Our skin is an impressive, complex organ that is capable of repairing itself, keeping us the right temperature and protecting everything that’s underneath it. All of this hard work that our skin carries out is thanks to a class of molecules in the body that help to control our genes, translating the impact of lifestyle and diet into physical effects on the ageing process, including in the skin. The study of these molecules is called epigenetics.
Spot The Difference
Genetics, conceptually, deals with the genes and gene function, whereas epigenetics deals with gene regulation. To be more specific, genetics focuses on how the DNA sequences lead to changes in the cell, while epigenetics focus on how DNA is regulated to achieve those changes.
The difference between genetic and epigenetic changes is that the epigenetic molecules do not involve a change to our DNA system, whereas genetic molecules involve the primary DNA sequence and its changes or mutations.
Whether a gene is active or not is controlled by a structure called an epigenome which is made up of chemical tags, attached to the DNA that react to external signals. These reactions cause the epigenome to change, switching our genes on and off – your DNA never changes, but the gene’s functionality is affected.
A lot of our biological markers can switch genes on and off but a class of molecules known as MicroRNAs act similarly to a dimmer switch, tuning the activity of a gene up or down and these changes are thought to play a huge role in health and ageing.
Genetics and Ageing
Genetics can determine our skin’s ability to generate collagen and elastic which is what keeps our skin looking full and youthful. Genetic variants in the MMP1 and STXBP5L genes have been linked to an increased risk of developing wrinkles and while we can’t change our genes, we do have the ability to develop good habits and a lifestyle that reduces our risk of premature signs of ageing.
The best anti-aging defence is to understand your individual risk factors which include limiting UV exposure, maintaining proper nutrition and so on. Over time, taking these factors into account can help to restore collagen and thus improve the skin’s appearance.
Now, DNA testing is available to allow us to dive deeper and identify the specific genes that increase our susceptibility to premature ageing. By understanding our genetic predisposition to wrinkles, it is possible to make proactive changes to delay or eliminate the signs.
Epigenetics and Ageing
Each cell in your body contains the same set of DNA but each ends up working in a very different way. An example would be a liver cell, which looks and acts very differently to a brain cell, even though they are made up of the same DNA. The reason for these differences is because of epigenetics.
Going back to MicroRNAs, these molecules are thought to target over 60 per cent of human genes and they can impact them in multiple ways which can trigger differences in the different cell types. The molecules can impact how the cells develop and die, as well as how our bodies respond to stress and control our metabolism.
Scientists are interested to see how MicroRNAs may be playing a leading role in skin ageing and how these molecules change as we age. At the same time, they are also interested in our circadian rhythms and how our biological processes change with the time of day.
Research suggests that our skin barrier is more resilient and protective during the day when it needs to shield us most from environmental damage whereas overnight, the focus is on repairing the damage that has occured throughout the day. There is a MicroRNAs that is linked to this circadian rhythm and it’s known as Mir-164a. As collagen levels decline, so do levels of this Mir-146a and when this happens, the skin cells are less able to respond to the damaging effects of UV light and less able to repair cellular damage, which is what leads to signs of ageing.
Epigenetics are all about counteracting the changes that happen within the genes as we age and as our bodies change. Although we can’t directly stop these adjustments from happening, the more we understand why they’re happening and whether it’s down to genetics or epigenetics, we can counteract them and become more able to control them.