Effect of Dairy Protein Intake on Muscle Mass among Korean Adults: A Prospective Cohort Study

Abstract

This cohort study aimed to identify the associations of dairy protein intake with the risk of developing a low muscle mass during a 12-year follow-up period, using data from 4412 middle-aged Korean Genome and Epidemiology Study participants with a normal baseline muscle mass. Dairy protein intake at baseline was assessed using a semi-quantitative Food Frequency Questionnaire. Skeletal muscle mass index (SMI), defined as the weight-adjusted skeletal muscle mass, was measured biennially using multi-frequency bioelectrical impedance analyses. Cox proportional hazards regression analysis was used to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Overall, 395 subjects developed a low SMI (%) during an average follow-up of 141 (19–152) months. The average consumption of milk and other dairy products was 73.6 and 104.1 g/day, respectively. In men, a higher dairy protein intake was associated with a decreased risk of developing a low SMI (tertile 3 [T3] vs. T1, HR: 0.63; 95% CI: 0.42, 0.94; p for trend = 0.029). In a stratified analysis according to a total protein intake, this association was stronger in the lower-protein intake group (HR: 0.59; 95% CI: 0.35, 0.99; p for trend = 0.036) but not detected in the higher-protein intake group. Men who consumed milk ≥1 time/day had a significantly lower risk of developing a low SMI (HR: 0.62; 95% CI: 0.39, 0.98; p for trend = 0.023). No significant associations were observed in women. In summary, dairy consumption appears to be beneficial for decreasing the risk of developing a low muscle mass in middle-aged Korean men.

D‐galactose might mediate some of the skeletal muscle hypertrophy‐promoting effects of milk—A nutrient to consider for sarcopenia?

“…[ 16 ] The results from a 12‐year‐long prospective cohort in Korea suggested that a high intake of dairy protein was associated with a decreased risk of developing low weight‐adjusted SMM in men (although the association was absent in women). [ 20 ] A meta‐analysis by Hanach et al. analyzed 1424 (61‐81 years old) participants from 14 studies and confirmed the potential of dairy protein to increase the appendicular SMM in the elderly.…”

“…The ability of D-galactose to promote MPS by counteracting catabolic signaling via several complementary mechanisms (Figure 3) might be particularly important in the context of sarcopenia. In fact, some of the beneficial effects of milk and dairy products in sarcopenia [20,[34][35][36] may be at least partially mediated by D-galactose. Sarcopenia is characterized by a chronic catabolic state in which the intracellular and extracellular environment promotes long-lasting activation of MPB-related processes.…”

“…[16] The results from a 12-year-long prospective cohort in Korea suggested that a high intake of dairy protein was associated with a decreased risk of developing low weight-adjusted SMM in men (although the association was absent in women). [20] A meta-analysis by Hanach et al analyzed 1424 (61-81 years old) participants from 14 studies and confirmed the potential of dairy protein to increase the appendicular SMM in the elderly. [15] A number of human studies have shown that milk is superior to other protein sources when it comes to stimulating MPS, [9][10][11][21][22][23][24] even in comparison to other animal protein sources that generally outperform plant protein (possibly due to the amino acid content, digestion, and absorption kinetics [9,24,25] ).…”

Role of muscle-targeted nutritional therapy: new data

“…Although medical care is likely to be provided when a patient is already suffering from a disease, the importance of primary prevention strategies should be never underestimated. Pro-active nutritional care is a reasonable approach and is currently being considered (Table 2), at least in high-risk populations, also recent prospective studies have shown that diet quality is a risk factor for muscle loss and/or dysfunction [36,37].…”

Quality of life, household income, and dietary habits are associated with the risk of sarcopenia among the Chinese elderly

“…Another recent study found that the development of sarcopenia was related to lifetime occupation in the elderly, with blue-collar workers being most affected by sarcopenia and white-collar workers being most affected by sarcopenic obesity [15]. It is worth noting that the provision of lifestyle such as physical activity [16], smoking habits [17], and type of dietary intake [18,19] also has great influence on the status of HRQoL, regardless of socioeconomic status. Indeed, decreased physical activity, smoking, excessive alcohol drinking, and insufficient nutrient intakes have been reported to be essential factors for the lifestyle changes that lead to sarcopenia [20].…”