What Is The Genetic Theory Of Aging?

Aging is a natural part of life, but understanding the process and its effects on the body have long been a topic of research. Many theories have been developed to explain why we age and what can be done to promote healthy aging and longevity. Damage or error theories are concerned with how various factors damage our bodies over time, and programmed theories suggest that aging is predetermined and our bodies naturally age with time, according to a 2010 article in Aging and Disease.

The genetic theory of aging suggests that aging depends on genes we inherit from our parents (via Healthline). In this way, this theory can be considered to be a programmed theory of aging. According to Scientific American, you can inherit specific genes that can either ward off disease or facilitate it.

But it's a little more complicated than that. As you age, your cells gradually stop dividing due to the shortening of telomeres, according to a 2016 review in Aging. Telomeres are the protective caps at the ends of chromosomes, and they are gradually eroded each time a cell divides. When telomeres get too short, the cell can no longer divide and it becomes senescent. Senescent cells accumulate with age, leading to many of the signs of aging.

According to the University of Utah, there is also a relationship between telomere length and genetic mutations. Cells with shorter telomeres are more likely to accumulate genetic mutations, which can lead to cancer and other diseases. However, a 2021 study in Nature Genetics suggests that aging isn't always about the build-up of too many genetic mutations. The study found that healthy cells can continue to grow in spite of the many gene mutations.

It's also not necessarily about what your parents pass on to you. The same 2021 study in Nature Genetics says that twins don't always have the same health outcomes. The study also notes that the older we get, the more our genes and our lifestyle can impact how we age. A 2021 review in eLife says that damage to the DNA in our cells can occur from environmental stressors or stressors that naturally occur within us. According to a 2016 review in Immunity & Ageing, genes account for 25% of longevity, and some people can prolong life by changing their lifestyles.