What is Epigenetics and its Influence on Your Health?
Published 23 Mar 2024 • By Somya Pokharna
A new and fascinating area of biology explores that the genetic makeup that we are born with isn’t solely in charge of our health and well-being. Rather, our genes are influenced by a symphony of external factors and are capable of changing throughout our lives.
So, what is this study called? How are these genetic changes even possible? Do they have any influence on our well-being?
Read on to find all the answers!
What is Epigenetics?
The term "epigenetics" comes from the Greek prefix "epi-" meaning "above" or "on top of." It refers to the study of changes in gene expression that do not involve alterations to the underlying DNA sequence – a change "on top of" genetics. These changes can activate or deactivate genes in ways that affect how cells read the genes. Epigenetics is at the forefront of modern genetics, challenging the old notion that our DNA destiny is fixed at birth.
How Does Epigenetics Work?
Imagine your DNA is an instruction manual that contains all the guidelines for building and running your body. Epigenetic changes are like bookmarks or sticky notes that control which parts of the manual are read and used.
- DNA Methylation: This is like adding sticky notes to certain pages of the manual. These sticky notes block the proteins that read the manual from accessing the gene instructions written on those pages. Methylation turns genes "off" by covering them up, while demethylation removes these sticky notes, allowing the genes to be read and used.
- Histone Modification: Think of DNA as a long string that wraps around proteins called histones. When histones are tightly packed together, it's like the pages are stuck together tightly, making it hard for proteins to access the gene instructions. This turns the gene "off." But when histones are loosely packed, it's like the pages are spread out and easy to read. Chemical groups can be added or removed from histones to control how tightly they pack together, thus turning genes "on" or "off."
- Non-coding RNA: In our instruction manual analogy, non-coding RNA is like a special marker pen that highlights specific sentences. These markers can either break down the sentences (coding RNA) so they can't be read, or they can signal for the book pages (histones) to be modified, turning genes "on" or "off."
How Can Your Epigenetics Change?
Epigenetic changes can occur throughout your life due to various factors. Here are some ways epigenetics can change:
Environmental Factors
Your environment plays a significant role in influencing epigenetic changes. Factors such as diet, exposure to pollutants, toxins, stress, and even your living conditions can impact how genes are expressed. For example, certain nutrients in your diet can affect DNA methylation patterns, while exposure to toxins can alter histone modifications.
Lifestyle Choices
Your lifestyle choices, including diet, exercise, and sleep habits, can also influence epigenetic changes. Regular physical activity, for instance, has been shown to affect DNA methylation patterns associated with various health outcomes. Similarly, chronic stress or lack of sleep can induce epigenetic changes that may impact your overall well-being.
Developmental Stages
Epigenetic patterns can change during different stages of development. From infancy to adulthood, your cells undergo various epigenetic modifications to adapt to changing environmental cues and physiological demands. These changes help shape your growth, development, and maturation.
Diseases and Disorders
Epigenetic alterations are associated with various diseases and disorders, including cancer, neurological disorders, and metabolic conditions. For example, abnormal DNA methylation patterns are commonly observed in cancer cells, leading to the imbalance of gene expression and tumour development.
Therapeutic Interventions
Epigenetic modifications can be targeted for therapeutic interventions. Drugs known as epigenetic modifiers can be used to alter epigenetic marks and potentially reverse abnormal gene expression patterns associated with certain diseases. These treatments are being explored in clinical trials for conditions such as cancer and neurodegenerative disorders.
How can Epigenetics affect your Health?
Epigenetic changes can impact health in several ways:
- Infections: Germs can alter epigenetics to weaken the immune system, aiding their survival. For instance, Mycobacterium tuberculosis, which causes tuberculosis, can change histones in immune cells, suppressing genes that strengthen immunity, thus promoting its survival.
- Cancer: Certain epigenetic changes increase cancer risk. For example, increased DNA methylation can decrease expression of the BRCA1 gene, raising susceptibility to breast and other cancers. Epigenetic alterations, such as abnormal methylation patterns in colorectal cancer, are used in screening tests for early detection.
- Nutrition During Pregnancy: A pregnant woman's diet can alter her baby's epigenetics, impacting health later in life. For instance, exposure to famine during pregnancy can lead to epigenetic changes in the child, increasing the risk of diseases like heart disease and type 2 diabetes.
- Intellectual Disability: Fragile X syndrome, a genetic disorder causing intellectual disability, results from epigenetic changes like CGG repeat expansion and methylation-induced gene silencing.
Key Takeaways
Epigenetics explores gene expression changes without altering DNA sequence, challenging fixed genetic destiny. It works by adding or removing chemical groups from DNA and histones, affecting gene activation. Environmental factors, lifestyle choices, developmental stages, and diseases influence epigenetics.
Epigenetic changes impact health, weakening immunity, increasing cancer risk, and affecting prenatal health. Fragile X syndrome is an example of how epigenetic alterations, like gene silencing through methylation, contribute to intellectual disability. Understanding epigenetics offers insights into disease prevention and therapeutic interventions.
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Sources:
Epigenetic Influences and Disease – Nature.com
Epigenetics – Psychology Today
Epigenetics – something that we do not have in our genes, and we can still pass on to our children – Foundation of Research and Science Development
Epigenetics across the human lifespan – Frontiers
Epigenetics: Relevance and Implications for Public Health – PMC
Role of Epigenetics in Biology and Human Diseases – NIH National Library of Medicine
The Impact of Nutrition and Environmental Epigenetics on Human Health and Disease – International Journal of Molecular Sciences
What is Epigenetics? – CDC
What Is Epigenetics? – Cleveland Clinic
What is epigenetics? – MedlinePlus Genetics
What is Epigenetics? The Answer to the Nature vs. Nurture Debate – Center on the Developing Child, Harvard University