…Epigenetics, methylation and more
Have you ever thought to ask your grandmother what she ate for breakfast? We’re all aware that ‘you are what you eat’ but did you know that your health is determined not just by what you eat but what your parents and grandparents ate too?
This fascinating line of thinking comes from a relatively new area of genetic research called epigenetics which is starting to show us that our health is influenced not just by our own diet but by the diets of our ancestors too.
What is epigenetics? (The sciencey bit)
Our DNA contains all the instructions for building every single part of the body but DNA itself is only half the story. DNA is tightly wrapped around histones, and together these are covered in chemical tags. These chemical tags form a second layer of structure called the epigenome. The epigenome tightly wraps inactive genes making them unreadable and relaxes active genes making them easily accessible. Our DNA code is fixed for life, but the epigenome is flexible. Epigenetic tags react to signals from the outside world such as diet and stress. Your rapidly changing environment can trigger cellular signals that cause tags to be added or removed, this is one way an organism adapts to the changing world.
Epigenetics can span generations
During early embryonic development, most of the epigenetic tags from your parents are removed, however some are permanent and inherited by subsequent generations. These are imprinted on the genes of your offspring and this is how epigenetic tags and their consequences can span generations.
How does this affect my health?
Epigenetic alterations can affect disease risk. For example epigenetic tags can silence ‘tumour suppressor gene’ or activate ‘cell survival gene’, or even do both which may promote cancer development. Epigenetic alterations can influence the development of chronic health problems such as obesity, inflammatory disorders, cancer, type II diabetes and neurodegenerative disorders.
What can I do about it?
There are many dietary, lifestyle and environmental factors which can affect our epigenetics. One area that has been well researched is the influence of dietary methyl groups and this is where you can make a big difference to your health and that of future generations too.
The importance of methylation
Methyl groups are important epigenetic tags that silence genes. Essential nutrients such as folic acid, B vitamins and choline are crucial for this methyl-making pathway. Diets high in these methyl-donating nutrients can therefore rapidly alter our epigenetic profile. Increasing your intake of foods that contain methyl groups is a simple and effective way to improve your epigenetic profile.
Animal studies have shown that folate or choline deficiency (important methyl donors) during gestation and right after birth can lead to permanent under-methylation of certain areas of the genome. The same effect occurs in adults, but the good news is that the change is reversible by a diet full of methyl-donating foods.
Environmental chemicals such as bisphenol-A, which is found in high amounts in plastic food packaging and containers, can negatively affect your epigenetic gene expression too. Interestingly though, studies have shown that eating a diet with plenty of methyl-rich foods can also help to protect you from the DNA-altering effects of these chemicals.
Choose methylated nutrient forms
To ensure you are regularly getting an optimal supply of methyl-donating nutrients in your diet it is recommended that you invest in a high quality daily multivitamin & mineral formula that supplies these key nutrients in their methylated forms. Folic acid is best supplied as 5-methyltetrahydrofolate (5-MTHF) and vitamin B12 is best supplied as methylcobalamin for this very reason. In addition, make sure you eat plenty of organic leafy green vegetables, eggs, nuts & seeds, wholegrains, fish, soy and even some liver too to maximize your intake.
Feed the future…
There’s not much you can do to change your grandma’s diet but you can make some simple changes to your own diet to improve your own epigenetic profile now and that of future generations too…
Here’s a more detailed picture of the nutrients that affect our epigenome on a daily basis and where they come from in our diet.
|Nutrient||Food Origin||Epigenetic role|
|Methionine||Sesame seeds, Brazil nuts, fish, peppers, spinach||SAM synthesis|
|Folic Acid||Leafy green vegetables, sunflower seeds, baker’s yeast, liver||Methionine synthesis|
|Vitamin B12||Meat, liver, shellfish, milk||Methionine synthesis|
|Vitamin B6||Meats, whole grains, nuts, vegetables||Methionine synthesis|
|SAM-e||Unstable in food||Enzymes transfer methyl groups from SAM directly to the DNA|
|Choline||Egg yolks, liver, soy, cooked beef, chicken, veal and turkey||Methyl donor to SAM|
|Betaine||Wheat, spinach, shellfish, and sugar beets||Break down the toxic byproducts of SAM synthesis|
|Resveratrol||Red wine||Removes acetyl groups from histones, improving health (shown in lab mice)|
|Genistein||Soy, soy products||Increased methylation, cancer prevention, unknown mechanism|
|Sulforaphane||Broccoli||Increased histone acetylation turning on anti-cancer genes|
|Butyrate||Compound produced in the intestine from fermentation of dietary fibre||Increased histone acetylation turning on ‘protective’ genes, increased lifespan|
|Diallyl sulphide (DADS)||Garlic||Increased histone acetylation turning on anti-cancer genes|
(Table source: http://learn.genetics.utah.edu/content/epigenetics/nutrition/)