risk may drop even lower, as you can see at 2:06 in my video.

Cancer isn’t the primary reason people are told to avoid salt, though. What about miso soup and high blood pressure? Similar to the relationship between miso and cancer, the salt in miso pushes up our blood pressures, but miso’s soy protein may be relaxing them down. If we compare the effects of soy milk to cow’s milk, for example, and, to make it even more fair, compare soy milk to skim cow’s milk to avoid the saturated butter fat, soy milk can much more dramatically improve blood pressure among women with hypertension, as you can see at 2:43 in my video. But would the effect be dramatic enough to counter all the salt in miso? Japanese researchers decided to put it to the test.

For four years, they followed men and women in their 60s, who, at the start of the study, had normal blood pressure, to see who was more likely to be diagnosed with hypertension in that time: those who had two or more bowls of miso soup a day or those who had one or less. Two bowls a day may add a half teaspoon of salt to one’s daily diet, yet those who had two or more bowls of miso soup every day appeared to have five times lower risk of becoming hypertensive. So, maybe the anti-hypertensive effects of the soy in the miso exceed the hypertensive effects of the salt.


Indeed, miso paste, a whole soy food, can be used as a “green light” source of saltiness when cooking. That’s why I used it in my pesto recipe in How Not to Die and in my How Not to Die Cookbook. It can help you in Shaking the Salt Habit.

Not convinced that salt is bad for you? Check out these videos:

Not convinced that soy is good for you? See:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations: