By Ashley Aguillard, PhD Student in Nutrition
What if I told you that the food you eat can alter your genetics? Well, sort of.
Genetics is complicated and in its simplest, most straight-forward form, our genes are a code that when translated, creates a living and fully functioning organism. We all know, though, that mistakes can be made. If the code is mistyped without being corrected, mutations can develop. These mutations are usually harmless, but in rare cases, they can increase susceptibility to disease or directly cause disease. This aspect of genetics is probably one of the most well-known publicly and the longest-studied in relation to nearly every disease.
Contrary to popular belief, our genetic code alone does not determine our fate. In recent years, a new form of genetics has emerged, suggesting that environmental and lifestyle factors can impact how our genes are expressed. These alterations, known as epigenetic changes, can even be impacted by the food we eat.
A Crash Course in Epigenetics
Epigenetics is the study of changes that alter genetic regulation rather than the genetic code itself. Genes can be controlled like a switch to a light – they can be turned on or off. Epigenetics is another layer of information that will tell you how a gene should be expressed, without changing the actual genetic code. They are instructions on how the genetic code should be interpreted. Here is an analogy:
Let’s say you’re studying for a nutrition exam. Every sentence you read represents a gene. Here is the section you’re studying:
“Oranges are sweet and nutritious. They are a good source of vitamin C.”
For your exam, you want to make sure you focus on the most valuable information, so you bold the parts that are most important to you:
“Oranges are sweet and nutritious. They are a good source of vitamin C.”
In this analogy, every sentence represents a gene and the un-bold vs bold will represent an epigenetic modification. Notice that the words are still spelled correctly and appear in the same order, therefore, the genetic code itself has not changed. But, there is more attention being drawn to the letters marked in bold representing the epigenetic change. This causes your attention to be focused here and this is what happens in our bodies. Epigenetic changes are markers that bring attention to a certain gene. It can tell your body, for example, “Hey! This gene has been marked. This particular marker means we need to keep this gene turned on until further notice.”
Nutrition & Epigenetics: What the Research Says
Epigenetic markers appear on our genes in response to different exposures, including nutrients in our diet such as folate or B12. Some nutrients are especially important during fetal development and without them, the proper epigenetic markers won’t appear.
When these changes occur during development, they can often last a lifetime and in some cases, they are even heritable. One well-known example that shows the importance of nutrition during development would be the Dutch Famine Birth Cohort Study. This study was performed to evaluate the effects of starvation on pregnancy in a group of mothers who survived the Dutch Famine. The results concluded that starvation during pregnancy led to some expected deficits such as low birth weight and decreased cognitive function. But it also led to an increased risk of type II diabetes and cardiovascular disease. Subsequent genetic studies revealed changes in epigenetic markers in the children that are contributing to some of these changes in disease risk.
Our diet as adults also impacts our epigenetics. Many nutrients can lead to positive epigenetic changes that are protective against certain types of diseases including cardiovascular disease, type II diabetes, and even some forms of cancer.
“Western” diets rich in sugar and processed foods have been shown to contribute to drastic epigenetic changes that contribute to a number of nutrition-related diseases. Fortunately, some of these modifications are reversible! If a typical “Western” diet is altered to a more nutritious and beneficial diet, this can lead to beneficial epigenetic changes. In a way, we are feeding our genes by providing them with the right nutrients to help regulate them to keep us healthy.
We still have a ways to go with understanding what specific nutrients lead to which specific epigenetic changes, epigenetics is another layer of genetics that can vary greatly from individual to individual. It can help us further understand how our bodies respond to nutrients. This makes it a great potential target for personalized nutrition intervention.
And maybe one day, with a detailed understanding of genetics and epigenetics, we can individualize diets for every person.
Peer-edited by Bhavya Singh, MSc Candidate in Chemical Biology
Picture credit:
- Banner Image: Darryl Leja/NHGRI/Science Source, The Scientist Blog
- Image 1: Science in the News, Harvard University
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