Long Life Not Just Genetic
Why do identical twins with the same genes, living in a similar area under similar economic conditions often end up getting different diseases and dying on average more than 10 years apart?
As this recent article discusses, genes are good at predicting traits such as height, but not so good at predicting longevity.
The likely reason is that life span is determined by such a complex mix of events that there is no accurate predicting for individuals. The factors include genetic predispositions, disease, nutrition, a woman’s health during pregnancy, subtle injuries and accidents and simply chance events, like a randomly occurring mutation in a gene of a cell that ultimately leads to cancer.
The article highlights the findings of a recent study that looked at identical twins and longevity and found:
there was almost no genetic influence on age of death before 60, suggesting that early death has a large random component — an auto accident, a fall. In fact, the studies of twins found almost no genetic influence on age of death even at older ages, except among people who live to be very old, the late 80’s, the 90’s or even 100.
The same results were found in animals, in which cases the environments were much more tightly controlled.
So, what’s going on? Well, the researchers cited in the article say randomness, either a random event such as an infection or accident, or a random slight difference in cell growth and division that leads to different rates of deterioration later in life, may explain the longevity differences.
These factors may indeed play a role. It’s also likely, though, that other environmental factors, such as nutrition and toxin exposure, are very influential in explaining both the body’s ability to deal with many of these random events and the ultimate differences in longevity.
