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:

How Risky Is the Arsenic in Rice?

Getting rice down to the so-called safe water limit for arsenic would still allow for roughly 500 times greater cancer risk than is normally considered acceptable. Given the level of arsenic in rice, how could we figure out how much rice is too much? There are no U.S. standards for arsenic in rice, even though “food sources are the main source of exposure.” There are limits on arsenic in apple juice and tap water, though. To calculate those, experts must have sat down, determined out how much arsenic a day was too much—too risky—then figured people typically drink about four to eight cups of water a day, and set the limits that way, right? Okay, well, can’t we just use their how-much-arsenic-a-day-is-too-much-arsenic-a-day number, and, based on the average arsenic content in rice, figure out how-much-rice-a-day-is-too-much-rice? I discuss this in my video How Risky Is the Arsenic in Rice?.

“The allowable level established by the FDA for arsenic in bottled water is 10 ppb,” assuming people might drink a liter a day. So, based on that daily 10 ppb limit, how much rice is that?

“Each 1 g increase in rice intake was associated with a 1% increase in urinary total arsenic, such that eating 0.56 cups [a little over a half cup] of cooked rice was considered comparable with drinking 1 L/d,” one liter per day, of that maximally contaminated water. Well, if you can eat a half cup a day, why does Consumer Reports suggest eating just a few servings of rice a week? You could eat nearly a serving every day and still stay within the daily arsenic limits set for drinking water.

Well, Consumer Reports felt the 10 ppb water standard was too lax, so, it went with the “most protective standard in the country,” at 5 ppb. Guess where it came from? New Jersey. Good for New Jersey! So, by using 5 ppb instead of 10 ppb in the calculation, you can see how Consumer Reports got to its only-a-few-servings-of-rice-a-week recommendation. Presumably, that’s based on average arsenic levels in rice. If you choose a lower-arsenic rice, one with only half the level of arsenic, can you have four servings a week instead of two? And, if you boil rice like pasta and drain off the excess water, doesn’t that also cut levels in half? If so, then you are up to about eight servings a week. Based on the water standard, apparently, you could still safely eat a serving of rice a day if you choose the right rice and cook it right. I assumed the water limit is ultra-conservative since people are expected to drink water every day of their lives, whereas most people don’t eat rice every day, seven days a week. I made that assumption, but I was wrong. It turns out the opposite is true.

All this time, I had been assuming the current drinking guideline exposure would be safe, which in terms of carcinogens, is usually “1 in a million chances of getting cancer over a lifetime.” I’ve mentioned this before. It’s how cancer-causing substances are typically regulated. If a company wants to release some new chemical, it has to show that it doesn’t cause more than one in a million excess cancer cases. Of course, there are 300 million people in this country, so that one-in-a-million doesn’t make the 300 extra families who have to deal with cancer feel any better, but that’s just the kind of agreed upon “acceptable risk.”

The problem, according to the National Research Council, is that with the current federal drinking water standard for arsenic of 10 μg/L, we are not talking about an excess cancer risk of 1 in a million people, but as high as 1 case in 300 people. Those 300 extra cases of cancer just turned into a million more cases? A million more families dealing with a cancer diagnosis? “This is 3000 times higher than a commonly accepted cancer risk for an environmental carcinogen of 1 case in 1 000 000 people.” If we were to use the normally accepted 1 in a million odds of cancer risk, the water standard would have to be 500 times lower, .02 instead of 10. Even the New Jersey standard is 250 times too high. “While this is a rather drastic difference… it underlines just how little precaution is instilled in the current guidelines.”

Hold on. So why isn’t the water standard .02 instead of 10? Because that “would be nearly impossible to implement” as we just don’t have the technology to get arsenic levels in water that low. The technologically feasible level has been estimated at 3. Okay, so why is the limit 10 and not 3? The decision to use a threshold of 10 instead of 3 was “mainly a budgetary decision.” A threshold of three would cost a lot of money.

So, the current water “safety” limit “is more motivated by politics than by technology.” Nobody wants to be told they have toxic tap water. If they did, they might demand better water treatment and that would be expensive. “As a result, many people drink water at levels very close to the current guideline… and may not be aware that they are exposed to an increased risk of cancer.” Even worse, millions of Americans drink water exceeding the legal limit, as you can see at 5:10 in my video. But, even the people living in areas that meet the legal limit “must understand that current arsenic guidelines are only marginally protective.”

Perhaps we should tell people who drink water—i.e., everyone—“that current arsenic regulations are a cost-benefit compromise and that, based on usual health risk paradigms, the standards should be much lower… People must be made aware that regulatory targets for arsenic should be as close to zero as possible,” and, when it comes to water, we should aim for the reachable limit of 3. What does this mean for rice, though?

Well, first of all, so much for just trying to get rice down to the so-called safe water limit, since that “already exceeds standard [carcinogen] risks and is based on feasibility and cost-benefit compromises,” which “allows for a roughly 500 times higher risk of cancer” than is normally considered acceptable. So, “while authorities ponder when and how they will regulate arsenic concentration in rice,” perhaps we should “curtail or strongly limit our consumption of rice.”

This is the corresponding blog post to the pivotal video in my 13-part series on arsenic in the food supply. The final three videos focus on how to deal practically with the repercussions:


If you missed any of the first nine videos, see:

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

My arsenic series reminds me of the extensive video series I did on lead:

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:

Arsenic in Rice Milk, Rice Krispies, and Brown Rice Syrup

I recommend people switch away from using rice milk

For kids and teens, the amount of arsenic flowing through their bodies was found to be about 15 percent higher for each quarter cup of rice consumed per day, and a similar link was found in adults. A study of pregnant women found that consuming about a half cup of cooked rice per day could raise urine arsenic levels as much as drinking a liter of arsenic-contaminated water at the current upper federal safety limit. These findings “suggest that many people in the United States may be exposed to potentially harmful levels of arsenic through rice consumption.” which I explore in my video Arsenic in Rice Milk, Rice Krispies, and Brown Rice Syrup.

