Effect of dietary patterns on serum homocysteine - Results of a randomized, controlled feeding study

Background-Elevated blood levels of homocysteine are associated with an inc reased risk of atherosclerotic cardiovascular disease. Although numerous st udies have assessed the impact of vitamin supplements on homocysteine, the effect of dietary patterns on homocysteine has not been well studied. Methods and Results-During a 3-week run-in, 118 participants were fed a con trol diet, low in fruits, vegetables, and dairy products, with a fat conten t typical of US consumption. During an 8-week intervention phase, participa nts were then fed 1 of 3 randomly assigned diets: the control diet, a diet rich in fruits and vegetables but otherwise similar to control, or a combin ation diet rich in fruits, vegetables, and low-fat dairy products and reduc ed in saturated and total fat. Between the end of run-in and intervention p eriods, mean change in homocysteine was +0.46 mu mol/L in the control diet, +0.21 mu mol/L in the fruits and vegetables diet (P=0.47 compared with con trol), and -0.34 mu mol/L in the combination diet (P=0.03 compared with con trol, P=0.12 compared with the fruits and vegetables diet), In multivariabl e regression models, change in homocysteine was significantly and inversely associated with change in serum folate (P=0.03) but not with change in ser um vitamin B-12 (P=0.64) or pyridoxal 5' phosphate, the coenzyme form of vi tamin B-6 (P=0.83). Conclusions-Modification of dietary patterns can have substantial effects o n fasting levels of total serum homocysteine. These results provide additio nal insights into the mechanisms by which diet might influence the occurren ce of atherosclerotic cardiovascular disease.