In an article published online on January 25, 2012 in the American Journal of Clinical Nutrition, researchers from Northern Ireland report a benefit for the B vitamin riboflavin in men and women with a gene mutation that puts them at risk for elevated homocysteine and hypertension.
The study, conducted in 2008, included 83 participants in a 16 week placebo-controlled trial of riboflavin conducted in 2004. Thirty-one subjects who had the TT genotype of the gene encoding methylenetetrahydrofolate reductase (MTHFR, a folate-metabolizing enzyme), were again given 1.6 milligrams per day riboflavin or a placebo for 16 weeks, however, those who received riboflavin in 2004 were given a placebo in 2008, and vice-versa. (Riboflavin, in its coenzymatic form, is a cofactor for MTHFR.)
Those who had the TT genotype had higher systolic blood pressure in 2004 and 2008 than the remainder of the subjects. Although more subjects in this group were taking three or more antihypertensive medications, only 54 percent had achieved their goal blood pressure by 2008, compared to 70 percent of the other participants. For those that received riboflavin at either time point, systolic and diastolic blood pressure declined by an average of 9.2 mm Hg and 6.0 mm Hg.
"In this genetically at-risk group, significant lowering of blood pressure was achieved only with riboflavin treatment," the authors write. "To put these results into context, it would take approximately 10 kilograms of weight loss or an exercise regimen that burned 4200 kcal/week to achieve comparable decreases in blood pressure."
"Optimization of riboflavin status could be achieved in individuals through the use of low dose supplements or the consumption of foods naturally rich in riboflavin or in populations via food fortification," they note. "Such approaches could lower blood pressure in those genetically at risk without causing harm to those who are not."
- Journal abstracts: