By Dr. Attia Anwar
The moment we enter this world, genes determine so much of us, which is out of our control, like the color of our skin and eyes, our hair color, and the risk of certain diseases. Genes come from our biological parents. Genes are set in stone and predetermined. However, through studies, we have learned that we can modify our genes to work in our favor for the improvement of our health.
Epigenetics is a science that teaches us how the things around us and the choices we make can alter the way our genes function. These changes are done by the changes in chemicals that are attached to genes for their functioning. This study is opening new avenues in the causes and treatment of diseases. The scientists who are studying epigenetics are hoping for control and cure of many diseases, which are thought to be congenital. More people are getting interested in the topic. In short, we can change the expression of a gene without altering the DNA sequence. There are three mechanisms by which we can regulate our genes. They are DNA methylation, histone modification, and non-coding RNA-associated gene silencing. Our surroundings or environmental factors can affect genes in all three ways. Choices we make daily, from the food we eat to sleep, stress, exercise, and our surrounding environment in which we live, have a huge impact on how genes express themselves. These are carefully orchestrated chemical reactions in response to changes in surroundings that activate and deactivate certain genes. It is a kind of cellular memory that learns from experience. Cells listen for signals; everything is not predestined, and it can be modified by the right behaviors.
“Babies who were born during the Dutch famine (also known as the Hunger Winter- 1944–1945) were more likely to develop certain diseases like heart disease and schizophrenia”
We have known for a while that, irrespective of our genes, exposure to certain toxins causes cancer, dirty atmosphere can lead to asthma, and eating nutritious food is good for our brain and body. So we now know that our health and longevity do not depend only on our genes, but there are other factors at play also. Genes are basic units of our DNA. We can compare it to an instruction manual for our body to work. Our cells learn from DNA what to do and how to do it. Trillions of cells are present in our body and are constantly reproducing to replace the cells that die. It is because the same cells do not stick around throughout life; rather, they keep dying and being replaced by healthy cells. Our genes, plus everything that controls them, are called the epigenome. This is not constant but a dynamic thing that changes over time. It can be both for good and bad. The good thing is that if we eat nutritious food, exercise, and are exposed to manageable stress, our epigenome will work in our favor and promote health. At the same time, processed food, a lot of stress, and smoking can cause epigenetic changes that are harmful to health.
Epigenetic changes start before birth and continue throughout life. These processes of DNA methylation and others can change in response to behaviors and the environment. Babies who were born during the Dutch famine (also known as the Hunger Winter- 1944–1945) were more likely to develop certain diseases like heart disease and schizophrenia. Around 60 years after the famine, researchers looked at the DNA methylation levels in people whose mothers were pregnant during the famine. These people had decreased DNA methylation at some genes and increased DNA methylation at other genes, compared with their siblings.
Other examples of factors that can cause epigenetic changes are smoking, infections, and trauma. Gene regulatory proteins can switch the genes off or on based on experience. These experiences are passed to daughter cells. We were taught that our traits are hard-coded in our DNA, which we get from our parents and pass to future generations. New information is proving that epigenetics is going to give us a new understanding of inheritance. The most well-known factors that are epigenetic environmental with potential detrimental or beneficial effects on health are exercise and nutrition. They influence the proper developmental and functional lifestyle. These diet and exercise strategies starting from conception can bring about epigenetic changes for the prevention and treatment of human diseases.
If we talk about human behaviors, diet and physical activity are associated with multiple health outcomes. They are the first line for preventing chronic diseases. A sedentary lifestyle and unhealthy diet contribute to morbidities and mortalities. A healthy lifestyle, apart from helping in the prevention or treatment of diseases in other ways, also influences genetic expression. So we can carry these benefits into the next generation also. It has been shown that women with breast cancer who adopt a program of brisk treadmill walking show increased expression of the tumor suppressor gene after six months. While exercise is an important stimulus for the body to initiate epigenetic change, this is not possible without a diet that supports these changes. They provide the chemical tag, a fuel process within the cells to make these changes possible. Eating healthy, fresh, and minimally processed food is important.
The role of sleep and lack of stress is not extensively studied, but they help you in maintaining physical activity and avoiding junk food. Examples of specific foods that are great in bringing out epigenetic changes include garlic, broccoli, citrus fruits, cashew nuts, grapes, Soybeans, apples, cinnamon, and tea.
While none of us can change our genes, which we have inherited from our parents. But it is not as gloomy as it looks. By adopting healthy behavior, we can switch off some bad genes and increase the expression of some good traits. Although it is a very new and evolving field, by bringing some changes in our lifestyle, we can promote changes at the genetic level, which starts from conception and continues in the next generation.
The author, Dr. Attia Anwar, is a consultant family physician with a postgraduate degree from the Royal College of GPs in the UK. She is a strong advocate of health and well-being and wants patient participation in decision-making regarding health.
