A groundbreaking study recently published in the journal Nature Medicine offers a fascinating deep dive into how much our environment and genetics contribute to our health, aging, and longevity (1). Researchers analyzed a wealth of data from nearly 500,000 participants in the UK Biobank, focusing on three key questions:

1. Which environmental factors are most predictive of aging and premature death?
2. How do these factors impact biological aging, disease risks, and common aging biomarkers like cholesterol and inflammation?
3. How do environmental influences (the exposome) compare to genetic factors (the genome) in determining our risk of mortality and age-related diseases?

The Key Role of Lifestyle and Environmental Factors

The study began by looking at 164 lifestyle and environmental factors—everything from smoking and physical activity to sleep patterns, diet, socioeconomic status, and early-life conditions. After thorough testing and replication, 25 factors emerged as consistently linked to early mortality.

Interestingly, these factors didn’t just impact the likelihood of dying early—they also influenced proteomic aging, which estimates a person’s biological age. To do this they used a genetic clock, similar to the one that Dr Morgan Levine discussed in my podcast, Your Lifestyle Is Your Medicine, back in Episode 6.  What they found was that if an environmental factor predicted a higher risk of mortality, it was also associated with accelerated aging. 

What Are The Key Factors Associated With Aging and Mortality?

– Smoking status: and lifetime exposure to smoking, including prenatal exposure.

– Physical activity, especially gym attendance

– Sleep habits, like the frequency of naps or sleeping fewer than 7 hours or more than 9 hours per night

– Mood, including frequent feelings of being “fed up”.

– Socioeconomic factors, such as income, education, and employment status.

– Childhood growth patterns, including body size and height at age 10.

– Ethnicity, with differences observed between White, Black, Asian, and mixed populations.

How the Environment Affects Disease and Health

The study also revealed that environmental and lifestyle factors influence multiple biological systems in consistent patterns. For instance, beneficial exposures like higher socioeconomic status, regular physical activity, stable employment, and healthy sleep habits were associated with healthier biomarkers, such as:

– Better cholesterol profiles

– Lower inflammation

– Improved glucose metabolism

– Healthier kidney and liver function

– Longer telomeres (which indicate slower cellular aging)

– Better vitamin D status

On the flip side, harmful exposures like smoking, negative mood states, disrupted sleep, and socioeconomic deprivation consistently led to poorer health markers, including higher inflammation, poor lipid profiles, and accelerated cellular aging.

Perhaps most striking was the consistency of these patterns across various biomarkers—whether it was metabolism, inflammation, organ function, or cellular aging. These findings point to the profound impact of environmental and lifestyle factors on our biology, offering clear pathways linking the environment to early mortality and disease.

Genes vs. Environment: Who Wins?

One of the major revelations from the study was the comparison between genetics and environmental factors in predicting mortality and disease risk. While age and sex were by far the strongest predictors of mortality, yes, men get the short straw here,  both genes and the environment also played substantial roles.

– Environmental factors explained 16–19% of the variation in mortality risk, beyond basic demographics (age and sex).

–  Genes explained only 2–3% of the variance,

Environment vs. Genetics in Age-Related Diseases

What I thought was really interesting is that the contributions of genetics and environment varied significantly for different diseases:

– Diseases more strongly influenced by the “environment” included lung cancer, chronic liver disease, type 2 diabetes, rheumatoid arthritis, stroke, heart disease, and chronic kidney disease—all of which are heavily shaped by lifestyle choices like diet, smoking, physical activity, and socioeconomic status – which also suggest they are modifiable. 

– By contrast, diseases more strongly influenced by **genetics** included certain cancers (like breast, prostate, and ovarian cancers), Alzheimer’s disease, and macular degeneration—conditions known to have a strong hereditary component.

In Dr. Morgan Levine’s genetic clock research, she gives us a fascinating look into how we might measure biological age and the impact of genetics on aging. But even she didn’t think that genes played a huge role in how well we age because it might not be possible to outlive our genetic potential.
What this means for me is that even though my genetic expiry date might be less than my sisters, the environment I choose to live in might mean that I have a greater health span, mearing more healthy years of living.
To me, this is arguably the goal of investing in my health now.  Not to live a super long life but to live a life that is full of energy, laughter and adventure.

Let me know if you want any adjustments or additions!

 

1. https://www.nature.com/articles/s41591-024-03483-9?utm_source=brevo&utm_campaign=genes_vs_environment&utm_medium=email

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