Epigenetics: How Our Diets Can Affect Gene Expression
Epigenetics: The Basics
Epigenetics is a field of study that works to better understand how diet, lifestyle, and environmental factors can affect how our genes are expressed. To clarify, these factors do not alter the sequence of DNA that we are born with. Rather, they function as a switch that can turn genes “on” or “off”.
Epigenetic gene modification occurs primarily through DNA methylation (addition of a methyl group to DNA at the nitrogen bases of nucleotides, though demethylation, or the subtraction of a methyl group, can occur as well) and histone modification (Mierziak et al., 2021). Methylation and histone modifications do occur naturally and is not inherently a bad thing, but some modifications related to diet, nutrition status, and lifestyle factors can negatively impact function of individual genes.
Epigenetic changes related to diet and lifestyle are heritable, meaning that they can be passed on to offspring. One historical event that demonstrates this effect was the Dutch Hunger Winter, the Dutch famine occurring at the end of World War II during the winter of 1944-1945. Children who were in utero (particularly those in early gestation) during this event were found to have lower birth weights, increased risk for coronary heart disease, high blood pressure, glucose intolerance (increased risk for type II diabetes), higher risk of respiratory disease, and increased risk of cancer in adulthood compared to same-sex siblings born before or after the famine (Bleker et al, 2021). Higher rates of depression and anxiety were also observed. Additionally, these risks were seen in the following generation. Negative epigenetic changes are not permanent and can be reversed through healthy diet and lifestyle.
How Do Food Components Regulate Gene Expression?
Following a healthy dietary pattern that includes a variety of fruits, vegetables, nuts, seeds, lean proteins, and whole grains provides necessary nutrients and food constituents that help to minimize inflammation, oxidative stress, and metabolic dysfunction that can contribute to negative epigenetic changes over time.
Polyphenol rich foods and beverages have been studied for their role in supporting the body’s processes, modulating epigenetic changes, and reducing disease risk (Borsoi et al., 2023). These include:
Fruits with colorful skins (like berries, grapes, cherries)
Vegetables (spinach, garlic, onions, carrots, broccoli)
Nuts (almonds, walnuts, pecans)
Spices (turmeric, cloves, cinnamon, ginger, cumin)
Grains (oats, rye, and whole-wheat food products)
Teas and coffee (green tea, black tea)
Some of the beneficial compounds found within these foods include quercetin, resveratrol, gallic acid, curcumin, and ferulic acid.
Additionally, vitamins like B9 (folate) and vitamin B12 play an important role in one-carbon metabolism and DNA methylation processes. Deficiencies in these vitamins can lead to negative epigenetic changes.
What Lifestyle and Environmental Factors Can Influence Epigenetic Changes?
Aside from diet, lifestyle and environmental factors can also contribute to epigenetic changes. Regular physical activity is associated with decreased methylation in genes associated with metabolic dysfunction and inflammation, contributing a beneficial impact to overall health. It’s recommended to get at least 150 minutes of moderate-intensity physical activity, or 75 minutes of vigorous physical activity per week.
Environmental exposures to heavy metals, air pollution, pesticides, tobacco smoke, and excessive alcohol intake is associated with negative epigenetic modifications. Limiting exposure to these environmental factors beneficially impacts overall health.