Is White Rice a Yellow-Light or Red-Light Food?

Arsenic is not just considered to be a carcinogen; it’s also designated as a “nonthreshold carcinogen, meaning that any dose, no matter how small, carries some cancer risk”—so there really isn’t a “safe” level of exposure. Given that, it may be reasonable to “use the conservative ALARA” approach, reducing exposure As Low As Reasonably Achievable.

I have a low bar for recommending people avoid foods that aren’t particularly health-promoting in the first place. Remember when that acrylamide story broke, about the chemical found concentrated in french fries and potato chips? (See my video Acrylamide in French Fries for more.) My take was pretty simple: Look, we’re not sure how bad this acrylamide stuff is, but we’re talking about french fries and potato chips, which are not healthy anyway. So, I had no problem provisionally bumping them from my list of yellow-light foods into my red-light list, from “minimize consumption” to “ideally avoid on a day-to-day basis.”

One could apply the same logic here. Junk foods made out of brown rice syrup, rice milk, and white rice are not just processed foods, but also arsenic-contaminated processed foods, so they may belong in the red zone as red-light foods we should avoid. What about something like whole brown rice? That is more difficult, because there are pros to help outweigh the cons. I discuss this in my video Is White Rice a Yellow-Light or Red-Light Food?, where you can see a graphical depiction of my traffic light food system at 0:49.

The rice industry argues that the “many health benefits of rice consumption outweigh any potential risk,” which is the same sentiment you hear coming out of Japan about the arsenic-contaminated seaweed hijiki: Yes, “the cancer risk posed by hijiki consumption exceeds this acceptable [cancer risk] level by a factor of 10,” an order of magnitude, but the Japanese Ministry of Health stresses the “possible health benefits,” such as lots of fiber and minerals, as if hijiki was the only weed in the sea. Why not choose any of the other seaweeds and get all the benefits without the arsenic? So, when the rice industry says the “many health benefits of rice consumption outweigh any potential risk,” it’s as if brown rice was the only whole grain on the planet. Can’t you get the whole grain benefits without the risks by eating oatmeal, barley, or quinoa instead? Or, is there some unique benefit to rice, such that we really should try to keep brown rice in our diet?

Consumer Reports recommended moving rice to the yellow-light zone—in other words, don’t necessarily avoid it completely, but moderate your intake. The rice industry, in a fact sheet entitled “The Consumer Reports Article is Flawed,” criticized Consumer Reports for warning people about the arsenic levels in rice, saying “[t]here is a body of scientific evidence that establishes…the nutritional benefits of rice consumption; any assessment of the arsenic levels in rice that fails to take this information into account is inherently flawed and very misleading.” The rice industry cites two pieces of evidence. First, it asserts that rice-consuming cultures tend to be healthier, but is that because of, or despite, their white rice consumption? And what about the fact that rice-eating Americans tend to be healthier? Perhaps, but they also tend to eat significantly less saturated fat. So, once again, how do we know whether it’s because of—or despite—the white rice?

The rice industry could have cited the study I discuss at 3:12 in my video that showed that brown rice intake of two or more servings a week was associated with a lower risk of diabetes, but presumably, the reason it didn’t is because intake of white rice is associated with an increased risk of diabetes, and white rice represents 95 percent of the U.S. rice industry. Switching out a third of a serving of white rice a day for brown rice might lower diabetes risk by 16 percent, but switching out that same white rice for whole grains in general, like oats or barley, might work even better! So, other grains have about ten times less arsenic and are associated with even lower disease risk. No wonder the rice industry doesn’t cite this study.

It does cite the Adventist studies, though, and some in vitro data. For example, in a petri dish, as you can see at 4:05 in my video, there are rice phytonutrients that, at greater and greater doses, can inhibit the growth of colon cancer cells while apparently leaving normal colon cells alone, which is exciting. And, indeed, those who happened to eat those phytonutrients in the form of brown rice once or more a week between colonoscopies had a 40 percent lower risk of developing polyps. (The consumption of green leafy vegetables, dried fruit, and beans were also associated with lower polyp incidence.) But, the only reason we care about the development of polyps is that polyps can turn into cancer. But, there had never been studies on brown rice consumption and cancer…until now, which I discuss in my video Do the Pros of Brown Rice Outweigh the Cons of Arsenic?.


For those unfamiliar with my traffic light system, I talk about it in my book trailer. Check out How Not to Die: An Animated Summary.

Almost there! This is the corresponding article to the 12th in my 13-video series on arsenic in the food supply. If you missed any of the first 11 videos, see:

Ready for the finale? See Do the Pros of Brown Rice Outweigh the Cons of Arsenic?.

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:

How Much Arsenic in Rice Is Too Much?

What are some strategies to reduce arsenic exposure from rice?

