DNA Methylation: Can Your Diet Reduce Your Risk of Disease?
DNA methylation is an example of one of the many mechanisms of epigenetics. Epigenetics refers to changes in how your body “reads” your DNA. They don’t change the actual DNA sequence. That means these changes are potentially reversible.
Your DNA consists of four bases, called cytosine, guanine, adenine, and thymine. A chemical unit called a methyl group, which contains one carbon and three hydrogen atoms, can be added to cytosine.
When this happens, that area of the DNA is methylated. When you lose that methyl group, the area becomes demethylated.
DNA methylation often inhibits the expression of certain genes. This can change how your body functions, potentially affecting your health in many different ways.
The processes involved are complex. For example, the risk of developing breast cancer and certain other other cancers is associated with certain genes, including one called BRCA1. Increased methylation of the BRCA1 gene can increase cancer risk, because BRCA1 is protective against certain cancers.
Changes in DNA methylation have also been associated with negative health outcomes such as heart disease and reduced immune function.
Lifestyle changes can have an impact on methylation patterns. For example, smoking can decrease methylation on a gene called AHRR . But quitting smoking has been shown to increase methylation of AHRR, which means that former smokers can return to the same AHRR gene expression as non-smokers over time.
Experts are currently working to better understand the factors that affect DNA methylation. Based on their early findings, there’s some evidence that diet plays a role.
This opens up the potential to reduce genetic risk of developing certain conditions through simple lifestyle changes. However, it’s important to note that many of the details are still being investigated.
Read on to learn more about DNA methylation, including how to support your own methylation cycle through your diet.
Research looking at the extent to which DNA methylation affects gene expression is ongoing. Most of these studies have involved animal models or cell samples. However, a few initial studies are helping to reveal what influences methylation patterns in humans.
DNA methylation status throughout life
The patterns of DNA methylation change throughout your life. The process occurs the most during the stages of early development and later life.
A 2015 review found that DNA methylation patterns are constantly changing during fetal development. This allows all of the body’s organs and tissue to form properly.
A 2012 study further broke down the relationship between DNA methylation and age. People over the age of 100 had less methylated DNA than newborns.
People around the age of 26 had methylated DNA levels between those of newborns and centenarians, suggesting that DNA methylation slows down as you age. As a result, genes that were once repressed by methylated DNA start to become active, possibly resulting in a variety of diseases.
DNA methylation and diet
The process of DNA methylation partly relies on several nutrients. Evidence suggests that two nutrients may be particularly important: folate and vitamin B12.
For example, a 2014 study looked at DNA methylation of tumor cells in women with breast cancer. The study’s investigators found that participants who consumed more alcohol were more likely to have decreased DNA methylation.
In contrast, those who consumed a lot of folate were more likely to have increased methylation. These results support the idea that consuming certain nutrients affects DNA methylation.
In a 2020 meta-analysis , supplementation with folate, or folate and B12 together, significantly increased DNA methylation.
Plus, a 2018 review of studies found an association between increased folic acid intake and changes in DNA methylation patterns.