薬理と治療

Abstract

Objective　The effects on human immunity of oral supplementation with fish-derived collagen peptide were investigated with a placebo︱controlled double-blind trial. Methods　Healthy Japanese men and women（30-59 years of age）with daily tiredness and fatigue and relatively low Scoring of Immunological Vigor（SIV）scores, a comprehensive score reflecting immune status, were randomly assigned to two groups（n＝25）. Each participant ingested 10 g of placebo or collagen peptide every day for 8 weeks. Their immunological functions were measured with the SIV score and other parameters. Results　The ingestion of 10 g of collagen peptide for 8 weeks significantly improved the SIV score relative to that of the placebo group （P＝0.030）. A within︱group analysis showed that the SIV scores（P＝0.002）and numbers of T cells（P＝0.017）, memory T cells（P＝0.008）, CD8＋CD28＋ T cells（P＝0.039）, and NK cells（P＝0.038）increased significantly, and CD4／CD8 T cell ratio（P＝0.001）and the T-lymphocyte age（P＝0.047）, an index calculated from the CD8＋CD28＋ T︱cell number, decreased significantly in the collagen peptide group, but not in the placebo group. Significant improvement in the subjective symptoms of diarrhea（P＝0.041）and appetite（P＝0.043）were only observed in the collagen peptide group. No adverse effects attributable to collagen peptide ingestion were observed. Conclusions　These results suggest that the ingestion of 10 g of collagen peptide for 8 weeks improves the immunological status of humans, especially the number of T lymphocytes and their subsets.