Do you know where Americans get most of their rice arsenic? From Rice Krispies, though brown rice crisps cereal may have twice as much, as I discuss in my video Arsenic in Rice Milk, Rice Krispies, and Brown Rice Syrup.

“Organic brown rice syrup (OBRS) is used as a sweetener in organic food products as an alternative to high-fructose corn syrup.” Big mistake, as organic brown rice syrup products “may introduce significant concentrations” of toxic arsenic into people’s diets. For example, two energy chews sweetened with brown rice syrup might hit the provisional upper daily arsenic intake based on the water standards.

“Toddler formulas with added organic brown rice syrup have 20 times higher levels of inorganic [toxic] arsenic than regular formulas,” and in older children, thanks to brown rice syrup, a few cereal bars a day “could pose a very high cancer risk.”

What about rice milk? A consensus statement of both the European and North American societies for pediatric nutrition recommends the “avoidance of rice drinks for infants and young children,” and, generally, toxic “inorganic arsenic intake in infancy and childhood should be as low as possible.”

To this end, the United Kingdom has banned the consumption of rice milk for young children, a notion with which Consumer Reports concurred, recommending no servings a week of rice milk for children and no more than half a cup a day for adults, as you can see at 1:56 in my video.

The arsenic in various brands of rice milk ranges wildly—in fact, there’s a 15-fold difference between the highest and lowest contamination, suggesting manufacturers could make low arsenic rice milk if they wanted. As you can see at 2:16 in my video, Consumer Reports found rice drinks from Pacific and Rice Dream brands were right about average, though, for Rice Dream, it appears the vanilla or chocolate flavors may be lower. It doesn’t seem we have anything to worry about with rice vinegar, but rice pasta and rice cakes end up similar to pure rice in terms of arsenic levels, which makes sense because that’s pretty much what they are—pure rice. However, pasta is boiled, so we’d expect the levels to be cut 40 to 60 percent, like when you boil and drain rice.

If you just couldn’t live without rice milk for some reason, you could make your own using lower arsenic rice, like brown basmati from India, Pakistan, or California, but then your homemade rice milk might have even less nutrition, as most of the commercial brands are at least fortified. Better options might be soy, oat, hemp, or almond milk, though you don’t want kids to be drinking too much almond milk. There have been a few case reports of little kids drinking four cups a day and running into kidney stone problems due to its relatively high oxalate content, which averages about five times more than soy milk. More on oxalates in my video series starting with Oxalates in Spinach and Kidney Stones: Should We Be Concerned?

I have about 40 videos that touch on soy milk, discussing such topics as how it may normalize development in girls and reduce breast cancer risk, as well reduce prostate cancer risk in men. Some of the latest science on soy milk includes an association with better knee x-rays, suggesting protection from osteoarthritis, and an interventional study suggesting improved gut health by boosting the growth of good bacteria. However, drinking 3 quarts a day, which is 10 to 12 daily cups, for a year may inflame your liver, but two cups a day can have an extraordinary effect on your cholesterol, causing a whopping 25 percent drop in bad cholesterol after just 21 days.

An ounce and a half of almonds, about a handful, each day, can drop LDL cholesterol 13 percent in six weeks and reduce abdominal fat, though a cup of almond milk only contains about ten almonds, which is less than a third of what was used in the study. So, it’s not clear if almond milk helps much, but there was a study on oat milk compared to rice milk. As you can see at 4:37 in my video, five weeks of oat milk lowered bad cholesterol, whereas rice milk didn’t, and even increased triglycerides and may bump blood pressure a bit. However, the oat milk only dropped LDL about 5 percent and that was with three cups a day. As plant-based alternatives go, it appears soy milk wins the day.

So, why drink rice milk at all when there are such better options? There really isn’t much nutrition in rice milk. In fact, there are case reports of severe malnutrition in toddlers whose diets were centered around rice milk due to multiple food allergies. Infants and toddlers have increased protein requirements compared to adults, so if the bulk of a child’s diet is rice milk, coconut milk, potato milk, or almond milk, they may not get enough, as you can see at 5:23 in my video. In fact, cases of kwashiorkor—that bloated-belly protein- and calorie-deficient state of malnutrition—due to rice milk have been reported in Ethiopia…and Atlanta, Georgia, because literally 99 percent of the child’s diet was rice milk. So, these malnutrition cases were not because they drank rice milk, but rather because they drank rice milk nearly exclusively. I just use these examples to illustrate the relative lack of nutrition in rice milk. If you’re going to choose a milk alternative, you might as well go for one that has less arsenic—and more nutrition.

I have released several videos on soy milk, but only one on almond milk video so far: Prostate Cancer and Organic Milk vs. Almond Milk. I plan on producing many more on choosing between various milk options, so stay tuned.


If you’ve missed any of the useful material on dietary arsenic I’ve also shared, please see:

The final four videos in this series take all of this information and try to distill it into practical recommendations:

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:

 

Arsenic in Infant Rice Cereal

When it comes to rice and rice-based products, pediatric nutrition authorities have recommended that arsenic intake should be as low as possible.

“The US Food and Drug Administration (FDA) has been monitoring the arsenic content in foods” for decades, yet despite the “well-established science describing the health risks associated with arsenic exposure, no standards have been set limiting the amount of arsenic allowable in foods” in the United States. In 2001, the EPA “adopted a new stricter standard for arsenic in drinking water,” and in 2013, the FDA proposed a legal limit for apple juice. “There are still no standards for arsenic in food products despite the fact that food sources are our main source of exposure.”

