High blood pressure and large increases in blood pressure in midlife may be associated with brain pathologies in later life, according to an observational study of 502 people who have been tracked since their birth in 1946, published in The Lancet Neurology journal.

The study suggests that high blood pressure (140/90 mm Hg or higher) may lead to reductions in brain volume and higher levels of white matter hyperintensities within the brain (white matter brain lesions), but not with reduced cognition or the build-up of beta-amyloid plaques – one of the key proteins associated with Alzheimer's disease.

High blood pressure is known to increase risk for cognitive impairment later in life, but exactly how and when it increases risk is unclear. The new study tracked blood pressure from ages 36-69 to explore its influence on the brain, and found that the link may be there from a younger age than anticipated. The authors suggest that blood pressure monitoring and interventions may need to start at, or before, 40 years to maximise later brain health.