Epigenetics: how lifestyle affects genes
How much influence do we have on our genes? And how do our lifestyle and environmental factors shape our health, character and physical characteristics?
Perhaps you got your blue eyes from your dad and your curly hair and gait from your mum? In most cases, there are strong similarities between parents and their children thanks to the genes that are supplied by both the sperm and egg during conception.
But this genetic code – our DNA – isn’t solely responsible for our physical traits and characteristics.
As human beings, we are also shaped by the environment and our lifestyle; what we eat and drink, our social relationships, emotions and profound experiences, especially if they are traumatic.
Epigenetics simply explained
This is where epigenetics comes into play. Epigenetics is an area of research that examines how lifestyle and environmental factors can affect our genes – without actually changing them.
Genome and epigenome: what is the difference?
The genome (DNA) is the body’s instruction manual and is responsible for our inherited traits, for example whether we’re tall or short or have blue or brown eyes. DNA is largely unalterable and has limited repair capabilities when it is modified or damaged, for example, by mutations.
In contrast to the static genome, the epigenome is dynamic and influenced by environmental factors, our lifestyle and psyche.
“Imagine a computer,” says Isabelle Mansuy, professor for neuroepigenetics at the Medical Faculty of Zurich University and the Department of Health Sciences and Technology at ETH Zurich. “Genetics or our genetic code is like the hard drive, while epigenetics is the software that makes it possible to read and interpret the code.”
“To a certain extent, our lifestyle determines how our genes are activated or deactivated.”
Which factors influence epigenetics?
The epigenome is dynamic, modular and partially correctable. We all have countless epigenetic markers that are constantly changing – in both the short and long term. However, it’s hard to say which part of the epigenome changes and to what extent it does so.
For example, single-cell twins may have virtually identical DNA, but they can differ greatly physically, psychologically and in terms of their character. One twin may become overweight or develop schizophrenia during their lifetime, while the other doesn’t.
“To a certain extent, our lifestyle determines how our genes are activated or deactivated. However, aside from exposure to UV radiation, X-rays or carcinogens, we can’t change the DNA sequence of the genes themselves,” says Mansuy.
What exactly does this mean for our health?
Biologically speaking, an unhealthy lifestyle can have serious consequences, leading to – sometimes irreparable – cell damage. This, in turn, can lead to diseases such as cancer, diabetes or mental illnesses.
Collectively, a person’s genetic predisposition combined with all the individual environmental factors can influence their susceptibility to illness and overall lifespan.
Direct effects can be quickly registered, for example when we eat food. “When we eat beef burgers, the blood cells and pancreas are immediately activated, because they respond directly to food,” says Mansuy.
The epigenome that activates these cells will recover, but if you constantly only eat burgers, it may potentially have negative effects on your health. “Over time, an unhealthy diet can impact on several cell types, such as the brain cells, blood cells and germ cells,” explains Mansuy.
Is there such a thing as epigenetic inheritance?
“In the past, it was widely believed that epigenetic marks aren’t passed on, because they are erased in the early stages of embryonic development. But that’s not strictly true,” says Isabelle Mansuy.
As the genetic codes of sperm and egg cells are inherited, so too are epigenetic factors passed on to offspring. But researchers haven’t yet been able to study in humans what exactly is retained, transmitted, lost or doubled.
What our parents or even our grandparents ate, what psychological and social circumstances they were exposed to, how stressed they were, and so on, shapes their epigenome and can affect the next generation. This has been established through research on mice in laboratories.
Can trauma be inherited?
“It’s not the trauma itself that is inherited but rather the effects it has on people,” explains Mansuy. “Having long searched for a specific gene that causes depression or borderline personality disorder, research has shown that there is no such gene and that conditions like these are triggered by a combination of genetic disposition and environmental factors.”
However, it is important to consider that there are mechanisms that can enable the transmission of certain signals from previous trauma to the next generation. This may be a wartime experience or an environment or upbringing involving emotional, verbal or sexual violence.
This was demonstrated in experiments with laboratory mice, where risk behaviour was observed in fathers up to the fifth generation. With humans, it is of course much more complex and not fully researched.
In men who experienced trauma during childhood, we found epigenetic changes similar to those in mice,” says Mansuy. Depression, anxiety and phobias can be inherited from parents, but it can also be acquired in a number of different ways as a result of social or cultural factors.
Stress or traumatic experiences can have a positive or negative impact. Stressful situations can also make a person stronger and more resilient. “Positive stress, such as during an exam, is needed to mobilise energy from the brain, release glucose and enhance attention, cognitive alertness, and memory,” explains Mansuy.
“It’s not the trauma itself that is inherited but rather its effects.”
Can epigenetics be positively influenced?