Unlike the United States, China has standards. As of 2014, China set a maximum threshold of inorganic arsenic at 150 parts per billion, stricter than the World Health Organization’s limit of 200 ppb. In the United States, a 200 ppb limit wouldn’t change the cancer risk much. If we had China’s safety limits of 150 ppb, though, cancer risk would be reduced up to 23 percent and a maximum threshold of 100 ppb would lower cancer risk up to 47 percent—but that could seriously affect the rice industry. In other words, U.S. rice is so contaminated with arsenic that if a safety standard that really cut down on cancer risk were set, it “would wipe out the U.S. rice market.” However, with no limits, what’s the incentive for the rice industry to change its practices? Setting arsenic limits would not only directly protect consumers but also encourage the industry to stop planting rice paddies on arsenic-contaminated land.

Those cancer estimates are based on arsenic-contaminated water studies. Might the arsenic in rice somehow have a different effect? You don’t know…until you put it to the test. We know rice has a lot of toxic arsenic that urine studies have shown we absorb into our body, but there hadn’t been any studies demonstrating “deleterious health impacts” specific to rice arsenic—until now. Since arsenic causes bladder cancer, the researchers figured they would see what kind of DNA mutations the urine of rice eaters can have on human bladder cells growing in a petri dish. And, indeed, they clearly demonstrated that eating a lot of arsenic-contaminated rice every day can “give rise to significant amounts of genetic damage,” the kind that‘s associated with cancer. Yes, but the study used pretty contaminated rice. However, only about 10 percent of the rice in certain parts of Asia might ever reach those levels of contamination, though a quarter of rice in parts of Europe might and more half in the United States, making for considerable public health implications.

So, “there remains little mystery surrounding the health risks associated with arsenic levels in rice. The remaining mystery is why long-overdue standards for arsenic levels in rice have not been set by the FDA” in the United States, but that may be changing. In 2016, the FDA proposed setting a limit on toxic arsenic—at least in infant rice cereal, which I discuss in my video Arsenic in Infant Rice Cereal.

As you can see at 3:24 in my video, infants and children under four years of age average the highest rice intake, in part because they eat about three times the amount of food in relation to their body size, so there’s an especially “urgent need for regulatory limits” on toxic arsenic in baby food.

Pediatric nutrition authorities have recommended that when it comes to rice and rice-based products, “arsenic intake should be as low as possible,” but how about as early as possible? Approximately 90 percent of pregnant women eat rice, which may end up having “adverse health effects” on the baby.

You can estimate how much rice the mother ate while pregnant by analyzing arsenic levels in the infant’s toenail clippings. “Specifically, an increase of 1/4 cup of rice per day was associated with a 16.9% increase in infants toenail [arsenic] concentration,” which indicates that arsenic in rice can be passed along to the fetus. What might that arsenic do? A quarter cup of rice worth of arsenic has been associated with low birth weight, increased respiratory infections, and, above that, a 5- to 6-point reduction in IQ, among other issues. So, “based on the FDA’s findings, it would be prudent for pregnant women to consume a variety of foods, including varied grains (such as wheat, oats, and barley),” which is code for cut down on rice. Saying eat less of anything, after all, is bad for business.

Once the baby is weaning, “what’s a parent to do?” Asks Consumer Reports, “To reduce arsenic risks, we recommend that babies eat no more than 1 serving of infant rice cereal per day on average. And their diets should include cereals made of wheat, oatmeal, or corn grits, which contain significantly lower levels of arsenic”—that is, rely on other grains, which are much less contaminated than rice. As the American Academy of Pediatrics has emphasized, “there is no demonstrated benefit of rice cereal over those made with other grains such as oat, barley, and multigrain cereals, all of which have lower arsenic levels than rice cereal.” As you can see at 5:28 in my video, reducing consumption of infant rice cereal to just two servings per week could have an even more dramatic effect on reducing risk.

 The proposed limit on toxic arsenic in infant rice cereals would end up removing about half of the products off the shelves. The FDA analyzed more than 500 infant and toddler foods, and the highest levels of toxic arsenic were found in organic brown rice cereals and “Toddler Puffs.” Based on the wording in the report, these puffs appear to be from the Happy Baby brand. Not-so-happy baby if they suffer brain damage or grow up to get cancer. A single serving could expose infants to twice the tolerable arsenic intake set by the EPA for water. I contacted the Happy Baby company and was told they “are not able to provide any comments” on the FDA’s results.

“Eliminating all rice and rice products from the diets of infants and small children up to 6 years old could reduce the lifetime cancer risk from inorganic arsenic in rice and rice products by 6% and 23% respectively.” That is, there would be a 6 percent lower chance of developing lung or bladder cancer later in life if infants stopped, and a 23 percent lower chance if young kids stopped. However, switching to other grains is a move described as “drastic and dramatic,” creating “a huge crisis”—for the rice industry, presumably—and therefore “not feasible at all.”

I was hoping Happy Baby, upon learning of the concerning FDA arsenic toddler puffs data (regardless of whether the data were about its brand or not) would have kicked its own testing and potential remediation into high gear like Lundberg did (see Which Brands and Sources of Rice Have the Least Arsenic?). But, unfortunately, in my email correspondence with the company, I got no sense that it did.


For more videos on this topic, see:

And here are five more:

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:

Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?

What happens when our crops are grown in soil contaminated with arsenic-based pesticides and arsenic drug-laced chicken manure?

