Genetics and epigenetics of ageing
Ageing is a natural process which happens to all of us as time goes by. It involves change. In humans, it means the development and at a certain point of life the slowing down and deterioration of the body processes which keep us alive and healthy.
Ageing can be observed on the genetic level. This means that as we age, our genes and DNA undergo a number of transformations. These are conditioned both by the genetic code we are born with (genetic factors), our own choices and the environmental factors we are exposed to through our lives (epigenetic factors).
What is epigenetics?
To understand some of the reasons for ageing, we need to look at epigenetics - a relatively new branch of science which researches how our genes get affected by various factors and what it means for us.
"Epigenetics, as a simplified definition, is the study of biological mechanisms that will switch genes on and off." - https://www.whatisepigenetics.com/what-is-epigenetics/
Before epigenetics became part of genetic research, scientists looked at genes in the in a static sort of way. The general view was that our body, health, mental and emotional development was predetermined by the genetic makeup we were born with. This was known as the "Central Dogma" of genetics.
However, in 1990, the US Department of Health and the National Institutes of Health decided to map up the accumulate human genetic material. This was the start of what was known as the Genome Project which lasted for 13 years involving a huge amount of international research.
Having completed the Genome Project, the scientists had ended with more questions than when they started. The idea that all our traits, features, health and wellbeing were determined solely by the genetic factors could no longer stand the scientific scrutiny.
How could people with identical genetic material (e.g. twins) but raised in different circumstances be so different from each other? This was the start of another, very exciting science was born.
The reason I talk about it in such detail is that epigenetic factors have a direct influence on how well (or badly) we age and how long we live.
What are the 5 groundbreaking discoveries about ageing?
- That the genes we are born with determine only 2-5% of how healthy we are and how fast we age.
- That the other 95-98% of these factors is determined by how our genes are expressed as a result of epigenetic factors - the food we eat, the water we drink, the air we breathe, the thoughts we think, the things we are in direct contact with, our lifestyle and decisions, as well as our ability to adapt to the environment surrounding us.
- Even in the 2-4% of people who are genetically predisposed to certain diseases (e.g. Alzheimer's), these genes can lie dormant under the circumstances which don't promote their expression. Only 1% of people with the faulty gene develop the condition due to mutations of certain genes. So in the vast majority of cases, people who develop the disease are exposed to various environmental factors, nutrition and own lifestyle choices.
- That our state of health and ageing depends mostly on how our genes are expressed which in turn is influenced by the external and internal factors they are exposed to (the ones I've already mentioned here).
- The most exciting discovery of all is that we can reverse our gene expression by changing the environment, nutrition, our state of mind and lifestyle. So basically, we can repair the genes which have already been damaged and reverse the harm done to our health. This also means that we can reverse the process of ageing.
What I have said earlier means that only a tiny part of the population will age in a certain way and at a certain speed due to hereditary genetic mutations. For the rest of us, it is the choices we make throughout our lives, the thoughts we think and the environment we are exposed to. This, in turn, means that nurture takes over nature and that we are in charge of our own destiny. Isn't that exciting?