PROBLEM TO BE SOLVED: To provide an anti-aging agent having a more powerful sirtuin activation effect than that of resveratrol and inhibiting the aging, and a pharmaceutical composition and foodstuff containing the anti-aging agent.SOLUTION: An activating agent, pharmaceutical composition and foodstuff are provided by containing an extract of the fruit or seed of melinjo which is a plant of Gnetaceae, or gnetin C, as an active ingredient, having the activation effect of the sirtuin having an NAD-dependent deacetylation enzyme activity associated with the realization of the prolongation of life, since calorie restriction is an effective treatment for realizing the prolongation of the life and anti-aging.SELECTED DRAWING: Figure 1