When arsenic-containing drugs are fed to chickens, not only does the arsenic grow out into their feathers, which are then fed back to them as a slaughterhouse byproduct, but the arsenic can also get into their tissues and then into our tissues when we eat eggs or meat, a cycle depicted at the start of my video Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?. This explains why national studies have found that those who eat more poultry have tended to have more arsenic flowing through their bodies. Why would the industry do that? In modern poultry farms, often called CAFOs for concentrated animal feeding operations, there can be 200,000 birds under one roof and the floors of these buildings become covered with feces. While this so-called factory farming decreases costs, it also increases the risk of disease. That’s where arsenic-containing drugs and other antibiotic feed additives can come in: to try to cut down the spread of disease in such an unnatural environment. If you’re feeling a little smug because you don’t eat chicken, what do you think happens to the poop?

As depicted at 1:17 in my video, from chicken manure, the arsenic from the drugs in the animal feed can get into our crops, into the air, and into the groundwater, and find its way into our bodies whether we eat meat or not. Yes, but how much arsenic are we really talking about? Well, we raise billions of chickens a year, and, if, historically, the vast majority were fed arsenic, then, if you do the math, we’re talking about dumping a half million pounds of arsenic into the environment every year—much of it onto our crops or shoveled directly into the mouths of other farm animals.

Most of the arsenic in chicken waste is water soluble, so, there are certainly concerns about it seeping into the groundwater. But, if it’s used as a fertilizer, what about our food? Studies on the levels of arsenic in the U.S. food supply dating back to the 1970s identified two foods, fish aside, with the highest levels—chicken and rice—both of which can accumulate arsenic in the same way. Deliver an arsenic-containing drug like roxarsone to chickens, and it ends up in their manure, which ends up in the soil, which ends up in our pilaf. “Rice is [now] the primary source of As [arsenic] exposure in a non seafood diet.”

I was surprised to learn that mushrooms are in the top-five food sources of arsenic, but then it made sense after I found out that poultry litter is commonly used as a starting material to grow mushrooms in the United States. As you can see at 2:58 in my video, over the years, the arsenic content in mushrooms has rivaled arsenic concentration in rice, though people tend to eat more rice than mushrooms on a daily basis. Arsenic levels in mushrooms seemed to be dipping starting about a decade ago, which was confirmed in a 2016 paper that looked at a dozen different types of mushrooms: plain white button mushrooms, cremini, portobello, shiitake, trumpet, oyster, nameko, maitake, alba clamshell, brown clamshell, and chanterelle. Now, mushrooms are only averaging about half the arsenic content as rice, as you can see at 3:37 in my video.

Just like some mushrooms have less arsenic than others, some rice has less. Rice grown in California has 40 percent less arsenic than rice grown in Arkansas, Louisiana, Mississippi, Missouri, and Texas. Why? Well, arsenic-based pesticides had been used for more than a century on millions of acres of cotton fields, a practice noted to be “dangerous” back in 1927. Arsenic pesticides are now effectively banned, so it’s not simply a matter of buying organic versus conventional rice because millions of pounds of arsenic had been laid down in the soil well before the rice was even planted.

The rice industry is well aware of this. There’s an arsenic-toxicity disorder in rice called “straighthead,” where rice planted in soil too heavily contaminated with arsenic doesn’t grow right. So, instead of choosing cleaner cropland, they just developed arsenic-resistant strains of rice. Now, lots of arsenic can build up in rice without the plant getting hurt. Can the same be said, however, for the rice consumer?

It’s the same story with wine. Arsenic pesticides were used, decade after decade, and even though they’ve since been banned, arsenic can still be sucked up from the soil, leading to “the pervasive presence of arsenic in [American] wine [that] can pose a potential health risk.” Curiously, the researchers sum up their article by saying that “chronic arsenic exposure is known to lower IQ in children,” but if kids are drinking that much wine, arsenic toxicity is probably the least of their worries.

Hold on. Chickens are being fed arsenic-based drugs? See Where Does the Arsenic in Chicken Come From? to find out more.


 I expect the arsenic-in-rice issue brought up a lot of questions, and giving you answers is exactly why I’m here! 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:

Açaí vs. Wild Blueberries for Artery Function

“Plant-based diets…have been found to reduce the risk of cardiovascular disease” and some of our other leading causes of death and disability. “Studies have shown that the longest living and least dementia-prone populations subsist on plant-based diets.” So why focus on açaí berries, just one plant, for brain health and performance?

Well, “foods rich in polyphenols…improve brain health,” and açaí berries contain lots of polyphenols and antioxidants, so perhaps that’s why they could be beneficial. If you’re only looking at polyphenols, though, there are more than a dozen foods that contain more per serving, like black elderberry, regular fruits like plums, flaxseeds, dark chocolate, and even just a cup of coffee.

As you can see at 1:02 in my video The Benefits of Açaí vs. Blueberries for Artery Function, in terms of antioxidants, açaí berries may have ten times more antioxidant content than more typical fruits, like peaches and papayas, and five times more antioxidants than strawberries. But blackberries, for instance, appear to have even more antioxidants than açaí berries and are cheaper and more widely available.

Açaí berries don’t just have potential brain benefits, however. Might they also protect the lungs against harm induced by cigarette smoke? You may remember the study where the addition of açaí berries to cigarettes protected against emphysema—in smoking mice, that is. That’s not very helpful. There is a long list of impressive-looking benefits until you dig a little deeper. For example, I was excited to see a “[r]eduction of coronary disease risk due to the vasodilation effect” of açaí berries, but then I pulled the study and found they were talking about a vasodilator effect…in the mesenteric vascular bed of rats. There hadn’t been any studies on açaí berries and artery function in humans until a study published in 2016.

