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:

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:

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:

Mini-nuclear plants may be an experiment worth exploring

Roll-Royce gave an eye-catching pitch but the economics of nuclear power needs further inspection

An energy white paper is in the offing, so consider Rolls-Royce’s pitch for the wonders of small modular reactors (SMRs) a piece of last-minute lobbying. After all, it is clear already that more nuclear, in combination with more offshore wind capacity, is likely to be judged a central way to meet the UK’s targets for cutting carbon emissions.

It’s an eye-catching pitch. “A domestic energy solution for the first time in a generation, with a product that is engineered, designed and manufactured in the UK,” as Tom Samson, the chief executive of the nine-member Rolls-led UK SMR consortium puts it. So not one of those mammoth £20bn-plus French-led and Chinese-backed Hinkley Point C constructions.

Continue reading…

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:

 

Why You Don’t Want “Normal” Blood Lead Levels

“By the 1950s, lead—a dangerous neurotoxin that was once buried deep in the ground, far away from humans—had polluted the entire planet.” We have leaded gasoline to thank for this. It’s hard to imagine “a better strategy for maximizing population exposure to a poison than to have it emitted by a ubiquitous mobile source and to line the surfaces of dwellings” and our neighborhoods with it.

“Overall, about 5 million metric tons of lead was deposited in the environment as a result of the combustion of leaded gasoline” by our automobiles before it was regulated. A single busy street could receive more than a metric ton a year, and the lead just built up, decade after decade. Finally, thanks to regulations starting in the 1970s, we stopped spewing so much into the air. As you can see at 0:57 in my video “Normal” Blood Lead Levels Can Be Toxic, as lead use dropped, so did the levels of lead in our blood, resulting in a 98 percent reduction in the percentage of young children with elevated blood lead levels. Of course, the term “elevated” is relative.

“Prior to 1970, lead poisoning was defined by a blood lead concentration of 60 mg/dL or higher” but “since then, the blood lead concentration for defining lead toxicity gradually has been reduced” to 40 mg/dL, then 30 mg/dL, then 25 mg/dL, and then further down to 10mg/dL, as lead levels “previously thought to be safe or inconsequential for children have consistently been shown to be risk factors” for cognitive and behavioral problems.

Currently, an elevated blood lead level is considered to be more than 5 mg/dL. So, under 5 mg/dL, your lead level is considered to be non-elevated or normal. But what does having a “normal” lead level mean?

“Virtually all residents of industrialized countries have bone lead stores that are several orders of magnitude greater than those of our preindustrial ancestors.” If you go to a museum and test the lead levels of ancient skeletons buried a millennium ago, they are a thousand times lower compared to people today, “which indicates the probable existence within most Americans of dysfunctions caused by poisoning from chronic, excessive overexposures to industrial Pb lead.”

You can see a graphical representation of “body burdens of lead” in a preindustrial ancestor, a typical American citizen, and a person with overtly symptomatic lead poisoning, where he might be doubled over in pain, at 2:30 in my video. What the medical and research communities had failed to understand is that they had only concerned themselves with people with actual lead poisoning and those at “typical” lead levels, but “the new value for natural lead levels in [preindustrial] humans shows that typical levels of lead in humans are quite definitely not properly described by the term ‘very low levels’ at all, but instead constitute grossly excessive, 1000-fold over-exposure levels.”

 The bottom line? “No level of lead exposure appears to be ‘safe’ and even the current ‘low’ levels of exposure in children are associated with neurodevelopmental deficits,” including reduced IQ. It could have been a lot worse if we hadn’t started restricting leaded gas. Thanks to falling blood lead levels starting in the 1970s, preschoolers born in the 1990s were two to five IQ points higher than kids like me born before 1976. So, when we see our kids and grandkids being such wizzes at technology that it’s hard to keep up with them, a small part of that may be them not suffering as much lead-induced brain damage as we did. And, what that means for the country is potentially hundreds of billions of dollars of improved productivity because our children are less brain-damaged.

If that seems like a lot for just a few IQ points, as you can see at 4:26 in my video, what you have to realize is that even a small shift in average IQ could result in a 50 percent increase in the number of the “mentally retarded,” millions more in need of special education and services.

