Can Vitamin C Supplements Help with Lead Poisoning?

“Even if a nutritional manipulation is proven effective in reducing blood lead levels, reliance on such an intervention places most of the burden for prevention on those most affected and least responsible for the underlying environmental causes of lead toxicity. Nutritional interventions, therefore, must never substitute for efforts to reduce lead exposure to safe levels. On the other hand, when used as an adjunct to environmental measures, some nutritional changes may prove to have benefits beyond any impact on lead toxicity.” For example, consumption of vitamin C-rich foods may help with “blood pressure, blood lipid profiles, and respiratory symptoms,” in addition to perhaps influencing “lead toxicity through an influence on absorption of lead, elimination of lead, transport within the body, tissue binding, or secondary mechanisms of toxicity,” that is, even just helping ameliorate some of the damage. But what is this based on?

In 1939, a remarkable study was published, entitled “Vitamin C treatment in lead poisoning,” in which 17 lead industry workers were given 100 mg of vitamin C a day, the amount found in one or two oranges, and “with practically all of them there was a marked gain in vigor, color of skin, cheerfulness, blood picture, appetite and ability to sleep well.” The 17 workers were chosen because they seemed to be in pretty bad shape and possibly even had scurvy, so it’s no wonder a little vitamin C helped. But vitamin C is an antioxidant, and oxidation is “an important mechanism underlying lead toxicity,” so it’s conceivable that it may have mediated some of the harm. But, the vitamin C didn’t appear to just reduce the damage from the lead—it also reduced the lead itself. As you can see from 1:43 in my video Can Vitamin C Help with Lead Poisoning?, the amount of lead in a painter’s urine over a period of a month after starting 200 mg of vitamin C a day exhibited a five-fold drop, suggesting he was absorbing less of the lead into his body. He was one of three painters researchers tried this on, and evidently all three painters’ levels dropped. The researchers concluded that those “exposed to lead…should be advised to include in their diet plenty of such rich sources of vitamin C as tomatoes (fresh or canned), raw cabbage, oranges or grapefruit, raw spinach (or even cooked, in very little water), raw turnips, green bell peppers, cantaloupe, etc.”

Now, this drop in lead in the subjects’ urine was seen with only three painters, and the study didn’t have a control group of painters who didn’t take vitamin C, so perhaps everyone’s lead levels would have dropped for some other reason or perhaps it was just a coincidence. You don’t know…until you put it to the test.

Those original data were so compelling that others were inspired to try to replicate them. I mean, if it actually worked, if vitamin C could help with lead poisoning, grapefruits could be handed out at the factory door! The earlier study didn’t have a good control group, but the researchers weren’t going to make that same mistake this time. In this study, half of the group got 100 mg of vitamin C a day—not just for a month but for a year—and the other group got nothing. The result? “Careful study of a large group of lead workers failed to reveal any effect of ascorbic acid vitamin C…on the lead concentration in the blood…or urine” (emphasis added). There was no difference in their physical condition and no changes in their blood work, so “no reason has been found for recommending the use of ascorbic acid vitamin C to minimize effects of lead absorption.” What a disappointment. It looked so promising!

Whenever I study a topic, I try to read the research chronologically so I can experience the discoveries as they happened throughout history. At this point, though, I was so tempted to jump to a recent review to see what had happened in the intervening 74 years since that first study was published, but I didn’t want to spoiler alert! myself, so I kept reading the papers sequentially. There were in vitro studies where researchers dripped antioxidants on lead exposed cells and it seemed to help, so they jumped on the cantaloupe bandwagon, too, but these were test tube studies.

The first population study was published in 1999, and, as you can see at 4:02 in my video, researchers did find that those with high vitamin C levels in their blood tended to have lower lead levels. Youths with the highest vitamin C levels had a nearly 90 percent lower prevalence of elevated blood lead levels compared to those with the lowest vitamin C levels. Now, this was a cross-sectional study, just a snapshot in time, so we don’t know if the vitamin C caused a drop in lead or if perhaps the lead caused a drop in vitamin C. Lead is a pro-oxidant, so maybe it ate up the vitamin C. And who has higher vitamin C levels? Those who can afford to have higher vitamin C levels and eat lots of fruits and vegetables. “It is also possible that higher ascorbic acid levels may represent healthier lifestyles or greater socio-economic status.” Indeed, maybe lower vitamin C levels are just a proxy for being poor, and that’s the real reason for higher lead levels.