Researchers gave overweight men either a smoothie containing about two-thirds of a cup of frozen açaí pulp and half a banana or an artificially colored placebo smoothie containing the banana but no açaí. As you can see at 2:26 in my video, within two hours of consumption of their smoothie, the açaí group had a significant improvement in artery function that lasted for at least six hours, a one or two point bump that is clinically significant. In fact, those walking around with just one point higher tend to go on to suffer 13 percent fewer cardiovascular events like fatal heart attacks.

As I show at 2:52 in my video, you can get the same effect from wild blueberries, though: about a one-and-a-half-point bump in artery function two hours after blueberry consumption. This effect peaks then plateaus at about one and a half cups of blueberries, with two and a half cups and three and a half cups showing no further benefits.

What about cooked blueberries? As you can see at 3:12 in my video, if you baked the blueberries into a bun, like a blueberry muffin, you get the same dramatic improvement in artery function.

Cocoa can do it, too. As shown at 3:30 in my video, after having one tablespoon of cocoa, you gain about one point, and two tablespoons gives you a whopping four points or so, which is double what you get with açaí berries.

One and a quarter cups’ worth of multicolored grapes also give a nice boost in artery function, but enough to counter an “acute endothelial insult,” a sudden attack on the vulnerable inner layer of our arteries? Researchers gave participants a “McDonald’s sausage egg breakfast sandwich and two hash browns.” They weren’t messing around! As you can see at 3:56 in my video, without the grapes, artery function was cut nearly in half within an hour, and the arteries stayed stiffened and crippled three hours later. But when they ate that McMuffin with all those grapes, the harmful effect was blunted.

Eat a meal with hamburger meat, and artery function drops. But if you eat that same meal with some spices, including a teaspoon and a half of turmeric, artery function actually improves.

What about orange juice? Four cups a day of commercial orange juice from concentrate for four weeks showed no change in artery function. What about freshly squeezed orange juice? Still nothing. That’s one of the reasons berries, not citrus, are the healthiest fruits.

For a beverage that can improve your artery function, try green tea. Two cups of green tea gives you that same effect we saw with cocoa, gaining nearly four points within just 30 minutes. And, as you can see at 5:05 in my video, that same crazy effect is also seen with black tea, with twice as powerful an effect as the açaí berries.

So, why all the focus on just that one plant? Why açaí berries? Well, the real reason may be because the author owns a patent on an açaí-based dietary supplement.


How do the antioxidant effects of açaí berries compare to applesauce? See The Antioxidant Effects of Açaí vs. Apples.

What about the effects of other foods on artery function? Coronary artery disease is, after all, our leading cause of death for men and women. See:

What else can blueberries 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:

The Antioxidant Power of Açaí vs. Apples

There are so many açaí products on the market now, from frozen pulp in smoothie packs to freeze-dried powder and supplements. How is it eaten traditionally? “In the Brazilian Amazon, the Indian tribes of the forest cut down the tree and eat the palm heart…then urinate on the rest of the tree to attract a species of palm beetle to lay its eggs inside the tree. Several weeks later, they return to harvest 3–4 pounds of beetle grub larvae….” I think I’ll just stick to my smoothie pack.

“Despite being used for a long time as food and beverage” in the Amazon, açaí berries have only been researched scientifically since the beginning of this century. A number of years ago, I reviewed that research in my video Clinical Studies on Açaí Berries, starting with in vitro studies showing that açaí could kill leukemia cells in a petri dish at levels you might expect to find in the bloodstream after eating one or two cups of açaí pulp and could also cut the growth of colon cancer cells in half.

Unfortunately, as I discuss in my video The Antioxidant Effects of Açaí vs. Apples, subsequent published studies have failed to find such benefits for that particular type of colon cancer, a different type of colon cancer, or an estrogen-receptor negative form of breast cancer. An açaí extract did appear to kill off a line of estrogen-receptor positive breast cancer cells, but to achieve that level of açaí nutrients in your breast, you’d have to eat about 400 cups of açaí pulp.

The problem with many of these petri dish studies is that they use concentrations that you could never realistically achieve in your bloodstream. For example, as you can see at 1:48 in my video, açaí berries may exert a neuroprotective effect, blocking the buildup of amyloid fibers implicated in Alzheimer’s—but only at a dose reached by drinking about 2,000 cups at one time. They may also have an anti-allergy effect or decrease bone loss—at a mere 1,000 cups a day.

In my previous video Clinical Studies on Açaí Berries, I also talked about a clinical study in which subjects were asked to drink less than a cup a day of açaí in a smoothie. They appeared to get significant improvements in blood sugar, insulin levels, and cholesterol. Now, there was no control group and it was a small study, but there’d never been a bigger study trying to replicate it until a study published in 2016.

As you can see at 2:37 in my video, researchers gave subjects the same amount of açaí for the same duration as the previous study, but they found no significant improvements in blood sugars, insulin, or cholesterol. Why did this study fail to show the benefits seen in the first study? Well, this study was publicly funded with “no conflicts of interest,” while the first study was funded by an açaí company, which always makes you suspect that perhaps it was somehow designed to get the desired result. And, indeed, the participants in that first study were not just given açaí smoothies, but they were explicitly told to avoid processed meat, “for example bacon and hot dogs.” No wonder their numbers looked better at the end of the month. Now, the new study did find a decrease in markers of oxidative stress in the participants’ bloodstreams, a sign of how rich in antioxidants açaí berries can be.

Those who hock supplements love to talk about how açaí consumption can “triple antioxidant capacity” of your blood. And, if you look at the study they cite, you’ll find that the antioxidant capacity of participants’ blood did actually triple after eating açaí—but the same or even better tripling was achieved after consuming just plain applesauce, which the researchers used as a control that happens to be significantly cheaper than açaí berries or supplements. You can see the graph at 3:42 in my video.

