Normal/high-fat milk consumption is associated with higher lean body and muscle mass in Japanese women aged between 40 and 60 years: a cross-sectional study

BACKGROUND: Milk is known to contain various nutrients that may have health benefits for postmenopausal women who are at an increased risk of cardiovascular and musculoskeletal diseases. We investigated the association between normal/high- and low-fat milk consumption and body composition in Japanese women aged 40 to 60 years. METHODS: This cross-sectional study used the baseline data collected in a previous study that examined the effects of a dietary supplement on a variety of health parameters in 85 Japanese women aged 40 to 60 years. Participants had been assessed for age, menopausal status, lifestyle factors, and body composition. We estimated the consumption of normal/high- and low-fat milk using a brief-type self-administered diet history questionnaire (BDHQ). Normal/high- and low-fat milk intake were classified as consumer (drank milk at least twice a week) or non-consumer (drank milk at most once a week), in order to identify the parameters that were independently associated with the consumption of normal/high- and low-fat milk. RESULTS: Of the 85 participants who completed the BDHQ, 27 were categorized as non-consumers, 18 as exclusive low-fat milk consumers, and 29 as exclusive normal/high-fat milk consumers. 11 women who consumed both low-fat and normal/high-fat milk were excluded from the analysis. Compared with non-consumers and exclusive low-fat milk consumers, exclusive high-fat milk consumers had significantly higher lean body mass (mean ± standard deviation [SD], 39.4 ± 2.7 kg vs. 37.9 ± 2.2 kg and 37.6 ± 2.9 kg, P < 0.05) and muscle mass (mean ± SD, 37.2 ± 2.5 kg vs. 35.8 ± 2.0 kg and 35.5 ± 2.7 kg, P < 0.05). Both lean body and muscle masses were significantly correlated with vitamin D intake from milk (Pearson r = 0.29, P = 0.008, and Pearson r = 0.29, P = 0.008, respectively). CONCLUSION: Normal/high-fat milk consumption was associated with higher lean body and muscle mass in middle-aged Japanese women presumably through high vitamin D intake.