Roundup: Lifestyle Factors Outweigh Genetics in Influencing Health and Aging; and More News

Lifestyle, Environmental Factors Have Greater Influence on Health and Aging Than Genetics: Researchers

Our environment—particularly lifestyle choices and living conditions—has a far more significant impact on our health and risk of premature death than our genetic makeup, according to a new study by researchers at Oxford Population Health, part of Oxford University's Medical Sciences Division in the United Kingdom.

Published in Nature Medicine, this research challenges the common belief that our genes determine much of our lifespan, showing instead that lifestyle factors such as smoking, physical activity, and socioeconomic status play a more influential role.

The study analyzed data from nearly half a million participants in the UK Biobank, a large-scale biomedical database and research resource. Researchers assessed the effects of 164 environmental factors, alongside genetic risk scores for 22 major diseases. The researchers sought to determine the contributions of both environmental exposures and genetics to aging, age-related diseases, and premature death.

The results of the study demonstrate the sharp contrast between the influence of genetics and environment on health outcomes:

• Environmental factors were responsible for 17 percent of the variation in the risk of death, while genetic factors accounted for less than 2 percent. This suggests that, in terms of longevity and health, our environment and lifestyle choices matter far more than our genes.
• Among the 25 independent environmental factors identified, smoking, socioeconomic status, physical activity, and living conditions were found to have the most profound effect on mortality and biological aging.
• Smoking was linked to 21 diseases, while socioeconomic factors—such as household income, home ownership, and employment status—were associated with 19 diseases. Physical activity, a critical factor in overall health, was tied to 17 diseases.
• Significantly, 23 of the environmental factors identified in the study are modifiable, meaning they can be changed through personal choices or public policy.

One of the most compelling findings from the study is the long-lasting impact of early life exposures. The researchers found that factors such as body weight at age 10 and maternal smoking around birth can influence the risk of premature death and the rate of biological aging up to 80 years later. This underscores the critical importance of childhood health and the lasting effects of early life circumstances.

While environmental exposures were found to have a greater effect on diseases related to the lungs, heart, and liver, genetic predispositions were found to dominate in conditions like dementia and breast cancer. This differentiation highlights the need for tailored health interventions based on individual risk factors and disease types.

A key innovation in this research was the use of a new “aging clock,” which tracks biological aging through blood protein levels. This tool allowed researchers to directly connect environmental factors with biological markers of aging and predict the onset of age-related diseases. The study was not limited to the UK Biobank data -- but was also validated in large cohort studies from China and Finland.

In a news release, Austin Argentieri,. M.D., the study’s lead author, states: “These findings underscore the potential benefits of focusing interventions on our environments, socioeconomic contexts, and behaviors for the prevention of many age-related diseases and premature death.”

By identifying combinations of modifiable environmental factors—what is called the "exposome"—the study opens the door to more effective prevention strategies targeting premature death and chronic diseases.

With 23 of the identified environmental factors being modifiable, there is ample room for public health interventions, policy changes, and individual behavior shifts to improve health outcomes globally, the researchers conclude.

Related article: How to Avoid Heart Disease: 8 Lifestyle Changes You Can Make Today

Researchers Find Common Artificial Sweetener May Raise Risk of Heart Disease

For years, artificial sweeteners have been marketed as a healthier way to satisfy the sweet tooth while avoiding the health risks of sugar. From diet sodas to sugar-free ice cream, many consumers have embraced these low-calorie alternatives. However, a new study published in Cell Metabolism this month suggests that aspartame, one of the most commonly used artificial sweeteners, may have unexpected and harmful effects on cardiovascular health.

The study, led by cardiovascular health experts from the Karolinska Institute in Sweden, was sparked by a simple observation. The study’s senior author Yihai Cao recalls a casual moment during a project meeting when a colleague was drinking diet soda. This prompted him to suggest researching the potential effects of artificial sweeteners on health.

What followed was research into how aspartame affects vascular health, specifically contributing to atherosclerosis—a condition where fatty plaques build up in the arteries, potentially leading to heart attacks and strokes. Atherosclerosis is considered a form of heart disease.

In the study, researchers fed mice daily doses of food containing 0.15 percent aspartame, a quantity equivalent to drinking three cans of diet soda each day for humans. After just 12 weeks, the results were significant. Mice that consumed aspartame developed significantly larger and more fatty plaques in their arteries compared to those that didn’t receive the sweetener, the study found. These plaques are a clear sign of atherosclerosis, a condition that can obstruct blood flow and increase the risk of cardiovascular events.

The researchers also found that the aspartame-fed mice experienced higher levels of inflammation, which is another hallmark of poor cardiovascular health. These findings are particularly concerning given the widespread consumption of artificial sweeteners in various foods and drinks.

