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:

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:

 

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: