Effects of Milk and Dairy Products on Bone Metabolism in Rats Fed a High-fat Diet

This study investigated the effects of milk and dairy products on bone metabolism in rats fed a high-fat diet. A total of 40 Sprague-Dawley male rats (12 weeks old) were divided into five groups: a basal control diet group (Normal), a high-fat diet group (Fat), a high-fat with skimmed milk powder diet group (Fat＋Milk), a high-fat with powdered fermented milk diet group (Fat＋Yogurt), and a high-fat with whey powder and whey protein concentrate diet group (Fat＋Whey). Eighty-four days after the start of diet feeding, the total volume and polar moment of inertia of cross-sectional areas of the lumbar spine were significantly higher in the Fat＋Yogurt group than in the Fat group. Also, the cancellous BMD of the lumbar vertebrae was significantly higher in the Fat＋Whey group than in the Fat group. Interestingly, the level of serum 1α,25(OH)2D3 was significantly lower in the Fat＋Milk and Fat＋Whey groups than in the Fat group. Further analysis of the components in milk and dairy products and their effects on bone metabolism are necessary for the prevention and treatment of osteoporosis.