What causes our brains to age?
While some degree of brain aging is inevitable, the extent to which our brains degrade over time can be influenced by a range of internal and external factors.
Researchers from the U.K.'s University of Oxford have previously identified a "weak spot" in the brain that is particularly vulnerable to age-associated degeneration as well as schizophrenia and Alzheimer's disease. But, according to new research, some modifiable risk factors have a greater impact on this fragile brain region than others.
In a new study, published in the journal Nature Communications, the same team scoured through 40,000 brain scans from the UK Biobank—a large-scale biomedical database investigating the contributions of genetics and environment to the development of various diseases—to determine which environmental factors had the greatest impacts on this brain area.
To investigate these effects, the researchers examined 161 risk factors for dementia and ranked them according to their impacts on this region over and above what would be expected from normal aging. These were then divided into 15 broad categories: blood pressure, cholesterol, diabetes, weight, alcohol consumption, smoking, depressive mood, inflammation, pollution, hearing, sleep, socializing, diet, physical activity and education. And through this investigation, three key risk factors shone out.
"We know that a constellation of brain regions degenerates earlier in aging, and in this new study we have shown that these specific parts of the brain are most vulnerable to diabetes, traffic-related air pollution—increasingly a major player in dementia—and alcohol, of all the common risk factors for dementia," said Gwenaëlle Douaud, an Oxford research fellow and leader of the study, in a statement.
Type 2 diabetes occurs when your body's cells become resistant to the hormone insulin. It is often preventable, with risk factors including being overweight, not getting enough exercise and genetics. Diet can also play an important role. Meanwhile, exposure to air pollution often depends on location and lifestyle habits, although our levels of exposure are not always within our control.
Of the three identified risk factors, alcohol consumption is the most easy to control at an individual level.
Anderson Winkler, a professor and study co-author who is with the National Institutes of Health and the University of Texas Rio Grande Valley, said the study's findings are particularly interesting because of its comprehensive and holistic approach.
"What makes this study special is that we examined the unique contribution of each modifiable risk factor by looking at all of them together to assess the resulting degeneration of this particular brain 'weak spot,'" he said in a statement.
The team also found several genetic factors that influence this brain region, specifically those that have been associated with cardiovascular disease, schizophrenia, Alzheimer's disease and Parkinson's.
Of course, these results are still purely observational, and more work needs to be done to understand the biochemical basis of the findings. But the study provides important insights into some of the most critical risk factors for dementia and offers exciting avenues for future prevention strategies and targeted interventions.
Is there a health problem that's worrying you? Do you have a question about dementia? Let us know via health@newsweek.com. We can ask experts for advice, and your story could be featured on Newsweek.
Uncommon Knowledge
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
About the writer
Pandora Dewan is a Senior Science Reporter at Newsweek based in London, UK. Her focus is reporting on science, health ... Read more
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