An item in the September issue of Nutrition Action, the newsletter of the Center for Science in the Public Interest (CSPI), caught my eye, with a report on some possible down-sides to widespread folic acid fortification, which prompted us to look more closely at the issue. Can we get too much of a good thing?

Folate is a water-soluble B vitamin that occurs naturally in food. Foods that are good sources of folate include legumes (beans), green leafy vegetables, and whole grains – especially quinoa, wild rice, millet and amaranth. A diet high in folate can dramatically decrease the incidence of certain birth defects, especially spine and brain development problems called neural tube defects. 

But, since most people don’t eat enough of healthy foods like these – and since birth defects are such a tragic and largely-avoidable problem – refined grains in the U.S. have been fortified with extra folic acid (the synthetic form of folate) since 1998. According to the CDC (Centers for Disease Control and Prevention), neural tube defects in the U.S. dropped by about 36% from 1996 to 2006 – a very good result.

Nature is all about balance, however. Too much of any nutrient can be as detrimental to the body as too little. So scientists have been tracking the folate / folic acid issue to learn what could happen if we get too much folic acid. Some research shows that the liver can’t metabolize folic acid into the folate needed by the body quite as readily as earlier thought, and many of us now have rising levels of unmetabolized folic acid circulating in our blood.

The CSPI article cautioned that seniors low in vitamin B-12 and high in unmetabolized folic acid do more poorly on cognitive tests. We scurried to check out the original June 2010 study and learned that seniors in the same group who had normal levels of B-12 actually benefited, cognitively, from high levels of unmetabolized folic acid. That one seemed to be a draw.

As I read additional studies, however, I learned that post-menopausal women with high folic acid levels showed decreased immune “killer cell” function, and that high folic acid levels may reduce the effectiveness of some drugs used against malaria, rheumatoid arthritis, psoriasis, and cancer. (This last was in an article actually titled “Is Folic Acid Good for Everyone?” in the American Journal of Clinical Nutrition.)

In fact, according to the BBC, the growing body of research about unmetabolized folic acid led a group of top UK researchers to protest against plans for mandatory folic acid fortification in that country. In 2007, The Institute of Food Research warned that the liver could easily become saturated by folic acid. At the same time, Sir Liam Donaldson, Chief Medical Officer of England, requested further consideration of two studies linking folic acid to bowel cancer, before going ahead with fortification. According to the website of the UK’s Food Standards Agency, the project is still on hold.

In other countries, Australia decided to start folic acid fortification in 2009, while New Zealand, which had been expected to act in tandem, decided to hold off until 2012. In March of 2009, a Food Safety Authority of Ireland (FSAI) committee determined “there would be no public health benefit from mandatory folic acid fortification” since voluntary efforts by the food industry had already resulted in a drop in birth defects, and since the data on possible adverse effects were unclear. EU-wide, EFSA (the European Food Safety Authority) produced a report in November 2009 concluding that “current data are insufficient to allow a full quantitative risk assessment of folic acid and that scientific developments within this area should be closely monitored,” as a result of which, no E.U.-wide action has been taken.

Here at Oldways and the Whole Grains Council, we’re not concerned about the levels of folic acid found in fortified and enriched grain products – especially for those who follow Dietary Guidelines recommendations to make at least half your grains whole. But the latest chapters in the folic acid story remind us that our bodies have evolved for eons enjoying nutrients in certain forms, in certain relative and balanced amounts, as they appear in nature. When in doubt, get your nutrients from a variety of real, whole foods, grown in fertile, live soil. Whole grains, anyone? (Cynthia)