Studies of twins show that about 25 percent of variation in human life span can be attributed to genetics. This means that about 75 percent that could be attributed to modifiable risk factors that can make a positive change in a human life.
"Laurel B. Yates, M.D., M.P.H., of Brigham & Women’s Hospital, Boston, and colleagues studied a group of 2,357 men who were participants in the Physician’s Health Study. At the beginning of the study, in 1981 to 1984, the men (average age 72) provided information about demographic and health variables, including height, weight, blood pressure and cholesterol levels and how often they exercised. Twice during the first year and then once each following year through 2006, they completed a questionnaire asking about changes in habits, health status or ability to do daily tasks," reports the study.
The study involved 2,357 men 41 percent of which lived to age 90 or older. Several modifiable factors were associated with survival to this exceptional age.
“Smoking, diabetes, obesity and hypertension significantly reduced the likelihood of a 90-year life span, while regular vigorous exercise substantially improved it,” the authors write. “Furthermore, men with a life span of 90 or more years also had better physical function, mental well-being, and self-perceived health in late life compared with men who died at a younger age. Adverse factors associated with reduced longevity—smoking, obesity and sedentary lifestyle—also were significantly associated with poorer functional status in elderly years.”
According to the research estimate a 70-year-old man who did not smoke and had normal blood pressure and weight, no diabetes and exercised 2 to 4 times per week had a 54 percent probability of living to age 90. However, if he had adverse factors, his probability of living to age 90 was reduced to the following amount:
Sedentary lifestyle, 44 percent
Hypertension (high blood pressure), 36 percent
Obesity, 26 percent
Smoking, 22 percent
Three factors, such as sedentary lifestyle, obesity and diabetes, 14 percent
Five factors, 4 percent
Interesting Fact About Long Living
More women than men survive to extremely old age, the male centenarians in this study appeared to have better mental and physical function than their female counterparts. “One explanation for this may be that men must be in excellent health and/or functionally independent to achieve such extreme old age,” the authors write. “Women on the other hand may be better physically and socially adept at living with chronic and often disabling health conditions.”
