Untreated high blood pressure is known to increase risk of developing dementia by causing damage to blood vessels in the brain. Now, a major study reveals that interventions to improve blood pressure control — including two dietary changes — can slash risk of the condition by up to 15%.

The four-year trial involved almost 34,000 patients in rural China, all aged 40 and over. Some 17,400 received the interventions which included medication, health coaching on home blood pressure monitoring and lifestyle changes, such as advice on weight loss and reducing their intakes of salt and alcohol. The rest received standard care.

As well as reducing dementia risk by 15%, the intensive blood pressure management appeared to reduce risk of cognitive impairment — such as difficulties with thinking, memory and problem-solving — by 16%.

Writing in the journal Nature Medicine, an international team of researchers led by the University of Texas said their method “should be widely adopted and scaled up to reduce the global burden of dementia”.

Professor Joanna Wardlaw, an expert in applied neuroimaging at the University of Edinburgh, described the study as “large and rigorous and important”.

She said: “This is not just about blood pressure control — the intensive BP control was alongside strong lifestyle advice including on smoking, weight loss, exercise and better diet including reducing salt. The control group received usual blood pressure management and did not receive the lifestyle advice.

“The findings add weight to the results of the FINGER trials which have so far conducted mainly in Europe and which also showed that intensive vascular risk factor management along with lifestyle interventions helped delay cognitive decline in older individuals.”

Prof Wardlaw added: “No one, anywhere in the world, should be living with less than optimal blood pressure control, for a whole bunch of reasons, and we have to pay more attention to smoking cessation, exercise, salt reduction, a healthy diet and good sleep hygiene.”

Dr Julia Dudley, head of research at Alzheimer’s Research UK, said the study provided “further evidence that addressing high blood pressure could be one way to reduce dementia risk”.

She added: “Existing medicines and lifestyle changes to reduce blood pressure could present a more accessible way to lower dementia risk for those with high blood pressure.

“Looking after our heart and blood vessel health is something we can all do to improve our overall wellbeing and reduce our risk of dementia. 

“With no current treatments available on the NHS to slow or stop the diseases that cause dementia, there has never been a more pressing need to promote good brain health and to gain a deeper understanding of how we can reduce our risk of developing dementia.”