For many years we have been curious to go deeper into our bodies to find out what happens inside the tiniest of cells in a vision to tame the ‘diseases’ which might occur to us. But in the recent past, there have been some interesting pop-ups related to our susceptibility towards diseases. Amidst a pandemic where immunity and tolerance levels are hot topics, we might have to look beyond conventional methods. Epigenetics is one such buzzing new affair.
Humans and the scientific world have fast-forwarded to supersonic levels in terms of decoding our body. For centuries we believed that understanding of genetic structure and inheritance could help us achieve a healthier society. Along with other advancements in medical sciences, we have now reached a level where it is possible to edit your genome! In other words, we probably can control what happens to our offspring before birth. But having said that the diseases due to genetic dysfunction comprise a very small amount on a global level.
According to WHO, Dysfunctional gene behaviour is commonly termed as a mutation. These mutations are responsible for causing illnesses. Moreover, if the gene mutations exist in the egg or sperm cell, children can inherit the defective gene from their parents. Diseases can occur due to a defect in a single gene or a set of genes.
Genes are also known to play a role in the occurrence of infectious diseases like tuberculosis and AIDS as well as some non-communicable diseases like cancer and diabetes. Keeping aside the infectious diseases where the pathology and spread can be clearly defined, our attention should fall on the non-communicable diseases which is, in fact, the leading cause of mortality and morbidity across the globe. One such area of bafflement is carcinoma and malignancy. The carcinomatous transformation of normal cells is still a mystery. Hence it’s clear that not just the genetic mutations control it, but something beyond that.
Exactly what epigenetics is about. It is everything ‘beyond or surrounding the gene itself’. If our genes are the structural components, Epigenes could be called as the notes or instructions for the genetic expression. Traditional genetics describes the way the DNA sequences in our genes are passed from one generation to the next, epigenetics describes passing on the way the genes are used. Cancer was probably the early disease which led to the discovery of this allied branch of genomics. The epigenetics control the genetic expression through various processes like DNA methylation, histone modification and RNA transcription. In short, it acts as a switch for the gene per se through these processes.
Carcinoma was one of the earliest diseases which caused a shift in thinking. It wasn’t merely the genotypical changes that decided the carcinomatous change of cells, but a lot of external factors too.
CDC( genomics and precision health)
Having a mutation in the BRCAI gene that prevents it from working properly makes you more likely to get breast and other cancers. Similarly, increased DNA methylation that results in decreased BRCA1 gene expression raises your risk for breast and other cancers. While cancer cells have increased DNA methylation at certain genes, overall DNA methylation levels are lower in cancer cells compared with normal cells. Different types of cancer that look alike can have different DNA methylation patterns. Epigenetics can be used to help determine which type of cancer a person has or can help to find hard to detect cancers earlier.
The non-communicable disease spectrum which includes dyslipidemia, diabetes or even stroke also involves these external factors in their disease pathology. It further became evident when the genotype of a pair of twins was assessed. They had similar looking genotype, which means they will have a similar pattern of diseases too. But when examined over years, it was found that both of them had entirely 2 different rates of susceptibility towards diseases and also the type of diseases as well.
What are these external factors?
Not so much of rocket science. It is the food we eat, the physical activity we choose to do and the thoughts we let ourselves be in. Pretty basic right? Exactly why the epigenetics is a problem and solution by itself. Just imagine the fact that we can control our genetic expression without going to strange-looking labs! The studies are vigorously progressing to explain more and more disease pathologies in connection to epigenetic factors. In one such example, it has been demonstrated that sleep deprivation leads to hypermethylation and in turn leads to insulin resistance. Ultimately making us more susceptible to diabetes. Even the stress factors during gestation do make a huge impact on the foetal health index in the long run. Not just disease pathology, epigenetics is involved in our physiology too. Every cell in our body has the same DNA, but are all the cells same? Of course not! The cell differentiates into various organs and tissues because certain genes are turned off or on and thus differentially expressed. This is a developmental epigenetics. Epigenetic profile changes with age too. A newborn will have the highest number of DNA methylation sites compared to an adult.
Is this a novel concept?
Probably No. Ayurveda being one of the medical sciences of the world, did explain a lot of concepts which correlate to the modern-day epigenetics. Ayurveda’s concept of ‘swasthya’ or good health is good food and physical practices. The prime propagators of Ayurveda like Caraka, Vaghbata and Susrutha explains that intake of nutritious food, a healthy mind, rightful deeds and physical fitness helps us attain harmony of the body elements thus bringing about health and longevity. The Ayurvedic key concepts of Prakriti and Vikriti also breaks down to the basics of epigenetics. The Prakriti simply means the factors directly inherited from the parents and that which forms the basic framework of an individual. It can be correlated to the DNA itself. Whereas Vikruti is everything external that creates an impact on the body as the individual grows older. Hence vikruti also becomes the deciding factor which shapes the person’s health and longevity index. As said earlier, it’s the lifestyle choices. Also beyond the above-said principles, Ayurveda instils huge focus on the choices we make as a human being. The environment, the activities, the routines and each of such tiny nuances that we choose to let ourselves in plays a massive role in shaping our health. Not just physical but mental health as well. Early childhood trauma developing to anxiety or depressive disorders in adult life is one of those basic examples.
Why care about it?
Since many NCDs involve epigenetic changes, it seems sensible to counteract them with epigenetic treatments. Because by nature it is a reversible change and hence an easy target, unlike DNA. Even our unhealthy habits are proven to create an impact on epigenetics. On a study conducted among smokers, the levels of DNA methylation are lesser in heavy smokers compared to average smokers. And after quitting smoking it showed a gradual increase, yet again proving the reversibility. The fact that DNA methylation sites can be added or deleted with our mere lifestyle changes paves way for a slow down of our ageing process too. The recent discovery of epigenetics assisted ‘age clocks’ does exactly this by predicting the biological age by assessing DNA methylation sites.
The probability to reverse a disease incidence even if we do have a strong family history is how Epigenetics becomes important in our lives. Despite not having exposure to mutagens per se, each of the steps in our daily routine plays an integral part in genetic expression and silencing.
Hence, being mindful about our nutrition, physical activity and thought process can help us attain a better quality of living. We may not be able to realign our genetic ladder but sure can alter these external factors which control them.
Your genetics load the gun. Your lifestyle pulls the trigger.
Mehmet Oz
