Benefits of Turmeric for Arsenic Exposure

What happened when turmeric curcumin was put to the test to see if it could reverse DNA damage caused by arsenic exposure?

Arsenic is a carcinogenic heavy metal, and the major mechanism of arsenic-related damage appears to be oxidative stress. It’s the arsenic-induced accumulation of free radicals that can kill off cells and damage our DNA, and the double whammy is that it may also disrupt our body’s ability to repair our DNA once it’s damaged. Well, if the damage is oxidation, what about eating antioxidant-rich foods, such as the spice turmeric, which contains an antioxidant pigment known as curcumin. I examine this in my video Benefits of Turmeric for Arsenic Exposure.

As anyone familiar with my videos can attest, “numerous clinical studies have suggested that curcumin has therapeutic efficacy against a variety of human diseases,” including cancer, diabetes, Alzheimer’s, and inflammatory bowel, joint, lung, skin, and eye diseases.

In terms of protection against heavy metals, studies suggest turmeric may help scavenge free radicals, as well as chelate, or bind up, heavy metals. But it’s all just theory, until you put it to the test. Until recently, all we had was research studying whether curcumin can protect against heavy metal-induced oxidation in puréed rat brains, for example. Why can’t you just give some turmeric to people? It’s not like there aren’t millions of people out there who’ve been exposed to arsenic and could use some help.

Indeed, in what became the greatest chemical disaster in human history, “tube-wells” were installed in Bangladesh to provide clean water. UNICEF meant well—too bad they didn’t test the water for arsenic. People started showing up with lesions on their feet, as you can see at 1:52 in my video, and as many as one in ten people in some parts of the country will now go on to die from cancers caused by the arsenic exposure. This disaster allowed the medical community to document all sorts of “interesting” cancers, but why not give them something that may help, like turmeric curcumin?

Researchers did just that. After they determined the extent of DNA damage in study subjects, half were randomly selected and prescribed curcumin capsules blended with a little black pepper compound, while the other half were given a placebo. As you can see at 2:25 in my video, before the study started, the amount of DNA damage found in the curcumin and placebo groups of arsenic-exposed individuals was higher than the DNA damage found in a control group of individuals not exposed to arsenic, which remained the same throughout the study. The researchers wanted to establish a baseline in the arsenic-exposed groups, so they waited for three months before starting the study. And, indeed, the DNA damage remained stable during that time. Then, for three months, they proceeded to give the groups the curcumin or the placebo. The placebo didn’t do much, but within the first month, the researchers could see the curcumin working. And, by the third month, the DNA damage in the curcumin-treated arsenic group was no worse than in those who hadn’t been exposed to arsenic at all. Amazing! “The comparison of the populations receiving curcumin and placebo established that curcumin had an effective role in regression of DNA damage and as an excellent antioxidant agent,” and what they found subsequently is that the curcumin undid the arsenic crippling of our DNA repair enzymes—both helping to prevent the damage and facilitating its repair. “Thus, curcumin intervention may be a useful modality for the prevention of arsenic-induced carcinogenesis [cancer development].”

Of course, you have to make sure the turmeric itself isn’t contaminated with heavy metals. Nearly a quarter of spices purchased in Boston had lead in them, and it’s not just a matter of buying U.S. versus foreign brands, as the difference in lead levels was not found to be statistically significant, as you can see at 3:52 in my video.

What about just eating antioxidant-rich fruits and vegetables? The reason we care about DNA damage is that we care about cancer. What if you measured the beta-carotene levels in people exposed to arsenic who went on to develop cancer, compared to those who got exposed to the same amount of arsenic but didn’t get cancer? Beta-carotene is like a proxy for healthy fruit and vegetable intake. The way you get high levels in your blood is by eating lots of healthy foods, like greens and sweet potatoes. Compared to those with low levels of beta-carotene in their blood, those with high levels had 99 percent lower odds of getting arsenic-induced cancer, as you can see at 4:34 in my video. So, if you’re going to eat rice, why not have some rice with some sweet potatoes on top?


What’s the rice connection? I produced a 13-part series on arsenic in rice. Air-pop some popcorn, sit back, and enjoy:

What else can turmeric do? Glad you asked!

Who Shouldn’t Consume Curcumin or Turmeric? Watch the video to find 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:

Lowering Your Cancer Risk by Donating Blood

Back in the early 1980s, a pathologist in Florida suggested that the reason premenopausal women are protected from heart disease is that they have lower stores of iron in their body. Since oxidized cholesterol is “important in atherosclerosis, and oxidation is catalyzed by iron,” might the lower iron stores of menstruating women reduce their risk of coronary heart disease? “The novel insight suggesting that the longevity enjoyed by women over men might relate to the monthly loss…of blood is remarkable,” but is it true? I discuss this in my video Donating Blood to Prevent Heart Disease?.

The consumption of heme iron—the iron found in blood and muscle—is associated with increased risk of heart disease. Indeed, “an increase in heme iron intake of 1 mg/day appeared to be significantly associated with a 27% increase in risk of CHD,” coronary heart disease. But, heme iron is found mainly in meat, so “it is possible that some constituents other than heme iron in meat such as saturated fat and cholesterol are responsible” for the apparent link between heme iron and heart disease. If only we could find a way to get men to menstruate, then we could put the theory to the test. What about blood donations? Why just lose a little blood every month when you can donate a whole unit at a time?