So, “removal of lead from gasoline in the United States has been described as one of the great public health achievements of the 20th century, but it almost did not happen.” Indeed, “tremendous pressure by the lead industry itself was brought to bear to quiet, even intimidate, researchers and clinicians who reported on or identified lead as a hazard.” Decent “scientists and health officials faced enormous opposition but never lost sight of the mandate to protect public health.”

Two of the “young, idealistic employees” at the newly formed Environmental Protection Agency, who played key roles in the fight, recount how “naïve [they were] to the ways of Washington”:

“Our youth was also used against us. Our inexperience was cited as a reason for rejecting the lead regulatory proposals….Finally, in retrospect, our youth and inexperience also helped us to succeed in taking on a billion dollar industry. We were too young to know, that regulating lead in gasoline was impossible.”


What about lead exposure after childhood? That’s the topic of my video The Effects of Low-Level Lead Exposure in Adults.

What can we do about lead exposure? See:

If you missed the first three videos in this series, check out:

For the effects of mercury, another heavy metal, 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:

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 Explains the Egg-Cancer Connection

The reason egg consumption is associated with elevated cancer risk may be the TMAO, considered the “smoking gun” of microbiome-disease interactions.

“We are walking communities comprised not only of a Homo sapiens host, but also of trillions of symbiotic commensal microorganisms within the gut and on every other surface of our bodies.” There are more bacterial cells in our gut than there are human cells in our entire body. In fact, only about 10 percent of the DNA in our body is human. The rest is in our microbiome, the microbes with whom we share with the “walking community” we call our body. What do they do?

Our gut bacteria microbiota “serve as a filter for our largest environmental exposure—what we eat”—and, “technically speaking, food is a foreign object that we take into our bodies” by the pound every day. The “microbial community within each of us significantly influences how we experience a meal…Hence, our metabolism and absorption of food occurs through” this filter of bacteria.

However, as you can see at 1:22 in my video How Our Gut Bacteria Can Use Eggs to Accelerate Cancer, if we eat a lot of meat, including poultry and fish, milk, cheese, and eggs, we can foster the growth of bacteria that convert the choline and carnitine in those foods into trimethylamine (TMA), which can be oxidized into TMAO and wreak havoc on our arteries, increasing our risk of heart attack, stroke, and death.

We’ve known about this “troublesome” transformation from choline into trimethylamine for more than 40 years, but that was way before we learned about the heart disease connection. Why were researchers concerned back then? Because these methylamines might form nitrosamines, which have “marked carcinogenic activity”—cancer-causing activity. So where is choline found in our diet? Mostly from meat, eggs, dairy, and refined grains. The link between meat and cancer probably wouldn’t surprise anyone. In fact, just due to the industrial pollutants, like PCBs, children probably shouldn’t eat more than about five servings a month of meats like beef, pork, or chicken combined. But, what about cancer and eggs?

Studies going back to the 1970s hinted at a correlation between eggs and colon cancer, as you can see at 2:45 in my video. That was based just on so-called ecological data, though, showing that countries eating more eggs tended to have higher cancer rates, but that could be due to a million factors. It needed to be put to the test.

This testing started in the 80s, and, by the 1990s, 15 studies had been published, of which 10 suggested “a direct association” between egg consumption and colorectal cancer, “whereas five found no association.” By 2014, dozens more studies had been published, confirming that eggs may indeed be playing a role in the development of colon cancer, though no relationship was discovered between egg consumption and the development of precancerous polyps, which “suggested that egg consumption might be involved in the promotional” stage of cancer growth—accelerating cancer growth—rather than initiating the cancer in the first place.

This brings us to 2015. Perhaps it’s the TMAO made from the choline in meat and eggs that’s promoting cancer growth. Indeed, in the Women’s Health Initiative study, women with the highest TMAO levels in their blood had approximately three times greater risk of rectal cancer, suggesting that TMAO levels “may serve as a potential predictor of increased colorectal cancer risk.”

As you can see at 4:17 in my video, though there may be more evidence for elevated breast cancer risk with egg consumption than prostate cancer risk, the only other study to date on TMAO and cancer looked at prostate cancer and did indeed find a higher risk.

“Diet has long been considered a primary factor in health; however, with the microbiome revolution of the past decade, we have begun to understand how diet can” affect the back and forth between us and the rest of us inside, and the whole TMAO story is “a smoking gun” in gut bacteria-disease interactions.

