Recent research indicates that environmental factors play a significantly larger role than genetics in determining the likelihood of early mortality, with experts suggesting that the environment is roughly ten times more influential than genetic predispositions.

This study draws on data from nearly 500,000 individuals within the UK BioBank database. It includes extensive questionnaires pertaining to lifestyle, along with detailed records of deaths and health conditions that arose after participants joined the study.

Researchers emphasize the concept of the “exposome,” which encompasses the myriad of environmental elements people are exposed to throughout their lives, from living conditions to smoking habits. This work is pivotal in understanding health, aging, and the onset of chronic diseases associated with aging.

Dr. Austin Argentieri, the lead author from Harvard and the Broad Institute, stated, “In many instances, the risk associated with various diseases is largely influenced by environmental factors and the exposome. Investing in efforts to understand and modify our surroundings could significantly enhance public health outcomes.”

In their publication in Nature Medicine, Argentieri and collaborators from Oxford Population Health and other institutions explored the link between 164 environmental factors—ranging from dietary salt intake to having a partner—and the risk of early death.

After ruling out certain exposures tied to pre-existing conditions or those that might reflect another important factor, researchers identified 85 environmental exposures linked to increased risk of premature death.

They further analyzed blood proteins to determine which of these exposures correlated with biological aging speed.

The final 25 identified exposures included childhood experiences, such as whether mothers smoked during pregnancy, as well as contemporary factors like employment status and household income.

Interestingly, aspects like alcohol consumption and dietary habits were excluded from this list, likely due to challenges in accurately capturing these behaviors in questionnaires and inconsistencies in their associations.

The team found that many of the 25 environmental factors correlated with specific age-related diseases and biological aging markers, with the critical note that 23 of these factors are modifiable.

In additional analyses, age and sex accounted for roughly 50% of the variation in early mortality risk, while the 25 environmental factors contributed an extra 17%. In stark contrast, genetic predispositions for 22 significant diseases accounted for less than 2% of the variation.

Moreover, these environmental factors were found to be more influential than genetics in explaining why some individuals face a higher probability of developing conditions affecting the lungs, heart, and liver as they age.

Conversely, for diseases like breast cancer, prostate cancer, and dementia, genetics appeared to play a more crucial role.

Argentieri emphasized, “Our study provides some of the first robust evidence mapping the various exposures that affect biological aging. Additionally, we show that these exposures are significantly connected to the overall aging process across adulthood and linked to key biological mechanisms involved in aging, the future risk of age-related conditions, and mortality.”

This research does have its limitations, including potential variations in results across different countries, the fact that environmental exposures were only assessed at one point in time, the difficulty in establishing clear cause-and-effect relationships, and the possibility of unmeasured environmental factors.

Dr. Stephen Burgess from the University of Cambridge noted that this study reinforces earlier findings that indicate genetic factors do not predominantly dictate our future health outcomes.

Burgess remarked, “While genetics may set certain odds, it is ultimately our actions that determine the outcome.” However, he cautioned that the study’s findings do not definitively claim direct causal relationships regarding potential changes to risk factors and environmental conditions.