Telomeres, the protective tail end of DNA chromosomes, tell the tale of your life. Every time a cell divides, a tiny bit of the telomere attached to its DNA is lost. Over time, when those ends become too short to protect the cell, your stem cells stop dividing and “die.”

When that natural cell-aging process is sped up by chronic stress, smoking, obesity, poor nutrition, lack of exercise, and/or exposure to toxins in the environment, you end up with shortened telomeres. That increases your risk for premature aging, cancer, and chronic conditions such as diabetes, dementia, and heart disease.

Fortunately, research shows you can do a great deal to preserve your telomeres — and slow down cellular aging. The top four steps you can take are:

1. Add polyphenols to your diet from fiber, soy protein, and healthy fats found in avocados, olives, nuts, and fatty fish.

2. Eat seeds such as chia, sesame, and flax for snacks and with veggies.

3. Indulge in foods rich in vitamins E and C, including as kiwi, blackberries, broccoli, sprouts, and tomatoes.

4. Reduce stress and increase exercise with daily physical activity (at least 30 minutes a day) and meditation. We like 10 minutes in the morning and before bed.

And soon there may be a drug that helps lengthen your telomeres — two are now in large animal trials.