There's a vulnerable spot in the human brain, a specific high-level network that not only develops late into adolescence but also shows early degeneration in old age. A recent study published in Nature Communications has found that this brain network is particularly susceptible to the influences of schizophrenia and Alzheimer's disease.
On the left side of the image, the red and yellow colors indicate areas of the brain that deteriorate earlier than other parts, making them prone to Alzheimer's disease. These regions are responsible for processing and integrating information from different senses. On the right side, each point represents brain data from a participant in the UK Biobank study. The overall curve indicates that degeneration accelerates in these vulnerable areas of the brain with age. Image Source: G. DOUAUD and J. MANUELLO.
Researchers from the University of Oxford examined brain scan images of over 40,000 participants aged 45 and above from the UK Biobank, aiming to understand the impact of genetics and variability on these vulnerable brain regions.
They examined 161 dementia risk factors and ranked their impact on "weak brain areas," surpassing the natural effects of aging. They listed 15 modifiable risk factors (factors that can be changed throughout life to reduce the risk of dementia), namely blood pressure, cholesterol, diabetes, weight, alcohol consumption, smoking, depression, inflammation, pollution, hearing, sleep, social engagement, diet, physical activity, and education.
Professor Gwenaëlle Douaud, who led the study, stated that a series of brain regions known to deteriorate earlier during aging. The new study found that among all common risk factors for dementia, these specific brain regions are most susceptible to the effects of diabetes, traffic-related air pollution, and alcohol.
The study also found that several variations in the genome affect this brain network, associated with cardiovascular death, schizophrenia, Alzheimer's disease, Parkinson's disease, and two antigens of a little-known blood type, the elusive XG antigen system, which is a novel and unexpected finding.
Researchers found two of seven genes located in specific regions containing the XG blood type gene, and this region is highly atypical because it is shared by X and Y sex chromosomes.
What sets this study apart is that the team assessed all modifiable risks together to evaluate the degeneration in this specific "weak brain area," studying the unique contributions of each modifiable risk. Through this comprehensive, holistic approach, and considering the effects of age and gender, researchers identified the three most harmful modifiable risk factors: diabetes, air pollution, and alcohol.
(Original Title: Revealing Risk Factors Promoting Brain Aging: Diabetes, Air Pollution, and Alcohol Rank Top Three Among Modifiable Risks)
