Nutrition and Epigenetics: How Diet Affects Gene Expression
Have you ever considered your DNA as a piece of hardware and your lifestyle choices as the software that runs it? Stanford lecturer and epigenetics expert Lucia Aronica, PhD, says this is precisely how we should think about the relationship between our genes and our daily choices.
“Epigenetics is the software to our DNA hardware,” says Dr. Aronica. “The prefix epi means ‘on top,’ and epigenetics is the study of molecules that sit on top of our genes, turning them up or down, much like a dimmer switch that modulates the brightness of a light in a room.”
How Does Nutrition Affect Epigenetics?
Dr. Aronica explains that while our genes remain unchanged throughout life, our daily habits impact how our genes are expressed. What we eat, how we move, and how we manage stress send signals that either create or remove epigenetic molecules, hence rewriting our epigenetic “software” on a daily basis. So, even though we don’t have control over what genes we inherit, we do have some control over which genes—the “good” or the “bad”—get expressed.
“Among all the lifestyle factors, nutrition is one of the most powerful tools for influencing gene expression,” says Dr. Aronica. “Proper nutrition can even slow our biological age by expressing genes that reduce inflammation.”
Chronological Age vs Biological Age
Our chronological age is the number of years we’ve lived, however, our biological age refers to the age of our cells and tissues. For example, a 65-year-old person actively engaged in all seven of the lifestyle medicine pillars may have a biological age of 55 or younger.
Dr. Aronica says our diet impacts the rate of cellular aging. She was on the research team for a Stanford study that looked at the biological age of twin siblings after one of the twins ate a vegan diet and the second twin ate a diet containing animal products. After eight weeks, the results showed that the vegan participants saw a reduction in biological age across multiple age-calculating algorithms.
Rather than pointing to animal products as the reason for a lack of reduction in biological age, researchers hypothesized that reductions were caused by a lower caloric intake and greater fiber intake compared to the omnivores. (This study was featured on Netflix as the docuseries, “You Are What You Eat: A Twin Experiment.”)
“The twin study showed that nutrition plays a significant role in our biological age. Although the results found that a vegan diet reduced biological age, we have also found that some animal products, like fish and eggs, also promote the expression of genes related to healthy aging,” says Dr. Aronica. “Epi-nutrition illustrates a beautiful synergy between animal and plant foods, each offering unique benefits to support our genes.”
Which Foods Should We Eat to Express Genes for Healthy Aging?
Dr. Aronica explains that epi-nutrients are nutrients that have the ability to switch on the “good” genes in our DNA. Here are the two categories of epi-nutrients and the foods in which they are found:
- Methyl Donors: These nutrients, found in foods such as green leafy vegetables (rich in folate), eggs and liver (choline), and fish (B12), provide the building blocks for methylation, which is a key epigenetic modification that helps regulate gene expression.
- Epi-Bioactives: These compounds regulate the activity of enzymes that write or erase epigenetic marks. Examples include polyphenols found in colorful fruits and vegetables, spices, coffee, green tea, olive oil, and butyrate from fermented foods. These nutrients promote healthy aging by reducing inflammation. Cruciferous vegetables like broccoli, brussels sprouts, and kale contain sulforaphane, a powerful epi-bioactive that activates antioxidant pathways and suppresses inflammation.
Dr. Aronica also points out that our genes can influence how we absorb and utilize nutrients. This concept, known as nutrigenetics, influences dietary requirements for optimal health and disease prevention.
“Epigenetics meets people where they are and helps explain, at a molecular level, why food matters,” says Dr. Aronica. “It doesn’t matter if you’re vegan, omnivore, or somewhere in between; we can all benefit from understanding how to eat in a way that rewires our biology for health and longevity.”
