Can Vitamin C Help with Lead Poisoning?

Can Vitamin C Help with Lead Poisoning?
4.58 (91.63%) 43 votes

Those who have higher vitamin C levels tend to have less lead in their bloodstream, but what happens when people are given vitamin C supplements to put it to the test?

Discuss
Republish

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

“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…. Nutritional interventions, therefore, must never substitute for efforts to reduce lead exposure to safe[r] levels. On the other hand, when used as an adjunct…, some nutritional changes may prove to have benefits beyond…lead toxicity.” For example, vitamin C-rich foods may help with a bunch of things, in addition to perhaps influencing lead toxicity through an effect on absorption of lead, elimination of lead, transport within the body, tissue binding, or just helping ameliorate some of the damage. But, based on what?

Well, in 1939, a remarkable study was published, entitled “Vitamin C Treatment in Lead Poisoning,” in which 17 lead industry workers were given 100mg 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, [their blood], appetite, and ability to sleep….” Now, they were chosen because they seemed in pretty bad shape, maybe even had scurvy; so, 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, but reduced the lead itself. This is the amount of lead a painter was peeing out over a month after starting 200mg of vitamin C a day—a five-fold drop, suggesting he was absorbing less of the lead into his body. And, he was one of three painters they tried it on, and evidently all their levels dropped. The researchers concluded that those exposed to lead should be advised to include in their diet plenty of vitamin C-rich foods, such as tomatoes, citrus, spinach, turnips, bell peppers, cantaloupe, etc.

Now, this was just three painters, and they didn’t have a control group of painters that didn’t take vitamin C. So, maybe everyone’s lead levels would have dropped regardless, for some reason, or it was just a coincidence. You don’t know until you put it to the test.

These original data were so compelling that other researchers decided to replicate the study. I mean, if it actually worked, they could start handing out grapefruits at the factory door. The earlier study didn’t have a good control group, but they weren’t going to make that same mistake this time. Half the group got 100mg of vitamin C a day, not just for a month but for a year. The other group got nothing, and “[c]areful study of [the] group…failed to reveal any effect [of vitamin C] on the lead concentration in [their] blood…or urine.” “No difference…in [their] physical condition,” no changes in their blood work; and so, “No reason…for recommending the use of [vitamin C] to minimize effects of lead absorption.” Bummer. Oh, it looked so promising.

Whenever I study a topic, I try to read the research chronologically, so as to experience the discoveries as they happened throughout history, but I was so tempted at this point to just jump to a recent review to see what had happened in the intervening 74 years since this was published, but I didn’t want to spoiler alert myself. There were in vitro studies where they 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 they 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% lower prevalence of having elevated blood lead levels, compared to those with the lowest C. 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. Maybe the lead caused a drop in vitamin C. Lead is a pro-oxidant; so, maybe it just ate up the vitamin C. And hey, who has higher vitamin C levels? Those who can afford to have higher vitamin C levels—those who eat lots of fruits and vegetables. Maybe the lower vitamin C levels were just a proxy for being poor, and that was the real reason for their higher lead levels. 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 it actually helps with lead poisoning or not. And, to know that, we need to put it to the test.

Unfortunately, most of the published interventions are like this: what are the “[e]ffects of dietary vitamin C supplementation on lead-treated sea cucumbers”? Well, that’s not very helpful. And, there’s a surprising number of articles on the effects of C supplementation on mouse testicles, but that’s because lead may impair male fertility. Lead workers appear to have a reduced likelihood of fathering children. This may, in part, be due to “oxidative stress.” So, how about giving an antioxidant, like vitamin C, and putting it to the testes? No, not rat testes. No, not frog testes. No, not crab testes (I didn’t even know crabs had testicles). Here we go, the “[c]linical relevance of vitamin C among lead-exposed infertile men”—human men, which I’ll cover, next.

Please consider volunteering to help out on the site.

Icons created by James Keuning from the Noun Project.

Image credit: Jon Bunting via Flickr. Image has been modified.