A study in Nebraska suggested that blood donors were at “reduced risk of cardiovascular events,” but another study in Boston failed to show any connection. To definitively resolve the question, we would really have to put it to the test: Take people at high risk for heart disease, randomly bleed half of them, and then follow them over time and see who gets more heart attacks. Maybe it could turn “bloodletting” from the past into “bleeding-edge technology.” In fact, that was actually what was suggested in the original paper as a way to test this idea: “The depletion of iron stores by regular phlebotomy could be the experimental system for testing this hypothesis…”

It took 20 years, but researchers finally did it. Why did it take so long? There isn’t much money in bloodletting these days. I suppose the leech lobby just isn’t as powerful as it used to be.

What did the researchers find? It didn’t work. The blood donors ended up having the same number of heart attacks as the non-donor group. Something extraordinary did happen, however: The cancer rates dropped. There was a 37 percent reduction in overall cancer incidence, and those who developed cancer had a significantly reduced risk of death. An editorial in the Journal of the National Cancer Institute responded with near disbelief, saying the “results almost seem to be too good to be true.” “Strikingly,” they started to see cancer reduction benefits within six months, after giving blood just once. As the study progressed, the cancer death rates started to diverge within just six months, as you can see at 2:46 in my video, but this is consistent with the spike in cancer rates we see within only six months of getting a blood transfusion. Is it possible that influx of iron accelerated the growth of hidden tumors?


I continue this wild story in my video Donating Blood to Prevent Cancer?.

What if you feel faint when you give blood? Don’t worry. I’ve got you covered. Check out How to Prevent Fainting.

What might iron have to do with disease? See The Safety of Heme vs. Non-Heme Iron and Risk Associated with Iron Supplements.

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:

Comparing Pollutant Levels Between Different Diets

The results of the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study were published recently. This study of a California birth cohort investigated the relationship between exposure to flame retardant chemical pollutants in pregnancy and childhood, and subsequent neurobehavioral development. Why California? Because California children’s exposures to these endocrine disruptors and neurotoxins are among the highest in the world.

What did they find? The researchers concluded that both prenatal and childhood exposures to these chemicals “were associated with poorer attention, fine motor coordination, and cognition” (particularly verbal comprehension) by the time the children reached school age. “This study, the largest to date, contributes to growing evidence suggesting that PBDEs [polybrominated diphenyl ethers, flame retardant chemicals] have adverse impacts on child neurobehavioral development.” The effects may extend into adolescence, again affecting motor function as well as thyroid gland function. The effect on our thyroid glands may even extend into adulthood.

These chemicals get into moms, then into the amniotic fluid, and then into the breast milk. The more that’s in the milk, the worse the infants’ mental development may be. Breast milk is still best, but how did these women get exposed in the first place?

The question has been: Are we exposed mostly from diet or dust? Researchers in Boston collected breast milk samples from 46 first-time moms, vacuumed up samples of dust from their homes, and questioned them about their diets. The researchers found that both were likely to blame. Diet-wise, a number of animal products were implicated. This is consistent with what’s been found worldwide. For example, in Europe, these flame retardant chemical pollutants are found mostly in meat, including fish, and other animal products. It’s similar to what we see with dioxins—they are mostly found in fish and other fatty foods, with a plant-based diet offering the lowest exposure.

If that’s the case, do vegetarians have lower levels of flame retardant chemical pollutants circulating in their bloodstreams? Yes. Vegetarians may have about 25% lower levels. Poultry appears to be the largest contributor of PBDEs. USDA researchers compared the levels in different meats, and the highest levels of these pollutants were found in chicken and turkey, with less in pork and even less in beef. California poultry had the highest, consistent with strict furniture flammability codes. But it’s not like chickens are pecking at the sofa. Chickens and turkeys may be exposed indirectly through the application of sewer sludge to fields where feed crops are raised, contamination of water supplies, the use of flame-retarded materials in poultry housing, or the inadvertent incorporation of fire-retardant material into the birds’ bedding or feed ingredients.

Fish have been shown to have the highest levels overall, but Americans don’t eat a lot of fish so they don’t contribute as much to the total body burden in the United States. Researchers have compared the level of PBDEs found in meat-eaters and vegetarians. The amount found in the bloodstream of vegetarians is noticeably lower, as you can see in my video Flame Retardant Pollutants and Child Development. Just to give you a sense of the contribution of chicken, higher than average poultry eaters have higher levels than omnivores as a whole, and lower than average poultry eaters have levels lower than omnivores.

What are the PBDE levels in vegans? We know the intake of many other classes of pollutants is almost exclusively from the ingestion of animal fats in the diet. What if we take them all out of the diet? It works for dioxins. Vegan dioxin levels appear markedly lower than the general population. What about for the flame retardant chemicals? Vegans have levels lower than vegetarians, with those who’ve been vegan around 20 years having even lower concentrations. This tendency for chemical levels to decline the longer one eats plant-based suggests that food of animal origin contributes substantially. But note that levels never get down to zero, so diet is not the only source.

The USDA researchers note that there are currently no regulatory limits on the amount of flame retardant chemical contamination in U.S. foods, “but reducing the levels of unnecessary, persistent, toxic compounds in our diet is certainly desirable.”

I’ve previously talked about this class of chemicals in Food Sources of Flame Retardant Chemicals. The same foods seem to accumulate a variety of pollutants:

Many of these chemicals have hormone- or endocrine-disrupting effects. See, for example:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: