According to a recent study, factors that influence the health of our blood vessels, such as smoking, high blood and pulse pressures, obesity and diabetes, are linked to less healthy brains.

The study examined the associations between seven vascular risk factors and differences in the structures of parts of the brain. The strongest links were with areas of the brain known to be responsible for our more complex thinking skills, and which deteriorate during the development of Alzheimer's disease and dementia. The researchers, led by Simon Cox, a senior research associate at the University of Edinburgh (UK), examined MRI scans of brains of 9,772 people, aged between 44 and 79, who were enrolled in the UK Biobank study - one of the largest groups of people from the general population to have data available on brain imaging as well as general health and medical information.

All had been scanned by a single scanner in Cheadle, Manchester, and most of the participants were from the north-west of England. This is the world's largest single-scanner study of multiple vascular risk factors and structural brain imaging. The researchers looked for associations between brain structure and one or more vascular risk factors, which included smoking, high blood pressure, high pulse pressure, diabetes, high cholesterol levels, and obesity as measured by body mass index (BMI) and waist-hip ratio. These have all been linked to complications with the blood supply to the brain, potentially leading to reduced blood flow and the abnormal changes seen in Alzheimer's disease.

They found that, with the exception of high cholesterol levels, all of the other vascular risk factors were linked to greater brain shrinkage, less grey matter (tissue found mainly on the surface of the brain) and less healthy white matter (tissue in deeper parts of the brain). The more vascular risk factors a person had, the poorer was their brain health.

Findings of the study were published in the Journal of European Heart Journal. "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. Although the differences in brain structure were generally quite small, these are only a few possible factors of a potentially huge number of things that might affect brain ageing," Cox explained.

Smoking, high blood pressure and diabetes were the three vascular risk factors that showed the most consistent associations across all types of brain tissue types measured. High cholesterol levels were not associated with any differences in the MRI scans. According to Cox, 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."