Study Reveals: Environmental Factors Outweigh Genetics in Determining the Rate of Organism Aging

New research has shed light on the significant impact that environmental factors such as smoking and socioeconomic status have on aging and premature death, indicating a stronger influence than genetics—thus redefining our approach to disease prevention.

Study: Integrating the Environmental and Genetic Architectures of Aging and Mortality

An article published in Nature Medicine explores how genetic factors are compared against environmental influences on aging and early death. The study examines both human aging, a complex process involving biological changes starting from mid-life (ages 40 to 60), as well as the role of non-genetic environmental exposures that can double the risk of premature mortality.

The exposome, defined as all environmental influences on an individual over their lifetime, has been studied extensively. However, few comprehensive studies have delved into how it affects population-level health outcomes and age-related diseases.

About the Study

This research compares genetic and exposomic contributions to premature death and major age-related illnesses using a sophisticated method to evaluate potential reverse causation and confounding. It begins by analyzing environmental exposures across 176 unique factors, common among men and women in both England (436,891 UKB participants) and Scotland/Wales (55,676), identifying those that are independently associated with the risks of early death.

A phenome-wide analysis follows to remove sensitive exposures. The findings link these 25 independent exposomic factors to various biomarkers of aging and 25 major diseases, demonstrating that primary contributors include socioeconomic status, smoking habits, number of household vehicles, physical activity level, ethnicity, relationship status (living with a partner), sleep patterns, and mental/physical well-being.

For instance:
– Maternal smoking during pregnancy
– Height and body size at age 10

Causal modeling through Cox proportional hazards models reveals that these exposures significantly raise the risk of developing age-related diseases associated with early death. Each exposure links to a multitude of aging biomarkers across various organs, suggesting interconnected environmental causes.

Genetics vs. Environment: Key Contributors to Aging and Mortality

The research underscores the high variability in disorders influenced by both genetic and environmental factors:

• Diseases like all-cause dementia, macular degeneration, Alzheimer’s disease, as well as prostate and breast cancers are predominantly impacted by polygenic risk.
• Conversely, conditions such as rheumatoid arthritis, ischemic heart disease, kidney diseases show a more significant influence from the exposome.

Conclusions

The study highlights the importance of large-scale biobanks in understanding genetic-environmental interactions in aging and mortality. It underscores that environment-focused interventions hold potential for preventing premature death and numerous age-related diseases. Furthermore, the exposome plays a crucial role in shaping unique patterns of disease risk.

Future research should focus on causal modeling to pinpoint specific environmental exposures contributing to health outcomes.