Increased dairy consumption differentially improves metabolic syndrome markers in male and female adults.

Background: Effects of dairy consumption on metabolic health and adiposity are inconsistent. Most clinical trials have investigated dairy intake, frequently during caloric restriction, in overweight or obese populations but not in a metabolic syndrome population. We investigated the effect of increased dairy intake without caloric restriction on anthropometrics, plasma lipids, and glucose in typically low-dairy consumers who met the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) metabolic syndrome criteria.

Methods: Male (n=14) and female (n=23) adults (54.1 ± 9.7 years) with metabolic syndrome were randomized to consume low-fat dairy (LFD) (10 oz of 1% milk, 6 oz of nonfat yogurt, 4 oz of 2% cheese) or carbohydrate control (CNT) (1.5-oz granola bar and 12 oz of 100% juice) foods for 6 weeks in a crossover study design. Anthropometrics, metabolic syndrome parameters, insulin resistance, and parathyroid hormone were measured. Body composition was analyzed by a dual-energy X-ray absorptiometry scan for a subset of subjects (n=22).

Results: LFD modulated metabolic syndrome parameters differently according to gender. Following LFD, men had lower glucose (95.4 ± 9.1 vs. 98.9 ± 10.6 mg/dL, P=0.048), whereas women had lower body weight (BW), waist circumference, and body mass index (P<0.01) compared to CNT. Women also had lower energy intake following LFD compared to CNT. Increases in phosphorus (a dairy nutrient) were negatively correlated with decreases in BW (r=-0.537; P<0.01) and body fat in women (r=-0.593, P<0.025), whereas the decreases in energy intake had no correlation with anthropometrics.

Conclusions: Three dairy servings/day promoted small but significant improvements differentially by gender in a metabolic syndrome population.