Epigenetics and Diet: How Food Influences Gene Expression

While you can’t change the genes you’re born with, you can impact how those genes are expressed with diet, lifestyle, and behavior modifications. The field of epigenetics studies how your environment and your behaviors (like the foods you choose to eat or how you manage your stress) impact how your genes work.  Nutrition, in particular, is one of the most studied and better understood epigenetic factors, with studies showing that foods can trigger epigenetic modifications to genes throughout the lifespan, with early life nutrition being particularly important. Instead of looking at genetics as the sole contributor to the presence or absence of optimal health, it’s important to shift the thinking of genetics to something that can be positively (or negatively) influenced by our daily choices to promote better health and longevity. Once that shift occurs, it becomes very empowering to understand that the foods we eat can have a massive impact on health and disease by affecting how we function at the cellular level. 

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Basic Understanding of Epigenetics

Think of epigenetic activity as a switch that can turn genes “on” or “off.” Nutritional choices can affect how genes are expressed, with no change to the underlying DNA sequence itself. There are three primary ways that epigenetic changes occur, including DNA methylation, histone modification, and non-coding RNA. 

DNA methylation involves the addition of a chemical group (called a ‘methyl group’) to DNA at specific places where it blocks the ability of proteins in the body to “read” that section of DNA, effectively turning the gene “off.” The opposite can also occur - de-methylation can remove a methyl group and turn a gene “on.”

A second primary way epigenetic changes can occur is by modifying histone complexes. With histone modification, DNA wraps around specific proteins called histones, which makes it difficult for proteins to “read” the gene - resulting again in that gene being turned “off” while wrapped around the histone. Chemical groups may be added or removed from histones, making them more tightly or loosely packed, consequently turning gene expression on or off. 

The third primary mechanism by which epigenetic changes can occur has to do with something called non-coding RNA. Your DNA is used as an instruction manual to make two types of RNA, coding and non-coding. Coding RNA is used to make different proteins, while non-coding RNA competes with coding RNA to control the expression of different genes by interrupting the coding sequences.

While these three mechanisms sound quite complex, they are at the core of how gene expression can be changed without changing the DNA structure. Epigenetics is all about what genes are allowed to be expressed and actually create the proteins they encode, and we have the power to influence this process through our daily nutritional choices.

The Relationship Between Diet and Gene Expression

While your diet can’t influence the genes you have, it can influence how those genes are expressed. The impact of nutrition on gene expression starts in utero, with studies showing that infants born in famine or in states of malnutrition have epigenetic changes such as decreased methylation. Carbohydrates, fats, and amino acids can all play a role in gene expression, highlighting the relationship between nutrient intake and epigenetic activity throughout the lifespan.  

Various foods and nutrients may also have epigenetic effects. For example, the vitamin folate is an important source of one of the carbon groups that is key to methylation, making intake of folate essential for the process. Methylation is key during the developmental process for human beings, which is why ensuring adequate folate intake during pregnancy is so important.  

Additionally, several different bioactive compounds in plant foods can affect gene expression in a variety of ways. Catechins (found in green tea) and genistein (found in tea, soybeans, or fava beans) can affect an enzyme involved in methylation called DNA methyltransferase. Compounds such as resveratrol (found in red and blue plant food), butyrate, sulforaphane (found in broccoli and other cruciferous vegetables), and curcumin all affect enzymes that play a role in histone modification. Intake of these foods may impact the effectiveness of different epigenetic processes. 

Epigenetics in Disease Prevention and Management

Studies continue to look at the role of nutrition in inducing epigenetic changes that may help prevent or treat diseases such as cancer, cardiovascular disease, and other metabolic disorders. Epigenetic processes play a part in the development of diabetes, obesity, non-alcoholic fatty liver disease, thyroid disorders, osteoporosis, and others.  

Several different bioactive compounds have been identified as having anti-carcinogenic properties, aiding in an overall lifestyle aimed at cancer prevention and impacting the progression of existing cancers. These foods include teas, soy, herbs, curcumin, cruciferous vegetables, purple grapes, and garlic.  Research has linked these foods to activation of tumor suppressor genes, apoptosis, and repression of cancer-related genes through their impact on epigenetic activity. 

