Diet and Sarcopenia : Swedish Cohort Studies in Aging Populations

Abstract: Sarcopenia is a growing public health concern, involving a loss of muscle mass and function, thus resulting in functional impairment. The role of diet in sarcopenia is unknown.Paper I identified equations by Mifflin-St Jeor and Harris-Benedict as accurate predictive equations for resting energy expenditure among 22 octogenarian men, from the Uppsala Longitudinal Study of Adult Men (ULSAM), using indirect calorimetry as a reference. Our results address the importance of validating the equation in the study population.Papers II, III, and IV aimed to increase the understanding of the role of dietary patterns (DP) in sarcopenia and its individual components. Lean muscle mass index (LMI) was determined using dual-energy X-ray absorptiometry (DXA).In Papers II and III, DPs were defined at baseline using a 7-day food record from ULSAM (mean age 71 years). Sarcopenia was defined 16 years later. In Paper IV, DPs were defined at baseline using a food frequency questionnaire in women from the Swedish Mammography Cohort Clinical (SMCC; mean age 67 years). Sarcopenia was defined 12 years later.Paper II used the old definition by the European Working Group on Sarcopenia in Older People (EWGSOP1) (prevalence of sarcopenia: 21% of 254). Papers III and IV used the new definition (EWGSOP2) (prevalence of sarcopenia: 19% of 257, and incidence of sarcopenia 4% of 1,212, respectively).Paper II used two a priori DPs (modified Mediterranean Diet Score and modified Healthy Diet Indicator). Higher adherence to a Mediterranean-like diet was associated with a lower prevalence of sarcopenia at follow-up.Paper III defined four a posteriori DPs. Higher adherence to DP2 (characterized by high intake of vegetables, fruits, poultry, rice, and pasta) was associated with a lower prevalence of sarcopenia at follow-up.In Paper IV, the associations between DPs (an a priori defined Mediterranean-like and three a posteriori) and sarcopenia displayed no clear associations. However, a DP characterized by a high intake of vegetables, fruits, nuts, grains, poultry, fatty fish, and fermented milk was associated with a higher appendicular LMI at baseline, better muscle function at follow-up, and displayed non-linear associations with changes in appendicular LMI. A DP characterized by a high intake of boiled potatoes, dairy, grains, pancake, and sweet bakery, and a low intake of wine/spirits and poultry displayed non-linear associations with changes in appendicular LMI.Thus, dietary patterns with a common feature of being considered a healthy choice may be important for muscle function, muscle mass, and sarcopenia.