Epigenetics and Health: How Lifestyle Influences Your Genes

GENES ARE NOT A DESTINY, AND SCIENCE EXPLAINS WHY

What if I told you that your genes don't tell your whole story?

For many years we believed that genetics was a kind of sentence. We inherited certain genes and there was little to do. But the science of recent decades has revealed something extraordinary: genes are important, but they don't work alone.

The way we eat, sleep, deal with stress, move and even the environment in which we live can influence the way our genes express themselves. We call this process epigenetics.

In simple words, genetics provides the script. Epigenetics helps you decide which pages will be read. And this is one of the most powerful messages in modern biology: we don't choose the genes we are born with, but we can influence the environment in which these genes live.

What is epigenetics, after all?

And no, you don't need to know biology to understand what follows. I'll explain with a simple image:

Imagine that your DNA is a very large library. All the books are there, but not all are opened at the same time.

Epigenetics works as a set of markers that indicate which books and chapters should be read, ignored or highlighted.

From a biological point of view, these markings work through mechanisms such as DNA methylation (the addition of small chemical groups that tend to silence genes) and the modification of histones (the proteins around which DNA wraps, and which make certain regions more or less accessible). These markers do not change genes, but influence the way they work.

That's why cells with exactly the same DNA can perform completely different functions. And that's also why lifestyle can have such a profound impact on our health.

The mice that changed color

There is a classic experiment that illustrates this in an almost magical way.

In the early 2000s, researchers Robert Waterland and Randy Jirtle worked with mice that have a particular gene, called agouti. When this gene is very active, mice are born with yellow fur, a tendency for obesity and a higher risk of disease. When silenced, they are born brown, thin and healthy.

The extraordinary detail is this: the mice were genetically identical. The difference was in the mothers' diet during pregnancy. When the maternal diet was enriched with nutrients that provide "methyl groups", such as folic acid, vitamin B12, choline and betaine, the agouti gene of the offspring was silenced, and they were born brown and healthy.

The DNA was the same.

But the result was different.

It was one of the most notable demonstrations that the environment can influence the way genes express themselves.

From the laboratory to Gambia

Does something similar happen to people?

This was the question that led Robert Waterland, one of the scientists of the agouti mice, to study rural communities in Gambia, in West Africa. What he and his team found is, for me, one of the most beautiful stories in epigenetics.

In rural Gambia, women's diet varies significantly between the dry season and the rainy season. These differences influence the amount of nutrients available during conception and beginning of pregnancy.

The researchers accompanied pregnant women and then analyzed their babies. The conclusion was remarkable.

Scientists observed that the season in which the child had been conceived left a measurable mark on babies' DNA methylation patterns. As with mice, maternal nutrition early in life was helping to define which genes were "on" or "off".

This study shows, with solid data, that women's diet before and during pregnancy has a real impact on the health of the next generation. Furthermore, it reminds us of something that many African cultures have always valued: taking care of the mother is also taking care of future generations.

Can we influence our epigenetics?

This is the million dollar question, and the answer is: yes, at least in part.

Although we cannot change the genes we have inherited, we can influence many of the signals that regulate their activity. Our epigenetic markings are not fixed. Research suggests that they respond to what we eat, how much we move, sleep quality, stress and the environment around us.

Does this mean that we have absolute control over our health?

Almost.

Genetics, age, environment and many other factors continue to play an important role.

But it means that everyday choices are not insignificant.

The body is constantly responding to the signals we give it.

What does this mean for you?

The great message behind epigenetics is not that we control everything, because we don't. Genetics, chance and factors out of our control continue to weigh.

The actual message is more subtle and more powerful:

Day-to-day choices are not lost. Eating well, moving the body, getting enough sleep, managing stress, cultivating good relationships and spending time in nature are not vague gestures of "well-being". They are concrete ways to talk to your biology.

Here are two ideas worth saving:

• The first is that these changes are gradual and cumulative: epigenetics responds to consistency, not to miraculous solutions.

• The second is that it is rarely too late, because the body continues to "listen" to our habits at any stage of life.

Your genes write the draft and your lifestyle helps to make the editing. This is, perhaps, the most beautiful way to think about the care you have with yourself every day.

What can you do this week?

None of this requires a revolution. Epigenetics responds to small repeated gestures with consistency. Here are five, simple to start now:

•     Add more colour to your plate: Green leaves, legumes, eggs and seeds provide such "methyl groups" that help regulate genes. Aim to include these foods to at least one meal a day.

•     Move your body everyday: A 20-30 minute walk does make a difference in your health.

•     Protect your sleep: Choose a time to go to bed and try to stick to it this week. Sleep is one of the great regulators of the body.

•     Create a calm moment: Five minutes of breathing, silence or prayer. Managing stress also leaves a mark.

•     Honour your roots: Reconnect with a family tradition or recipe that brings you comfort and meaning.

Epigenetics reminds us that health is not built in a single day. It is built on the small choices that we repeat throughout life.

Referências

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Dominguez-Salas P, Moore SE, Baker MS, et al. Maternal nutrition at conception modulates DNA methylation of human metastable epialleles. Nature Communications. 2014;5:3746. doi:10.1038/ncomms4746

Fitzgerald KN, Hodges R, Hanes D, et al. Potential reversal of epigenetic age using a diet and lifestyle intervention: a pilot randomized clinical trial. Aging (Albany NY). 2021;13(7):9419-9432. doi:10.18632/aging.202913

Horvath S. DNA methylation age of human tissues and cell types. Genome Biology. 2013;14(10):R115. doi:10.1186/gb-2013-14-10-r115

Jirtle, R., Skinner, M. Environmental epigenomics and disease susceptibility. Nat Rev Genet 8, 253–262 (2007). https://doi.org/10.1038/nrg2045

McGowan PO, Sasaki A, D'Alessio AC, et al. Epigenetic regulation of the glucocorticoid receptor in human brain associates with childhood abuse. Nature Neuroscience. 2009;12(3):342-348. doi:10.1038/nn.2270

Waterland RA, Jirtle RL. Transposable elements: targets for early nutritional effects on epigenetic gene regulation. Molecular and Cellular Biology. 2003;23(15):5293-5300. doi:10.1128/MCB.23.15.5293-5300.2003

Waterland RA, Kellermayer R, Laritsky E, et al. Season of conception in rural Gambia affects DNA methylation at putative human metastable epialleles. PLoS Genetics. 2010;6(12):e1001252. doi:10.1371/journal.pgen.1001252