Vitamin B2: Disease Prevention & Treatment

Disease Prevention:

Cataracts
Age-related cataracts are the leading cause of visual disability in the U.S. and other developed countries. Research has focused on the role of nutritional antioxidants because of evidence that oxidative damage of lens proteins from light may lead to the development of age-related cataracts. Two case-control studies found significantly decreased risk of age-related cataract (33% to 51%) in men and women in the highest quintile of dietary riboflavin intakes (1.6 to 2.2 mg/day) compared with those in the lowest quintile (0.08 mg/day). Individuals in the highest quintile of riboflavin nutritional status, as measured by red blood cell glutathione reductase activity, had approximately one half the occurrence of age-related cataract as those in the lowest quintile of riboflavin status, though the results were not statistically significant (17). Recently, a cross-sectional study of 2,900 Australian men and women, 49 years of age and older, found that those in the highest quintile of intake for riboflavin were 50% less likely to have cataracts than those in the lowest quintile. A prospective study of more than 50,000 women did not observe a difference between rates of cataract extraction between women in the highest quintile of riboflavin intake (1.5 mg/day) and those in the lowest quintile (1.2 mg/day). However, the range between the highest and lowest quintiles was small, and median intake levels for both were above the current RDA for riboflavin. Although these observational studies provide support for the role of riboflavin in the prevention of cataracts, placebo-controlled intervention trials are needed to confirm the relationship.

Disease Treatment:

Migraine headaches
Some evidence indicates that impaired mitochondrial oxygen metabolism in the brain may play a role in the pathology of migraine headaches. As the precursor of the two flavin coenzymes (FAD and FMN) required by the flavoproteins of the mitochondrial electron transport chain, supplemental riboflavin has been investigated as a treatment for migraine. A randomized placebo-controlled trial examined the effect of 400 mg of riboflavin/day for 3 months on migraine prevention in 54 men and women with a history of recurrent migraine headaches. Riboflavin was significantly better than placebo in reducing attack frequency and the number of headache days, though the beneficial effect was most pronounced during the third month of treatment. It should be noted, however, that only about 25 mg of riboflavin can be absorbed in a single oral dose. A more recent study by the same investigators found that treatment with either a medication called a beta-blocker or high-dose riboflavin resulted in clinical improvement, but each therapy appeared to act on a distinct pathological mechanism; beta-blockers on abnormal cortical information processing and riboflavin on decreased brain mitochondrial energy reserve. Though these findings are preliminary, they suggest that riboflavin supplementation might be a useful adjunct to pharmacologic therapy with beta-blockers in migraine prevention.