Those who are exposed to the most arsenic in rice are those who are exposed to the most rice, like people who are eating plant-based, gluten-free, or dairy-free. So, at-risk populations are not just infants and pregnant women, but also those who may tend to eat more rice. What “a terrible irony for the health conscious” who are trying to avoid dairy and eat lots of whole foods and brown rice—so much so they may not only suffer some theoretical increased lifetime cancer risk, but they may actually suffer arsenic poisoning. For example, a 39-year-old woman had celiac disease, so she had to avoid wheat, barley, and rye, but she turned to so much rice that she ended up with sky-high arsenic levels and some typical symptoms, including “diarrhea, headache, insomnia, loss of appetite, abnormal taste, and impaired short-term memory and concentration.” As I discuss in my video How Much Arsenic in Rice Is Too Much, we, as doctors, should keep an eye out for signs of arsenic exposure in those who eat lots of rice day in and day out.

As you can see at 1:08 in my video, in its 2012 arsenic-in-rice exposé, Consumer Reports recommended adults eat no more than an average of two servings of rice a week or three servings a week of rice cereal or rice pasta. In its later analysis, however, it looked like “rice cereal and rice pasta can have much more inorganic arsenic—a carcinogen—than [its] 2012 data showed,” so Consumer Reports dropped its recommendation down to from three weekly servings to a maximum of only two, and that’s only if you’re not getting arsenic from other rice sources. As you can see from 1:29 in my video, Consumer Reports came up with a point system so people could add up all their rice products for the week to make sure they’re staying under seven points a week on average. So, if your only source of rice is just rice, for example, then it recommends no more than one or two servings for the whole week. I recommend 21 servings of whole grains a week in my Daily Dozen, though, so what to do? Get to know sorghum, quinoa, buckwheat, millet, oatmeal, barley, or any of the other dozen or so common non-rice whole grains out there. They tend to have negligible levels of toxic arsenic.

Rice accumulates ten times more arsenic than other grains, which helps explain why the arsenic levels in urine samples of those who eat rice tend to consistently be higher than those who do not eat rice, as you can see at 2:18 in my video. The FDA recently tested a few dozen quinoa samples, and most had arsenic levels below the level of detection, or just trace amounts, including the red quinoas that are my family’s favorite, which I was happy about. There were, however, still a few that were up around half that of rice. But, overall, quinoa averaged ten times less toxic arsenic than rice. So, instead of two servings a week, following the Consumer Reports recommendation, you could have 20. You can see the chart detailing the quinoa samples and their arsenic levels at 2:20 in my video.

So, diversifying the diet is the number-one strategy to reduce exposure of arsenic in rice. We can also consider alternatives to rice, especially for infants, and minimize our exposure by cooking rice like pasta with plenty of extra water. We found that a 10:1 water-to-rice ratio seemed best, though the data suggest the rinsing doesn’t seem to do much. We can also avoid processed foods sweetened with brown rice syrup. Is there anything else we can do at the dining room table while waiting for federal agencies to establish some regulatory limits?

What if you eat a lot of fiber-containing foods with your rice? Might that help bind some of the arsenic? Apparently not. In one study, the presence of fat did seem to have an effect, but in the wrong direction: Fat increased estimates of arsenic absorption, likely due to the extra bile we release when we eat fatty foods.

We know that the tannic acid in coffee and especially in tea can reduce iron absorption, which is why I recommend not drinking tea with meals, but might it also decrease arsenic absorption? Yes, by perhaps 40 percent or more, so the researchers suggested tannic acid might help, but they used mega doses—17 cups of tea worth or that found in 34 cups of coffee—so it isn’t really practical.

What do the experts suggest? Well, arsenic levels are lower in rice from certain regions, like California and parts of India, so why not blend that with some of the higher arsenic rice to even things out for everybody?

What?!

Another wonky, thinking-outside-the-rice-box idea involves an algae discovered in the hot springs of Yellowstone National Park with an enzyme that can volatize arsenic into a gas. Aha! Researchers genetically engineered that gene into a rice plant and were able to get a little arsenic gas off of it, but the rice industry is hesitant. “Posed with a choice between [genetically engineered] rice and rice with arsenic in it, consumers may decide they just aren’t going to eat any rice” at all.


This is the corresponding article to the 11th in a 13-video series on arsenic in the food supply. If you missed any of the first ten videos, watch them here:

You may also be interested in Benefits of Turmeric for Arsenic Exposure.

Only two major questions remain: Should we moderate our intake of white rice or should we minimize it? And, are there unique benefits to brown rice that would justify keeping it in our diet despite the arsenic content? I cover these issues in the final two videos: Is White Rice a Yellow-Light or Red-Light Food? and Do the Pros of Brown Rice Outweigh the Cons of Arsenic?.

