Out of a host of possible risk factors for dementia, three really stood out in a new analysis: Diabetes, air pollution and alcohol.

British and American researchers used brain scans to focus on a neurological network they labeled a “weak spot” in the brain. This network is known to be vulnerable to the effects of aging, as well as Alzheimer’s disease, Parkinson’s disease and other conditions.

The neural network only begins to develop during adolescence, and also shows signs of degeneration earlier in old age, explained a team led by Gwenaëlle Douaud, an associate professor of clinical neurosciences at the University of Oxford.

Her group examined brain scans from over 40,000 seniors, all of who also provided complex lifestyle and medical histories as part of the ongoing U.K. Biobank project.

The study looked at the impact on the targeted neural network of 161 different risk factors for dementia. These included blood pressure, cholesterol, diabetes, weight, alcohol consumption, smoking, depressive mood, inflammation, pollution, hearing, sleep, socialization, diet, physical activity and education.

Three risk factors appeared to weaken the network the most, Douaud said.

“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,” she said in an Oxford news release.

The team also gained insights into specific genetics that might make a person’s brain more or less vulnerable.

“Several variations in the genome influence this brain network, and they are implicated in cardiovascular deaths, schizophrenia, Alzheimer’s and Parkinson’s diseases,” Douaud said.

The study was published March 27 in the journal Nature Communications.

Study co-author Dr. Anderson Winkler is an associate professor of human genetics at The University of Texas Rio Grande Valley in Brownsville.

“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,'” Winkler said.

“Once we had taken into account the effects of age and sex — that three emerged as the most harmful: diabetes, air pollution and alcohol,” he said.

More information

Find out more about risk factors for dementia at the Alzheimer’s Association.

SOURCE: University of Oxford, news release, March 27, 2024

Source: HealthDay