The researchers’ investigation revealed that the aspartame triggered a surge in insulin levels in the mice. This is not entirely surprising, as sweetness receptors are found in our mouths and intestines, helping to regulate insulin release. However, aspartame is about 200 times sweeter than sugar, which seems to fool the body’s receptors into releasing more insulin than necessary, researcher say.

Elevated insulin levels, in turn, contributed to the growth of the fatty plaques in the mice’s arteries. Insulin appears to be the critical link between aspartame consumption and the development of atherosclerosis, as it promotes plaque buildup in the arterial walls

The research team identified a specific immune signal called CX3CL1, which is activated by elevated insulin and plays a central role in this process. CX3CL1 is unique because it sticks to the inner lining of blood vessels, where it acts as a trap for immune cells, fueling inflammation and promoting plaque formation.

“Because blood flow through the artery is strong and robust, most chemicals would be quickly washed away as the heart pumps,” says Mr. Cao, in a news release. “Surprisingly, not CX3CL1. It stays glued to the surface of the inner lining of blood vessels. There, it acts like a bait, catching immune cells as they pass by.” 

Many of these trapped immune cells are known to stoke blood vessel inflammation. 

The research team plans to verify their findings in humans. Mr. Cao also foresees CX3CL1 as “a potential target for chronic conditions beyond cardiovascular disease, given that blood vessel inflammation is involved in stroke, arthritis, and diabetes,” states a news release on the study. 

Even Small Amounts of ‘Moderate to Vigorous Physical Activity’ are Linked to Lower Risks of Dementia

A recent study conducted by researchers at the Johns Hopkins Bloomberg School of Public Health indicates that just small amounts of movement may help in reducing the risk of dementia, even among “frail older adults.”

The study revealed that taking part in just 35 minutes of moderate to vigorous physical activity weekly -- when compared to those who did not participate in any physical activity -- was linked to a 41 percent decrease in the risk of developing dementia over an average follow-up duration of four years.

This trend persisted even among “frail older adults” who are typically at a higher risk of experiencing negative health outcomes, with increased activity correlating to reduced dementia risks, researchers said in a news release.

Further analysis demonstrated that the risk of dementia decreased with higher levels of physical activity. Participants engaging in 35 to 69.9 minutes of exercise per week saw a 60 percent lower risk; those in the 70 to 139.9 minutes category showed a 63 percent lower risk, and individuals exercising for 140 minutes or more per week had a 69 percent lower risk.

The researchers analyzed data gathered from nearly 90,000 adults in the U.K. who utilized smart-watch-type activity trackers for the study. The findings were published in the Journal of the American Medical Directors Association.

In a statement, lead author Amal Wanigatunga, Ph.D., MPH, an assistant professor in the Department of Epidemiology at the Bloomberg School, emphasizes that the “findings suggest that even a modest increase in physical activity, such as just five minutes per day, can significantly lower dementia risk among older adults."

Dr. Wanigatunga, who is a core faculty member at the Johns Hopkins Center on Aging and Health and holds a joint appointment at the Johns Hopkins University School of Medicine, indicates that this research contributes to a growing body of evidence supporting the notion that some exercise is better than none—particularly regarding age-related brain disorders for which no cure exists.

Dementia, often stemming from Alzheimer’s disease, is prevalent among older adults and affects an estimated seven million individuals in the U.S., with approximately one-third of those aged 85 and older being affected. Despite the increase in dementia risk with age, recent studies have suggested that adopting lifestyle changes, such as improved management of cholesterol, blood pressure, and blood sugar, as well as increased physical activity, may be effective in partially preventing dementia within a typical lifespan.

The specific minimum amount of exercise required to significantly reduce dementia risk remains unclear. Many older adults, particularly those who are frail, may find the recommended levels of activity, such as the 150 minutes of moderate-intensity exercise per week suggested by both the U.S. Department of Health and Human Services and the U.K. National Health Service, to be unattainable, potentially deterring them from exercising altogether.

The new study utilized data gathered from British adults participating in the UK Biobank project, which is an extensive ongoing study involving approximately 500,000 individuals. The recent analysis focused on 89,667 adults, predominantly aged 50 and above, who wore wrist accelerometers to monitor their physical activity over a week between February 2013 and December 2015. The follow-up period, extending on average for 4.4 years, revealed that 735 participants were subsequently diagnosed with dementia.

The analysis compared participants who logged some moderate to vigorous activity weekly against those who recorded none, while controlling for age and other health conditions. The resulting correlations between increased activity levels and diminished dementia risk were notable, with individuals in the lowest activity category (1 to 34.9 minutes per week) displaying an approximate 41% risk reduction.

When assessing participants identified as frail or “pre-frail,” the relationship between heightened activity and reduced dementia risk remained essentially unchanged.

“This indicates that even those who are frail or nearing frailty may still lower their risk of dementia through light exercise,” Dr. Wanigatunga suggests.

The researchers recommend that future clinical trials should explore low-dose exercise as a critical first step in promoting physical activity as a strategy to prevent dementia.