Abstract
BACKGROUND: Collagen ingestion reportedly benefits connective tissues, such as skin, bone, muscle, tendon, and ligament. However, the quantity of collagen intake in the diet of European adults is unknown. OBJECTIVES: This study aims to investigate collagen intake in the habitual diets of Irish adults, and whether it differed according to sex and/or age. METHODS: We conducted secondary analysis of the Irish National Adult Nutrition Survey, which assessed typical dietary intake using a 4-d food diary in 1500 adults, aged 18-90 y. We categorized participants into 3 age groups: young (18-39 y, n = 630), middle-aged (40-64 y, n = 644), and older (≥65 y, n = 226) adults. Collagen composition of each individual food item in the database was determined by applying a percentage collagen value from analytical sources, allowing computation of collagen mean daily intake (MDI), collagen MDI relative to body mass, and collagen/total protein MDI. Differences in intakes between age groups and sexes were evaluated using physical activity level as a covariate. RESULTS: Collagen MDI for the entire population was 3.2 ± 2.0 g/d, representing 3.6% ± 1.9% total protein intake. Males had higher absolute and relative collagen MDI than females, regardless of age (4.0 ± 2.1 g/d compared with 2.3 ± 1.4 g/d, P < 0.001), whereas older adults had lower absolute collagen MDI than middle-aged adults (2.9 ± 1.8 g/d compared with 3.3 ± 2.0 g/d, P = 0.021). CONCLUSIONS: Collagen intake in the Irish adult population was considered low (relative to total protein intake and to dose-response studies), particularly in females and older individuals. Increasing daily collagen intake may therefore be warranted to optimize the health of collagen-rich tissues.