Knowing that you have higher than normal blood pressure – and taking daily medication to treat it – may be a key to avoiding dementia later in life, according to a new study.
Scientists already know that high blood pressure, particularly between the ages of 40 and 65, increases the risk of developing dementia later in life, study co-author Ruth Peters, associate professor, said by email. at the University of New South Wales in Australia.
But she added that the research has been less clear on whether lowering blood pressure in older people would reduce this risk.
“What’s so exciting about our study is that the data shows that people who took blood pressure-lowering drugs had a lower risk of being diagnosed with dementia than those who took a matching placebo,” Peters said. , who is also a principal investigator. at Neuroscience Research Australia, a not-for-profit research organization.
Blood pressure is measured in units of millimeters of mercury (abbreviated as mmHg), which consists of two numbers: an upper or systolic reading which represents the maximum pressure in your arteries, and the lower or diastolic reading which shows the pressure in your arteries when your heart muscle is resting between beats.
The study, published this week in the European Heart Journal, combined data from five large randomized studies, double-blind clinical trials on more than 28,000 elderly people with an average age of 69 in 20 countries. All had a history of hypertension.
Each of the clinical trials compared people taking blood pressure medication with people taking a matching placebo pill and followed them for an average of 4.3 years. Pooling the data, Peters and his team found that a drop of about 10 mm/Hg on systolic and 4 mm/Hg on diastolic blood pressure readings at 12 months significantly reduced the risk of dementia diagnosis.
Moreover, there was a broad linear relationship: as blood pressure decreased, cognitive risk also decreased, which remained true until at least 100 mm/Hg systolic and 70 mm/Hg diastolic, according to the study. . There was also no sign that blood pressure medications could impair blood flow in the brain at later ages.
When sex, age or history of stroke were taken into account, there was no difference in the result.
“We know that what we do throughout life is likely to impact brain health in later life,” Peters said. “So the best advice we can give you is to lead a healthy life at any age, and of course, if you are prescribed medication to control your blood pressure, take it as instructed by your doctor.”
According to the American Heart Association, lifestyle changes can add to or, in some cases, replace the need for blood pressure medication. Suggested actions include limiting alcohol, managing stress, quitting smoking, eating a balanced, low-salt diet, getting plenty of exercise and sleep, and taking blood pressure medication as directed.
Research shows such changes can walk. A 2021 study found that diet, exercise and low salt intake also lowered blood pressure in people with resistant hypertension, which is high blood pressure that does not respond to medications.
In a 16-week study published in 2018, people who followed a low-salt diet, exercise, and practiced weight management techniques (such as watching portion sizes) lowered their blood pressure on average. 16 mmHg systolic and 10 mmHg diastolic, the American Heart Association said.
The diet used was the DASH diet, which stands for Dietary Approaches to Stop Hypertension. An award-winning diet plan, DASH has a simple premise: Eat more vegetables, fruits, and low-fat dairy products; limit foods high in saturated fat; and limit your sodium intake to 2,300 milligrams a day, or about 1 teaspoon of table salt.
The DASH meal plan includes four to six servings of vegetables and another four to six servings of fruit; three servings of whole grain products; two to four servings of fat-free or low-fat dairy products; and several servings each of lean meats and nuts, seeds, and legumes each day.
However, if lifestyle changes do not significantly reduce blood pressure within six months, the American Heart Association recommends adding prescription blood pressure medication while continuing to practice healthy behaviors.