Diet and Gene Expression: You are What you Eat by Lucia Aronica, PhD
Updated: Nov 14, 2019
We tend to think that good genes make us thin and healthy, whereas bad genes make us fat and sick. But what if we could turn our “good” genes on and our “bad” genes off by making the right lifestyle choices? And what if this could affect not only us but also future generations? The science of epigenetics suggests this might be possible. “Epi,” from Greek means over, above, on the top. Epigenetics means “on top of DNA.” Through the science of epigenetics, we are learning that genetic expression can be altered via mechanisms that lie on top of the DNA rather than altering the actual DNA sequence. It is important to understand that DNA (our genes) codes for proteins, which are the building blocks and workhorses of every single cell in our body.
Epigenetic markers can turn genes on or off and, hence, activate or inhibit the production of proteins. Defects in epigenetic mechanisms can lead to the production of proteins that are not needed at a given time or place, or suppress the production of proteins that are presently needed in the cell. This aberrant protein production can ultimately translate to disease.
What exactly does it mean to turn a gene on or off? It is perhaps best explained through cell differentiation. Every cell in our body has the same DNA. So, how is it possible for some cells to differentiate into hair cells and some into skin cells and some into muscle cells? All humans have one single hardware (DNA) but a different software (epigenome) in different types of cells. It is this software, or epigenome, that switches the genes on or off, like a dimmer switch connected to a light fixture that makes lights go on or off. This turning on or off of genes explains how cells with the same DNA differentiate into a variety of cell types.
Diet and Gene Expression How can your diet change your gene expression? Perhaps the most fascinating property of these epigenetic switches is that they are dynamically influenced by lifestyle factors such as diet, exercise and stress.
Below is a list of nutrients and foods that can change or modulate our epigenome. When we eat these specific nutrients, we support optimal function of our epigenome. They can positively impact our gene expression, per evidence from the scientific literature. These nutrients can be classified into two groups: methyl-donating nutrients and epigenetic modifiers.
Methyl-donating Nutrients Methyl-donating nutrients are essential for the production of methyl groups. The most common type of methyl-donating nutrient consists of one carbon atom bonded to three hydrogen atoms (CH3), and it provides the building block for your gene switches. When methyl groups are added on top of DNA, gene expression is generally turned off. Methyl-donating nutrients include:
Folate (green leafy vegetables)
Vitamin B12 (meat, liver, shellfish, milk)
Vitamin B6 (meat, nuts, vegetables)
Choline (egg yolks, meat, soy)
Betaine (wheat, spinach, shellfish)
Methionine (Brazil nuts, fish, sesame seeds)
Epigenetic modifiers Epigenetic modifiers regulate the activity of enzymes that place methyl groups and other epigenetic marks on your genes. They include the following:
Tea polyphenols (green and black tea)
Sulforaphane (broccoli and other cruciferous vegetables)
Resveratrol (red wine)
Diallyl disulfide (garlic)
Genistein (soy products)
Avoid the following foods and lifestyle habits that can turn “bad” genes on and cause disease. They can potentially all have long-term negative effects on your gene expression, as demonstrated by many studies conducted in both animals and humans.
Inflammatory vegetable oils (soybean, cottonseed, sunflower)
Partially hydrogenated vegetable oils (“trans-fat”)
The good news is that it looks as if the negative effects of poor food and lifestyle choices may be reversible. We can potentially reprogram our epigenome after a lifestyle change such as a weight-loss diet.
The Bottom Line The science of epigenetics suggests that genes are not the only variable in the health equation and that we can control our destiny more than we thought by adopting lifestyle habits that promote a flourishing epigenome. Eat a variety of plant and animal foods that can positively influence the expression of your genes: green leafy vegetables, nuts, seeds, fish, meat, eggs and milk. These foods contain bioactive compounds that are essential to turn your good genes on and your bad genes off. Try to consume only whole foods and avoid processed foods, which often contain sugar and vegetable oils that can negatively impact your gene expression. Avoid smoking and sedentary habits.
Aronica, Lucia. "Epigenetics: The Ghost Behind Your Genes." 10 May 2015. www.youtube.com/watch?v=eKBS2fu1uoc&list=PLU7a7O4lr4QCnIMMyBxVT0aFsh812AzGQ
Aronica, Lucia. "Epigenome and Environment." 10 May 2015. www.youtube.com/watch?v=kavQxrWNmMM&list=PLU7a7O4lr4QCnIMMyBxVT0aFsh812AzGQ&index=2
Dolinoy D.C., Huang D., Jirtle R.L. (2007). Maternal Nutrient Supplementation Counteracts Bisphenol A-induced DNA Hypomethylation in Early Development. PNAS, 104: 13056-13061. www.pnas.org/content/104/32/13056.long
Dolinoy D.C., Weidman J.R., Waterland R.A., Jirtle R.L. (2006). Maternal Genistein Alters Coat Color and Protects Avy Mouse Offspring from Obesity by Modifying the Fetal Epigenome. Environmental Health Perspectives, 114:567-572. ehp.niehs.nih.gov/wp-content/uploads/119/6/ehp.1103844.pdf
Kucharski R., Maleszka J., Foret S., Maleszka R. Nutritional Control of Reproductive Status in Honeybees via DNA Methylation (2008). Science, 319: 1827-1830 www.ncbi.nlm.nih.gov/pubmed/18339900
Mutzel, Mark. High Intensity Health. #169: How Low-Carb, Ketogenic Diets Change Genetic Expression, Epigenetics, Interview of Lucia Aronica, PhD. 23 Dec. 2016. highintensityhealth.com/169-lucia-aronica-phd-low-carb-ketogenic-diets-change-genetic-expression-epigenetics/
Park LK, Friso S, Choi SW. Nutritional influences on epigenetics and age-related disease. The Proceedings of the Nutrition Society 71(1), 75-83 (2012). www.ncbi.nlm.nih.gov/pubmed/22051144
Tobi EW, Goeman JJ, Monajemi R et al. DNA methylation signatures link prenatal famine exposure to growth and metabolism. Nature communications 5 5592 (2014). www.ncbi.nlm.nih.gov/pmc/articles/PMC4246417/
Lucia Aronica, PhD
Dr. Lucia Aronica received her PhD in epigenetics from the University of Vienna, Austria, and conducted postdoctoral research work at the University of Oxford, UK. As an epigenetic scientist, she researches the connections between diet, epigenetic changes and human health. At Stanford University, Dr. Aronica is studying how a type of epigenetic marker, called DNA methylation, changes in obese people during weight loss. In addition, she is evaluating whether these changes can predict the reversal of the metabolic consequences of obesity (increased blood pressure, a high blood sugar level, excess body fat around the waist and abnormal cholesterol levels) during weight loss. This would enable one to know if a diet is actually successful and to monitor whether the metabolic status continues to improve even when the weight-loss reaches a plateau.
Dr. Aronica’s work can be found in the journals Cell, Genes and Development, Nucleic Acid Research and the EMBO Journal. She is also an award-winning science communicator and educator who uses creative forms of communication such as digital drawings to explain complex topics from the world of epigenetics and science.
Dr. Aronica additionally works as a video producer for the podcast Goggles Optional, a weekly audio program featuring scientists from Stanford University who provide their professional yet humorous takes from the world of science.
To subscribe to the SOULFUL Insights health and wellness newsletter click here.