We know that resveratrol, an activator of SIRT1, boosts exercise tolerance and performance in mice (see Resveratrol: Breakfast of champions). Now it appears that the converse is also true: exercise increases SIRT1 activity in aged rats. From Ferrara et al.:
Exercise Training Promotes SIRT1 Activity in Aged Rats
The objective of this study was to determine the effects of aging and exercise training on SIRT1 activity and to identify a pathway linking SIRT1 to antioxidant response and cell cycle regulation in rats. SIRT1 is a NAD+-dependent deacetylase involved in the oxidative stress response and aging. The effects of aging and of moderate and prolonged exercise training in rats are unknown. We measured SIRT1 activity in heart and adipose tissue of young (6 months old), sedentary old (24 months), and trained old (24 months) rats using an assay kit. … Aging significantly reduced SIRT1 activity in heart, but not in adipose tissue, increased TBARS and 4-HNE and decreased Mn-SOD and catalase expression in both heart and adipose tissue. Aging did not affect FOXO3a protein expression in the heart or FOXO3a mRNA in adipose tissue. Exercise training significantly increased FOXO3a protein in the heart and FOXO3a mRNA in adipose tissue of aged rats. It also significantly increased Mn-SOD and catalase levels in both heart and adipose tissue. … We concluded that exercise training, which significantly increases SIRT1 activity, could counteract age-related systems impairment.
Note that the effects are observed both in cardiac tissue, where SIRT1 levels decrease with age, and in adipose, where SIRT1 activity remains constant throughout the lifespan.
These findings are consistent with recent observations that resveratrol induces the heat shock response, leading some to speculate that the compound exerts some of its positive effects via hormesis. Exercise is the quintessential example of beneficial hormesis: stress the body acutely now to make it more resistant to chronic stress later. Could resveratrol and exercise (and for that matter, calorie restriction) converge on a common pathway that confers stress resistance?
For those of you who lack the hepatic fortitude to consume 1000 bottles of red wine, I’m betting that New Year’s resolution to get off your duff and hit the gym is looking a lot more appealing.