There are lots of good reasons to be eating more fruits and vegetables, and we should be eating more spinach regardless, but it would be nice to know if vitamin C actually helps with lead poisoning. And, to know that, we need to put it to the test.

Unfortunately, most of the published interventions are not very helpful, with such titles as “Effects of dietary vitamin C supplementation on lead-treated sea cucumbers,….”  And, there is a surprising number of articles on the effects of vitamin C supplementation on mouse testicles. Why? Because lead may impair male fertility. Indeed, lead workers appear to have a reduced likelihood of fathering children, but this may in part be due to oxidative stress. In that case, how about giving an antioxidant, like vitamin C, and putting it to the test(es)? No, I’m not talking about rat testes or suggesting frog testes. Neither am I proposing crab testes. (I didn’t even know crabs had testicles!) Finally, here’s one to discuss: “Clinical relevance of vitamin C among lead-exposed infertile men.” A study of human men, which I will cover in Yellow Bell Peppers for Male Infertility and Lead Poisoning?.

I’m always conflicted about writing these kinds of blogs and producing videos like Can Vitamin C Help with Lead Poisoning?. I can imagine some just want “the answer,” but those with vested and commercial interests often exploit that natural impulse. This is problem with science in general, but perhaps particularly in nutrition. When it comes to something as life-or-death important as what to feed ourselves and our families we shouldn’t just follow someone’s opinions or beliefs on the matter. We should demand to see the science. That’s what I try to do: Present the available data as fairly and even-handedly as possible, and let you make up your own mind. You can imagine how easily someone could cherry-pick just one or two studies and present a distorted but compelling case for or against, in this case, vitamin C supplements. That’s why I feel it’s important to present each study in their historical context. Stay tuned for the thrilling conclusion in Yellow Bell Peppers for Male Infertility & Lead Poisoning?.


 For those of you who are thinking, Why should I care about lead? I don’t eat paint chips or use leaded gasoline. Anyway, what’s the big deal?, check out my full series of lead videos for information on how we got into this mess and some of the ways we can dig ourselves 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:

Food Combining for Prostate Cancer

What would happen if you secretly gave cancer patients four of the healthiest foods?

In my video Pomegranate vs. Placebo for Prostate Cancer, I discussed how pomegranate pills appeared useless in the treatment for prostate cancer, and the same disappointing results were seen with a pomegranate beverage, but that was just a pomegranate extract as well. So, maybe the pomegranate itself “cannot be blamed for the ineffectiveness seen in the study” but rather the low dose of the pomegranate active principles in the extract. But what is the active principle? Extracts will boast about the level of ellagic acid, definitely “one of the most potent of the phytochemicals found in pomegranate. However, it is not as strong as pomegranate” itself.

What researchers mean is that the components may act synergistically: The whole may be greater than the sum of its parts. As you can see at 1:07 in my video Best Supplements for Prostate Cancer, human prostate cancer cells in a petri dish churned away at 100 percent growth, but after dripping on a pomegranate fraction, the cancer growth rate was cut by 30 percent. However, dripping on a different fraction appeared useless. What do you think would happen if you added them both together? 30% suppression + 0% suppression = 70% suppression! That’s synergy, where 1 + 1 is greater than 2. Under a microscope, prostate cancer cells appeared sparser with the combination of fractions. “Any attempt to characterize the phytoceutical power of a medicinal food by standardizing a single chemical is missing the entire point” of plant-based medicine. So, the standardized extracts represent a “cynical, lucre-driven [money-driven] attempt to replace the power of the pomegranate with the power of ellagic acid. The pomegranate needs no such tricks or enhancements.” It’s powerful as is. So, why don’t researchers just try the fruit on cancer patients?

Because you can’t stuff a pomegranate in a pill, so you can’t compare it to an indistinguishable sugar pill placebo. Drugs are easy to study. People don’t know if they are taking the active drug or a placebo, but they tend to notice if they’re eating a pomegranate or not. So, if you gave a bunch of cancer patients some pomegranates to eat and the cancer slowed down, you wouldn’t know if it was the pomegranates or just the placebo effect. Of course, the patients wouldn’t care. They’d just care that they got better. But, to change medical practice, we want to know if the fruit is actually something special. I suppose you could create some kind of pomegranate smoothie versus a fake smoothie, but that sounds logistically difficult. So, researchers tried powdering it. Three times a day, 199 men with prostate cancer got either a placebo or a tablet containing 100 mg of powdered whole pomegranate—the whole fruit with just the water taken out. How much can fit in a tablet? It comes out to be about six pomegranate seeds’ worth a day, about 1/100th of a pomegranate each day. Since so little could fit into a pill, researchers tried to maximize their chances of beating back the cancer using diversity.

