It has long been appreciated that patients with high concentrations of homocysteine (an amino acid) in their blood are at much higher risk for stroke and heart disease, despite their young age. Among approaches being developed to reduce cardiovascular risk has been supplementation with folate, Vitamin B12 and Vitamin B6, which in combination are known to lower homocysteine levels. Alan Chait and workers at 10 medical research centers in the U.S. and Canada found that adequate intake of these nutrients in prescribed diets can effectively decrease homocysteine concentrations in persons with attendant risk factors for cardiovascular disease.
Elevated homocysteine concentrations can result from either genetic disorders or vitamin deficiencies. A wide variety of determinants such as gender, age, obesity and alcohol consumption can come into play in placing an individual into a "cardiovascular high risk" category; however, the 491 subjects in this study all had been treated for hypertension, high cholesterol, type 2 diabetes or a combination of the three. They were randomly assigned to either a "self-selected diet" following American Dietetic Association guidelines, or a "prescription diet" fortified by the researchers to provide greater than or equal to 100% of the RDA for 23 micronutrients including folate. Those who self-selected their diet showed no change in their homocysteine levels in the course of the study, whereas the prescription diet group showed significant reduction in homocysteine concentrations.
The richest sources of folate in the American diet are: enriched breakfast cereal, hard boiled eggs, asparagus and green peas. Foods richest in B6 include enriched breakfast cereal, baked potato with skin, and bananas. Sources of B12 are milk, enriched breakfast cereal, fish and meat.
Chait, A et al. Increased dietary micronutrients decrease serum homocysteine concentrations in patients at high risk of cardiovascular disease. Am J. Clin Nutr 1999.
Corresponding Author: Dr. Alan Chait
University of Washington
achait@uwashington.edu
Journal
American Journal of Clinical Nutrition