The Do Good Institute at the University of Maryland School of Public Policy says the percentage of Americans doing formal volunteering has stayed at 20% to 30% of the population for the past 40 years. That adds up to 7.7 billion hours annually spent volunteering, according to the funding support group Double the Donation, and contributes $175 billion in nonpaid work to the economy. The highest rates of volunteering are among people ages 65 and older.

That’s impressive, and it’s great for communities and causes across the country.

But do you know what else it's good for? The vitality and longevity of the volunteers.

A study in the journal Social Science & Medicine confirmed that volunteering for even an hour a week slows your rate of aging by improving immune health, protecting your organ systems, and reducing the risk of premature death.

Another recent study in the journal Psychoneuroendocrinology confirms the association between volunteering and keeping you young. Researchers looked at data from the Health and Retirement Study and found that volunteering prevents multiple age-related epigenetic changes in the body's DNA.

Why does volunteering slow down aging? Because it provides you with a sense of purpose and increases physical activity, social connections, and mental agility.

Reach out in your area to see what you can contribute to your community — and to your good health.

For more on the power of a sense of purpose and a posse, read my book "The Great Age Reboot."