Overweight, out-of-shape and heading for the homestretch? It's never too late to improve your habits and increase the likelihood of living a longer, healthier life, according to a study by Hawai'i medical researchers that is gaining national attention.

The study led by Drs. Bradley J. Willcox and David Curb suggests that avoiding risk factors in midlife such as smoking, carrying extra pounds, excessive drinking and hypertension can affect how long and how well we age.

Although the research focused on Japanese-American men, Willcox said there's every reason to believe the findings apply to other ethnic groups and women.

Willcox and Curb are with the Pacific Health Research Institute, Kuakini Medical Center and the Department of Geriatric Medicine in the John A. Burns School of Medicine at the University of Hawai'i. Their study will be published in the Nov. 15 issue of the Journal of the American Medical Association, a theme issue on men's health.

Lessons from the research — get healthy, live longer — may seem like a no-brainer, but Willcox said the study is significant for a number of reasons, including the fact it is the largest and longest-running study of its kind and because it provides stark evidence that eliminating health risk factors in mid-age can improve the prospects for better health at older ages.

The research also is noteworthy for investigating the link between the risk factors and a half-dozen major ailments that commonly strike the elderly, including coronary heart disease, stroke, cancer, chronic obstructive pulmonary disease, Parkinson's disease and diabetes.

"This study shows that these risk factors apply across six different age-related diseases, and that's very important when you can find risk factors that we have some control over and can reduce your chances of suffering from such a diverse group of diseases," said Willcox, who was to present the findings today in New York at a media briefing.

The Hawai'i physician is an internationally known expert in the fields of aging, nutrition and health and author of the best-selling books "The Okinawa Program" and "The Okinawan Diet Plan."

Willcox, 45, maintains his own health by running Diamond Head four or five times a week and engaging in strength and flexibility training. He also relies on an "Asian-fusion" diet that includes Okinawan sweet potatoes, lots of vegetables, fruit and fish "and tons of green tea."

The study involved 5,820 healthy Japanese-American men, with an average age of 54, who were participants in the Kuakini Honolulu Heart Program/Honolulu Asia Aging Study. The men were followed for up to 40 years, from 1965 to 2005, to assess "overall and exceptional survival."

Exceptional survival was defined as survival to a specified age (75, 80, 85, or 90 years) without the onset of any of the six major chronic diseases.

Of the original participants, 2,451, or 42 percent, survived to age 85 years, and 655, or 11 percent, met the criteria for exceptional survival to age 85 years. The study found that high grip strength and avoidance of being overweight, smoking, excessive alcohol consumption, hyperglycemia and hypertension were associated with both overall and exceptional survival.

In addition, the study found that a higher level of education and avoidance of hypertriglyceridemia (elevated triglyceride level) were associated with exceptional survival, and lack of a spouse was associated with death before age 85.

Willcox and his team calculated a "survivor risk score" based on cumulative risk factors that suggests the probability of survival to age 85 years is as high as 69 percent with no risk factors at age 55, and as low as 22 percent with six or more risk factors. The probability of exceptional survival to age 85 years was 55 percent with no risk factors but decreased to 9 percent with six or more risk factors.

The good news for men who have let themselves go in middle age is that the risk factors can be controlled, so even someone with a low survivor risk score can significantly improve his prospects by adopting a healthy lifestyle.

"There's a lot of hope for aging men. The results suggest that you can do something about it," Willcox said. "It's never too late. If you've got those risk factors, you can work on eliminating them."

The study also deserves notice because it measures in more precise terms what constitutes "healthy aging." For example, hand grip was one of the measurements used to determine health status.

"It's extremely rare to have a study that has all these measures over this length of time," Willcox said. "We should be very grateful to the men who participated in this research over the last 40 years for their contributions to public health."

Grip strength is an indicator of overall fitness and strength, he said, and the study shows the importance of being "physically robust" in midlife. "You can't do anything about your genes but you can do something about fitness. Strength training is important when you get older. Being strong helps you survive," he said.

"There's a lot you can do to age more healthfully and a lot of it appears to be under your control, so go see your doctor and get working on your survival risk score," Willcox said.

The study was funded by the National Heart, Lung and Blood Institute, the National Institute on Aging, and the Hawai'i Community Foundation.

Reach Christie Wilson at cwilson@honoluluadvertiser.com.