A genetic predisposition for high blood pressure earlier in life may be a predictor of cognitive problems in older age.
New research, conducted by the UNSW Sydney Centre for Healthy Brain Ageing (CHeBA), shows signs of cognitive decline can start appearing in people with a genetic risk of high blood pressure in their 50s, and sometimes even 40s.
This goes against traditional medical literature, which states the cognitive effects of high blood pressure usually don’t start appearing until much later in life.
“Previously, the literature generally indicated that the cognitive effects of high blood pressure were not seen until late in life,” says Dr Matt Lennon, lead author of the study.
“We have found that there are subtle but real changes several decades earlier.”
The study results have been published in the journal Hypertension.
The study used the health data of 448,575 individuals from the UK Biobank and differed from many previous studies by using a genetic quantification of blood pressure risk rather than a direct measurement of blood pressure, which can often be inaccurate.
It wasn’t all bad news, however, Dr Lennon points out.
“The relationship of blood pressure with brain function is complex,” he says.
“Those with a genetic predisposition to higher blood pressure had significantly better reaction time, particularly in males.”
He says the positive correlation between blood pressure and reaction time may explain why hypertension is so prevalent in modern society.
“We know that high blood pressure is remarkably common in the community, especially among males, and part of this may be explained by the fact that there are some genetic advantages to this in reaction time – measuring how quickly an individual responds to a stimulus – although ones that come at the long-term costs of poorer cognitive health and greater risks of heart attacks and strokes.”
In plainer terms, your body appears to be prioritising your reaction time when you’re younger, without regard for your long-term brain health.
The study authors suggest that, in future, prevention strategies for cognitive decline may be more targeted and personalised based on an individual’s genetic risk for high or low blood pressure, as well as their age and sex.
Professor Perminder Sachdev, co-author of the study and co-director of CHeBA, says the results show intervention against cognitive decline and disorders such as Alzheimer’s disease should occur much earlier than previously thought.
“Hypertension impacts over one billion individuals worldwide and is the single, most prevalent risk factor for cognitive decline,” he says.
“It is critical we understand the complexities of this modifiable risk factor for dementia, particularly in people in their 40s and 50s, to develop strategies of earlier intervention and prevention of cognitive decline and dementia.”
In Australia, it’s estimated that high blood pressure is the major contributing factor in 5.8 per cent of the total burden of disease and that 21 per cent of those with hypertension had the condition because of a high-sodium diet.
When was the last time you had your blood pressure measured? Do you eat a lot of salt? Let us know in the comments section below.
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