Since choline and carnitine are the primary sources of TMAO production, the logical intervention strategy might be to reduce meat, dairy, and egg consumption. And, if we eat plant-based for long enough, we can actually change our gut microbial communities such that we may not be able to make TMAO even if we try.

“The theory of ‘you are what you eat’ finally is supported by scientific evidence.” We may not have to eat healthy for long, though. Soon, Big Pharma hopes, “we may yet ‘drug the microbiome’…as a way of promoting cardiovascular health.”

What did the egg industry do in response to this information? Distort the scientific record. See my video Egg Industry Response to Choline and TMAO.


This is not the first time the egg industry has been caught in the act. See, for example:

For background on TMAO see my original coverage in Carnitine, Choline, Cancer, and Cholesterol: The TMAO Connection and then find out How to Reduce Your TMAO Levels. Also, see: Flashback Friday: How to Reduce Your TMAO Levels.

This is all part of the microbiome revolution in medicine, the underappreciated role our gut flora play in our health. For more, 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:

Combating Air Pollution Effects with Food

There is a food that offers the best of both worlds—significantly improving our ability to detox carcinogens like diesel fumes and decreasing inflammation in our airways—all while improving our respiratory defenses against infections.

Outdoor air pollution may be the ninth leading cause of death and disability in the world, responsible for millions of deaths from lung cancer, emphysema, heart disease, stroke, and respiratory infection. In the United States, living in a polluted city was associated with 16, 27, and 28 percent increases in total, cardiovascular, and lung cancer deaths, compared to living in a city with cleaner air. As well, living in a city with polluted air may lead to up to a 75 percent increase in the risk of a heart attack. “Additionally, the possibility of dying in a traffic jam is two and a half times greater in a polluted city.” No one wants to be living in a traffic jam, but it’s better than dying in one.

In addition to causing deaths, air pollution is also the cause of a number of health problems. It may not only exacerbate asthma but also increase the risk of developing asthma in the first place. These pollutants may trigger liver disease and even increase the risk of diabetes. Indeed, “even when atmospheric pollutants are within legally established limits, they can be harmful to health.” So, what can we do about it?

Paper after paper have described all the terrible things air pollution can do to us, but “most…failed to mention public policy. Therefore, while science is making great strides in demonstrating the harmful effects of atmospheric pollution on human health, public authorities are not using these data” to reduce emissions, as such measures might inconvenience the population “and, therefore, might not be politically acceptable.” We need better vehicle inspections, efficient public transport, bus lanes, bicycle lanes, and even urban tolls to help clean up the air, but, while we’re waiting for all of that, is there anything we can do to protect ourselves?

As I discuss in my video Best Food to Counter the Effects of Air Pollution, our body naturally has detoxifying enzymes, not only in our liver, but also lining our airways. Studies show that people born with less effective detox enzymes have an exaggerated allergic response to diesel exhaust, suggesting that these enzymes actively combat the inflammation caused by pollutants in the air. A significant part of the population has these substandard forms of the enzyme, but, either way, what can we do to boost the activity of whichever detoxification enzymes we do have?

One of my previous videos Prolonged Liver Function Enhancement from Broccoli investigated how broccoli can dramatically boost the activity of the detox enzymes in our liver, but what about our lungs? Researchers fed some smokers a large stalk of broccoli every day for ten days to see if it would affect the level of inflammation within their bodies. Why smokers? Smoking is so inflammatory that you can have elevated C-reactive protein (CRP) levels for up to 30 years after quitting, and that inflammation can start almost immediately after you start smoking, so it’s critical to never start in the first place. If you do, though, you can cut your level of that inflammation biomarker CRP nearly in half after just ten days eating a lot of broccoli. Broccoli appears to cut inflammation in nonsmokers as well, which may explain in part why eating more than two cups of broccoli, cabbage, cauliflower, kale, or other cruciferous veggies a day is associated with a 20 percent reduced risk of dying, compared to eating a third of a cup a day or less, as you can see at 3:41 in my video.

