How important the role of genetics is in determining the length and quality of life is still an area of debate in the scientific community. An important contribution to this debate comes from a study published in BMJ Evidence-Based Medicine that examined the association between genetic factors and lifestyle and human lifespan, using data collected from the largest registry of its kind in the world, the UK’s UK Biobank. The data included more than 350,000 people, followed for a period of about 12 years, and the modifiable risk factors included were: alcohol, smoking, physical activity, sleep duration and diet.
What the Polygenic Risk Score is
The patients were divided according to their genetic risk measured through the PRS (Polygenic Risk Score), splitting them into categories. This method makes it possible to analyze hundreds of genes simultaneously and weigh their cumulative impact, using very sophisticated algorithms.
The results revealed that a high genetic risk, measured through the PRS, is correlated with a 21% increase in the risk of early death (before age 75) compared with a low genetic risk, regardless of lifestyle. Conversely, an unfavorable lifestyle is associated with an increase in the risk of death of about 78% compared with a favorable lifestyle, within and across genetic risk categories.
More than 5 extra years of healthy life
However, adherence to healthy lifestyles emerged as a factor capable of significantly attenuating the genetic risk of a shorter lifespan or premature death, with an extremely important finding: individuals with a high genetic risk could extend their lifespan by about 5.22 years at age 40 by adopting a favorable lifestyle.
This leads us to reflect on at least 4 different themes:
1 – That adherence to a healthy lifestyle could significantly offset an unfavorable genetic risk of a shorter lifespan or premature death, leading to a substantial increase in longevity, understood not only as length of life (lifespan) but also as years of life in good health (healthspan).
2 – The importance of a predictive genetic analysis that also includes the PRS, which could identify the people most at risk early on, ensuring a targeted and personalized intervention, all the more so if risk factors are present.
3 – The crucial importance of public health policies and of the concept of prevention and health promotion, aimed at improving people’s lifestyles, which must start first and foremost with us health professionals, but also with people themselves.
4 – That genetics is not our destiny.
