For much of the twentieth century, biology seemed to deliver a rather sobering message: your genes determine your destiny.

If heart disease ran in your family, the assumption was that you would probably face the same fate. If your parents developed diabetes or dementia, those outcomes were often viewed as written into your biological blueprint.

Yet over the past two decades, a quiet revolution has been unfolding in medical science. Researchers have discovered that our genes are not fixed instructions carved in stone. Instead, they behave more like a complex set of switches — switches that can be influenced by the environment around us and the way we live.

This field of science is known as epigenetics. Epigenetics (from the Greek epi, meaning “above” or “on top of”) describes biological mechanisms that influence how genes are expressed without changing the DNA sequence itself. In other words, the genes you inherit may set the stage, but lifestyle helps shape which ones are active and which remain quiet. (Epigenetics and lifestyle – NIH (PMC))

What is gene expression?

Every cell in your body contains essentially the same DNA. Yet a brain cell behaves very differently from a skin cell, and a muscle cell differs again. The reason is gene expression — the process by which specific genes are “read” and used to produce proteins that carry out essential functions.

Epigenetic mechanisms help regulate gene expression. The best-studied include DNA methylation (chemical tags that can reduce gene activity), histone modification (changes to the proteins DNA wraps around, affecting how accessible genes are), and non-coding RNA molecules that influence how genetic information is used. (Abdul et al., 2017 – PubMed)

The discovery of epigenetic clocks (and why biological age matters)

One of the most talked-about developments in epigenetics is the rise of “epigenetic clocks” — tools that estimate biological age by analysing DNA methylation patterns. A landmark paper by Steve Horvath (2013) described a DNA-methylation-based method for estimating age across many tissues and cell types. (Horvath, 2013 – Genome Biology)

These approaches suggest that biological age can differ from chronological age — and that lifestyle and health factors may influence ageing trajectories. This does not mean we can control everything (we can’t), but it does support a more hopeful idea: biology is responsive.

Can lifestyle influence gene activity?

The honest answer is: lifestyle can influence biological signals that affect gene expression, but it does not “rewrite” your DNA. Think of it more like adjusting volume knobs and dimmer switches.

A classic study by Ornish and colleagues (2008) found that men with low-risk prostate cancer who adopted intensive lifestyle changes (including a predominantly plant-based diet, moderate exercise, stress management and social support) showed changes in the expression of hundreds of genes over three months. (Ornish et al., 2008 – NIH (PMC))

Importantly, epigenetics is not a promise that we can fully override genetic risk. Rather, it offers a more nuanced and empowering perspective: genes interact with environment, and many environmental inputs are modifiable.

7 lifestyle factors that may influence epigenetic patterns

1) A plant-rich, fibre-forward diet

Nutrients and bioactive food compounds can influence pathways involved in DNA methylation and histone modification. In everyday terms, a diet centred on vegetables, fruit, beans, lentils, whole grains, nuts, seeds and herbs/spices supplies fibre, polyphenols and micronutrients that support metabolic and inflammatory balance — both relevant to healthy ageing. (See: Stanford Lifestyle Medicine: Nutrition & Epigenetics)

2) Blood-sugar stability and metabolic health

Large swings in blood sugar and insulin are linked with oxidative stress and inflammation — two processes that influence cellular signalling. Balanced meals (fibre + protein-rich plant foods + healthy fats) and regular movement can support steadier energy, which may create a healthier internal environment for gene regulation.

3) Regular physical activity

Exercise is one of the most consistent lifestyle factors associated with favourable metabolic outcomes, and researchers have documented epigenetic changes in response to physical activity in muscle and blood. You do not need punishing workouts: brisk walking, resistance training with bodyweight, and “movement snacks” across the day all count. (For a broader overview of lifestyle influences on epigenetic states, see: CAS Insights: Epigenetics & lifestyle factors)

4) Restorative sleep and circadian rhythm

Sleep is when the body carries out critical repair work, including immune regulation and metabolic housekeeping. Persistent short sleep and circadian disruption can alter stress hormones and inflammatory signalling. A consistent sleep window, morning daylight, and an earlier, lighter evening meal are simple but potent levers.

