Investigating the efficacy of 18-week salmon protein hydrolysate supplementation on metabolic inflammation, well-being, and cosmetic outcomes: A pilot clinical trial in healthy adults

Background: Fatigue is a common and debilitating symptom associated with aging, which significantly reduces quality of life. Salmon protein hydrolysate (SPH) has recently been investigated for its potential benefits in improving energy levels, reducing oxidative stress, and promoting cosmetic health. Objective: The primary objective of this proof-of-concept clinical trial was to evaluate the effects of daily low-dose SPH supplementation on energy levels, oxidative stress, inflammation, and cosmetic outcomes in healthy adults, with a focus on potential gender-specific effects. Methods: This open-label, single-arm study involved 20 participants, of which 70.6% were female. Participants consumed 4g of SPH daily for 128 days. Key outcomes measured included changes in perceived energy levels, antioxidant gene expression (HMOX1 and FTH1), free radical activity, serum cytokine levels (IL-5, IL-8, CRP, IL-2, IL-10), hematological parameters, and self-reported cosmetic outcomes. Assessments were made throughout the study to track changes over time. Results: SPH supplementation led to a significant 10.24% improvement in perceived energy levels (P = 0.004), with a greater improvement observed among women (14.55%, P = 0.008). A 9% reduction in oxidative stress (P < 0.001) was accompanied by up regulation of HMOX1 and FTH1 genes by 4.09-fold and 3.77-fold, respectively. Pro-inflammatory markers IL-5, IL-8, and CRP decreased significantly (P < 0.001), while anti-inflammatory markers IL-2 and IL-10 increased (P < 0.001). Self-reported cosmetic outcomes improved by 23.7% (P = 0.03), with women reporting a 34.5% enhancement in hair, skin, and nail health (P = 0.009). Conclusion: Daily supplementation with low-dose SPH improved energy levels, reduced oxidative stress, and modulated inflammatory markers in healthy adults. Notably, women experienced greater improvements in both energy levels and cosmetic outcomes, suggesting SPH may be a beneficial supplement for enhancing overall well-being and cosmetic health, particularly among women. Keywords: Salmon protein hydrolysate, oxidative stress, inflammation, fatigue, cosmetic outcomes, aging.