Ethnic Difference In Homocysteine And Folate Concentrations

Nutrition Research Newsletter, Sept, 1999 by Glenn T. Gerhard, M. Rene Malinow, Thomas G. DeLoughery

Recent studies have shown that premenopausal black women have a two- to three-times greater rate of coronary artery disease than do premenopausal white women. An increased rate of obesity and hypertension among black women may contribute to their greater rate of CHD. However, further evidence shows that their lipid profile is less atherogenic than white women; i.e., black women have higher HDL cholesterol and lower triacylglycerol concentrations.

Current research has added increased homocysteine levels to the list of CHD risk factors, but no studies have reported plasma homocysteine concentrations in premenopausal black women. A recent study published in The American Journal of Clinical Nutrition compared plasma total homocysteine, folate, and vitamin [B.sub.12] concentrations in healthy black and white premenopausal women. The researchers hypothesized that the black women had higher fasting total homocysteine concentrations, which could be contributing to their increased rate of CHD.

Eighty-nine black and 90 white women between the ages of 18-45, living in Portland, OR, were recruited for this study. Serum homocysteine, folate, vitamin [B.sub.12], and creatinine (which may be correlated with fasting plasma total homocysteine levels) levels were determined after a 12-hour fast. Eating behavior questionnaires were also administered that measured dietary intake of foods rich in folate. Alcohol consumption, which is associated with lower plasma folate and higher homocysteine concentrations, was also measured by the Diet Habit Survey.

The results showed that plasma total homocysteine levels were significantly higher in black women, while plasma folate concentrations were significantly lower. Approximately 44% of black women had low or low-normal plasma folate levels, while only 24.4% of white women did. Vitamin [B.sub.12] concentrations were also significantly higher among the black women. White women had a higher rate of daily multivitamin use (42.4% vs. 24.7%) and consumed more ready-to-eat cereal, which is now fortified with folic acid, than the black women. However, after correcting for multivitamin use and intake of ready-to-eat cereal, plasma total homocysteine concentrations did not differ significantly between the two groups of women, while serum folate did remain significantly lower in the black women.

As one of the first research studies to investigate homocysteine levels in premenopausal black women, this study discovered an interesting fact. The higher homocysteine and lower folate concentrations in these black women were likely due to their lower intakes of folate-containing multivitamins and ready-to-eat cereals. The researchers could not prove that the higher homocysteine concentrations contributed to the greater rate of CHD in premenopausal women. However, it may be helpful for premenopausal black women to increase their intakes of ready-to-eat cereals and consider taking a folate-containing multivitamin, two cost-effective ways of fighting and possibly reducing coronary artery disease.

Glenn T. Gerhard, M. Rene Malinow, Thomas G. DeLoughery, et al., Higher Total Homocysteine Concentrations and Lower Folate Concentrations in Premenopausal Black women Than In Premenopausal White Women, Am J Clin Nutr; 70(2): 252-260 (August 1999) [Correspondence: G. T. Gerhard, Dept. of Medicine, L465, Oregon Health Sciences University, 3181 SW Sam Jackson Park Rd., Portland. OR 97201-3098. E-mail: gerhard@ohsu.edu.]