Why Was Chicken the Primary Source of Arsenic Exposure in Children?

What was the National Chicken Council’s response to public health authorities calling for the industry to stop feeding arsenic-based drugs to poultry?

“Dietary practices influence our exposure to pesticides, toxic heavy metals, persistent organic pollutants, and industrial pollutants….A diet high in fish and other animal products, for example, results in greater exposure to persistent organic compounds and metals than does a plant-based diet because these compounds bioaccumulate up the food chain.” Researchers at UC Davis analyzed the diets of children and adults in California to see just how bad things have gotten.

Cancer benchmark levels were exceeded by all children—100 percent of children—for arsenic, the banned pesticides dieldrin and DDT, metabolite DDE, as well as dioxins, and not just by a little. As you can see at 0:51 in my video Where Does the Arsenic in Chicken Come From?, researchers found more than a hundred times the acceptable daily exposure for arsenic in preschoolers, school-aged children, parents, and older adults, about ten times the acceptable levels for various pesticides, and up to a thousand times the daily dose for dioxins. Where are all these toxins coming from?

The number-one source of dioxins in the diets of Californian preschoolers, kids, parents, and grandparents appears to be dairy for all age groups, followed by meat, and then white potatoes, refined grains, mushrooms, poultry, and fish.

These days, our DDT legacy is also mostly from dairy. Dieldrin was created as a safer alternative to DDT, but it was banned just two years later, in 1974, though it’s still found in our bodies, mostly thanks to dairy, meat, and, evidently, cucumbers.

Chlordane made it into the 1980s before being banned, though we’re still exposed through dairy (and cukes). Lead is — foodwise — also mostly from dairy, and mercury is not surprisingly mostly from tuna and other seafood. But the primary source of arsenic in children? Surprisingly, mostly from chicken. Why?

Let me tell you a tale of arsenic in chicken. Arsenic is “well known as a poison by anyone who reads mysteries or the history of the Borgias, and with its long and colourful history, arsenic is not something that people want in their food.” So, when a biostatistics student went to the USDA in 2000 in search of a project for his master’s degree, he decided to look into it. He found a startling difference: Arsenic levels in chicken were three times higher than in other meats. His veterinary colleagues weren’t at all surprised and explained that four different types of arsenic-containing antibiotic drugs are fed to poultry—and have been fed to them since 1944.

“While arsenic-based drugs had been fed to poultry since the 1940s, recognition of this source of exposure [for humans] only occurred after appropriate statistical analysis of the data”—that is, after this student churned through the data. It was published in 2004 and expanded upon in 2006. The National Chicken Council (NCC) was none too pleased, saying lots of foods are contaminated with arsenic. “By focusing specifically on chicken, IATP [the Institute for Agriculture and Trade Policy] makes it clear that it is producing a publicity-oriented document focused on the objective of forcing [chicken] producers to stop using these safe and effective products”—by which the NCC means these arsenic-containing drugs. In fact, the NCC admits to using them but says we don’t need to worry because chicken producers use organic arsenic, “not the inorganic form made infamous in ‘Arsenic and Old Lace.’” Okay, so we don’t need to worry—until, apparently, we cook it. When chicken is cooked, it appears that some of the arsenic drug in the meat turns into the ”Arsenic and Old Lace” variety. So, the Poison-Free Poultry Act of 2009 was introduced into Congress, flopped, and was followed by the subsequent introduction of the Poison-Free Poultry Act of 2011. Did the second attempt fare any better? No, legislators once again said pish posh to poison-poor poultry. So, in 2013, a coalition of nine organizations got together and sued the FDA, and by December 31, 2015, all arsenic-containing poultry drugs were withdrawn. As of 2016, arsenic is no longer to be fed to chickens. The bad news is that without giving birds the arsenic-containing drug roxarsone, chicken may lose some of its “appealing pink color.”

In the end, the poultry industry got away with exposing the American public to arsenic for 72 years. “It should be noted that the European Union has never approved drugs containing arsenic for animal consumption” in the first place, saying, Hmm, feed our animals arsenic? No thanks, nein danke, no grazie, non, merci.

Europe has also long since banned the “urgent threat to human health” posed by feeding farm animals millions of pounds of human antibiotics. As you can see at 5:30 in my video, feeding chickens en masse literally tons of drugs like tetracyclines and penicillins to fatten them faster is a problem that gets worse every year instead of better and dates back to 1951 when drug companies whipped out the ALL CAPS in advertisements,  promising “PROFITS…several times higher!”, a dangerous practice the poultry industry has gotten away with for 68 years…and counting.


If you don’t eat poultry and are feeling a little cocky, you may want to check out my 12-video series on arsenic in rice before you gloat too much:

Think feeding arsenic to chickens is weird? Check out Illegal Drugs in Chicken Feathers.

And for more on the critical public health threat posed by antibiotic overuse in animal agriculture, 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:

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:

Can Soy Prevent and Treat Prostate Cancer?

