Environment Trumps Genes: Why Your Daily Choices Matter More Than Your DNA
Your lifestyle choices and environment are far more important to your health and longevity than your genes - so the control is mostly yours.
Credit: Haberdoedas, Unsplash
A groundbreaking study published in Nature Medicine (February 2025) brings powerful news for anyone concerned about their health:
The environment you create through your daily habits has far greater impact on your lifespan and health outcomes than your genetic makeup
The Power of Your Daily Environment
Researchers analysing data from nearly half a million UK Biobank participants found that environmental factors (collectively called the "exposome") explained a whopping 17% more variation in mortality risk than genetic factors, which contributed less than 2%.
This is incredibly empowering news. While we can't change our genetic code, we have direct control over most of the factors that actually determine our health trajectory:
Physical activity levels emerged as one of the strongest protective factors against premature death – move like your life depends on it
Sleep duration and quality showed significant impacts on biological ageing markers
Living with a partner provided substantial mortality protection (house sharing isn’t so bad after all!)
Employment status and household income both strongly predicted longevity
Smoking remained one of the most powerful negative influences
As expected, physical activity was one of the most important protectors of health. Move like your life depends on it.
Credit: Neom, Unsplash.
Overcoming Early Life Disadvantages
If you experienced health disadvantages in childhood, this research contains particularly encouraging findings. Even if you had:
A higher body weight at age 10
Exposure to maternal smoking during pregnancy
Growth or height challenges
You can still significantly alter your health trajectory through the environmental factors you control today. The study found that current lifestyle choices could effectively override many early life disadvantages.
Where Your Focus Matters Most
The research revealed fascinating patterns in which diseases are more influenced by genetics versus environment:
Environment-dominant conditions: Lung diseases, heart diseases, liver conditions, and rheumatoid arthritis were far more influenced by lifestyle factors than genetics.
Genetics-dominant conditions: Breast cancer, prostate cancer, dementia, and macular degeneration showed stronger genetic influences, although environment still played a significant role.
This suggests that targeting your lifestyle interventions based on your personal risk profile may yield better results. If your family history includes heart disease, your environmental choices carry even more weight.
The Multimorbidity Connection
Perhaps most striking was how environmental factors influenced the development of multiple conditions simultaneously. Poor sleep, physical inactivity, and social isolation didn't just predict single diseases – they created biological patterns that increased risk across numerous conditions.
This explains why people who make positive lifestyle changes often report improvements across multiple health dimensions – better mood, improved digestion, reduced pain, and enhanced energy – rather than just affecting a single condition.
Multiple environmental factors interact to affect health, including social isolation, poor sleep, and physical inactivity. A ‘broad diet’ of healthy behaviours has the greatest impact.
Practical Takeaways
Given these findings, here are the most evidence-backed actions you can take:
Prioritise physical activity – aim for daily movement rather than occasional intense workouts
Optimise sleep – 7-8 hours appears optimal; both too little and too much showed negative effects
Build relationships – living with a partner and social connections showed powerful protective effects
Quit smoking – it remains the most damaging modifiable factor identified
Manage stress – frequent tiredness and unenthusiasm strongly predicted poor outcomes
The research found that these factors work additively – each positive change you make compounds the benefits of others.
Bottom Line
Your daily choices create the environment that either accelerates or slows your biological ageing. While genetic factors do create some predispositions, the environment you create through your habits has far greater impact on your actual health outcomes.
This is genuinely good news – the factors that matter most for your longevity and healthspan are largely within your control, regardless of your genetic inheritance or early life experiences.
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