The Mediterranean diet, already proven to help guard against heart disease, dementia and some cancers, could keep your genes younger, too, according to a new Harvard School of Public Health study. It’s a great reason to munch on nuts, snack on fresh fruits and vegetables and drizzle olive oil over your leafy salads.

Researchers started by rating the diets of 4,676 middle-aged women. Participants got points for eating vegetables, fruit, whole grains, nuts, beans (legumes like kidney beans and black beans), fish and monounsaturated fats (found in olive oil, avocados and nuts). They got more points for drinking moderate amounts of alcohol (like red wine) and for not eating much red or processed meat.

The scientists then measured their telomeres, the protective “caps” at the end of DNA strands inside cells. Telomeres shorten with age.

The result: Women who followed a more Mediterranean-style diet had longer telomeres than those whose plates were piled with “Western” fare — red meat, butter, high-fat dairy products, eggs, sweets, French fries and refined grains.

Telomeres shield genes from fraying and scrambling, the way the little plastic sleeves on the ends of shoelaces keep them intact. Longer telomeres are better — other research links them with a lower risk for heart disease, diabetes and cancer.  

You don’t have to move to a Greek island to give your diet a Mediterranean makeover. Instead, aim to adopt as many Mediterranean eating habits as possible. Harvard researchers found that no single food group was good for telomeres. It was the combination that helped. These steps make it simple:

Eat more vegetables. Scramble spinach with your breakfast eggs, add grated carrots to pancakes, tuck tomatoes and lettuce into sandwiches, toss peas into pasta, add a variety of veggies to soups, stews and casseroles, serve two or three types with dinner. Make it easy by picking up pre-washed, pre-chopped, ready-to-cook veggies in the produce department.

Advocates of Mediterranean eating, like the group Oldways, say it’s almost impossible to get too many veggies. In fact, the American Institute for Cancer Research says a key feature of Mediterranean eating is that vegetables (and fruit) aren’t just sides, they’re the centerpieces of meals.

Swap white breads for whole grains. Try whole-wheat bread or whole-grain pasta. Don’t have 45 minutes to cook brown rice? Try barley, quinoa or bulgur — these whole grains cook faster. You’ll get extra nutrients and hunger-stopping fiber, too. And instead of white potatoes, try sweet potatoes.

Reach for yummy fruit for dessert. Treat yourself to in-season favorites, like juicy apples, sweet strawberries and sun-ripened peaches and pears. Keep unsweetened frozen fruit on hand for quick fruit salads, smoothies and yogurt toppings, too. Try tossing frozen raspberries into spinach salad, topped with toasted nuts.

Get protein from fish, poultry and beans. Eat less red meat and less processed meat (like lunch meat, bacon, hot dogs and sausage). Instead, go for fish, skinless chicken or turkey, beans and meat alternatives like tofu and tempeh. 

Go a little nuts. Snack on a small handful of pecans or peanuts or almonds. Dip apple slices in cashew butter. Spread almond butter on your toast. Women with the highest Mediterranean diet scores in the Harvard study ate about a half-serving of nuts (half an ounce, or about 11 almonds) per day.

Enjoy more good fats, fewer saturated ones. Use olive and canola oil instead of butter. Tuck avocado slices into your sandwich (or mash on toast) instead of adding cheese or slathering on mayo or margarine. Choose low-fat or fat-free dairy products.

Toast your good health with a glass of wine. If you already drink alcohol in moderation, a little red wine (a glass of wine a day for women, up to two for men) is in keeping with Mediterranean cuisine, according to the Academy of Nutrition and Dietetics. Skip alcohol, however, if you have a personal or family history of alcohol abuse or your doctor has advised against it.

Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.