As you can see at 4:01 in my video, two groups of people ate approximately the same amount of fruits and vegetables, but one group ate a relatively low biological diversity diet, where they ate tons of really healthy foods but just less variety than did a second group who ate smaller servings of a high diversity diet. Which group do you think would win in terms of protecting their DNA from free radical damage? The high diversity group. This suggests that “smaller amounts of many phytochemicals may have greater potential to exert beneficial effects than larger amounts of fewer phytochemicals.”

Same result for inflammation. Greater variety in fruit and vegetable intake is associated with lower inflammation even if you eat the same number of servings. Same with improving cognitive function, too. Greater variety in fruit and vegetable intake is also associated with a better mental status, executive function, attention, and memory function in some cases, even after adjustment for total quantity. So, if you have two people eating the same number of servings of healthy foods, the one eating a greater variety may do better.

Going back to the study with the 199 prostate cancer patients getting either a placebo or a tablet with 100 mg of powdered whole pomegranate three times daily, the researchers didn’t just put in pomegranate powder. They also added powdered broccoli, powdered turmeric, and powdered green tea concentrate. So, the tablet contained a fruit, a vegetable, a spice, and a leaf in tiny amounts—about one floret of broccoli a day, less than an eighth of a daily teaspoon of turmeric, and about one sixth of a tea bag worth of green tea. All great plants, but could such tiny amounts actually affect the progression of cancer? Yes. As you can see at 5:55 in my video, in the group of men with early stage prostate cancer trying to avoid surgery, the PSA levels in the placebo group rose nearly 50 percent, indicating that the cancer continued to flourish, whereas the PSAs didn’t rise at all in the pomegranate, broccoli, turmeric, and green tea food supplement group. And, in those with more advanced disease—patients who had already had surgery or radiation and were trying to avoid chemo—there was a 70 percent greater rise in PSA levels in the placebo group. This was enough to significantly delay some of these more toxic treatments. Indeed, the study found significant, short-term, favorable effects. However, they only had enough money to run the study for six months, because it was a “non-commercial” endeavor, funded by charities, not some supplement company. In fact, there was no supplement until the investigators dreamed it up from scratch for the study. Of course, now there’s a supplement, given the study’s extraordinary results, but the only reason the researchers put the foods in pill form was to match it with a placebo. In my mind, what this study should tell cancer patients is to eat curried broccoli with fruit for dessert and to sip some green tea. A completely plant-based diet may even shrink the tumor, not just slow it down, but there’s no reason we can’t do both with a plant-based diet chock full of especially powerful plants.

I love that study! You and I both know why these types of studies aren’t performed more often. Who would profit? (Other than the millions of people suffering and dying from cancer, of course!)

The note I ended on, the landmark Ornish study, is detailed in Cancer Reversal Through Diet. For those unwilling or unable to make such significant dietary changes, there’s still something you can do. See Prostate Cancer Survival: The A/V Ratio. Changing a Man’s Diet After a Prostate Cancer Diagnosis isn’t easy!


For more on the 2 + 2 > 4 concept, see Food Synergy.

What about preventing prostate cancer in the first place? Check out my videos like Prostate Cancer and Organic Milk vs. Almond Milk and Eggs, Choline, and Cancer to get a sense of what you might want to avoid. But, in terms of what to eat, see The Role of Soy Foods in Prostate Cancer Prevention and Fermented or Unfermented Soy Foods for Prostate Cancer Prevention?.

Also, see: 

In health,

Michael Greger, M.D.

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

The Crowding Out Strategy to Eating Healthier

It may be more expedient politically to promote an increase in consumption of healthy items rather than a decrease in consumption of unhealthy items, but it may be far less effective.

The World Health Organization has estimated that more than a million deaths “worldwide are linked to low fruit and vegetable consumption.” What can be done about it? I explore this in my video Is it Better to Advise More Plants or Less Junk?

There’s always appealing to vanity. A daily smoothie can give you a golden glow as well as a rosy glow, both of which have been shown to “enhance healthy appearance” in Caucasian, Asian, and African skin tones, as you can see at 0:24 in my video.

What about giving it away for free?

