Is Folic Acid Still Worth Considering?
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In September the AHA removed folic acid from its list of dietary supplements that might help prevent myocardial infarction (MI) or stroke. The research and data behind this decision are worth examining to better determine whether folic acid might still be worth taking.

Folate is a B vitamin found naturally in green leafy vegetables, citrus fruits, dried beans, and peas. Its supplement form is folic acid. Folate plays an important role in the formation of red blood cells, DNA, and RNA. In 1998 the U.S. decided to fortify grain products with folic acid to help prevent birth defects. Folate (as well as other B vitamins) breaks down the amino acid homocysteine—high concentrations of which are associated with MI, stroke, and even cognitive impairment and certain cancers. While experts reasoned that folic acid supplements might help keep these diseases at bay, the research has not borne this out with much certainty.

Some of the data suggesting that people with folate-rich diets were less likely to suffer MI or stroke has come from self-reporting dietary habits. But more reliable, placebo-controlled studies of folic acid supplements found that even though homocysteine levels dropped among those taking a daily supplement, these subjects were no less likely to suffer MI or stroke than those assigned a placebo. With self-reported, observational dietary studies, it is impossible to establish a direct causal relationship, and these studies are much more unreliable in general. There is yet to be a large scale, placebo-controlled study unequivocally confirming the benefits of taking a folic acid supplement.

Regardless, it is still important to consume enough folate—whether or not it ultimately protects you from heart disease or cancer. The FDA’s Recommended Daily Allowance (RDA) of folate is 400 micrograms. Folic acid is water soluble, which means that it is acceptable to take greater than the U.S. RDA, and those on certain medications known to interfere with the body’s ability to use folate may be good candidates for a daily supplement. Too much folate can exacerbate a B12 deficiency, however. Older people are more susceptible to B12 deficiency, since as we age it becomes harder for the body to absorb vitamins. But B12 deficiency is relatively rare; talk to your doctor about your B12 levels before starting on a folic acid supplement.

Among the medications that interfere with folic acid utilization are dilantin and other anticonvulsants, metformin (a type-2 diabetes drug), and blood-pressure lowering diuretics. If you are on of these medications, ask your doctor whether a folic acid supplement may be appropriate. A folate-rich diet, in any case, is a good idea: fortified breakfast cereals (100-400 mcg), and cooked spinach (100 mcg), asparagus (85 mcg), and green peas (50 mcg) all contain desirable amounts of folate.

 Health After 50, 2007, Vol. 19, No. 6, p. 6

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