UC Davis

Sarcopenia is a major health problem as it is debilitating age-associated condition that can lead to fractures, disabilities, prognosis of diseases, and even death. Therefore, there is interest exploring whether food components can mitigate sarcopenia. Polyphenols, highly abundant in grapes, are well known for their ability to alleviate disease pathologies through anti-inflammatory properties; however, the exact influence of grapes and their phenolic compounds mitigating sarcopenia in humans remains unknown. Our particular emphasis is on irisin, a recently implicated myokine in the prevention of sarcopenia. For this purpose, we initiated a double-blinded pilot clinical study that aims to characterize the role of freeze-dried grape powder on the mitigation of sarcopenia parameters and its key metabolic regulators. We aimed to investigate key metabolic markers of sarcopenia in 14 healthy postmenopausal women on a 6-week supplementation of either grape powder or a control and determined the efficacy of daily grape powder on the mitigation of skeletal muscle loss via hand grip strength. We performed 80 telephone screenings, 25 participants were clinically screened, 15 were recruited, and 14 completed the study. We observed a significant increase in hand grip scores from baseline to week 6 in the grape group compared to control group (p-value: 0.007). Additionally, we observed that over the period of 6 weeks chair sit-to-stand speed and gait speed significantly increased in the grape group compared to the control (p-value: 0.0309, p-value: 0.036). Irisin levels were approaching a significance increase in the grape group (p-value: 0.0519). Therefore, the combined approaches will provide enhanced knowledge surrounding the role of grape powder on the development of sarcopenia and investigate irisin as a therapeutic target aimed at ameliorating the progression of sarcopenia.