How to Live to 100

A recent Danish study on twins suggested that only 10 percent of health problems can be attributed to genes. The remaining 90 percent could be avoided if people changed their lifestyle. For example, about one-third of the cancers diagnosed each year are believed to be caused by the way people live. Even the aging process itself could be slowed through a few alterations to diet, exercise, and even mental attitude. The inhabitants of Okinawa and Sardinia frequently live an exceptionally long time. These rather isolated places, known as "Blue Zones," have been studied, and similarities were discovered and lessons learned.

First, it is important to keep active. Sardinia, the area with the highest life expectancy, is settled mostly by shepherds, whose lives involve regular, gentle exercise. While most people know exercise is important, fewer realize it is best to keep it light. Too many people spend their working life sitting down. To compensate, they exhaust themselves twice a week in a local gym or in rough contact sports. This can do more harm than good, as excessive, demanding activity causes inflammation in the body. Studies have shown that professional football players, men of great physical strength and fitness, live no longer than average. It is suspected that the violent, and thus inflammatory, nature of their sport is to blame. So undertake a regimen of light, daily activity. Choose walking or swimming over boxing or weight lifting.

Communities like those in Sardinia and Okinawa also provide significant social support for the elderly, who are valued and respected rather than merely tolerated. Isolation kills. Loneliness can affect physical as well as mental health, and the isolated are more likely to develop cancer and heart disease. This may be in part because social interaction boosts the immune system. The elderly residents of Western Europe and North America often find themselves alone in their final years as friends and family move away, something far less common in traditional societies.

There is also a wider cultural problem. In countries like the U.S and the U.K, life is roughly divided into three parts: youth, maturity and old age, with the final part often viewed as the pointless "tail end." However, that is not true in all cultures. Many have no equivalent word for "retirement." As someone ages, their standing within the community rises. And people are expected to continue contributing in some way. In Okinawa, for example, people of all ages are encouraged to have an ikigai, translated as "a reason for being."

Your ikigai can best be carried out when you are fit and healthy. Many people combine a sedentary lifestyle with a diet full of sugar and fat. Those who live in the Blue Zone were found to have diets rich in fresh, organic, multi-colored fruits and vegetables. Few ate junk food. In Okinawa, this vegetable-based diet was supplemented by lots of fresh, oily fish and green tea.

Attaining longevity need not be complicated. Keep active, but make your exercise regular and light. Do not underestimate the difference friends and family can make in your life; reach out to people, and try to widen and deepen your social circle. Find your ikigai as well, in anything, from painting the garage to reading Proust. And finally, take a good look at your diet. Try eating less sugar and junk food, and more fresh, organic vegetables and oily fish. Don't blame aching joints on genes or the passing of time. With a few changes, you may yet live to see 100 candles on your birthday cake.