Effects on blood lipids of a blood pressure-lowering diet: the Dietary Approaches to Stop Hypertension (DASH) Trial

Background: Effects of diet on blood lipids are best known in white men, an d effects of type of carbohydrate on triacylglycerol concentrations are not well defined. Objective: Our goal was to determine the effects of diet on plasma lipids, focusing on subgroups by sex, race, and baseline lipid concentrations. Design: This was a randomized controlled outpatient feeding trial conducted in 4 field centers. The subjects were 436 participants of the Dietary Appr oaches to Stop Hypertension (DASH) Trial [mean age: 44.6 +/-; 60% African A merican; baseline total cholesterol: less than or equal to6.7 mmol/L (less than or equal to 260 mg/dL)]. The intervention consisted of 8 wk of a contr ol diet, a diet increased in fruit and vegetables, or a diet increased in f ruit, vegetables, and low-fat dairy products and reduced in saturated fat, total fat, and cholesterol (DASH diet), during which time subjects remained weight stable. The main outcome measures were fasting total cholesterol, L DL cholesterol, HDL cholesterol, and triacylglycerol. Results: Relative to the control diet, the DASH diet resulted in lower tota l (-0.35 mmol/L, or -13.7 mg/dL), LDL(-0.28 mmol/L, or -10.7 mg/dL), and HD L- (-0.09 mmol/L, or -3.7 mg/dL) cholesterol concentrations (all P < 0.0001 ), without significant effects on triacylglycerol. The net reductions in to tal and LDL cholesterol in men were greater than those in women by 0.27 mmo l/L, or 10.3 mg/dL (P = 0.052), and by 0.29 mmol/L, or 11.2 mg/dL (P < 0.02 ), respectively. Changes in lipids did not differ significantly by race or baseline lipid concentrations, except for HDL, which decreased more in part icipants with higher baseline HDL-cholesterol concentrations than in those with lower baseline HDL-cholesterol concentrations. The fruit and vegetable diet produced few significant lipid changes. Conclusions: The DASH diet is likely to reduce coronary heart disease risk. The possible opposing effect on coronary heart disease risk of HDL reducti on needs further study.