A new study has shown significant improvements in artery function after eating açaí berries, but are they any more effective than other common fruits and vegetables? You can learn more about that in my video The Benefits of Açaí vs. Blueberries for Artery Function.


What’s so great about antioxidants? Check out:

Where else can you get them? See Flashback Friday: Antioxidants in a Pinch and Antioxidant Power of Plants vs. Animal Foods.

What are the nutritional aspects of those grub-kabobs? See Bug Appétit: Barriers to Entomophagy and Good Grub: The Healthiest Meat.

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:

Topical Green Tea for Acne and Fungal Infections

Which plant should we use for which skin disease? That’s the topic of my video Natural Treatment for Acne and Fungal Infections. Thousands of studies have been published to date about the health effects of green tea, but it wasn’t until fairly recently that researchers began to look at the possibility of using green tea for the prevention and treatment of infections. Patents have been taken out on the antibacterial, antifungal, and antiviral properties of tea. Let’s review some of the evidence.

In terms of fungal infections, green tea compounds have demonstrated “potent antifungal activity” against the primary cause of athlete’s foot, fungal nail infections, jock itch, and ringworm—comparable, in some cases, to powerful antifungal drugs like fluconazole. This was shown in a petri dish, though. How about a green tea footbath for athlete’s foot fungus between the toes? Evidently, tea leaves were once used as a folk remedy for the fungus, so why not put it to the test? Indeed, a once-a-day, 15-minute dilute green tea footbath led to a significant improvement in symptoms compared to controls.

Green tea baths also appeared to help with fungus-associated atopic dermatitis, though there was no control group in that study, and a full-strength green tea may help clear candida yeast from poorly cleaned dentures. What about the bacteria that cause plaque and gingivitis? Even a 2% green tea mouthwash was found to be effective. Yes, you should be able to control plaque just with proper brushing and flossing—with an emphasis on “proper.” Most people don’t brush for the recommended four minutes a day, so a dilute green tea mouthwash may help.

In terms of plaque bacteria-killing ability, green tea was beaten out by a “garlic with lime mouth rinse,” but I think I’ll just stick to green tea, especially when green tea appears to not only kill plaque bugs directly but also boost the antibacterial capacity of saliva after you drink it.

What about green tea for acne? Six weeks of a 2% green tea lotion cut the number of pimples by more than half and significantly reduced the severity, as you can see at 2:48 in my video, making it a cheap, effective treatment for acne.

Impetigo is another bacterial skin infection that can affect the face, but a tea ointment can affect an 80 percent cure rate, on par with antibiotics given topically or orally.

What about bladder infections? We know a certain concentration of green tea compounds can kill the type of E. coli that causes urinary tract infections. The question then becomes how much tea do you have to drink to achieve those concentrations in your bladder? Not much, it turns out. Just one cup of tea might have an effect, but you may need to space out multiple cups over the day because it gets cleared out of your system within about eight hours, as you can see at 3:45 in my video.

So, where do we stand now? The test tube data look promising, but there has yet to be a single study to put it to the test. At this point, green tea should just be used as an adjunct therapy for bladder infections. But, with emerging multidrug-resistant organisms, green tea certainly holds potential.

Wait a moment. If green tea is so good at killing bacteria, might we be killing the good bacteria in our gut when we drink it? No. That’s what’s so amazing. “It has also been shown that green tea has no effect over intestinal flora, which is a great advantage against other bactericidal [bacteria-killing] agents.” But that may not actually be true. Drinking green tea may actually boost the levels of our good bacteria by acting as a prebiotic, thereby improving the colon environment, so it may actually have some effect on our gut flora after all, but it appears to be all good.


Drinking tea with meals may impair iron absorption, so it’s better to drink it between meals. For more on green tea, one of my favorite beverages, along with water and hibiscus tea, see:

For more on acne, 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 Flint Lead Crisis May Be the Tip of the Iceberg

Back in the 1960s, a Pulitzer prize-winning scientist described the problem of childhood lead poisoning as “so well defined, so neatly packaged with both causes and cures known, that if we don’t eliminate this social crime, our society deserves all the disasters that have been forecast for it.”

As I discuss in my video Lead in Drinking Water, “We have the knowledge required to redress this social crime. We know where the lead is, how people are exposed, and how it damages health. What we lack is the political will to do what should be done.” Unfortunately, “many policy makers consider the costs of action primarily in economic and financial terms and ignore the costs of inaction on human health and communities’ livelihoods.”

“At this point, most Americans have heard of the avoidable and abject failure of government on the local, state and federal level; environmental authorities; and water company officials”—in fact, failure across the board—“to prevent the mass poisoning of hundreds of children and adults in Flint, Michigan.”

“A government plan to save some money had led public officials to switch the city’s water source from Lake Huron to the Flint River, once the sewer for the auto industry.” Flint citizens “complained that their tap water was foul and discolored. But city, state, and federal officials took no heed.”

Why? Could it have anything to do with the fact that those who complained are “among the poorest in America, mostly African American”?

Officials failed to act for eighteen months, “until a local pediatrician revealed dramatically elevated lead levels in children’s blood.” An investigation didn’t just find fault but highlighted seeming falsification of water-quality results to keep people in the dark.

Though “the specific breed of alleged government corruption” may be unique to Flint, “the end result might not be so rare in the USA—home to an ageing water system.” As the president of the Children’s Health Fund said, “The Pandora’s box is now wide open.” Flint may be only “the tip of an enormous iceberg”—potentially “just one of a great many icebergs.”

