Many researchers today are more interested in studying lifestyle factors when it comes to longevity than genetics. A lot has been learned about genetics in the past few decades to understand now that one’s genes play a limited part in having a long life.
Recent studies have concluded that your genes only impact your longevity by about 20% to 30%. It means that most of what determines your longevity is other factors. You do not automatically start aging at a certain point in your life.
It is understood that if you have short-lived parents, you probably will not have a long life, either. In the case of identical twins, which have been the focus of many studies, a difference in environment impacted the lifespan of the twins differently.
When deciding whether genes or another factor determines longevity, a hindrance to finding a solution is that children often adopt their parents’ lifestyle habits. They may also stay within similar environments. Generations of some people within families have many old people – such as in Okinawa – a Blue Zone.
The longevity of people in the United States extended considerably in the 1900’s. In 1900, the life expectancy of Americans was 48 years. In 1940, it was 62 years, in 1980, it was 73 years. In 2020, life expectancy continued to rise to 78 years. During those changes in lifespan, the genes did not change.
The difference was they had more access to clean water, better food and housing, and increased access to medical care. These are all lifestyle factors. In addition, many people who live longer either abstain from alcohol or drink in moderation, do not smoke, eat healthy, and get exercise.
Recent studies have shown some other factors have an impact on lifespan. Among them is education – the longer you go to school, the longer you live; the more social support you have – the better; your stress levels; a higher economic status; and whether you are frequently exposed to air pollution and toxins.
Having a healthy diet helps maintain and even strengthen your immune system. Some of your genes help your body survive when you encounter environments not as friendly as you are used to – such as hotter climates and less available water or food. By keeping you healthy while they are able, they can help extend your lifespan.
Instead of having an “aging” gene, your body slowly accumulates enough old cells that do not function properly. The result is that your body no longer retains its ability to fight off diseases or heal itself. Eventually, the old cells and the diseases overtake you – and you die.
There is still much to learn about why some people live longer than others. Many researchers and labs are trying to solve the puzzle. The secret to extending the average person’s lifespan has yet to be discovered. It is known that it is not a single factor – but many.
One thing that remains unknown (among others) is what causes some genes to be turned on or off. This field of study is called epigenetics. These changes in the status of the genes do not change the DNA sequence but are another factor.
Although your genetics have a role in your longevity, there is more under your control than your genes. Your lifespan will be more determined by how much you exercise, stay away from harmful substances, eat healthy (including excessive sugar and salt), and reduce stress.