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:

Updating Our Microbiome Software and Hardware

Good bacteria, those living in symbiosis with us, are nourished by fruits, vegetables, grains, and beans, whereas bad bacteria, those in dysbiosis with us and possibly contributing to disease, are fed by meat, junk food and fast food, seafood, dairy, and eggs, as you can see at 0:12 in my video Microbiome: We Are What They Eat. Typical Western diets can “decimate” our good gut flora.

We live with trillions of symbionts, good bacteria that live in symbiosis with us. We help them, and they help us. A month on a plant-based diet results in an increase in the population of the good guys and a decrease in the bad, the so-called pathobionts, the disease-causing bugs. “Given the disappearance of pathobionts from the intestine, one would expect to observe a reduction in intestinal inflammation in subjects.” So, researchers measured stool concentrations of lipocalin-2, “which is a sensitive biomarker of intestinal inflammation.” As you can see at 1:13 in my video, within a month of eating healthfully, it had “declined significantly…suggesting that promotion of microbial homeostasis”—or balance—“by an SVD [strict vegetarian diet] resulted in reduced intestinal inflammation.” What’s more, this rebalancing may have played a role “in improved metabolic and immunological parameters,” that is, in immune system parameters.

In contrast, on an “animal-based diet,” you get growth of disease-associated species like Bilophila wadsworthia, associated with inflammatory bowel disease, and Alistipes putredinis, found in abscesses and appendicitis, and a decrease in fiber-eating bacteria. When we eat fiber, the fiber-munching bacteria multiply, and we get more anti-inflammatory, anti-cancer short-chain fatty acids. When we eat less fiber, our fiber-eating bacteria starve away.

They are what we eat.

Eat a lot of phytates, and our gut flora get really good at breaking down phytates. We assumed this was just because we were naturally selecting for those populations of bacteria able to do that, but it turns out our diet can teach old bugs new tricks. There’s one type of fiber in nori seaweed that our gut bacteria can’t normally breakdown, but the bacteria in the ocean that eat seaweed have the enzyme to do so. When it was discovered that that enzyme was present in the guts of Japanese people, it presented a mystery. Sure, sushi is eaten raw, so some seaweed bacteria may have made it to their colons, but how could some marine bacteria thrive in the human gut? It didn’t need to. It transferred the nori-eating enzyme to our own gut bacteria.

“Consequently, the consumption of food with associated environmental bacteria is the most likely mechanism that promoted this CAZyme [enzyme] update into the human gut microbe”—almost like a software update. We have the same hardware, the same gut bacteria, but the bacteria just updated their software to enable them to chew on something new.

Hardware can change, too. A study titled “The way to a man’s heart is through his gut microbiota” was so named because the researchers were talking about TMAO, trimethylamine N-oxide. As you can see at 3:33 in my video, certain gut flora can take carnitine from the red meat we eat or the choline concentrated in dairy, seafood, and eggs, and convert it into a toxic compound, which may lead to an increase in our risk of heart attack, stroke, and death.

This explains why those eating more plant-based diets have lower blood concentrations of TMAO. However, they also produce less of the toxin even if you feed them a steak. You don’t see the same “conversion of dietary L-carnitine to TMAO…suggesting an adoptive response of the gut microbiota in omnivores.” They are what we feed them.

As you can see at 4:17 in my video, if you give people cyclamate, a synthetic artificial sweetener, most of their bacteria don’t know what to do with it. But, if you feed it to people for ten days and select for the few bacteria that were hip to the new synthetic chemical, eventually three quarters of the cyclamate consumed is metabolized by the bacteria into another new compound called cyclohexylamine. Stop eating it, however, and those bacteria die back. Unfortunately, cyclohexylamine may be toxic and so was banned by the FDA in 1969. In a vintage Kool-Aid ad from 1969, Pre-Sweetened Kool-Aid was taken “off your grocer’s shelves,” but Regular Kool-Aid “has no cyclamates” and “is completely safe for your entire family.”

But, if you just ate cyclamate once in a while, it wouldn’t turn into cyclohexylamine because you wouldn’t have fed and fostered the gut flora specialized to do so. The same thing happens with TMAO. Those who just eat red meat, eggs, or seafood once in a while would presumably make very little of the toxin because they hadn’t been cultivating the bacteria that produce it.


Here’s the link to my video on TMAO: Carnitine, Choline, Cancer, and Cholesterol: The TMAO Connection. For an update on TMAO, see How Our Gut Bacteria Can Use Eggs to Accelerate Cancer, Egg Industry Response to Choline and TMAO, and How to Reduce Your TMAO Levels.

