We all know a case of a person who takes care of himself, leads a healthy life, eats well, plays sports, does not smoke … and yet ends up dying young. Hazards of life? Obviously, we cannot predict a traffic accident or other unnatural death, but the rest of the information is hidden in our DNA and, now, scientists are beginning to develop tools to reach it.
In 2013, a team of researchers from the University of UCLA (USA) designed what they call: ‘epigenetic clock’ , which allows estimating the rate of aging of blood and other tissues . To do this, they quantify methylation, a natural process that chemically alters the structure of our genetic material as time goes by. With this clock, scientists can evaluate whether the ‘biological age’ of a tissue corresponds to its ‘chronological’ age, and thanks to this they have made such significant discoveries as that female breast tissue ages much faster than the rest, which would partly explain the higher incidence of breast cancer.
Now, scientists have used this clock to analyze the biological age of DNA contained in blood samples from more than 13,000 people in Europe and the US , and publish their findings in the journal Aging . “The results reveal that the epigenetic clock is capable of predicting the life expectancy of Hispanics, Caucasians and African Americans, once the calculations are adjusted based on other risk factors associated with lifestyle: smoking, diet, exercise …” explains Steve Horvath, lead author of the work.
“We have found that 5% of the population ages – biologically – faster than the rest, and as a result their life expectancy is shorter.” For example, imagine two healthy 60-year-old adults, both under a high level of stress. The epigenetic aging rate of the former is around 5%, while that of the latter is average. The probability that the first man will die in the next 10 years is 75%, while that of the second is 60%.
“While a healthy lifestyle increases our life expectancy , natural aging processes prevent us from avoiding death forever,” says Horvath.
Does this mean that we should forget about sports and start smoking because, totally, “death is written in our genes”? Absolutely. The epigenetic clock allows us to compare the life expectancy of people regardless of their habits but, as the researcher has explained, “risk factors such as tobacco, diabetes or high blood pressure are still a predictor of mortality a lot. more exact “ . That is to say: if you lead a bad life, there will be no “epigenetic youth” that will save you from an early death.
The next puzzle to be solved is the way in which these epigenetic changes associated with chronological age act: are they the direct cause of the death of older people? Perhaps they favor the development of other diseases , or do they stop the body’s ability to respond to them? To find out, it will be necessary to study well-documented cases of natural deaths in depth and look for the relationship between epigenetic age and certain specific diseases.