DNA methylation has also been found to play a role in several aspects of the development of cardiovascular disease, including hypertension, heart failure, and coronary heart disease. Excessive caloric intake, as well as deficiencies of folate and other B vitamins, can influence inflammation, stress, and development of atherosclerosis due to epigenetic effects, while including polyphenols (such as resveratrol and curcumin) and epigallocatechin gallate (EGCG) from green tea can mitigate inflammation and development of cardiovascular disease. The Mediterranean diet, in particular, has been found to be cardioprotective due to its impact on methylation and gene expression related to inflammation. 

Personalized Nutrition and Epigenetics

Epigenetic testing can provide a simple way to start personalizing nutrition for the individual to take preventative steps to support optimal health and longevity. Through testing such as the DNA Diet panel by DNA Life and the Methylation Profile by Doctor’s Data, patients can gain insight into the best way to personalize their nutrition to support favorable epigenetic activity and be proactive about their health. Additionally, micronutrient testing such as SpectraCell’s Micronutrient Test can help bring to light any areas where foods containing specific vitamins and minerals important for epigenetic health need to be emphasized. While the concept of “eating for your epigenetics” sounds appealing, many studies on this topic are epidemiological in nature, with more research needed on the clinical applications of specific nutritional recommendations for individuals based on their genetic profiles.

Functional Foods and Epigenetic Modification

As mentioned earlier, several functional foods have been identified as having significant epigenetic impacts, including cruciferous vegetables, purple grapes, and other polyphenol-rich foods like berries, green tea, curcumin, and garlic. Incorporating these foods into one’s diet can lead to positive epigenetic changes that help mitigate chronic disease risk and progression.  

Cruciferous vegetables such as broccoli, kale, and Brussels sprouts contain several compounds, such as sulforaphane and indole-3-carbinol, that can regulate non-coding RNA and can also inhibit enzymes related to methylation and histone modification, making them potent epigenetic regulators when consumed regularly. This group of vegetables has been studied for their epigenetic impact on cancer prevention and metabolism in general.

Polyphenol-rich foods such as berries and red grapes are anti-carcinogenic, influencing epigenetic changes that favor anti-tumor activity and reduce inflammation overall. These foods contain compounds such as quercetin, resveratrol, and gallic acid, which have been found to help reverse epigenetic changes associated with activating cancer-related genes.

Even a meal containing raw, crushed garlic has been observed to influence epigenetic changes across several genes related to cancer and immune health, bringing to light the potent properties of these functional foods. 

Practical Tips for Epigenetic Health Through Diet

While we may not have all of the answers yet regarding supporting epigenetic health through diet, there are some practical tips for individuals when making the best choices for optimal health and gene expression.  

First, limiting excessive calorie intake as well as alcohol intake can help drive positive gene expression by reducing inflammation and overall stress on the body. Both alcohol use and excessive food intake have been linked to epigenetic changes that drive inflammation and metabolic disease over time.  

Additionally, including a variety of bioactive foods that have been well-studied for their positive impact on epigenetic health can also be a helpful way to support epigenetics through diet. Cruciferous vegetables such as broccoli, green tea, garlic, turmeric, and polyphenol-rich foods, including red grapes and berries, can all be part of a well-balanced, anti-inflammatory diet that also supports epigenetic expression and reduces disease risk. These foods are all part of a Mediterranean-type diet, linked in many studies to optimal health and longevity. 

Regarding lifestyle support for epigenetic health, regular exercise has been linked to positive epigenetic changes that benefit overall health. Avoiding alcohol and tobacco use, limiting exposure to environmental pollutants, and reducing stress are lifestyle changes that can promote positive epigenetic changes.  

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Epigenetics and Diet: Key Takeaways

Making simple diet and lifestyle changes can help support optimal epigenetic health and increase the potential to positively influence gene expression to reduce chronic disease risk. Following a Mediterranean-type diet that emphasizes foods linked to positive epigenetic changes, such as cruciferous vegetables, berries, grapes, garlic, turmeric, and green tea, is a simple way to support optimal health and longevity. Working with a functional medicine practitioner to evaluate DNA and epigenetic potential can help personalize nutritional and lifestyle recommendations at the individual level and provides an approach that can be studied more in the future to help better shape nutritional guidelines for longer healthspans and lower disease risk.