This article How Health and Lifestyle Choices Can Change Your Genetic Make-Up gives the details.

However, the "rules" we already know apply: Eat a healthy diet and exercise. 

Sorry ... no magic pill. However, this tends to work:

Exercise is better than any drug or anything else we have for aging. There's no downside. If this were a drug, it would be the safest, most effective drug in the universe. - Dr. James O. Hill

Exercise is medicine. It reduces blood pressure, cholesterol, blood sugar, weight, stress and depression. It increases energy and well-being. - Dr. Stuart Seale