A free school fruit scheme was introduced in Norway for grades 1 through 10. Fruit consumption is so powerfully beneficial that if kids ate only an additional 2.5 grams of fruit a day, the program would pay for itself in terms of saving the country money. How much is 2.5 grams? The weight of half of a single grape. However, that cost-benefit analysis assumed this minuscule increased fruit consumption would be retained through life. It certainly seemed to work while the program was going on, with a large increase in pupils eating fruit, but what about a year after the free fruit program ended? The students were still eating more fruit. They were hooked! Three years later? Same thing. Three years after they had stopped getting free fruit, they were still eating about a third of a serving more, which, if sustained, is considerably more than necessary for the program to pay for itself.

There were also some happy side effects, including a positive spillover effect where not only the kids were eating more fruit, but their parents started eating more, too. And, although the “intention of these programs was not to reduce unhealthy snack intakes,” that’s exactly what appeared to happen: The fruit replaced some of the junk. Increasing healthy choices to crowd out the unhealthy ones may be more effective than just telling kids not to eat junk, which could actually backfire. Indeed, when you tell kids not to eat something, they may start to want it even more, as you can see at 2:20 in my video.

Which do you think worked better? Telling families to increase plants or decrease junk? Families were randomly assigned to one of two groups, either receiving encouragement to get at least two servings of fruits and veggies a day, with no mention of decreasing junk, or being encouraged to get their junk food intake to less than ten servings a week, with no mention of eating more fruits and veggies. What do you think happened? The Increase Fruit and Vegetable intervention just naturally “reduced high-fat/high-sugar intake,” whereas those in the Decrease Fat and Sugar group cut back on junk but didn’t magically start eating more fruits and vegetables.

This crowding out effect may not work on adults, though. As you can see at 3:12 in my video, in a cross-section of over a thousand adults in Los Angeles and Louisiana, those who ate five or more servings of fruits and veggies a day did not consume significantly less alcohol, soda, candy, cookies, or chips. “This finding suggests that unless the excessive consumption of salty snacks, cookies, candy, and sugar-sweetened beverages”—that is, junk—“is curtailed, other interventions…[may] have a limited impact….It may be politically more expedient to promote an increase in consumption of healthy items rather than a decrease in consumption of unhealthy items, but it may be far less effective.” In most public health campaigns, “messages have been direct and explicit: don’t smoke, don’t drink, and don’t take drugs.” In contrast, food campaigns have focused on eat healthy foods rather than cut out the crap. “Explicit messages against soda and low-nutrient [junk] foods are rare.”

In the United States, “if one-half of the U.S. population were to increase fruit and vegetable consumption by one serving each per day, an estimated 20,000 cancer cases might be avoided each year.” That’s 20,000 people who would not have gotten cancer had they been eating their fruits and veggies. The U.S. Department of Agriculture recommends we “fill half [our] plate with colorful fruits and vegetables,” but less than 10 percent of Americans hit the recommended daily target. Given this sorry state of affairs, should we even bother telling people to strive for “5 a day,” or might just saying “get one more serving than you usually do” end up working better? Researchers thought that “the more realistic ‘just 1 more’ goal would be more effective than the very ambitious ‘5 a day’ goal,” but they were wrong.

As you can see at 4:56 in my video, those told to eat one more a day for a week, ate about one more a day for a week, and those told to eat five a day for a week did just that, eating five a day for a week. But here’s the critical piece: One week after the experiment was over, the group who had been told to eat “5 a day” was still eating about a serving more, whereas the “just 1 more” group went back to their miserable baseline. So, more ambitious eating goals may be more motivating. Perhaps this is why “in the US ‘5 a day’ was replaced by the ‘Fruits and Veggies—More Matters’ campaign…in which a daily consumption of 7–13 servings of fruits and vegetables – FVs –  is recommended.” However, if the recommendation is too challenging, people may just give up. So, instead of just sticking with the science, policy makers evidently need to ask themselves questions like “How many servings are regarded as threatening?”


For more on appealing to vanity to improve fruit and vegetable consumption, see my videos Eating Better to Look Better and Beauty Is More Than Skin Deep.

What does the science say about smoothies? See:

The flipside of free fruit programs is to tax instead of subsidize. Learn more by checking out my video Would Taxing Unhealthy Foods Improve Public Health?

For more on the paternalistic attitude that you don’t care enough about your health to be told the truth, see my videos Everything in Moderation? Even Heart Disease? and Optimal Diet: Just Give It to Me Straight, Doc.

I explore this same patronizing attitude when it comes to physical activity in How Much Should You Exercise?

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: