A new study shows that men who led a healthy lifestyle in their 70s were more likely to live into their 90s and have a better quality of life. And a related study shows that people who live to be 100 don't necessarily do it by avoiding disease entirely, but by not becoming disabled by them.
Researchers say studies of twins have shown that genetic factors account for just 25% of the variation in life span, and that these findings reinforce the importance of the other 75% affected by lifestyle factors within people's control.
Healthy Lifestyle Helps People Live Longer
In the first study, published in the Archives of Internal Medicine, researchers followed 2,357 men who were part of the Physicians' Health Study. The men were evaluated when they started the study at about age 72 and were surveyed at least once a year for the next two decades.
Overall, 970 men survived to age 90 or beyond.
Researcher Laurel B. Yates, MD, MPH, of Brigham and Women's Hospital, and colleagues estimated that a 70-year-old man who did not smoke, had normal blood pressure and weight, no diabetes, and exercised two to four times a week had a 54% chance of living to age 90.
But for each of these common health risk factors, the chances of living to age 90 were reduced as follows:
Having three of these risk factors drastically reduced the odds of surviving to age 90 to 14%, and having five risk factors dropped the chance to just 4%.
Secret of Centenarians
In the second study, Dellara F. Terry, MD, MPH, of the Boston University School of Medicine and Boston Medical Center, and colleagues studied 523 women and 216 men aged 97 or older.
Researchers split the participants into two groups based on gender and the age they developed diseases, such as heart disease, diabetes, high blood pressure, dementia, stroke, chronic obstructive pulmonary disease (COPD), osteoporosis, and Parkinson's disease. If they developed disease at age 85 or older, they were considered "delayers," and those who developed disease at a younger age were called "survivors."
The results showed that 32% were survivors and 68% were delayers. But researchers found that those who developed heart disease or high blood pressure before age 85 and still survived to 100 had similar levels of function as those who developed disease later.
Researchers say the results suggest that the timing of disease may not be as important in living longer as how the disease affects people's health, which is mitigated by lifestyle factors.