Scientists have found that even slightly elevated blood pressure (BP) can have a detrimental effect on the brain and this damage is not just confined to older people.

The US team analysed blood pressure readings and brain scans from almost 600 people aged between 19 and 63.

They found that a raised BP could affect the structure of the brain of people in their 30s and 40s. For example, the brain of a 40-year-old with a BP of 140/90 - this is considered clinically high - looks more than seven years older than the brain of a 40-year-old with normal BP.

Furthermore, they also saw changes in the brains of people whose BP readings were only slightly higher than normal.

"The message here is really clear. People can influence their late-life brain by knowing and treating their blood pressure at a young age, when you wouldn't necessarily be thinking about it," the scientists from the University of California said.

They noted that their findings show that measurable damage to the brain can occur years before the appearance of any kind of dementia signs.

The team added that these results 'should have a substantial impact on how physicians regard hypertension (high BP) diagnosis and treatment'.

Details of these findings are published in the journal, Lancet Neurology.