Breast cancer is the most common cancer in North American women. It makes up almost 30% of all female cancers and is the leading cause of death among women 40-55 years old.1 There are numerous risk factors that are associated with breast cancer. However, one of the most well established is increased exposure to estrogen.2 Women that experience early menarche and a later onset menopause have a higher risk of breast cancer due to the lengthened exposure to estrogen during their lifetime.3 External sources of estrogen such as hormone replacement therapy and the birth control pill have also been linked
By: Dr. Robyn Murphy, ND
Are your genes your destiny? This common question is top of mind for most, especially for those who are considering genetic testing. Questioning whether or not you really want to know, in fear that nothing can be done. Well, the simple answer is, NO, your genes are not your destiny. While this may be due to a number of factors, such as the impact of the gene, the main topic of this article is discussing how epigenetics and particular lifestyle strategies can positively influence health, and that knowing your genes may just be the missing key. The term, epigenetics, is gaining popularity around discussions of our genetic potential. Whether knowing your specific genetic code can actually provide useful information, while epigenetics has such an impact on the fate of our genes.
What are epigenetics?
Epigenetics refers to the chemical changes in DNA that alters genes expression, without changing the DNA sequence itself. The term, “epigenetics” comes from Greek, loosely meaning “above genes”, referring to how these chemical tags switch genes on and off to alter gene activity. There are a few different types of epigenetic modifications. The most common is called methylation, which involves attaching small molecules called methyl groups to segments of DNA. This causes the gene to turn off, so that no protein is produced from that gene.1,2
The term epigenetics is also common lingo referring to the environmental changes that influence gene expression. Gene expressionis the process by which proteins are manufactured from instructions stored in the DNA.3 These may include behaviours, diet, lifestyle and health products that impact how specific genes get turned on and off. While some of these factors may actually cause long-term epigenetic changes, it is not through the same way using chemical tags. A slight distinction worth mentioning to clear confusion.
Epigenetic modifications occur throughout life in response to environmental changes. It is a way for cells to ‘learn’ and adapt to their surroundings to maximize chances of survival. Such changes may affect the body’s metabolic response, leaving ‘scars’ on the DNA to be passed down through generations. Interesting studies of mothers born during the Dutch famine (1944–1945) examine how the fetal environment influence future offspring. Due to epigenetic changes, their children acquired a metabolic ‘skill set’ adapted towards an increase in fat storage, which resulted in an increase in birth weight and decrease in length. While these changes may have improved the body’s ability to retain fat in preparation for future periods of starvation, this was not ideal for their current calorically abundant environment. Researchers found that these changes lead to an 80% increase in risk of poor health later on in life.4
Impact on Health
Scientists continue to investigate the connection between the genome and environmental factors that modify it and human health. 5 Recent epigenetic studies have shown that epigenetics plays a pivotal role in the cause of complex disorders. 6 Changes in nutritional requirements7 and development of diseases such as, inflammatory bowel disease (IBD), 6 cardiovascular disease, 8 obesity, diabetes, and other chronic conditions9 are intimately linked to epigenetics.
It is important to know which environmental influences determine what genes are turned on or off. The environment is not only the external environment, such as a person’s diet or exposure to pollutants that elicit a physiological response, but also the internal environment that surrounds the cell. The internal environment is made up of neurotransmitters, hormones, nutrients and numerous other substances, which may reflect everything from our emotional and psychological state to nutrient status.
Researchers show how a number of environmental factors impact health through epigenetic modifications, including:
- Diet – Nutritional requirements, such as choline, and dietary intake of folate 7,10
- Drugs – Antidepressants (SSRIs) during pregnancy may impact baby’s brain development 11
- Exercise and Lifestyle – Regular exercise modifies over 500 genes, turning on disease preventing genes and turning off disease promoting genes
- Perceptions, Stress and Beliefs – Maternal stress alters baby’s stress response, increasing their sensitivity to stress and production of stress hormones, cortisol 12
- Pollutants (heavy metals, pesticides, air pollution, benzene, BPA, dioxin, chlorination by-products) – many chemicals cause changes in genes expression and are linked to cancer, cardiovascular diseases, neurological disorders and autoimmune diseases. These changes to the DNA can be long-lived, existing well beyond the removal of the exposure 5
- Prenatal care – Referred to as “the 1,000 days”, in utero and early life exposures to chemicals, stress, and nutrient deficiencies may have long-lasting effects on development and disease risk. 9
- Radiation and Electromagnetic Frequencies – neurodevelopmental and neurobehavioral changes in children due to exposure to wireless technologies13
To impact health long-term, it is important to take into consideration both the genetic blueprint and epigenetic factors. By having a clear understanding of the unique genetic makeup, such as individual nutrient requirement, sensitivity to stress, tendency for hormone imbalances and disease predilections, strategies to combat genetic predispositions can be implemented according to the individual. This is the basis of personalized medicine. The strategies implemented, such as increasing particular foods, or engaging in meditation, or regular exercise will be customized to not only improve the success of those strategies but have long-term benefits through epigenetics. “If the human genome is the book of life, then [epigenetics] is its editor”.3 Highlighting the important relationship between the two.
Note: For actionable ways to tap into your epigenetics see Part II
- Reference GH. What is epigenetics? Genetics Home Reference. https://ghr.nlm.nih.gov/primer/howgeneswork/epigenome. Accessed November 7, 2019.
- Anderson OS, Sant KE, Dolinoy DC. Nutrition and epigenetics: An interplay of dietary methyl donors, one-carbon metabolism, and DNA methylation. J Nutr Biochem. 2012;23(8):853-859. doi:10.1016/j.jnutbio.2012.03.003
- Qigong Institute – Epigenetics and Psychoneuroimmunology. https://www.qigonginstitute.org/category/15/epigenetics-and-psychoneuroimmunology. Accessed May 1, 2017.
- Painter RC, Osmond C, Gluckman P, Hanson M, Phillips DIW, Roseboom TJ. Transgenerational effects of prenatal exposure to the Dutch famine on neonatal adiposity and health in later life. BJOG Int J Obstet Gynaecol. 2008;115(10):1243-1249. doi:10.1111/j.1471-0528.2008.01822.x
- Hou L, Zhang X, Wang D, Baccarelli A. Environmental chemical exposures and human epigenetics. Int J Epidemiol. 2012;41(1):79-105. doi:10.1093/ije/dyr154
- Loddo I, Romano C. Inflammatory Bowel Disease: Genetics, Epigenetics, and Pathogenesis. Front Immunol. 2015;6. doi:10.3389/fimmu.2015.00551
- Zeisel SH. Gene response elements, genetic polymorphisms and epigenetics influence the human dietary requirement for choline. IUBMB Life. 2007;59(6):380-387. doi:10.1080/152165407014689
- Handy DE, Castro R, Loscalzo J. Epigenetic Modifications: Basic Mechanisms and Role in Cardiovascular Disease. Circulation. 2011;123(19):2145-2156. doi:10.1161/CIRCULATIONAHA.110.956839
- Indrio F, Martini S, Francavilla R, et al. Epigenetic Matters: The Link between Early Nutrition, Microbiome, and Long-term Health Development. Front Pediatr. 2017;5. doi:10.3389/fped.2017.00178
- Crider KS, Yang TP, Berry RJ, Bailey LB. Folate and DNA Methylation: A Review of Molecular Mechanisms and the Evidence for Folate’s Role2. Adv Nutr. 2012;3(1):21-38. doi:10.3945/an.111.000992
- Videman M, Tokariev A, Saikkonen H, et al. Newborn Brain Function Is Affected by Fetal Exposure to Maternal Serotonin Reuptake Inhibitors. Cereb Cortex. 2017;27(6):3208-3216. doi:10.1093/cercor/bhw153
- Perroud N, Rutembesa E, Paoloni-Giacobino A, et al. The Tutsi genocide and transgenerational transmission of maternal stress: epigenetics and biology of the HPA axis. World J Biol Psychiatry. 2014;15(4):334-345. doi:10.3109/15622975.2013.866693
- Sage C, Burgio E. Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development. Child Dev. 2018;89(1):129-136. doi:10.1111/cdev.12824
- Kanherkar RR, Stair SE, Bhatia-Dey N, Mills PJ, Chopra D, Csoka AB. Epigenetic Mechanisms of Integrative Medicine. Evid-Based Complement Altern Med ECAM. 2017;2017. doi:10.1155/2017/4365429
- Stankiewicz AM, Swiergiel AH, Lisowski P. Epigenetics of stress adaptations in the brain. Brain Res Bull. 2013;98:76-92. doi:10.1016/j.brainresbull.2013.07.003