Folic acid and cancer: New data might add to suspicion or, better, to discussion

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We’re not trying to pick on folic acid, honest. As food additives go, the synthetic version of vitamin B9, aka folate, is one of the more noble ones, widely credited -- heralded even -- for reducing the rate of neural tube birth defects. But we are trying to point out, again, that if a little is good, a lot is not necessarily better.

Several months ago we offered up this story in the Health section:

Folic acid might be losing its sheen

It said: ‘New studies suggest that getting too much folic acid might fuel certain cancers in some people. And with the vitamin showing up in ready-to-eat cereals, bread, snack bars, multivitamins and more, some health experts fear that it’s easy to far exceed the recommended daily intake of 400 micrograms. There is now an urgent need, experts say, to figure out how much folate is enough but not too much for different segments of the population.’

That urgent need isn’t going away. Now we have a study, published today in the Journal of the American Medical Assn., that might cause another eyebrow or two to be raised at this miracle of fortification.

Researchers in Norway analyzed data from 6,837 people with ischemic heart disease treated with folic acid, B6 and B12; folic acid and B12; just B6 or a placebo. Those treated with folic acid and B12 had higher rates of cancer, cancer deaths and deaths in general over the course of several years. Lung cancer contributed significantly to the cancer numbers.

Of note, Norway doesn’t fortify its foods with folic acid, as does the U.S., meaning baseline blood levels were lower to start with than they would be here. Also of note, the researchers point out: Although the folic acid doses in the study were higher than what the typical American would consume through fortification alone, they were below the limits set by our Institute of Medicine.

Just as a lot of folic acid isn’t necessarily a good thing, fortification isn’t necessarily a bad thing. The researchers conclude:

‘Our results need confirmation in other populations and underline the call for safety monitoring following the widespread consumption of folic acid from dietary supplements and fortified foods.’

Here’s that abstract and more on folic acid from Medline Plus.

-- Tami Dennis