# Habitual Dietary Collagen Intake Is Lower in Females and Older Irish Adults Compared with Younger Males

## TL;DR

Irish adults consume low amounts of collagen, with females and older individuals consuming significantly less than younger males.

## Contribution

This study quantifies habitual collagen intake in Irish adults and identifies sex- and age-related differences.

## Key findings

- Males consumed significantly more collagen than females across all age groups.
- Older adults consumed less collagen than middle-aged adults.
- Collagen intake represented only 3.6% of total protein intake on average.

## Abstract

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.

This study aims to investigate collagen intake in the habitual diets of Irish adults, and whether it differed according to sex and/or age.

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.

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).

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.