Longevity Isn’t Really About Our Genes, Study Reveals
Authored by Emma Suttle, D.Ac, AP via the Epoch Times
How often have you pondered your dad’s diabetes or the heart disease that runs in the family and thought, “Am I going to get that? Is it inevitable?” With all we’ve learned about genetics, it seems reasonable to think that some of our health outcomes will be determined by those invisible forces buried deep in our DNA. But a new study has shown that how long we live has more to do with our behaviour than with our genes, implying that our choices may have a much more profound impact on our longevity than we may have thought.
The authors of the study, published in the Human Kinetics Journal, sought to analyze the relationship between physical activity and sedentary behavior, and their associations with mortality based on a score that evaluated genetic risk factors. The study involved 5,446 post-menopausal women 63 years of age or older. The women were put into three groups based on their genetic risk factors. These risk factors were measured by a “small selection of single-nucleotide polymorphisms” that are well-known to affect longevity.
Single-nucleotide polymorphisms (SNPs) are variations in a genetic sequence that affects one of the sequence’s basic building blocks—adenine, thymine, cytosine, or guanine. SNPs help predict an individual’s response to certain drugs, his or her susceptibility to environmental factors such as toxins, pesticides, or industrial waste, and his or her risk of developing certain diseases.
The study authors conclusively found that, regardless of their genetic risk factors, participants who had a higher rate of physical activity showed a lower risk of mortality, and those who had a higher level of sedentary behaviour increased their chances of dying during an average follow-up period of more than six years. Ultimately, the findings support the importance of more physical activity and less sedentary behaviour for reducing mortality risk in older women, regardless of their genetic predisposition for longevity.
An article titled “Human Longevity: Genetics or Lifestyle? It Takes Two to Tango,” published in Immunity and Aging in 2016, found that a combination of genetic and non-genetic factors determines healthy ageing and longevity in humans. It says that family studies found that about 25 per cent of the variation in human longevity is due to genetic factors. Interestingly, the article also states that studies have indicated that caloric restriction, as well as epigenetic factors, genetics, and lifestyle, play a role in healthy ageing.
Epigenetics is the study of how our behaviours and environment can change the way our genes function. Unlike genetic changes, these epigenetic changes are reversible because they don’t affect our DNA.
In contrast, a study published in 2018 in the journal Genetics analyzed a staggering 54.43 million family trees by collecting birth and death records for 406 million people born from the 19th century to the mid-20th century from the databases of Ancestry.com. The study found that a mere 7 per cent of people’s lifespan can be attributed to genetics or heritability.
Heritability measures how the differences in human genes account for the differences in individuals’ particular characteristics or traits. These include eye colour, height, hair colour, intelligence, and disorders such as schizophrenia and autism.