Interested in more on keeping our gut bugs happy? 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:

Eating to Block Lead Absorption

Intake of certain nutrients has been associated with lower lead levels in the body. For example, women with higher intake of thiamine, also called vitamin B1, tended to have lower blood lead levels, and the same was found for lead-exposed steel workers—and not just with thiamine, as “content of dietary fiber, iron, or thiamine intake each correlated inversely with blood lead concentrations in workers…” The thinking is that the fiber might glom onto the lead and flush it out of the body, the iron would inhibit the lead absorption, and the thiamine may accelerate lead removal through the bile. So, researchers suggest that eating lots of iron, fiber and especially thiamine-rich foods “may induce rapid removal and excretion of the lead from the tissues.” But thiamine’s never been put to the test by giving it to people to see if their lead levels drop. The closest I could find is a thiamine intervention for lead-intoxicated goats.
 

And much of the fiber data are just from test tube studies. In one, for example, researchers used simulated intestinal conditions, complete with “flasks” of feces, and both soluble and insoluble dietary fiber were able to bind up large amounts of mercury, cadmium, and lead to such an extent that they may have been able to block absorption in the small intestine. But, when our good gut flora then eat the fiber, some of the heavy metals may be re-released down in the colon, so it’s not completely fail safe. And, as with thiamine, there haven’t been controlled human studies.

But where is thiamine found? At 1:47 in my video How to Lower Lead Levels with Diet: Thiamine, Fiber, Iron, Fat, Fasting?, I feature a list of some of the healthiest sources of thiamine-rich foods that also contain fiber, which include highly concentrated, super healthy foods like beans and greens—foods we should all be eating anyway. So, even if thiamine- and fiber-rich foods don’t actually lower lead levels, we’ll still end up healthier.

What happened when iron was put to the test? It failed to improve the cognitive performance of lead-exposed children and failed to improve behavior or ADH symptoms, which is no surprise, because it also failed to bring down lead levels, as did zinc supplementation. It turns out that while iron may limit the absorption of lead, “it may also inhibit excretion of previously absorbed lead” that’s already in your body. What’s more, iron may not even inhibit lead absorption in the first place. That was based on rodent studies, and it turns out we’re not rodents.

We get the same story with zinc. It may have helped to protect rat testicles, but didn’t seem to help human children. “Nevertheless, iron is routinely prescribed in children with lead poisoning.” But, “given the lack of scientific evidence supporting the use of iron [supplementation] in…children with lead poisoning, its routine use should be re-examined.” Though, obviously, supplementation may help if you have an iron deficiency.

High fat intake has been identified as a nutritional condition that makes things worse for lead-exposed children. In fact, dietary fat has been associated with higher lead levels in cross-sectional, snapshot-in-time type studies, and there is a plausible biological mechanism: Dietary fat may boost lead absorption by stimulating extra bile, which in turn may contribute to lead absorption, but you really don’t know until you put it to the test.

In addition to testing iron, researchers also tested fat. They gave a group of intrepid volunteers a cocktail of radioactive lead and then, with a Geiger counter, measured how much radiation the subjects retained in their bodies. Drinking the lead with iron or zinc didn’t change anything, but adding about two teaspoons of vegetable oil boosted lead absorption into the body from about 60 percent up to around 75 percent, as you can see at 4:17 in my video.

The only thing that seemed to help, dropping lead absorption down to about 40 percent, was eating a light meal with the lead drink. What was the meal? Coffee and a donut. I think this is the first donut intervention I’ve ever seen with a positive outcome! Could it have been the coffee? Unlikely, because if anything, coffee drinking has been associated with a tiny increase in blood lead levels. If fat makes things worse, and the one sugar they tried didn’t help, the researchers figured that what made the difference was just eating food—any food—and not taking in lead on an empty stomach. And, indeed, if you repeat the study with a whole meal, lead absorption doesn’t just drop from 60 percent to 40 percent—it drops all the way down to just 4 percent! That’s extraordinary. That means it’s 15 times worse to ingest lead on an empty stomach.

Lead given 12 hours before a meal was absorbed at about 60 percent, so most of it was absorbed. When the same amount of lead was given three hours after a meal and also seven hours after a meal, most of it was absorbed at those times, too. But, if you get some food in your stomach within a few hours of lead exposure, you can suppress the absorption of some or nearly all of the lead you ingested, which you can see at 0:11 in my video How to Lower Lead Levels with Diet: Breakfast, Whole Grains, Milk, Tofu?.

This is why it’s critical to get the lead out of our tap water. Although it’s estimated that most of our lead exposure comes from food, rather than water, it’s not what we eat that matters, but what we absorb. If 90 percent of the lead in food is blocked from absorption by the very fact that it’s in food, 10 to 20 times more lead could be absorbed into your bloodstream simply by consuming the same amount of lead in water drank on an empty stomach.

And, since children empty their stomachs faster than adults because kids “have more rapid gastric emptying times,” the timing of meals may be even more important. With little tummies emptying in as few as two hours after a meal, offering midmorning and midafternoon snacks in addition to breakfast and regular meals may cut down on lead absorption in a contaminated environment. And, of course, we should ensure that children wash their hands prior to eating.

