Research at the Cardiovascular Clinical Research Facility has found that blood vessels in the brains of young adults with elevated blood pressure are altered by exercise, even when blood pressure doesn’t fall.
The study, published in the journal NeuroImage: Clinical, suggests that even if exercise does not have an obvious effect on blood pressure, it still had benefits that may delay dementia and reduce the likelihood of strokes as these adults get older.
The researcher team gathered a cohort of young adults who had untreated high blood pressure, and who were physically inactive. The study participants randomly allocated to either 16 weeks of running/cycling for three one hour sessions each week, or sign-posted to educational materials on hypertension and recommended lifestyle behaviours At the start of the study, the researchers recorded a snapshot of the participants brain vascular structure using specialized MRI scans that tracked blood flow through and size of blood vessels in the brain.
After 16 weeks, the team repeated the MRI scan, and found that even though the group who had exercised had no statistically significant reductions in their blood pressure, their blood vessels had changed; the internal carotid artery, carrying blood to the brain, was physically larger compared to those who were only directed to lifestyle advice. These changes in the blood vessels allowed for more to flow through to the brain at rest. Interestingly, this effect was not related to blood pressure, which was not reduced by the intervention. The effect was especially marked in the brain blood vessels closest to the heart – these experience a lot of ‘shear’ mechanical stress as the heart pumps harder.
Dr Winok Lapidaire, senior postdoctoral researcher and first author of the study “This can help young people with higher blood pressure to improve their brain health using exercise, which is readily available with no negative side effects. It also demonstrates that exercise can be beneficial for the brain even when blood pressure does not come down.”
”By imaging the blood vessels and the blood flow through the brain in a randomized controlled trial, we have found that the structure of the blood vessels might be key in allowing more blood flow through the brain.”
“This suggests that in young adults who are therefore at risk of developing future cardiovascular disease and stroke due to elevated blood pressure and can use exercise as a first prevention tool. The benefits of exercise should not only be measured by blood pressure changes.”
The researchers now plan to use computational modeling to better understand how high blood pressure in young adults develops, and what factors influence it.