5) Stress regulation

Chronic stress affects cortisol and inflammatory pathways, and stress biology is a major epigenetic research interest. Practices such as mindfulness, Yoga Nidra, breathwork, gentle yoga, and time in nature are not “nice extras”; they are biological inputs that can shift nervous-system tone and inflammatory signalling. (See: Alegría-Torres et al., 2011 – NIH (PMC))

6) Environmental exposures

Air pollution, tobacco smoke and certain endocrine-disrupting chemicals are associated with epigenetic changes in observational research. While we cannot control everything, we can reduce avoidable exposures: choose fragrance-free or low-toxin household products where possible, ventilate living spaces, and avoid smoking (including passive smoke exposure). (NIH (PMC) review)

7) Social connection, meaning and emotional wellbeing

Supportive relationships, community, and a sense of meaning are not merely psychological — they are part of the environment your biology responds to. This is one reason why the most sustainable health plans are rarely “all willpower”; they are built around support, structure and self-kindness.

Common myths to avoid

• “Epigenetics proves you can reverse any disease.” Not quite. Epigenetic research helps explain mechanisms, but outcomes depend on many factors, including the condition, severity, medical care, and social determinants of health.
• “One superfood changes your genes overnight.” Epigenetic patterns shift in response to overall dietary pattern and long-term exposures. Consistency matters far more than perfection.
• “If lifestyle influences genes, illness is your fault.” Absolutely not. Epigenetics highlights influence, not blame. Many exposures are outside personal control, and genetics, life events, access to care, and environment all play roles.

A simple, evidence-informed starting point

If you want to apply this without becoming overwhelmed, try these three anchors for the next seven days:

1. Add one extra portion of colourful plants daily (berries, greens, beans, cruciferous veg).
2. Walk for 10–20 minutes after one meal (supporting glucose regulation).
3. Protect a consistent bedtime and wake time (even at weekends, as much as possible).

Small changes, repeated, create the biological “signal” your cells respond to.

What this means for you

Epigenetics invites a kinder, more practical way of thinking about health. You are not “stuck” with your family history, yet you are not to blame for every health challenge either. Biology is responsive. The same lifestyle foundations that support cardiovascular, metabolic and mental wellbeing — plant-forward eating, movement, sleep, stress regulation, cleaner environments and connection — are also the most plausible levers for supporting healthy gene expression over time.

If you would like a deeper, step-by-step approach to building a lifestyle that supports long-term vitality, you may enjoy my book Rewind Your Body Clock.

Explore more about the way that lifestyle impacts our health, well-being, and longevity here on my website in my blog pages

Reflective practice

If your daily habits are constantly sending signals to your genes, what messages are you sending most often right now — and which one change would feel both realistic and meaningful this week?

References (APA 7)

• Alegría-Torres, J. A., Baccarelli, A., & Bollati, V. (2011). Epigenetics and lifestyle. Epigenomics, 3(3), 267–277. https://pmc.ncbi.nlm.nih.gov/articles/PMC3752894/
• Abdul, Q. A., Yu, B. P., Chung, H. Y., Jung, H. A., & Choi, J. S. (2017). Epigenetic modifications of gene expression by lifestyle and environment. Archives of Pharmacal Research, 40, 1219–1237. https://pubmed.ncbi.nlm.nih.gov/29043603/
• Horvath, S. (2013). DNA methylation age of human tissues and cell types. Genome Biology, 14, R115. https://genomebiology.biomedcentral.com/articles/10.1186/gb-2013-14-10-r115
• Ornish, D., Magbanua, M. J. M., Weidner, G., Weinberg, V., Kemp, C., Green, C., Mattie, M. D., Marlin, R., Simko, J., & Shinohara, K. (2008). Changes in prostate gene expression in men undergoing an intensive nutrition and lifestyle intervention. Proceedings of the National Academy of Sciences, 105(24), 8369–8374. https://pmc.ncbi.nlm.nih.gov/articles/PMC2430265/
• Stanford Lifestyle Medicine. (2025, June 2). Nutrition and epigenetics: How diet affects gene expression. https://lifestylemedicine.stanford.edu/nutrition-epigenetics/

All external resources are provided for educational purposes and reflect current evidence and public health guidance at the time of publication.