Motion graphics by Avocado Video

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

“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…. Nutritional interventions, therefore, must never substitute for efforts to reduce lead exposure to safe[r] levels. On the other hand, when used as an adjunct…, some nutritional changes may prove to have benefits beyond…lead toxicity.” For example, vitamin C-rich foods may help with a bunch of things, in addition to perhaps influencing lead toxicity through an effect on absorption of lead, elimination of lead, transport within the body, tissue binding, or just helping ameliorate some of the damage. But, based on what?

Well, in 1939, a remarkable study was published, entitled “Vitamin C Treatment in Lead Poisoning,” in which 17 lead industry workers were given 100mg 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, [their blood], appetite, and ability to sleep….” Now, they were chosen because they seemed in pretty bad shape, maybe even had scurvy; so, 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, but reduced the lead itself. This is the amount of lead a painter was peeing out over a month after starting 200mg of vitamin C a day—a five-fold drop, suggesting he was absorbing less of the lead into his body. And, he was one of three painters they tried it on, and evidently all their levels dropped. The researchers concluded that those exposed to lead should be advised to include in their diet plenty of vitamin C-rich foods, such as tomatoes, citrus, spinach, turnips, bell peppers, cantaloupe, etc.

Now, this was just three painters, and they didn’t have a control group of painters that didn’t take vitamin C. So, maybe everyone’s lead levels would have dropped regardless, for some reason, or it was just a coincidence. You don’t know until you put it to the test.

These original data were so compelling that other researchers decided to replicate the study. I mean, if it actually worked, they could start handing out grapefruits at the factory door. The earlier study didn’t have a good control group, but they weren’t going to make that same mistake this time. Half the group got 100mg of vitamin C a day, not just for a month but for a year. The other group got nothing, and “[c]areful study of [the] group…failed to reveal any effect [of vitamin C] on the lead concentration in [their] blood…or urine.” “No difference…in [their] physical condition,” no changes in their blood work; and so, “No reason…for recommending the use of [vitamin C] to minimize effects of lead absorption.” Bummer. Oh, it looked so promising.

Whenever I study a topic, I try to read the research chronologically, so as to experience the discoveries as they happened throughout history, but I was so tempted at this point to just jump to a recent review to see what had happened in the intervening 74 years since this was published, but I didn’t want to spoiler alert myself. There were in vitro studies where they 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 they 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% lower prevalence of having elevated blood lead levels, compared to those with the lowest C. 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. Maybe the lead caused a drop in vitamin C. Lead is a pro-oxidant; so, maybe it just ate up the vitamin C. And hey, who has higher vitamin C levels? Those who can afford to have higher vitamin C levels—those who eat lots of fruits and vegetables. Maybe the lower vitamin C levels were just a proxy for being poor, and that was the real reason for their higher lead levels. 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 it actually helps with lead poisoning or not. And, to know that, we need to put it to the test.

Unfortunately, most of the published interventions are like this: what are the “[e]ffects of dietary vitamin C supplementation on lead-treated sea cucumbers”? Well, that’s not very helpful. And, there’s a surprising number of articles on the effects of C supplementation on mouse testicles, but that’s because lead may impair male fertility. Lead workers appear to have a reduced likelihood of fathering children. This may, in part, be due to “oxidative stress.” So, how about giving an antioxidant, like vitamin C, and putting it to the testes? No, not rat testes. No, not frog testes. No, not crab testes (I didn’t even know crabs had testicles). Here we go, the “[c]linical relevance of vitamin C among lead-exposed infertile men”—human men, which I’ll cover, next.

Please consider volunteering to help out on the site.

Icons created by James Keuning from the Noun Project.

Image credit: Jon Bunting via Flickr. Image has been modified.

Motion graphics by Avocado Video

Doctor's Note

I’m always conflicted about doing these kinds of videos. I can imagine some just want “the answer,” but those with vested and commercial interests often exploit that natural impulse. This is a 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 its historical context. Stay tuned for the thrilling conclusion in my video Yellow Bell Peppers for Male Infertility and 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:

If you haven’t yet, you can subscribe to my videos for free by clicking here.

Pin It on Pinterest

Share This