As I discuss in my video The Role of Soy Foods in Prostate Cancer Prevention and Treatment, a compilation of 13 observational studies on soy food consumption and the risk of prostate cancer found that soy foods appear to be “protective.” What are observational studies? As opposed to interventional studies, in observational studies, researchers observe what people are eating but don’t intervene and try to change their diets. In these studies, they observed that men who ate more soy foods had lower rates of prostate cancer, but the problem with observational studies is that there could be confounding factors. For example, “people who choose to eat soy also make other lifestyle decisions that lower the risk of cancer (e.g., lower fat intake, higher vegetable and fruit intake, more frequent exercise),” maybe that is why they have less cancer. Most of the studies tried to control for these other lifestyle factors, but you can’t control for everything. What’s more, most of the studies were done in Asia, so maybe tofu consumption is just a sign of eating a more traditional diet. Is it possible that the reason non-tofu consumers got more cancer is that they had abandoned their traditional diet? If only we could look at a Western population that ate a lot of soy. We can: the Seventh-Day Adventists.

In the 1970s, more than 12,000 Adventist men were asked about their use of soy milk and then were followed for up to 16 years to see who got cancer and who did not. So, what did they find? Frequent consumption of soy milk was associated with a whopping 70 percent reduction of the risk of prostate cancer, as you can see at 1:33 in my video. Similarly, in a multiethnic study that involved a number of groups, soy intake appeared protective in Latinos, too.

Prostate cells carry beta type estrogen receptors, which appear to act as a tumor suppressor, a kind of “gatekeeper…inhibiting invasion, proliferation and…preventing” the prostate cells from turning cancerous. And, those are the receptors targeted by the phytoestrogens in soy, like genistein, which inhibits prostate cancer cell invasion and spread in a petri dish at the kind of levels one might get consuming soy foods. The prevention of metastases is critical, as death from prostate cancer isn’t caused by the original tumor, but its spread throughout the body, which explains why it “is recommended that men with prostate cancer consume soy foods, such as soybeans, tofu, miso and tempeh.”

Wait a moment. Dean Ornish and his colleagues got amazing results, apparently reversing the progression of prostate cancer with a plant-based diet and lifestyle program. Was it because of the soy? Their study didn’t just include a vegan diet, but a vegan diet supplemented with a daily serving of tofu and a soy protein isolate powder. There have been studies showing that men given soy protein powders develop less prostate cancer than the control group, but what was the control group getting? Milk protein powder. Those randomized to the milk group got six times more prostate cancer than the soy group, but was that due to the beneficial effects of soy or the deleterious effects of the dairy? Dairy products are not just associated with getting prostate cancer, but also with dying from prostate cancer. Men diagnosed with prostate cancer who then ate more dairy tended to die sooner, and “both low-fat and high-fat dairy consumption were positively associated with an increased risk of fatal outcome.”

The best study we have on soy protein powder supplementation for prostate cancer patients found no significant benefit, and neither did a series of soy phytoestrogen dietary supplements. But, perhaps that’s because they used isolated soy components rather than a whole soy food. “Taking the whole-food approach may be more efficacious,” but it can be hard to do controlled studies with whole foods: You can make fake pills, but how do you give people placebo tofu?

A group of Australian researchers creatively came up with a specially manufactured bread containing soy grits to compare to a placebo regular bread and gave slices to men diagnosed with prostate cancer awaiting surgery. As you can see at 4:31 in my video, they saw a remarkable difference in just about three weeks time. It was the first study to show that a diet incorporating a whole soy food could favorably affect prostate cancer markers, but you can’t just go out and buy soy grit bread. Another study was a little more practical. Twenty men with prostate cancer who had been treated with radiation or surgery but seemed to be relapsing were asked to drink three cups of regular soy milk a day. The PSA levels in each of the 20 patients were all rising before they started the soy milk, suggesting they had relapsing or metastatic cancer growing inside of them. However, during a year drinking soy milk, 6 out of the 20 subjects got better, 2 got worse, and the remaining 12 remained unchanged, as you can see from 5:02 in my video. So, they concluded that soy food may help in a subset of patients.

Based on all these studies, the results Ornish and his colleagues got were probably due to more than just the soy. Similarly, the low prostate cancer rates in Asia are probably because of more than just the soy, since the lowest rates are also found in parts of Africa, where I don’t think they’re eating a lot of tofu. Indeed, in the multiethnic study, other types of beans besides soy also appeared protective for Latinos and all the groups put together, when looking at the most aggressive forms of prostate cancer. So, the protection associated with plant-based diets may be due to eating a variety of healthy foods. 


That soy milk stat from the Adventist study is astounding. What about fermented soy foods, though? That was the subject of Fermented or Unfermented Soy Foods for Prostate Cancer Prevention?.

Reversing the progression of cancer? See How Not to Die from Cancer.

Given the power of diet, it’s amazing to me how difficult Changing a Man’s Diet After a Prostate Cancer Diagnosis can be. It’s not all or nothing, though. Check out Prostate Cancer Survival: The A/V Ratio.

For soy and breast cancer survival, see Is Soy Healthy for Breast Cancer Survivors?.

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: