BACKGROUND: Some epidemiologic studies have suggested inverse relations between intake of dairy products and components of the metabolic syndrome.
OBJECTIVE: The objective was to investigate the effects of an increased intake of dairy products in persons, with a habitually low intake of dairy products and with traits of the metabolic syndrome, on body composition and factors related to the metabolic syndrome.
STUDY DESIGN: Middle-aged overweight subjects (n = 36) with traits of the metabolic syndrome were recruited at the Lipid Clinic, Rikshospitalet Oslo University and randomly assigned into milk or control groups. The milk group was instructed to consume at least 3 portions of low- to moderate-fat dairy products daily. The control group maintained their habitual diet. Clinical investigations were conducted at baseline and after the six months intervention period.
RESULTS: There were no significant differences between changes in body weight or body composition, blood pressure, markers of inflammation, adiponectin, or oxidative stress between the milk and the control groups. There was a significantly decrease in E-selectin, a marker of endothelial function in the milk group at the end of the study compared to the control group (P = 0.008). Among participants with a low calcium intake at baseline (<700 mg/d), there was a significant treatment effect for waist circumference (P = 0.023).
CONCLUSIONS: This study gives no clear support to the hypothesis that a moderately increased intake of dairy products beneficially affects aspects of the metabolic syndrome. The apparently positive effects on waist circumference in subjects with a low calcium intake suggest a possible threshold in relation to effects on body composition.