This post was first published by Dr Reeta Karamchandani on the British Society of Lifestyle Medicine website, 27 May 2021.
Epigenetics – "the code of life"
Epigenetics is the study of how our behaviours and environment can trigger changes that affect the way our genes work. Unlike genetic changes, epigenetic changes are reversible and do not change our DNA sequence, they can change how our body reads a DNA sequence.
One example of epigenetics changes is the addition of a methyl group, or a “chemical cap,” to part of the DNA molecule, which prevents certain genes from being expressed. At least a half of all tumour suppressor genes are inactivated through epigenetic mechanisms in tumorigenesis.
Germs can change our epigenetics to weaken our immune system. This helps the germ survive.
Some of the strongest evidence shows progressive increase in DNA methylation in aging tissues, atherosclerotic blood vessels and other internal organs.
60 years after the Dutch Hunger Winter Famine (1944-1945), researchers looked at methylation levels in people whose mothers were pregnant with them during the famine. Differences in methylation could explain why these people had an increased likelihood for heart disease, schizophrenia, and type 2 diabetes later in life.
Lowered cortisol and dysfunctional response to stressors in children born to mothers who experienced PTSD post the twin tower incident is well documented.
Epigenetics can be used to detect the type of cancer a person has or can help to find hard to detect cancers earlier.eg breast cancer.
Lifestyle factors can trigger these epigenetic changes
Some epigenetic changes are not permanent, they can be added or removed in response to changes in behaviour or environment, e.g. by smoking.
Studies are being undertaken to unravel the interactions of Lifestyle factors, the environment, cancer, and ways to therapeutically reverse methylation linked with cancer which could lead to personalised medicine such as epigenetic diet.
The foods we consume can turn on or off certain genetic markers which play a key role in our health outcomes. Garlic helps to prevent cancer as it can enhance genetic repair, slow down cell proliferation, and prevent the formation of carcinogenic substances in the body.
When an individual consumes health foods like ginger, these epigenetic tags attached to histone proteins around which the DNA is wrapped can be adjusted, influencing the expression of genes linked to inflammatory and neuroprotective pathways.
Superfood Blueberries are high in their nutrient content – including fibre, vitamin C and K, and manganese. Berries epigenetically reduce the DNA damage, thereby protecting humans against aging and cancer.
While most natural dietary products have shown beneficial effects on the epigenome, some dietary components (i.e. alcohol) are associated with harmful epigenetic modifications. Put simply, what we eat will not change the sequence of our DNA, but our diet has a significant effect on how we ‘express’ our DNA.
Another important lifestyle intervention, namely exercise, has the ability to induce epigenetic changes related to inflammation pathways, type 2 diabetes, weight gain, cardiovascular disease and lipid management. Intense and prolonged exercise can induce inflammation, whereas low to moderate endurance exercise can improve the inflammatory profiles.
More research is required to identify epigenetic biomarkers which would help prescribe a personalised exercise plan in terms of the type, duration, intensity of exercise which would be beneficial for an individual who could be a highly trained athlete or a moderately active healthy person or someone with chronic diseases.
The impact of stress, sleep, positive psychology, emotional connectedness on epigenetic mechanisms would be an exciting field.
The Future: Personalised medicine OR Epigenetic discrimination.
A better understanding of which elements within our environment and how they affect epigenetic modifications is long overdue.
Personalized medicine is the future as science identifies the varying effects of different substances on an individual’s health. Not only is there a need for further research on how our environment and lifestyle choices like diet - impacts epigenetic markers on human DNA, but how the outcomes will differ depending on a person’s body.
Although the exact mechanism of transgenerational epigenetic inheritance has yet to be understood, epigenetic research offers fascinating insight into the possibilities and can help guide us to make better decisions for ourselves and our future children.