(evaluated by body mass index (BMI) and waist-hip ratio)and damage to brain structure and health.
All the above conditions have been known to reduce blood supply
to the brain, potentially leading to reduced blood flow and changes associated with dementia
and Alzheimer's disease
- The research team analyzed MRI scans of the brains of 9,772 participants aged between 44 and 79 years enlisted in the UK Biobank study - one of the biggest databases available from the general population to provide information about brain scan as well as general health and other medical information.
- This is the world's largest MRI scanning study of association between multiple vascular risk factors and brain damage
- Most of the participants were from the north-west of England and all of them underwent scanning by a single scanner in Cheadle, Manchester.
- The team found that except for high cholesterol levels, all of other vascular risk factors were associated with greater brain shrinkage, less amount of grey matter (tissue found mainly on the brain surface) and unhealthy white matter (deeper brain tissue).
- Not surprisingly, the more vascular risk factors a patient had, the more unhealthy their brain tissue was
- Interestingly, the areas of the brain mostly affected by these risk factors were those areas responsible for performing complex thinking, memory and understanding, and typically affected in dementia and Alzheimer's disease
- Smoking, high blood pressure and diabetes were the three vascular risk factors most consistently present for all types of brain tissue damage. High cholesterol levels did not influence the brain structure as seen on the MRI scans
- On quantifying the brain damage, it was found that persons with the most number of vascular risk had suffered around 18ml, or nearly 3% loss of grey matter, and one-and-a-half times the damage to their white matter compared to persons with the least number of risk factors
The findings of the study do suggest an association between smoking
, diabetes, and hypertension with poor brain health
. Appropriate lifestyle changes can prevent or control these conditions and improve brain health and overall health outcome.
Dr Cox said, "The large UK Biobank sample allowed us to take a comprehensive look at how each factor was related to many aspects of brain structure. 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".
Future Research Plans
- In future studies, the team plans to measure the association between the occurrence of these vascular risk factors and how thinking skills in the Biobank participants are affected rather than only looking at MRI changes in the brain. Prior studies have shown a link between number of vascular factors and loss of thinking skills and occurrence of dementia
- The current study did not include persons older than 79 years and the team plans to followup older people, performing multiple scans and tests of thinking skills
- The findings of the current study can pave the way for future research to understand the biological mechanisms by which vascular risk factors affect different brain areas and brain matter
Common risk factors such as smoking, diabetes, obesity and hypertension can cause brain damage and loss of brain matter. Making suitable lifestyle changes and keeping these risk factors under control is beneficial for brain health. Reference :
- Associations between vascular risk factors and brain MRI indices in UK Biobank - (http://dx.doi.org/10.1093/eurheartj/ehz100)