How to Lower Lead Levels with Diet: Thiamine, Fiber, Iron

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 may 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 below, 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, “[g]iven 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.

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.

This is why it’s critical to “get the lead out” of our tap water, but it’s estimated that most of our lead exposure comes from food, rather than water. It’s not what we eat, however, 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, you could get 10 to 20 times more lead absorbed into your bloodstream consuming the same amount of lead in water you drink on an empty stomach.

More on lead here.

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—2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not to Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Related on Care2:

69 comments

Danny C
Danny Chan14 hours ago

I am hardly surprised that more lead comes from food than water. With all that lead in our water it is inevitable that it is absorbed by plants and makes its way up the food chain. In any event thank you for sharing. :-)

SEND
BobbyKat L
BobbyKat L2 days ago

Thank you.

SEND
Amy F
Amy F3 days ago

Thanks

SEND
Paulo R
Paulo R4 days ago

ty

SEND
Angeles Madrazo
Angeles Madrazo6 days ago

Good to know. Thank you

SEND
Judith Hannah
Judith Hannah8 days ago

Thankyou

SEND
Chad A
Chad Anderson13 days ago

Thank you.

SEND
Hannah A
Hannah A14 days ago

thank you

SEND
Lisa M
Lisa M15 days ago

Thanks.

SEND
Lisa M
Lisa M15 days ago

Thanks.

SEND