So, do preschoolers who eat breakfast have lower levels of lead in their blood? In the first study of its kind, researchers found that, indeed, children who ate breakfast regularly did appear to have lower lead levels, supporting recommendations to provide regular meals and snacks to young children at risk for lead exposure.

Is there anything in food that’s particularly protective? Researchers tested all sorts of foods to find out, and it turns out the “effect of a meal was probably largely due to its content of calcium and phosphate salts but lead uptake was probably further reduced by phytate which is plentiful in whole cereals,” but if calcium and phosphates are protective, you’d think dairy would work wonders. And, indeed, they started giving milk “to workers to prevent lead exposure” ever since calcium was shown to inhibit lead absorption in rats. But, in humans, there’s something in milk that appeared to increase lead uptake, and it wasn’t the fat because they found the same problem with skim milk.

“For over a century milk was recommended unreservedly to counteract lead poisoning in industry,” but this practice was abandoned in the middle of the last century once we learned that milk’s “overall effect is to promote the absorption of lead from the intestinal tract.” What’s the agent in milk that promotes the absorption of lead from the gut? It may be the milk sugar, lactose, though the “mechanism by which lactose enhances lead absorption is not clear.”

The bottom line? “In the past…milk was used as a prophylactic agent to protect workers in the lead industry. Recent studies, however, suggest that this practice is unjustified and may even be harmful.” So, giving people whole grains may offer greater protection against lead uptake.

However, the most potently calcium and phytate-rich food would be tofu. Isolated soy phytonutrients may have a neuroprotective effect, at least this was the case in petri dish-type studies. As you can see at 3:45 in my video, if you add a little lead to nerve cells, you can kill off about 40 percent of them, but if you then give more and more soy phytonutrients, you can ameliorate some of the damage. This is thought to be an antioxidant effect. If you add lead to nerve cells, you can get a big burst of free radicals, but less and less as you drip on more soy compounds.

Nevertheless, even if this worked outside of a lab, cutting down on the toxic effects of lead is nice, but cutting down on the levels of lead in your body is even better. “Because tofu has high content of both calcium and phytic acid phytate…it is biologically plausible that tofu may inhibit lead absorption and retention, thus reducing blood lead levels.” But you don’t know, until you put it to the test.

Tofu consumption and blood lead levels were determined for about a thousand men and women in China. For every nine or so ounces of tofu consumed a week, there appeared to be about four percent less lead in their bloodstream. Those who ate up to two and a half ounces a day had only half the odds of having elevated lead levels, compared to those eating less than about nine ounces a week. Those consuming nearly four ounces a day appeared to cut their odds by more than 80 percent. This was just a cross-sectional study, or snapshot in time, so it can’t prove cause and effect. What you need is an interventional study where you randomize people into two groups, giving half of them some food to see if it drives down lead levels. I cover this in my video Best Food for Lead Poisoning: Chlorella, Cilantro, Tomatoes, Moringa?.


Where does all this lead exposure come from anyway? Check out the first five videos on this series:

For more about blocking lead absorption, as well as what to eat to help rid yourself of the lead you’ve already built up, see:

Or, even better, don’t get exposed in the first place. Find out more in these videos:

Some of my other videos on lead include:

And what about lead levels in women? 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:

 

What Happens if You Have Red Wine or Avocados with a Meal?

Whole plant sources of sugar and fat can ameliorate some of the postprandial (after meal) inflammation caused by the consumption of refined carbohydrates and meat.

Studies have shown how adding even steamed skinless chicken breast can exacerbate the insulin spike from white rice, but fish may be worse. At 0:18 in my video The Effects of Avocados and Red Wine on Meal-Induced Inflammation, you can see how the insulin scores of a low-carbohydrate plant food, peanuts, is lower compared to common low-carb animal foods—eggs, cheese, and beef. Fish was even worse, with an insulin score closer to doughnut territory.

At 0:36 in my video, you can see the insulin spike when people are fed mashed white potatoes. What do you think happens when they’re also given tuna fish? Twice the insulin spike. The same is seen with white flour spaghetti versus white flour spaghetti with meat. The addition of animal protein may make the pancreas work twice as hard.

You can do it with straight sugar water, too. If you perform a glucose challenge to test for diabetes, drinking a certain amount of sugar, at 1:10 in my video, you can see the kind of spike in insulin you get. But, if you take in the exact same amount of sugar but with some meat added, you get a higher spike. And, as you can see at 1:25 in my video, the more meat you add, the worse it gets. Just adding a little meat to carbs doesn’t seem to do much, but once you get up to around a third of a chicken’s breast worth, you can elicit a significantly increased surge of insulin.