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Nutrition
Nutrition is essential for a healthy lifestyle, our microbiome and for epigenetics, too. What we eat provides important nutrients for cell function and the entire organism. But what exactly and how much do we have to eat to have a positive influence on our genes?
There’s no such thing as an “epigenetic diet” with specific instructions. However, studies show that certain nutrients, vitamins and amino acids have a positive impact on epigenetic mechanisms. Above all, vitamins A1, B2, B6, B9, B12, but also choline and betaine as well as minerals such as zinc and magnesium are key drivers of DNA methylation (epigenetic modification).
Essentially, a Mediterranean diet, containing fresh (organic) fruit and vegetables, grains, pulses, nuts, fish and healthy fats (omega-3 fatty acids), is considered a good foundation for a healthy lifestyle. It helps prevent cardiovascular diseases, reduces the risk of cancer and diabetes, and generally increases life expectancy.
Additionally, a moderate, calorie-reduced diet is recommended, as it can positively influence the activation of certain genes.
Important vitamins and minerals
- Folic acid (vitamin B9): Important before and during pregnancy for the healthy development of the foetus and should therefore be taken in sufficient quantities as food or as a supplement. Foods containing folic acid include various leafy vegetables such as spinach, pulses, soy beans, white beans, wholemeal bread, wheat germ, brussel sprouts, broccoli, cauliflower, but also fruit such as strawberries, tomatoes and apples.
- Vitamin B12: Mainly found in animal products: eggs, meat, fish, dairy products. In the case of a vegan diet, vitamin B12 should be taken as a supplement. B12 is important in blood formation and for the development and functioning of the central and peripheral nervous system.
- Methionine: one of the nine essential amino acids that humans cannot produce themselves. It is found in all protein-containing (plant and animal) foods. Good sources include: Brazil nuts, lean red meat, hard-boiled eggs, fatty fish such as salmon or sardines.
- Antioxidants: protect the body from free radicals and can prevent cell damage. Raspberries and blackberries are good sources.
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Exercise
There is a clear link between health and exercise. Regular physical activity has a positive effect on gene expression. It can positively influence muscle cells (building and regeneration), fat cells and metabolism, and activate dopamine release in the brain. Even if only for a short time.
Even short bouts of activity trigger the body to produce important proteins that still have an effect hours or days later. A magic formula applies to both nutrition and exercise: regularity, habit and consistency make the difference.
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Stress reduction
Various studies show that stress can have a negative impact on our well-being and, in the longer term, our health. It can promote or exacerbate heart disease, behavioural problems or even mental illness.
It has been shown that calming activities, such as meditation or listening to (classical) music, have a positive effect on switching genes on or off and promote anti-inflammatory mechanisms. Changes are felt immediately, if only temporarily. However, the positive effects can last longer with regular training.
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Toxins
Alcohol, smoking and pesticides should be avoided as much as possible. Toxins can have a negative effect on cell activity and lead to irreparable cell changes.
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Social relationships
Social relationships should not be neglected. Positive meet-ups can promote the release of hormones such as oxytocin and vasopressin, so-called “prosocial” molecules that reduce stress and anxiety.
Especially in the first years of life, good bonds are important in order to develop (psychologically) healthily.
How can epigenetics help with treatments?
Most complex diseases, such as mental disorders, autoimmune or metabolic diseases, or certain forms of cancer, are thought to have various causes, resulting from a combination of genetic predisposition and exposure to environmental factors.
Epigenetics isn’t a method of treatment and doesn’t plan on revolutionising psychiatry, but it can provide a new perspective on a disease and open up new therapeutic measures.
“For example: A young woman feels guilty about her depression and blames herself for her condition. In this case, knowing that she inherited epigenetic changes from her parents can help her feel less guilty,” says Mansuy.
Can medicines positively stimulate the epigenome?
“The epigenome is very complex and hard to grasp because it is constantly changing,” says Isabelle Mansuy. It is not yet known exactly to what extent and at what speed the change will occur. It is also difficult to make individual prognoses for the treatment of diseases.
However, there are drugs that are being used in cancer therapy. With tumours, for example, where the majority of the cells have an epigenetic change.
For example: In the case of hypermethylation of certain genes – an excessive addition of methyl groups to the DNA – a drug can be used to eliminate or prevent these changes.
What costs does health insurance cover for prevention?
In Switzerland, basic insurance covers a whole range of measures for the early detection of diseases. For example:
- If there is an increased familial risk: preventive examinations such as colonoscopy or mammography
- Regular developmental checks for children
- Various vaccinations
Depending on the model chosen, supplementary insurance covers additional costs in terms of prevention. For example, for exercise, nutrition advice or mental health. Find out here which costs are covered by Sanitas.
