Living to see 100 may be determined by genes more than lifestyle
A new study of long-lived individuals reveals that the key to the fountain of youth may simply be in their genes. While many long-lived individuals turn out to indulge in many of the same unhealthy lifestyle habits that the rest of us do, this should not be taken as a carte blanche for immoderate self-indulgence and self-harm.
Researchers at Yeshiva University's Albert Einstein School of Medicine examined 477 Ashkenazi Jews – a genetically homogenous ethnic group from Eastern Europe – age 95 to 109, looking for factors that may have contributed to their longevity. They then compared the centenarians’ data to a group of shorter-lived people who died younger but who had participated in the National Health and Nutrition Examination Survey earlier on. Those people answered questions about their lifestyle when they were approximately 70 years old.
Researchers discovered that both groups had comparable numbers of people who were overweight or obese, as well as a comparable distribution of BMI (Body Mass Index) scores. Smoking was slightly more prevalent in the shorter-lived group, but shockingly, a full 60% of men in the long-lived group had smoked at some point in their lives. In fact, Nir Barzilai, director of the college's Institute of Ageing Research, said that he first woman he interviewed, a 109-year-old, told him she had smoked 40 cigarettes a day for 90 years. While most of us would have succumbed to emphysema, lung cancer, or some other grave lung disease putting that much smoke into our lungs each day, she remained unscathed.
The proportion of individuals who consumed alcohol daily among both sexes was also similar, and, most shockingly of all, the centenarians reported engaging less often in regular, moderate exercise than their counterparts who lived shorter lives.
"My population is as bad as every population," summarized Dr. Barzilai, who is also the paper's lead author. "They haven't listened to the doctor either."
Barzilai argues the study provides further proof of the key function of so-called longevity genes when it comes to determining who lives to 100 and who does not.
Barzilai pointed to the protein CETP as one such gene, explaining that it helps regulate HDL, or the “good” type of cholesterol, and seems to protect people against certain health problems that occur with age, including cardiovascular disease and Alzheimer's disease. Research is ongoing to develop drugs that would imitate such gene mutations, as a prevention effort against the diseases of aging.
Dr. Brazilai cautions that the findings should not be used as a license for a no-holds-barred unhealthy lifestyle. The fact remains that for most of us not endowed with genetic longevity prowess, a healthy lifestyle will extend our lives, even significantly. Moreover, the quality of our twilight years will be vastly improved. Surely it is much more enjoyable to be old and spry, rather than old and decrepit, whether that old age happens at 70 or 90. Deciding to forego exercise or taking up smoking could mean the difference between daily hikes and a wheelchair down the road.
Surprisingly, when centenarians were asked what contributed to their longevity, their number one answer was good genes, followed by healthy diet and exercise. This might imply that centenarians’ recollection of past bad lifestyle habits were inaccurate – which is always a liability in research which relies on self-report measures.
Interestingly, "God, religion or spirituality" did not get much credit, cited by only seven per cent of women and 2.5 per cent of men, which contrasts with other longevity studies that implied a greater correlation between these two factors.
The study is being published today (Wednesday) in the Journal of the American Geriatric Society.