What about air pollution? We know that the cruciferous compound “is the most potent known inducer” of our detox enzymes, so most of the research has been on its ability to fight cancer. But, for the first time, researchers tried to see if it could combat the pro-inflammatory impact of pollutants, such as diesel exhaust. They put some human lung lining cells in a petri dish, and, as you can see at 4:11 in my video, the number of detox enzymes produced after dripping on some broccoli goodness skyrocketed. Yes, but we don’t inhale broccoli or snort it. We eat it. Can it still get into our lungs and help? Yes. After two days of broccoli sprout consumption, researchers took some cells out of the subjects’ noses and found up to 100 times more detox enzyme expression compared to eating a non-cruciferous vegetable, alfalfa sprouts. If only we could squirt some diesel exhaust up people’s noses. That’s just what some UCLA researchers did, at an amount equal to daily rush hour exposure on a Los Angeles freeway. Within six hours, the number of inflammatory cells in their nose shot up and continued to rise. But, in the group who had been getting a broccoli sprout extract, the inflammation went down and stayed down, as you can see at 4:58 in my video

Since the dose in those studies is equivalent to the consumption of one or two cups of broccoli, their study “demonstrates the potential preventive and therapeutic potential of broccoli or broccoli sprouts,” but if broccoli is so powerful at suppressing this inflammatory immune response, might it interfere with normal immune function? After all, the battle with viruses like influenza can happen in the nose. So what happens when some flu viruses are dripped into the nostrils of broccoli-sprout eaters compared with people consuming non-cruciferous alfalfa sprouts? After eating broccoli sprouts, we get the best of both worlds—less inflammation and an improved immune response. As you can see at 5:55 in my video, after eating alfalfa sprouts, there is a viral spike in their nose. After eating a package of broccoli sprouts every day, however, our body is able to keep the virus in check, potentially offering “a safe, low-cost strategy for reducing influenza risk among smokers and other at risk populations.”

So, better immune function, yet less inflammation, potentially reducing the impact of pollution on allergic disease and asthma, at least for an “enthusiastic broccoli consumer.” But what about cancer and detoxifying air pollutants throughout the rest of our body? We didn’t know, until now. Off to China, where “levels of outdoor air pollution…are among the highest in the world.” By day one, those getting broccoli sprouts were able to get rid of 60 percent more benzene from their bodies. “The key finding…was the observed rapid and highly durable elevation of the detoxification of… a known human carcinogen.” Now, this was using broccoli sprouts, which are highly concentrated, equivalent to about five cups of broccoli a day, so we don’t know how well more modest doses would work. But if they do, eating broccoli could “provide a frugal means to attenuate…the long-term health risks” of air pollution. More on air pollution here.

I’ve been reading about the terrible effects of air pollution for a long time and I am thrilled there’s something we can do other than uprooting our families and moving out to the countryside.


For more on cruciferocity, see my videos Lung Cancer Metastases and Broccoli and Breast Cancer Survival Vegetable.

There’s a secret to maximizing broccoli’s benefits. See Flashback Friday:Second Strategy to Cooking Broccoli.

For more on Cooking Greens: How to Cook Greens and Best Way to Cook Vegetables.

What about broccoli sprout pills? See Broccoli: Sprouts vs. Supplements.

Speaking of respiratory inflammation, what about dietary approaches to asthma? Learn more:

There are sources of indoor pollution, too. See Throw Household Products Off the Scent.

There is one way what we eat can directly impact air pollution, beyond just personal protection. Check out Flashback Friday: Diet and Climate Change: Cooking Up a Storm.

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:

I believe Roundup gave me cancer. The Monsanto settlement is a slap in the face | Christine Sheppard

I have to inject myself with needles just to stay alive. Still, Bayer will continue to sell Roundup, and refused to label it as carcinogenic

Last Wednesday was my 71st birthday, a low-key celebration in these Covid-19 times. Then I heard the news that the pharmaceutical conglomerate Bayer has offered a settlement to resolve several massive class-action lawsuits alleging that the company’s herbicide, Roundup, is dangerous and causes cancer.

I’m one of the thousands of people who filed suit. The news of the settlement ruined my birthday.

Bayer admitted no guilt, will continue to sell Roundup, and refused to label it as carcinogenic. People will continue to get cancer from it

Christine Sheppard was born in Hertfordshire, England, and immigrated to the US in 1980. She is now a retired grandmother living in southern California

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