Could adding grapes to your daily routine help you stay strong as you age? A new clinical study suggests it might.
Researchers at the University of California, Davis, found that postmenopausal women who consumed 1½ cups of grapes a day saw modest improvements in hand grip and walking speed, two common markers of muscle strength. The study was published in Food & Function and is the first clinical trial to examine the effect of grape intake on muscle health in this population.
Participants were assigned to consume either a placebo powder or the equivalent of 1½ cups of grapes per day in the form of freeze-dried grape powder. After the intervention period, those who consumed grapes performed better on tests of strength and mobility.
The researchers also measured blood levels of irisin, a hormone associated with muscle and bone health. Women in the grape group saw a 14.4% increase in irisin levels, compared to a 7.8% drop in the placebo group. While the change in irisin was not statistically significant, the study did find a meaningful association between improved grip strength and rising irisin levels over time.
“These findings indicate that regularly consuming a modest amount of grapes — just 1½ cups per day — can help improve muscle strength in postmenopausal women who are at risk for muscle loss as part of aging,” said lead author Gerardo Mackenzie, PhD.
Sarcopenia, the gradual loss of muscle mass and strength with age, can begin as early as 40 and is a major contributor to loss of independence, mobility and increased health care costs later in life. Right now, there are few effective treatment options.
The study was funded by the California Table Grape Commission. While industry funding requires careful interpretation, the trial was randomized and peer-reviewed.