Effects of Polyphenol Supplementation and Exercise on Physical Performance in Older Adults

Overview

After approximately age 40 years, individuals experience a natural loss of muscle mass, strength, and physical function that is linked to higher risks of falls, disability, loss of independence, and mortality. These losses can also be a precursor to the development of frailty, which includes factors beyond impaired physical function such as cognitive impairment, psychological disorder, increased likelihood of hospitalization, need of long term-care, and mortality. Structured exercise-encompassing both resistance and aerobic training-is widely recognized as an effective lifestyle intervention for improving muscle health, cardiovascular capacity, and overall physical function in older adults. However, aging is accompanied by chronically elevated systemic inflammation, and although exercise remains highly beneficial, older adults exhibit a heightened inflammatory response to training and a diminished capacity for post-exercise recovery. Polyphenols, a group of naturally occurring bioactive compounds, have been shown to possess both anti-inflammatory and antioxidant benefits, positively impacting recovery and health. Polyphenol supplementation, particularly when paired with structured exercise, may elicit synergistic improvements in physical performance through combined effects on oxidative stress, inflammation, and muscle recovery, making polyphenols a compelling adjunct strategy for mitigating sarcopenia. In pursuit of refining strategies that support healthy aging and preserve functional capacity in older adults, this study aimed to determine the feasibility of implementing a 12-week resistance and aerobic exercise program combined with dietary supplementation in older adults. Participants will either consume a polyphenol blend or a placebo control of maltodextrin daily whilst undergoing 12 weeks of supervised resistance and aerobic exercise. Additionally, this study will test the hypothesis that polyphenol supplementation will augment the exercise-induced improvements in physical function and muscle health. Further, exploratory analyses of skeletal muscle biopsy and venous plasma samples will aid in elucidating the potential geroprotective effects of polyphenols at both cellular and molecular levels.

Life expectancy in Canada continues to rise, and by 2068 more than one-quarter of the population will be over the age of 65 years. Although Canadians are living longer, added years are not necessarily lived in good health. Aging is associated with increased sedentary behaviour, reduced physical performance, higher prevalence of chronic disease, and greater healthcare use. Sedentary behaviour, physical inactivity, and poor dietary habits accelerate age-related functional decline and contribute to chronic low-grade inflammation, a key driver of frailty, disability, and loss of independence in older adults. Exercise is strongly recommended to mitigate these risks, with clear dose-response benefits for all-cause and cardiovascular mortality; however, adherence can be limited, and age-related inflammation may blunt beneficial exercise adaptations. This underscores the need for accessible lifestyle strategies that support muscle function, physical performance, and healthy aging. Polyphenols-naturally occurring bioactive compounds found in fruits and vegetables-have demonstrated anti-inflammatory and antioxidant effects relevant to exercise recovery and muscle adaptation. The investigational supplement used in this study (Phyto-P) contains a six-polyphenol blend including chlorogenic acid, chicoric acid, anthocyanins, and quercetin derivatives. Preclinical and human trials of individual polyphenols show reductions in inflammatory cytokines, improvements in antioxidant capacity, and attenuation of exercise-induced muscle damage. Despite these promising findings, it remains unknown whether a multi-polyphenol blend such as Phyto-P can enhance exercise-induced improvements in muscle strength, functional capacity, or molecular markers of skeletal muscle adaptation in older adults. The purpose of this randomized, double-blind, placebo-controlled pilot feasibility trial is to determine whether it is practical to deliver a 12-week combined resistance band and aerobic exercise intervention with daily polyphenol supplementation in older adults. Feasibility outcomes-including recruitment, retention, exercise adherence, and supplement adherence-will determine whether a larger, fully powered efficacy trial is achievable. Secondary, exploratory outcomes will assess changes in physical function, muscular strength and power, skeletal muscle health and fiber-type distribution, cardiorespiratory fitness, self-reported well-being, and blood biomarkers, offering preliminary mechanistic insight to guide hypothesis generation for future studies. Participants aged ≥60 years will be recruited from the Kingston community and complete screening, baseline assessments, a 12-week supervised exercise program paired with polyphenol or placebo supplementation, a midpoint assessment at week 6, and post-intervention testing that mirrors baseline procedures. The data generated from this pilot study will inform the design, methodology, and sample size requirements of future large-scale randomized controlled trials aimed at improving skeletal muscle health, physical function, and healthy aging through combined nutritional and exercise-based strategies.