Fish protein supplementation in older nursing home residents: a randomised, double-blind, pilot study.

Background: Age-related loss of muscle mass and function is common in older adults, and studies investigating if dietary proteins may protect and possibly build lean body mass are needed. We assessed the feasibility of conducting a nutritional intervention study in older nursing home residents to investigate the effects of fish protein supplementation on markers of glucose metabolism and inflammation.

Methods: This was a double-blind randomised controlled pilot study. Twenty-four nursing home residents, without major cognitive impairment, received a daily oral nutritional supplement containing 5.2 g of fish protein or placebo for 6 weeks. Anthropometric measurements were conducted at baseline. Participants were screened for nutritional risk using the Mini Nutritional Assessment and activities of daily living using the Barthel index and dietary intake was registered. Hand grip strength was measured and fasting blood samples collected at baseline and endpoint.

Results: Compliance was high and dropout was low, but participant recruitment was challenging. Serum concentrations of monocyte chemoattractant protein-1 decreased, and C-reactive protein increased in the intervention group compared to control, with no changes in markers of glucose metabolism between groups.

Conclusion: Conducting a nutritional intervention using fish protein supplementation in older nursing home residents is feasible but should be conducted as a multi-centre study to account for the low recruitment rate observed in the present study. A full-scale study is needed to gain more knowledge on the potential effects of fish proteins on markers of glucose metabolism and inflammation in relation to the age-related loss of muscle mass and function.

Trial registration: ClinicalTrials.gov NCT03529344 18.05.2018 (retrospectively registered).