Epigenetics, or epigenomics, is the study of how the expression of genes that do not presuppose irreversible alterations in the underlying DNA sequence changes due to various factors, including diet, lifestyle, and environmental exposures. In addition, these changes can be passed down through generations. Introduced by Conrad Waddington in 1942, epigenetics was initially designed for the description of the way, in which certain genes were turned on or off in response to environmental cues, such as diet or exposure to toxins (Nebbioso et al. 1). Providing the examples of epigenetics, this paper demonstrates how lifestyle choices and external factors impact human health and vulnerability to diseases.
On the one hand, certain environmental exposures, such as toxins or poor diet, can lead to epigenetic changes that can increase the risk of certain diseases, such as cancer or neurological disorders. On the other hand, healthy lifestyle choices, such as a diet rich in vegetables, fruits, and other nutrients, along regular exercise, can promote healthy gene expression and reduce disease risk. According to researchers, epigenetic changes can also be passed down from one generation to the next, through a process called transgenerational epigenetics (National Human Genome Research Institute par. 1). In addition, certain experiences, such as exposure to toxins or malnutrition, can lead to epigenetic changes that can be passed down through multiple generations. This means that the health and disease risks of a person can be influenced not just by their own genes, but also by the genes of their ancestors.
One example of epigenetics is the phenomenon of genomic imprinting. It occurs when the expression of certain genes derives from the copy of the gene of only one parent rather than the copies of both parents. This can lead to differences in the way the gene is expressed, depending on whether it was inherited from the mother or the father. One of the best-known examples of genomic imprinting is the gene for insulin-like growth factor 2 (IGF2) responsible for growth and metabolic processes (Xu et al. 1). Normally, it is expressed from the copies of both parents, however, in the case of genomic imprinting, the father’s copy of the gene is more active in comparison with the mother’s one. This can lead to differences in growth and development, depending on which copy of the gene is inherited. Another variant of genomic imprinting is the gene for Angelman syndrome (AS), a rare genetic disorder that affects the nervous system. This disorder is caused by the loss of function of the UBE3A gene, normally expressed only from the mother’s copy. Inheriting two copies from the father can cause the disorder.
Genomic imprinting is a complex process that is not yet fully understood and examined. Nevertheless, it is thought to be mediated by of methylation, a process, in which a methyl group, a small chemical compound made up of one carbon and three hydrogen atoms, attaches to a specific location on the DNA molecule (Centers for Disease Control and Prevention par. 3). This attachment can change the way that the gene is expressed, by either turning it on or turning it off.
Another example of epigenetics is the way environmental exposures can affect gene expression. For example, research has shown that exposure to toxins such as lead or pesticides can lead to changes in the way certain genes are expressed (Giambò et al. 1). These changes can then increase the risk of certain diseases, such as cancer or neurological disorders. For example, exposure to lead can result in changes in the methylation of certain genes, which can increase the risk of neurological disorders such as ADHD. Similarly, exposure to pesticides can lead to changes in the expression of genes that regulate cell growth and division, increasing the risk of cancer (Giambò et al 1). Exposure to certain chemicals such as bisphenol A (BPA) can also lead to epigenetic changes as well.
A third example of epigenetics is the way that diet and lifestyle can affect gene expression. Studies have shown that a balanced diet that presupposes the consumption of whole grains, fruits, and vegetables may prevent certain diseases by the promotion of healthy gene expression (Lorenzo et al. 1725). Stress can also lead to epigenetic changes – chronic stress may contribute to changes in the expression of genes involved in the regulation of the stress response, which can increase the risk of certain diseases such as cardiovascular disease. In turn, regular exercise can lead to changes in the expression of genes involved in the regulation of energy metabolism, which can reduce the risk of obesity and certain diseases such as diabetes. Exercise can also lead to changes in the expression of genes involved in the regulation of inflammation and antioxidant defenses, which can reduce the risk of certain diseases such as cancer.
Maintaining a healthy weight is also important for promoting healthy gene expression. Obesity can lead to changes in the expression of genes involved in the regulation of energy metabolism, which can increase the risk of certain diseases such as diabetes and heart disease. Smoking and excessive alcohol consumption can also have a negative impact on gene expression and can increase the risk of certain diseases such as cancer and heart disease.
In conclusion, epigenetics is the study of factors may impact the expression of genes that may be passed down through generations without alterations on the DNA sequence. The well-known examples of epigenetics include genomic imprinting, environmental exposures, and the impact of diet and lifestyle. All of them demonstrate that environmental exposures, lifestyles, and inheritance may contribute to either prevention of or vulnerability to particular diseases.
Works Cited
Centers for Disease Control and Prevention. “What is Epigenetics?” Centers for Disease Control and Prevention, Web.
Giambò, Federica, et al. “Genetic and Epigenetic Alterations Induced by Pesticide Exposure: Integrated Analysis of Gene Expression, microRNA Expression, and DNA Methylation Datasets.” International Journal of Environmental Research and Public Health, vol. 18, no. 8697, 2021, pp. 1-25.
Lorenzo, Paula M., et al. “Epigenetic Effects of Healthy Foods and Lifestyle Habits from the Southern European Atlantic Diet Pattern: A Narrative Review.” Advances in Nutrition, vol. 13, no. 5, 2022, pp. 1725-1747.
National Human Genome Research Institute. “Epigenetics.” National Human Genome Research Institute, Web.
Nebbioso, Angela, et al. “Cancer Epigenetics: Moving Forward.” PLoS Genetics, vol. 14, no. 6, 2018, pp. 1-25.
Xu, Xiao, et al. “The Role of Insulin-Like Growth Factor 2 mRNA Binding Proteins in Female Reproductive Pathophysiology.” Reproductive Biology and Endocrinology, vol. 20, no. 89, 2022, pp. 1-12.