The number found to put people at a higher risk of dementia is lower than the threshold at which doctors prescribe blood pressure medication.
Blood pressure that is even a little higher than normal has been linked to dementia in later years, a new study has found.
The research showed that a person can have elevated risk of dementia even if their blood pressure is low enough not to require medication. Systolic blood pressure, the top number that reflects the pressure in your arteries when your heart beats, at a level as low as 130 mmHg increased the risk, but 140 mmHg is the level at which most doctors start prescribing treatment.
How much does blood pressure affect brain health? Scientists measured the blood pressure of 8,639 men and women between the ages of 35 and 55 starting in 1985, then again in 1991, 1997 and 2003. When they checked back in with the participants in 2017, 385 had dementia. When scientists examined the blood pressure levels after controlling for factors like stroke and heart failure, they found that having a blood pressure over 130 at the age of 50 translated to a 45 percent increased risk of dementia compared to those who were the same age with a lower systolic blood pressure.
The same association was not found at ages 60 and 70, and diastolic blood pressure, the bottom number, was not linked to dementia.
“Our analysis suggests that the importance of mid-life hypertension on brain health is due to the duration of exposure,” said lead study author Archana Singh-Manoux, research professor at Inserm, the French research institute, and honorary professor at University College London. “So we see an increased risk for people with raised blood pressure at age 50, but not 60 or 70, because those with hypertension at age 50 are likely to be exposed to this risk for longer.”
The study establishes an association between blood pressure over 130 at age 50 and dementia, but not a direct cause. Researchers still don’t know if taking medication to manage blood pressure in mid-life lessens the chances of dementia later.
Evidence shows that blood pressure and heart health do share a strong connection to the brain, though. High blood pressure has been linked to what’s known as silent or mini strokes, which cause brain damage and can lead to dementia.
To prevent high blood pressure, scientist Francesca Fang-Liao, a professor of pharmacology at the University of Tennessee, said you can make lifestyle choices that may help boost heart health to an extent. She recommended eating plenty of good fats from sources like olive oil and avocados to get Omega 3 and 6, and getting at least 10,000 steps per day combined with more vigorous exercise.
This study was published in the European Heart Journal.