“In addition to lead-based paint and residual lead in soil”—found everywhere from leaded gasoline—“a significant source of childhood lead exposure occurs through drinking water as a result of leaching from lead pipes, lead solder, or brass fixtures.” This has been recognized to be a health issue in the United States as early as 1845, a year our flag only had 26 stars. Yet, the use of lead in water pipes and solder was not restricted until the Safe Drinking Water Act Amendment, 141 years later. Was the city you’re living in built before 1986 when the amendment was passed? Today, the “exact number of lead water pipes currently in use is not clear” as about one in three cities surveyed shrugged their shoulders, “not being able to state how much lead piping exists.”

There are anti-corrosion chemicals you can add to tap water to try to keep the lead in the pipes. Flint could have done that, but it could have cost about $100 a day. Today, “the cost of repairing the Flint water system is estimated at $1.5 billion…”

Let me close with a quote from the heroic pediatrician who blew the whistle, Dr. Hanna-Attisha. She was asked, “What advice would you have for other physicians taking on a whistle-blower role?” She replied, “This is our job. This is why we went to medical school—to help people.”

Wasn’t there lead in paint, too, for the longest time? Yes, and that’s the subject of my video How the Lead Paint Industry Got Away with It. And what about leaded gasoline? How many of you remember going to the pumps and seeing the choice between leaded and unleaded? That’s the subject of How the Leaded Gas Industry Got Away with It.


I also get into what the effects are and what we can do about it. 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 the Lead Paint and Gas Industries Got Away with It

We have known for thousands of years that lead can be toxic and for more than a century that children could be poisoned by lead paint. Since those first cases, the “lead industry has mobilized against the advances of science,” as I discuss in my video How the Lead Paint Industry Got Away with It.

By 1926, lead poisoning was already “of relatively frequent occurrence in children,” yet “the United States continued to allow the use of lead-based paint until 1978.” In contrast, in Europe, many countries said, Hmm, poisoning children? No, thanks. and “banned the use of lead-based paint as early as 1909.” 

“The delay in banning lead-based paint in the United States was due largely to the marketing and lobbying efforts of the lead industry,” profiting from the poison. It knew it couldn’t hold off forever, but the industry boasted that its “victories have been in the deferral of implementation of…regulations.”

And now, “peeling paint turns into poisonous dust,” and guess where it ends up? As a Mount Sinai dean and a Harvard neurology professor put it: “Lead is a devastating poison. It damages children’s brains, erodes intelligence, diminishes creativity…” and judgment and language. Yet, despite the accumulating evidence, the lead industry didn’t just fail to warn people—“it engaged in an energetic promotion of lead paint.” After all, a can of pure white lead paint had huge amounts of lead, which meant huge profits for the industry.

But, as you can see in an old advertisement featured at 1:55 in my video, “[t]here is no cause for worry” if your toddler rubs up against lead paint, because those “fingerprint smudges or dirt spots” can be removed “easily without harming the paint.” Wouldn’t want to harm the paint. After all, “painted walls are sanitary…”

The director of the Lead Industry Association blamed the victims: “Childhood lead poisoning is essentially a problem of slum dwellings and relatively ignorant parents.”

“It seems that no amount of evidence, no health statistics, no public outrage could get industry to care that their lead paint was killing and poisoning children,” but how much public outrage was there really?

“It goes without saying that lead is a devastating, debilitating poison” and that “literally millions of children have been diagnosed with varying degrees of elevated blood lead levels…” Compare that to polio, for example. “In the 1950s, for example, fewer than sixty thousand new cases of polio per year created a near-panic among American parents and a national mobilization that led to vaccination campaigns that virtually wiped out the disease within a decade.” In contrast, despite “many millions of children [who have] had their lives altered for the worse by exposure to lead…[a]t no point in the past hundred years has there been a similar national mobilization over lead.” Today, after literally a century, the Centers for Disease Control and Prevention estimates over five hundred thousand children still suffer from “elevated blood-lead levels.”

The good news is that blood lead levels are in decline, which is celebrated as one of our great public health achievements. But, given what we knew, and for how long we knew, “it is presumptuous to declare the decline in childhood lead poisoning a public health victory.” Indeed, “even if we were victorious…it would be a victory diminished by our failure to learn from the epidemic and take steps to dramatically reduce exposures to other confirmed and suspected environmental toxicants as well as chemicals of uncertain toxicity.”

That’s one of the reasons I wanted to do this series on lead. We need to learn from our history so the next time some industry wants to sell something to our kids, we’ll stick to the science. And, of course, lead levels aren’t declining for everyone.

As the whistle-blowing pediatrician who helped expose the Flint drinking water crisis explained, “The people in Flint have a 20-year lower life expectancy than people in a neighboring suburb. We were already struggling with every barrier to our children’s success. Then we gave them lead.”

Her research showed that the switch in water supplies from the Great Lakes to the polluted Flint River “created a perfect storm” for lead contamination, doubling the percentage of kids with elevated lead levels in their blood, as you can see at 0:42 in my video How the Leaded Gas Industry Got Away with It, whereas out in the suburbs, where the water supply remained unchanged, children’s lead levels stayed about the same. That’s how she knew it was the switch in water supplies. That’s what broke the story of the Flint crisis: a doubling of elevated lead levels.

But wait a moment: Even before the switch from Lake Huron to the polluted Flint River, when everyone was getting the same water, lead levels in children in Flint were twice that of the suburbs. There was already a doubling in elevated lead levels in Flint and other poor communities around the country, but where have all the crisis headlines been? Indeed, even with all the bottled water in the world, the children in Flint will continue to live in a lead-polluted environment.

Many have pointed out the irony that the new water from the Flint River was “so corrosive” that the nearby General Motors plant switched back to a clean water source when it started noticing rust spots on its new parts, all while water quality complaints from Flint residents were being ignored. But, there is an additional irony: General Motors is a major reason why the world is so contaminated with lead in the first place, as GM invented leaded gasoline. “Shortly after manufacture began, workers…began to become floridly psychotic and die.”

