What is DNA methylation?

DNA methylation is an example of one of the many mechanisms of epigenetics. Epigenetics refers to inheritable changes in your DNA that 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. For example, the methylation process might stop a tumor-causing gene from “turning on,” preventing cancer.

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, such as breast cancer or heart disease, through simple lifestyle changes.

Read on to learn more about DNA methylation, including how to support you 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 involving humans have promising results.

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, possible resulting in a variety of diseases.

DNA methylation and diet

The process DNA methylation partly relies on several nutrients.

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.

Some other nutrients that may influence DNA methylation include:

Experts use several methods to analyze DNA methylation, depending on the type of information they’re looking for. However, a 2016 review of all the potential methods suggests that next-generation sequencing will likely become the standard method in the future. This method is generally more affordable and requires less complex equipment.

Some clinics do offer DNA methylation profile testing. The results of these tests are difficult to interpret, especially in a way that would be meaningful to you. In addition, several online retailers offer kits you can use to collect a sample of your own DNA to send off for analysis. However, they still won’t be able to tell you much about your own methylation cycle.

In the future, analyzing your own DNA methylation profile might be a routine method for preventing certain diseases. But experts still need to figure out how to effectively interpret the results of these tests in a way that’s useful to the general public.

While the relationship between diet and DNA methylation needs more exploration, nutrition does seem to play a role. Most of the existing research suggests that DNA methylation relies at least in part on folate, vitamin B-12, vitamin B-6, and choline, in addition to other vitamins and minerals.

Increasing your intake of these nutrients may help to support DNA methylation, preventing certain genes from being expressed. While all of these are available as dietary supplements, it’s best to get as much of them from food as possible.

In some, the gene that codes for methylation of folate, known as the MTHFR gene, may be compromised or have a mutation that prevents the vitamin from being properly used by the body. This is referred to as a “polymorphism” and can result in a variety of symptoms and diseases. An example is elevated levels of homocysteine (a type of amino acid), which can cause damage to arteries. Those who have this polymorphism may find it beneficial to take a supplement of L-methyfolate, the pre-methylated form of folate.


The National Institutes of Health (NIH) recommends that adults consume 400 micrograms (mcg) of folate per day. Women who are pregnant or nursing should consume closer to 600 mcg.

Good sources of folate include:

  • dark, leafy vegetables, such as spinach or mustard greens
  • asparagus
  • Brussels sprouts
  • nuts and beans, such as peanuts and kidney beans
  • whole grains
  • citrus fruit, such as oranges or grapefruit

Vitamin B-12

The recommended daily intake of vitamin B-12 for adults is 2.4 mcg. Food sources containing vitamin B-12 tend to be animal products, so if you follow a vegetarian or vegan diet, make sure to pay attention to your vitamin B-12 intake.

Food sources of vitamin B-12 include:

  • meat, particularly beef liver
  • fish or shellfish, particularly clams
  • chicken
  • eggs
  • dairy products, such as milk
  • fortified cereals
  • nutritional yeast

Vitamin B-6

The NIH recommends that adults between the ages of 19 and 50 consume 1.3 milligrams (mg) of vitamin B-6 per day, while older adults should get slightly more.

Food sources of vitamin B-6 include:

  • fish
  • poultry, such as chicken, turkey, or duck
  • organ meats, such as liver, kidney, or tongue
  • starchy vegetables, such as potatoes
  • non-citrus fruits, such as bananas


The recommended daily dose of choline differs between adult men and women. Women should aim for 425 mg, while men should get 550 mg.

Foods that contain choline include:

  • meat, especially beef and beef liver
  • fish, such as salmon, scallops, and cod
  • dairy products, including milk and cottage cheese
  • wheat germ
  • eggs
  • cruciferous vegetables, such as broccoli and cauliflower

DNA methylation is a complex process that could hold major clues to health and aging, but many more large-scale human studies are needed to fully understand its effects.

To improve DNA methylation, you can start by adding a few key nutrients, such as folate, B vitamins, and choline, to your diet. Across several studies, these vitamins and nutrients appear to play a role in DNA methylation. As well, they’ll also improve your overall health.