Alums Find Secret of Longer Life

By William J. Cromie

Gazette Staff

By quitting cigarettes and increasing physical activity, Harvard alums are adding almost four years to their life spans, which are already greater than the general population. Even among the oldest graduates, 75 to 84 years old, such changes added almost two years.

The College Alumni Health Study, which has followed graduates of Harvard and the University of Pennsylvania for 38 years, concludes that those who quit cigarettes between the 1960s and 1977 added almost two years to their lives.

Also, men between the ages of 45 and 84 years, who expended more than 1,500 calories a week in activities ranging from tennis to gardening, lived 1.6 years longer than those with less active lifestyles.

"While the gain was largest among those younger than 65, even men aged 65 to 84 enjoyed some benefit, indicating that it is never too late to change," notes I-Min Lee, an epidemiologist at the Harvard School of Public Health (SPH).

The alumni health study, begun by Ralph Paffenberger of the SPH in 1960, has tracked more than 71,000 alums from the two Ivy League schools. Participants include Harvardians from the classes of 1920-1954 and Pennsylvanians from the classes of 1932-1944. Today, 27,659 of them remain alive.

Harvard admitted no women during those years but the University of Pennsylvania did. Following these alumnae has revealed that exercise decreased their risk of breast cancer. This part of the study enrolled 1,566 women, aged 36 to 79 years in 1962, and followed them for 31 years. The resulting data suggest that postmenopausal women who expended more than 1,000 calories a week cut their breast cancer risk in half compared to women who burned less than 500 calories a week.

"In addition, results from this and other studies show that both men and women can lower their risks of heart disease, colon cancer, and diabetes by moderate levels of physical activity," Lee says. "There's no downside to exercise if you don't overdo it."

Women who walk at a brisk pace for 30 minutes a day, five days a week, will burn 1,000 or more calories, thus reducing by half their risks of breast and colon cancer.

Men also can get the benefit of added years by walking 45 minutes for five days, or 15 miles a week, an activity that burns about 1,500 calories.

For men and women from both colleges the most popular exercise activities included walking, tennis, golf, calisthenics/home exercises, gardening, and swimming.

According to Lee, two and a half hours of tennis a week should burn about 1,500 calories. Three and a half hours of golf a week, if you carry your own clubs, will do the same.

Healthier and Longer-Lived

An even longer investigation of Harvard alums, called the Grant Study, has been going on since 1937. It includes those who graduated in 1939 through 1944, and is one of the longest, if not the longest, study of people who stay healthy.

"After 60 years, we can say that our graduates are healthier and more long-lived than the general population," says George Vaillant, leader of the study and a professor of psychiatry at Harvard Medical School.

"About 60 percent of the 268 graduates in this study will live past 80 years and still be active and involved with life," he continues. "This unheard-of collective vitality offers a window into the future. Grant Study men represent a longevity that industrialized nations . . . will not achieve until between 2050 and 2075."

Such vitality "is true in general for those who attain the highest educational and socioeconomic levels," Lee points out. "These are people, who, like Harvard alums, smoke less, exercise more, and weigh less."

Another part of the College Alumni Health Study looked at the range of body weight associated with the lowest risk of death.

Obesity is a well-established high-risk factor for heart disease, stroke, and diabetes. Also, there is a controversial belief held by some researchers that too little weight can be hazardous. "We found that men with the lowest risk of death have a body mass index of less than 22.5," Lee notes.

Body mass index (BMI) is a measure of weight adjusted for height. To calculate it, divide your weight in kilograms (pounds multiplied by 0.45) by the square of your height in meters (inches multiplied by 0.025). A five-foot, eight-inch person who weighs 144 pounds would have a BMI of 22; so would a six-foot man who weighs 162, and a five-foot, four-inch woman weighing 128 pounds.

By this measure, Harvard and University of Pennsylvania alums could do better. The men averaged five feet, ten inches and 170 to 175 pounds, giving them BMIs between 25 and 25.7. That's not obese -- defined as a BMI of 27 or higher for those more than 35 years old -- but neither is it ideal.

"Like most older people, they're getting heavier as they grow older," admits Lee. "They should watch their weight and try to push it down."

Lee notes that previous results of the alum study show that the likelihood of heart disease among middle-aged men is decreased by participation in varsity and intramural sports during their college years. That protection, however, only lasts until about age 50. After that, it disappears unless men maintain moderate levels of physical activity.

"Sedentary college students who later take up an active and fit way of life are at a lower heart-attack risk than former varsity players who gave up or reduced exercise in middle age," Lee says. "I can't stress enough that it is never too late to start exercising."

Other studies have shown that moderate amounts of exercise also protects women against heart disease.

In addition, physical activity in middle age cuts the risk of developing diabetes for both men and women. For every 500 calories expended per week, diabetes risk drops 6 percent.