“In the wake of blaring headlines” about the lead-poisoned workers, public health leaders “warned of the potential for damage to broad swaths of the population” posed by putting this “well established toxin” into gasoline, “into the daily lives of millions of people. Yet, despite these warnings, millions…were harmed…and this entirely preventable poisoning still occurs today.”

“Virtually all the lead in the environment is there as a result of human activity.” Because we put it there. It used to be locked away, deep underground or under the ocean, but that was before we drove it around the Earth. “In the early 1970s, 200,000 tons of lead was emitted from automobiles in the United States each year, mostly in urban areas.” Had lead not been added to gasoline, the industry would have had to use higher-octane gas, which is less profitable. So, the “oil and lead industries…successfully thwarted government efforts to limit lead in gasoline for 50 years.” But, how were they able to do that? “Early public health warnings were not heeded because the industry assured the scientific community and the public that there was no danger.” I could see how a gullible public might be swayed by slick PR, but how do you manipulate the scientific community? By manipulating the science.

“The lead industry was able to achieve its influence in large part by being the primary supporter of research on health effects of lead,” and it got the best science money could buy. “Long before Big Tobacco, the lead industry understood the inestimable value of purchasing ‘good science.’”

“Consequently, the vast majority of relevant studies of lead in gasoline published [for decades]…were favorable to the lead industries.” What’s more, they “even sent a delegation to try to convince the U.S. EPA administrator that the lead regulation was not necessary because they alleged lead was an essential mineral required for optimum growth and development.”

Of course, the exact opposite is true. Lead is toxic to development. There are, however, nutritional interventions that can help alleviate lead toxicity. For example, there are food components that can help decrease the absorption of lead and help flush it out of your body. I’ve produced a series of three videos on specific dietary interventions, such as particular foods to eat, but—spoiler alert—in general, “food patterns that reduce susceptibility to lead toxicity are consistent with the recommendations for a healthy diet.”

As soon as I learned about the unfolding crisis in Flint, Michigan, I knew I had to take a deep dive into the medical literature to see if there is anything these kids might be able to do diet-wise to reduce their body burden.

Most of the time when I cover a subject on NutritionFacts.org, I’ve addressed it previously, so I just have to research the new studies published in the interim. But I had never really looked deeply into lead poisoning before, so I was faced with more than a century of science to dig through. Yes, I did discover there were foods that could help, but I also learned about cautionary tales like this one about our shameful history with leaded paint. By learning this lesson, hopefully, we can put more critical thought into preventing future disasters that can arise when our society allows profits to be placed over people.


This is part of a series on lead. You can view the rest of the series here:

 You may also be interested in How to Lower Heavy Metal Levels with Diet.

If you enjoyed this article, you may also like:

What relevance does this have for us today? See, for example, my video How Smoking in 1959 Is Like Eating in 2019.

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:

Boosting Antiviral Immune Function with Green Tea

Unlike most antiviral drugs, green tea appears to work by boosting the immune system to combat diseases such as genital warts (caused by HPV) and the flu (caused by the influenza virus).

According to one study, “The belief in green tea as a ‘wonder weapon’ against diseases dates back thousands of years.” I’ve talked about it in relation to chronic disease, but what about infectious disease? I explore this in my video Benefits of Green Tea for Boosting Antiviral Immune Function. Interest in the antimicrobial activity of tea dates back to a military medical journal in 1906, which suggested that servicemen fill their canteens with tea to kill off the bugs that caused typhoid fever. “However, this effect of tea was not studied further until the late 1980s” when tea compounds were pitted against viruses and bacteria in test tubes and petri dishes, but what we care about is whether it works in people. I had dismissed this entire field of inquiry as clinically irrelevant until I learned about tea’s effect on genital warts. External genital warts, caused by human wart viruses, “are one of the most common and fastest-spreading venereal diseases worldwide.”

Patients with external genital warts “present with one or several cauliflower-like growths on the genitals and/or anal regions…associated with…considerable impairment of patients’ emotional and sexual well-being.” But rub on some green tea ointment, and you can achieve complete clearance of all warts in more than 50 percent of cases.

If it works so well for wart viruses, what about flu viruses? As you can see at 1:41 in my video, it works great in a petri dish, but what about in people? Well, tea-drinking school children seem to be protected, but you don’t know about the broader population until it’s put to the test. If you give healthcare workers green tea compounds, they come down with the flu about three times less often than those given placebo, as you can see at 2:02 in my video. In fact, just gargling with green tea may help. While a similar effect was not found in high school students, gargling with green tea may drop the risk of influenza infection seven or eight-fold compared to gargling with water in elderly residents of a nursing home, where flu can get really serious.

Unlike antiviral drugs, green tea appears to work by boosting the immune system, enhancing the proliferation and activity of gamma delta T cells, a type of immune cell that acts as “a first line defense against infection.” According to the researchers, “Subjects who drank six cups of tea per day had up to a 15-fold increase in [infection-fighting] interferon gamma production in as little as one week”—but why?

There is in fact a molecular pattern shared by cancer cells, pathogens, and “edible plant products such as tea, apples, mushrooms, and wine.” So, eating healthy foods may help maintain our immune cells on ready alert, effectively priming our gamma delta T cells so they “then can provide natural resistance to microbial infections and perhaps tumors.” I guess I shouldn’t have been so surprised; tea, after all, is a “vegetable infusion.” You’re basically drinking a hot water extraction of a dark green leafy vegetable.


For more on what green tea can (and cannot) do, check out videos such as:

How else can we improve our immune function? See, for example:

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: