Did you know your environment or lifestyle choices can change the way your genes work? The science behind this process is called epigenetics. Over the past few decades, researchers have found that our environment—what we eat, how we move, our stress levels, and the toxins we’re exposed to—can modify the way our genes work without actually changing our genetic code. (6)
Think of it this way, your DNA is like the hardware in a computer. Its structure or “sequence” never changes. Epigenetics, on the other hand, is like software. This software, which can be modified by our environment, provides instructions to our DNA that govern how our genes are expressed. Epigenetic changes to this software can help determine whether genes are switched “on” or “off” and can influence the production of proteins in certain cells, ensuring that only necessary proteins are produced. One of the most important mechanisms in epigenetics is known as methylation.
Did you know? Methylation acts like a genetic “on/off switch” that influences how a gene expresses itself.
What is methylation?
Methylation is a metabolic process that involves attaching small molecules called methyl groups to fragments of DNA. Methyl groups are made up of one carbon atom and three hydrogen atoms. When a methyl group is added to a gene, it can act as a switch that can turn that gene “off”. When you lose that methyl group, the gene becomes demethylated. (21)
Methylation can also occur in histones, which are proteins that provide structural support to your chromosomes. Histones help package DNA into a compact unit that can fit inside the cell nucleus. Histone methylation has been found to play a key role in all biological processes, including DNA repair, cell cycle, and the stress response. (8)
Why is DNA methylation important?
When methylation works the way it should, it can positively impact many biochemical reactions in the body that regulate everything from cognition to detoxification to cardiovascular activity. These “on/off switches” often inhibit the expression of certain genes. (18) For example, methylation might keep a tumor-causing gene from “turning on”, which may help to prevent the development of cancer. (12)
However, methylation isn’t foolproof, and the process appears to decline with age. (29) This may be one reason why chronic illness is more prevalent in older people. (24)
Abnormal or low levels of methylation have been linked to many diseases, including:
- Alzheimer’s disease (28)
- Attention deficit hyperactivity disorder (ADHD) (9)
- Autism (20)
- Cancer, especially involving the colon, stomach, cervix, prostate, thyroid, and breast (12)(13)
- Cardiovascular disease (19)
- Cognitive decline (30)
- Depression (1)(2)
- Parkinson’s disease (28)
But here’s the good news: Unlike a mutated gene, which is unlikely to change back to a normal gene, epigenetic changes are potentially reversible. In other words, a gene with a defective methylation pattern might, under the right circumstances, be able to reestablish healthy activity and continue to function. (4)
Did you know? Histone methylation levels are involved in regulating longevity. (8)
Habits for healthy methylation
According to one study in the Proceedings of the National Academy of Sciences of the United States of America, methylation declines as you age. The study noted that newborns have considerably more methylated DNA than people over the age of 100, and people in their mid-20s have levels in between the two, suggesting that DNA methylation slows as you grow older. (10)
However, age isn’t everything. Your daily habits can influence methylation, either supporting it or undermining its beneficial effects. Replacing unhealthy habits like smoking or eating ultra-processed food with healthy alternatives like exercise or a nutritious diet can support healthy methylation. (14)(15) Here are several things you can do to support healthy DNA methylation:
Avoid tobacco smoke and second-hand smoke
Long-term exposure to cigarette smoke can affect DNA methylation and gene expression in adipose (fatty) tissue. Research links these changes to widespread and potentially devastating health consequences, including an elevated risk for diabetes and cancer. (26) However, according to Scottish researchers at the University of Edinburgh, these smoking-related methylation changes can be reversed, typically within an average of two years after quitting. (16)
Consume alcohol in moderation
A study published in PLOS Genetics evaluated tumors from 162 breast cancer patients and found that those who consumed large amounts of alcohol were more likely to have decreased methylation. This lends additional evidence supporting the health benefits of limiting alcohol intake in women. Interestingly, the researchers also found that the women who consumed the most folate from food had increased methylation. (3)
Eat a healthy, minimally processed diet
What you eat is one of the strongest modifiable factors influencing DNA methylation. Trading in nutritionally void foods for foods high in choline such as shellfish, poultry, eggs, leafy greens, cauliflower, lentils, soybeans, and flax seeds can help modulate methylation. (31) This is because, as choline is metabolised, it can donate one of these methyl groups, and thereby turn certain DNA genes off. Other methyl donors include asparagus, potatoes, spinach, bananas, oranges, legumes, liver, fish, rice, cheese, and milk. These foods are high in the B vitamins such as folate, which are essential for proper methylation. (25)
Engage in regular exercise
Exercise, even in modest doses, can change gene expression via methylation. This was demonstrated in a small 2013 study of 23 sedentary, slightly overweight, middle-aged men at Lund University. During the study, the men participated in indoor cycle and aerobics classes about twice a week. After six months, the researchers were surprised to find changes in the participants’ genes that influence type 2 diabetes and obesity. They concluded that physical activity altered DNA methylation, suggesting an epigenetic link between exercise and a lower risk of disease. (23)
Did you know? Being overweight can affect DNA methylation and increase the risk of cardiovascular problems, type 2 diabetes, and other metabolic diseases. (27)
Nutrients that support methylation
A growing number of studies looking into the relationship between nutrition and methylation suggest that the process relies on specific vitamins and minerals. A methylated B complex that provides an active form of vitamins B2, B6, B12, and folic acid can support methylation. Magnesium, an essential cofactor in DNA metabolism, is also important, and vitamin D stabilizes the structure of chromosomes and prevents DNA double-strand breaks. (7) Increasing your intake of these nutrients may help maintain healthy DNA methylation. To maximize the benefits of your supplements, look for the following:
- 5-MTHF, the active form of folic acid
- Methylcobalamin, the active form of vitamin B12
- Pyridoxal 5-Phosphate, the active form of vitamin B6
- Riboflavin 5’-Phosphate, the active form of vitamin B2 (5)(11)(17)(22)
Always consult a healthcare practitioner for all supplementation suggestions and health changes.
The bottom line
Methylation is an essential yet complicated process that plays a vital role in health, disease, and longevity. While more research needs to be done to understand how methylation and epigenetics can improve health, you can take these steps now to potentially enhance your genetic expression for a longer, healthier life.
- Bakusic J, Schaufeli W, Claes S, et al. (2017). Stress, burnout and depression: A systematic review on DNA methylation mechanisms. J Psychosom Res. 92:34-44.
- Chen D, Meng L, Pei F, et al. (2017). A review of DNA methylation in depression. J Clin Neurosci. 43:39-46.
- Christensen BC, Kelsey KT, Zheng S, et al. (2010). Breast cancer DNA methylation profiles are associated with tumor size and alcohol and folate intake. PLOS Genetics. 6(7):e100143.
- Costello JF & Plass C. (2001). Methylation matters. Journal of Medical Genetics. 38:285-303.
- Dalto, D.B. & Matte, J. (2017). Pyridoxine (vitamin B6) and the glutathione peroxidase system: a link between one-carbon metabolism and antioxidation. Nutrients. 9(3):189.
- Deans C, Maggert KA. (2015). What do you mean, “epigenetic?” Genetics. 199(4):887-96.
- Friso S, Choi SW. Gene-nutrient interactions and DNA methylation. (2002). Trans-HHS Workshop: Diet, DNA Methylation Processes and Health. J Nutr. 132:2382S-7S.
- Greer EL, Shi Y. (2014). Histone methylation: a dynamic mark in health, disease and inheritance. Nat Rev Genet. 13(5):343-57.
- Heinrich H, Grunitz J, Stonawski V, et al. (2017). Attention, cognitive control and motivation in ADHD: Linking event-related brain potentials and DNA methylation patterns in boys at early school age. Sci Rep. 7(1):3823.
- Heyn H, Li N, Ferreira HJ, et al. (2012). Distinct DNA methylomes of newborns and contrarians. Proc Natl Acad Sci USA. 109(26):10522-7.
- Kennedy, D.O. (2016). B vitamins and the brain: mechanisms, dose and efficacy – a review. Nutrients. 8(2):68.
- Kulis M, Esteller M. (2010). DNA methylation and cancer. Adv Genet. 70:27-56.
- Klutstein M, Nejman D, Greenfield R, et al. (2016). DNA methylation in cancer and aging. Cancer Res. 76(12):3446-50.
- Lim U, Song MA. (2012). Dietary and lifestyle factors of DNA methylation. Methods Mol Biol. 863:359-76.
- Maugeri, A. & Barchitta, M. (2020). How dietary factors affect DNA methylation: Lesson from epidemiological studies. Medicina (Kaunas), 56(8), 374.
- McCartney DL, Stevenson AJ, Hillary RF, et al. (2018). Epigenetic signatures of starting and stopping smoking. EBioMedicine. 37:214-20.
- Miller A. L. (2008). The methylation, neurotransmitter, and antioxidant connections between folate and depression. Alternative medicine review : a journal of clinical therapeutic, 13(3), 216–226.
- Moore LD, Le T, Fan G. (2013). DNA methylation and its basic function. Neuropsychopharmacology. 38(1):23-38.
- Nakatochi M, Ichihara S, Yamamoto K, et al. (2017). Epigenome-wide association of myocardial infarction with DNA methylation sites at loci related to cardiovascular disease. Clin Epigen. 9:54.
- Nardone S, Sams DS, Zito A, et al. (2017). Dysregulation of cortical neuron DNA methylation profile in autism spectrum disorder. Cereb Cortex. 27(12):5739-54.
- Phillips T. The role of methylation in gene expression. (2008). Nature Education. 1(1):116.
- Pfohl-Leszkowicz, A., Keith, G., Dirheimer, G. (1991). Effect of cobalamin derivatives on in vitro enzymatic DNA methylation: methylcobalamin can act as a methyl donor. Biochemistry. 30(32):8045-8051.
- Rönn T, Volkov P, Davegårdh, et al. (2013). A six months exercise intervention influences the genome-wide DNA methylation pattern in human adipose tissue. PLOS Genet. 9(6):e1003572.
- Salameh, Y., Bejaoui, Y., & El Hajj, N. (2020). DNA methylation biomarkers in aging and age-related diseases. Frontiers in Genetics, 11, 171.
- Taylor RM, Smith R, Collins CE, et al. (2018). Methyl-donor and cofactor nutrient intakes in the first 2-3 years and global DNA methylation at age 4: A prospective cohort study. Nutrients. 10(3).
- Tsai, P., Glastonbury, C.A., Eliot, M.N., Bollepalli, S., Yet, I., et al. (2018). Smoking induces coordinated DNA methylation and gene expression changes in adipose tissue with consequences for metabolic health. Clinical Epigenetics. 10(1):126.
- Wahl S, Drong A, Lehne B, et al. (2016). Epigenome-wide association study of body mass index, and the adverse outcomes of adiposity. Nature. 541(7635):81-86.
- Wen K, Miillc J, El-Khodor B, et al. (2016). The role of DNA methylation and histone modifications in neurodegenerative diseases: A systematic review. PLOS One. 11(12): e0167201.
- Xiao FH, Kong QP, Perry B, et al. (2016). Progress on the role of DNA methylation in aging and longevity. Briefings in Functional Genomics. 15(6):454-9.
- Xu X. DNA methylation and cognitive aging. (2015). Oncotarget. 6(16):13922-32.
- Zeisel S. (2017). Choline, other methyl-donors and epigenetics. Nutrients. 9(5).