So, a chicken sandwich may aggravate the metabolic harm of the refined carb white bread it’s on, but what about a PB&J? At 1:49 in my video, you can see that adding nuts to Wonder Bread actually calms the insulin and blood sugar response. What if, instead of nuts, you smeared on an all fruit strawberry jam? Berries, which have even more antioxidants than nuts, can squelch the oxidation of cholesterol in response to a typical American breakfast and even reduce the amount of fat in your blood after the meal. And, with less oxidation, there is less inflammation when berries are added to a meal.

So, a whole plant food source of sugar can decrease inflammation in response to an “inflammatory stressor” meal, but what about a whole plant food source of fat? As you can see at 2:38 in my video, within hours of eating a burger topped with half an avocado, the level of an inflammatory biomarker goes up in your blood, but not as high as eating the burger without the avocado. This may be because all whole plant foods contain antioxidants, which decrease inflammation, and also contain fiber, which is one reason even high fat whole plant foods like nuts can lower cholesterol. And, the same could be said for avocados. At 3:12 in my video, you can see avocado causing a significant drop in cholesterol levels, especially in those with high cholesterol, with even a drop in triglycerides.

If eating berries with a meal decreases inflammation, what about drinking berries? Sipping wine with your white bread significantly blunts the blood sugar spike from the bread, but the alcohol increases the fat in the blood by about the same amount. As you can see at 3:40 in my video, you’ll get a triglycerides bump when you eat some cheese and crackers, but if you sip some wine with the same snack, triglycerides shoot through the roof. How do we know it was the alcohol? Because if you use dealcoholized red wine, the same wine but with the alcohol removed, you don’t get the same reaction. This has been shown in about a half dozen other studies, along with an increase in inflammatory markers. So, the dealcoholized red wine helps in some ways but not others.

A similar paradoxical effect was found with exercise. If people cycle at high intensity for about an hour a half-day before drinking a milkshake, the triglycerides response is less than without the prior exercise, yet the inflammatory response to the meal appeared worse, as you can see at 4:18 in my video. The bottom line is not to avoid exercise but to avoid milkshakes.

The healthiest approach is a whole food, plant-based diet, but there are “promising pharmacologic approaches to the normalization” of high blood sugars and fat by taking medications. “However, resorting to drug therapy for an epidemic caused by a maladaptive diet is less rational than simply realigning our eating habits with our physiological needs.”

Protein from meat can cause more of an insulin spike than pure table sugar. See the comparisons in my video Paleo Diets May Negate Benefits of Exercise.

Interested in more information on the almond butter study I mentioned? I discuss it further in How to Prevent Blood Sugar and Triglyceride Spikes After Meals.

Berries have their own sugar, so how can eating berries lower the blood sugar spike after a meal? Find out in If Fructose Is Bad, What About Fruit?


For more on avocados, check out:

And here are more videos on red wine:

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:

Decreasing Inflammation and Oxidation After Meals

Within hours of eating an unhealthy meal, we can get a spike in inflammation, crippling our artery function, thickening our blood, and causing a fight-or-flight nerve response. Thankfully, there are foods we can eat at every meal to counter this reaction.

Standard American meals rich in processed junk and meat and dairy lead to exaggerated spikes in sugar and fat in the blood, as you can see at 0:13 in my video How to Prevent Blood Sugar and Triglyceride Spikes after Meals. This generates free radicals, and the oxidative stress triggers a biochemical cascade throughout our circulation, damaging proteins in our body, inducing inflammation, crippling our artery function, thickening our blood, and causing a fight-or-flight nerve response. This all happens within just one to four hours after eating a meal. Worried about inflammation within your body? One lousy breakfast could double your C-reactive protein levels before it’s even lunchtime.

Repeat that three times a day, and you can set yourself up for heart disease. You may not even be aware of how bad off you are because your doctor is measuring your blood sugar and fat levels while you’re in a fasting state, typically drawing your blood before you’ve eaten. What happens after a meal may be a stronger predictor of heart attacks and strokes, which makes sense, since this is where most of us live our lives—that is, in a fed state. And it’s not just in diabetics. As you can see at 1:30 in my video, if you follow non diabetic women with heart disease but normal fasting blood sugar, how high their blood sugar spikes after chugging some sugar water appears to determine how fast their arteries continue to clog up, perhaps because the higher the blood sugars spike, the more free radicals are produced.

So, what are some dietary strategies to improve the situation? Thankfully, “improvements in diet exert profound and immediate favorable changes…,” but what kind of improvements? “Specifically, a diet high in minimally processed, high-fiber, plant-based foods such as vegetables and fruits, whole grains, legumes, and nuts,”—antioxidant, anti-inflammatory whole plant foods—“will markedly blunt the post-meal increase” in sugar, fat, and inflammation.

But what if you really wanted to eat some Wonder Bread? As you can see at 2:23 in my video, you’d get a big spike in blood sugar less than an hour after eating it. Would it make a difference if you spread the bread with almond butter? Adding about a third of a cup of almonds to the same amount of Wonder Bread significantly blunts the blood sugar spike.

