The Mediterranean diet consistently has been linked with an array of health benefits, including decreased risk of heart disease, diabetes, dementia, and cancer. In a study published online Dec. 2, 2014, by the medical journal BMJ, researchers at Harvard-affiliated Brigham and Women's Hospital linked the Mediterranean diet to longer life as well. The researchers analyzed information from 4,676 healthy women in the Nurses' Health Study who had completed a food questionnaire and whose telomere lengths had been measured. (Telomeres are repetitive DNA sequences at the ends of chromosomes that get shorter every time a cell divides, and thus are markers of cell aging.) They found that a greater adherence to the Mediterranean diet was associated with longer telomeres, and that even small changes in diet made a difference. In effect, the women who had followed the Mediterranean diet were biologically younger than those who hadn't.

The Mediterranean diet is rich in fruits, vegetables, whole grains, olive oil, nuts, seeds, beans, and legumes. Animal protein is furnished by seafood and moderate amounts of poultry, eggs, and dairy. Red meat and sweets are considered occasional treats. This study gives another reason to follow this healthy—and tasty—eating plan.

Quick-start strength-training program

Work out at home or in your office to improve muscle mass.

Muscle mass tends to diminish with age, so making strength training part of your overall exercise regimen is very important. And while many people assume that effective strength-training programs require joining expensive fitness clubs and lifting heavy weights, there are plenty of strength-building exercises you can do at home and at work with little or no special equipment. "You really can strength train without the big machines and get effective results, without spending a lot of money," says Elissa Huber-Anderson, a physical therapist at Harvard-a-ffiliated Massachusetts General Hospital.

Give your body protection with fiber, good fats, whole grains, and omega-3s.

Inflammation is the body's response to an infection, injury, or some other stimulus that the body perceives as harmful. It can be helpful at first, but over time chronic inflammation can damage tissue, joints, artery walls, and organs. Fortunately, there are many healthy foods that can help lower inflammation in the body. "We focus on increasing fiber, whole grains, good fats, and omega-3s," says Debbie Krivitsky, director of clinical nutrition at the Cardiovascular Disease Prevention Center at Massachusetts General Hospital.

Be mindful of risks for fracture, low B12, and a spike in stomach acid.

Proton-pump inhibitors (PPIs) help treat symptoms of heartburn, but these powerful medications also carry their share of risks. "The risks are for long-term use," says Dr. Jacqueline Wolf, a Harvard Medical School associate professor. "Three months of use should be okay, but if someone needs a PPI longer than that, a doctor should be supervising use."

We often write in these pages that the Mediterranean diet is good for your heart and brain. Now it appears that the Mediterranean diet may also help protect your telomeres, according to a Harvard study published in the Dec. 2, 2014, BMJ. Telomeres sit at the ends of your chromosomes and help protect the ends from fraying. Telomere length is considered to be a biomarker of aging: shorter telomeres are associated with a lower life expectancy and higher rates of developing chronic diseases. After analyzing the detailed food questionnaires and telomere measurements of more than 4,600 women, Harvard researchers concluded that a greater adherence to the Mediterranean diet was associated with longer telomeres, and that even small changes in diet made a difference. The Mediterranean diet is rich in olive oil, fruits, vegetables, nuts, and fish; minimizes red meats and processed meats; and includes a moderate amount of cheese and wine.

New guidelines from the U.S. Preventive Services Task Force say that there’s no evidence vitamin D screenings help seemingly healthy people.

Confused about fats? Learn the latest on which fats offer the best health benefits.

There used to be one simple rule—all fat is bad. More recently, we've been told that fat is absolutely essential to our health, especially polyunsaturated fats in plant-derived oils. But, as research piles up, the picture of fats and health has sometimes become blurred.

Try some low-impact activities to ease into an exercise routine.

You know that regular exercise is good for your heart. But only about half of American adults manage the 2.5 hours per week of moderate exercise (such as brisk walking) recommended by the federal physical activity guidelines. Being too busy is a common excuse, but there are bona fide reasons for not exercising. If you're recovering from a heart attack, are overweight, or are simply out of shape, 30 minutes of exercise a day may feel out of reach.

Q. What is better for my heart—a fast run on the treadmill for 10 minutes or 30 minutes of light cycling on a machine?

A. The benefit of exercise on heart health depends on the dose; in other words, the more the better. So, my answer to your question is "Why not do both?" Exercise of virtually any kind prevents heart attacks, strokes, high blood pressure, and diabetes.

Don't rush into it, but don't wait longer than you need to.

More than 700,000 Americans will have one or both knee joints replaced this year, usually because of damage from wear-and-tear arthritis. Age itself is no barrier, and about half of total knee replacements go to people 65 and older. Replacing a joint damaged by osteoarthritis helps men stay active and independent.