Smoking, high blood pressure, diabetes and obesity linked with brain shrinkage: study

Individuals with high blood pressure appear to have a higher risk of dying from COVID-19, according to new research.

New UK research has found that unhealthy lifestyle factors and conditions such as smoking, high blood pressure, obesity and diabetes appear to also be linked with having an unhealthier brain.

Led by researchers at the University of Edinburgh, the new study looked at MRI scans of the brains of 9,772 people aged between 44 and 79 who were taking part in the UK Biobank study -- a large long-term study which includes genomic data on more than half a million UK residents as well as data on brain imaging, their general health, and medical information.

The researchers looked at the possible association between seven vascular risk factors -- risk factors which affect the health of our blood vessels -- and any changes in the structures of parts of the brain.

The vascular risk factors included smoking, high blood pressure, high pulse pressure, diabetes, high cholesterol levels, waist-hip ratio, and obesity, which was measured by body mass index (BMI).

All have previously been linked to problems with the blood supply to the brain, which can potentially lead to reduced blood flow to the brain and the brain changes seen in dementia.

The findings, published in the European Heart Journal, showed that all of the other vascular risk factors except for high cholesterol were linked to greater brain shrinkage, less grey matter and less healthy white matter.

Moreover, the more vascular risk factors a person had, the worse their brain health.

"We found that higher vascular risk is linked to worse brain structure, even in adults who were otherwise healthy. These links were just as strong for people in middle-age as they were for those in later life, and the addition of each risk factor increased the size of the association with worse brain health," commented lead researcher Dr. Simon Cox.

"Importantly, the associations between risk factors and brain health and structure were not evenly spread across the whole brain; rather, the areas affected were mainly those known to be linked to our more complex thinking skills and to those areas that show changes in dementia and 'typical' Alzheimer's disease."

Dr. Cox added that the findings suggest that making lifestyle changes to improve these vascular risk factors could also have an effect on cognitive aging and dementia risk.

"Lifestyle factors are much easier to change than things like your genetic code -- both of which seem to affect susceptibility to worse brain and cognitive ageing. Because we found the associations were just as strong in mid-life as they were in later life, it suggests that addressing these factors early might mitigate future negative effects. These findings might provide an additional motivation to improve vascular health beyond respiratory and cardiovascular benefits."