In that case, would any low-carb food help? Why add almond butter when you can make a bologna sandwich? Well, first of all, plant-based foods have the antioxidants to wipe out any excess free radicals. So, nuts can not only blunt blood sugar spikes, but oxidative damage as well. What’s more, they can even blunt insulin spikes. Indeed, adding nuts to a meal calms both blood sugar levels and insulin levels, as you can see at 3:02 in my video. Now, you’re probably thinking, Well, duh, less sugar means less insulin, but that’s not what happens with low-carb animal foods.

As you can see at 3:23 in my video, if you add steamed skinless chicken breast to your white rice, you get a greater insulin spike than if you had just eaten the white rice alone. So, adding the low-carb plant food made things better, but adding the low-carb animal food made things worse. It’s the same with adding chicken breast to mashed potatoes—a higher insulin spike with the added animal protein. It is also the same with animal fat: Add some butter to a meal, and get a dramatically higher insulin spike from some sugar, as you can see at 3:45 in my video.

If you add butter and cheese to white bread, white potatoes, white spaghetti, or white rice, you can sometimes even double the insulin reaction. If you add half an avocado to a meal, however, instead of worsening, the insulin response improves, as it does with the main whole plant food source of fat: nuts.


I’ve covered the effect adding berries to a meal has on blood sugar responses in If Fructose Is Bad, What About Fruit?, and that raises the question: How Much Fruit Is Too Much?

In addition to the all-fruit jam question, I cover The Effects of Avocados and Red Wine on Postprandial Inflammation.

Vinegar may also help. See Can Vinegar Help with Blood Sugar Control?.

Perhaps this explains part of the longevity benefit to nut consumption, which I discuss in Nuts May Help Prevent Death.

I also talk about that immediate inflammatory reaction to unhealthy food choices in Best Foods to Improve Sexual Function.

Surprised by the chicken and butter reaction? The same thing happens with tuna fish and other meat, as I cover in my video Paleo Diets May Negate Benefits of Exercise.

Also check:

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:

How to Foster a Healthy Gut Flora

What’s more important: probiotics or prebiotics? And where can we best get them?

“Virtually every day we are all confronted with the activity of our intestine, and it is no surprise that at least some of us have developed a fascination for our intestinal condition and its relation to health and disease.”

“Over the last years the intestinal microbiota [our gut flora] has been identified as a fascinating ‘new organ’” with all sorts of functions. Well, if the bacteria in our gut make up an entire, separate organ inside our body, what about doing an organ transplant? I discuss this in my video How to Become a Fecal Transplant Super Donor.

What would happen if you transferred intestinal bacteria from lean donors into obese subjects? Researchers figured that rebalancing the obesity-causing bacteria with an infusion of gut bacteria from a lean donor might help. They had wanted the study to be placebo-controlled, which, for drugs is easy, because the control subjects can just be given a sugar pill. But, when you’re inserting a tube down people’s throats and transplanting feces, what do you use as the placebo—or poocebo, if you will? Both the donors and the subjects brought in fresh stools, and the subjects were randomized to either get a donor’s stool or their own collected feces. So, the placebo was simply getting their own stool back.

What happened? As you can see at 1:32 in my video, the insulin sensitivity of the skinny donors was up around 50, which is a good thing. High insulin sensitivity means a low level of insulin resistance, which is the cause of both type 2 diabetes and prediabetes. The obese subjects started out around 20 and, after an infusion of their own feces, stayed around 20. The group of obese donors getting the skinny fecal infusion similarly started out low but then shot up near to where the slim folks were.

It’s interesting that not all lean donors’ stools conveyed the same effect on insulin sensitivity. Some donors, the so-called super-fecal donors, had very significant effects, whereas others had little or no effect, as you can see at 2:02 in my video. It turns out this super-donor effect is most probably conveyed by the amounts of short-chain fatty acid-producing intestinal bacteria in their feces. These are the food bacteria that thrive off of the fiber we eat. The short-chain fatty acids produced by fiber-eating bacteria may contribute to the release of gut hormones that may be the cause of this beneficial, improved insulin sensitivity.

“The use of fecal transplantation has recently attracted considerable attention because of its success in treatments as well as its capacity to provide cause–effect relations,” that is, cause-and-effect evidence that the bacteria we have in our gut can affect our metabolism. Within a few months, however, the bacterial composition returned back to baseline, so the effects on the obese subjects were temporary.

We can get similar benefits by just feeding what few good gut bacteria we may already have. If you have a house full of rabbits and feed them pork rinds, all the bunnies will die. Yes, you can repopulate your house by infusing new bunnies, but if you keep feeding them pork rinds, they’ll eventually die off as well. Instead, even if you start off with just a few rabbits but if you feed them what they’re meant to eat, they’ll grow and multiply, and your house will soon be full of fiber-eating bunnies. Fecal transplants and probiotics are only temporary fixes if we keep putting the wrong fuel into our guts. But, by eating prebiotics, such as fiber, which means “increasing whole plant food consumption,” we may select for—and foster the growth of—our own good bacteria.

However, such effects may abate once the high-fiber intake ceases. Therefore, our dietary habits should include a continuous consumption of large quantities of high-fiber foods to improve our health. Otherwise, we may be starving our microbial selves.


The microbiome is one of the most exciting research areas in medicine these days. For more information, see, for example:

For more on health sources of prebiotics, 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:

How to Treat Endometriosis with Diet

“Endometriosis is a major cause of disability and compromised quality of life in women and teenage girls.” It “is a chronic disease which is under-diagnosed, under-reported, and under-researched…[and for patients, it] can be a nightmare of misinformation, myths, taboos, lack of diagnosis, and problematic hit-and-miss treatments overlaid by a painful, chronic, stubborn disease.”

Pain is what best characterizes the disease: pain, painful intercourse, heavy irregular periods, and infertility. About one in a dozen young women suffer from endometriosis, and it accounts for about half the cases of pelvic pain and infertility. It’s caused by what’s called “retrograde menstruation”—blood, instead of going down, goes up into the abdominal cavity, where tissue of the uterine lining can implant onto other organs. The lesions can be removed surgically, but the recurrence rate within five years is as high as 50 percent.

Endometriosis is an estrogen-dependent disease, so might the anti-estrogenic effects of the phytoestrogens in flaxseeds and soy foods help, as they appear to do in breast cancer? I couldn’t find studies on flax and endometriosis, but soy food consumption may indeed reduce the risk of that disease. What about treating endometriosis with soy? While I couldn’t find any studies on that, there is another food associated with decreased breast cancer risk: seaweed.

Seaweeds have special types of fiber and phytonutrients not found in land plants, so in order to get these unique components, we would need to incorporate sea vegetables into our diet. Seaweeds, may have anti-cancer properties, including anti-estrogen effects. Japanese women have among the lowest rates of breast, endometrial, and ovarian cancers, as well as longer menstrual cycles and lower estrogen levels circulating in their blood, which may help account for their low risk of estrogen-dependent cancers. We assumed this was due to their soy-rich diets, but their high intake of seaweed might also be helping.

When seaweed broth was dripped on human ovary cells that make estrogen, estrogen levels dropped. Why? It either inhibits production or facilitates breakdown of estrogen. It may even block estrogen receptors, lowering the activity of the estrogen that is produced. This is in a petri dish, though. Does it happen in women, too? Yes.

Researchers estimated that an effective estrogen-lowering dose of seaweed for an average American woman might be around five grams a day, but, apparently, no one has tried testing it on cancer patients yet. However, it has been tried on endometriosis, as I discuss in my video How to Treat Endometriosis with Seaweed.

Three women with abnormal menstrual cycles, including two with endometriosis, volunteered to add a tiny amount of dried, powdered bladderwrack, a common seaweed, to their daily diet. This effectively lengthened their cycles and reduced the duration of their periods—and not just by a little. As you can see at 3:14 in my video, subject 1 had a 30-year history of irregular periods, averaging every 16 days. Taking just a quarter-teaspoon of this seaweed powder a day added 10 days onto her cycle, up to 26 days, and adding a daily half-teaspoon increased her cycle to 31 days, nearly doubling its length. Furthermore, as you can see at 3:38 in my video, all three women experienced marked reductions in blood flow and a decreased duration of menstruation. For 30 years, subject 1 had been having her period every 16 days, and it typically lasted 9 days. Can you imagine? Then, by just taking a daily half-teaspoon of seaweed, her period came just once a month and only lasted about four days. Most importantly, in the two women suffering from endometriosis, they reported “substantial alleviation” of their pain. How is that possible? There was a 75 percent drop in estrogen levels after just a quarter-teaspoon of seaweed powder a day and an 85 percent drop after a half-teaspoon. 

Of course, with just a few women and no control group in that study, we need bigger, better studies. But, that study was published more than a decade ago and not a single such study has been published since. Millions of women are suffering with these conditions. Does the research world just not care about women? The more pointed question is: who’s going to fund the work? Less than a teaspoon of seaweed costs less than five cents, so a larger study may never be done. But, without any downsides, I suggest endometriosis sufferers give it a try.


For more on endometriosis, see my video What Diet Best Lowers Phthalate Exposure?, and, to learn about the anti-estrogenic effects of the phytoestrogens in flaxseeds on breast cancer, see Flaxseeds and Breast Cancer Survival: Clinical Evidence.

Interested in more on sea vegetables? See:

I recommend staying away from kelp and hijiki, though. Why? See Too Much Iodine Can Be as Bad as Too Little.

Learn more about other natural remedies for menstrual problems:

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: