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  • Researchers analyzed data from clinical trials involving over 28,000 people to determine if people using high blood pressure drugs had a reduced risk of dementia compared to those who did not use these drugs.
  • Approximately one out of 10 people older than 65 have dementia.
  • Blood pressure medications may help reduce narrowing or blocking of key arteries in the body.

According to the Centers for Disease Control and Prevention, high blood pressure (hypertension) is a significant risk factor for dementia, especially for people with uncontrolled blood pressure in midlife.

But can treating hypertension in later life reduce this risk?

New research from the University of New South Wales (UNSW) in Australia shows the strongest evidence yet that it can.

“We already know that having higher blood pressure, particularly in midlife (between 40-65 years) increases our risk of developing dementia in later life,” Ruth Peters, PhD, Associate Professor at UNSW Sydney and Program Lead for Dementia in The George Institute’s Global Brain Health Initiative, told Healthline.

Dr. Peters, lead author on the study, pointed out that there has been “some uncertainty” about whether lowering blood pressure in older adults would reduce dementia risk.

So Peters and team decided to look at whether people taking blood pressure-lowering medication (anti-hypertensives) had a lower risk of dementia diagnosis than people taking a matching placebo/dummy treatment.

“We combined data from five large clinical trials of blood pressure lowering in older adults,” she said.

For this study, researchers conducted a meta-analysis of data from five studies that included information from over 28,000 people with an average age of 69 and a history of high blood pressure across 20 different countries. The follow up in this population was conducted for an average of four years.

They found people with a sustained reduction in blood pressure thanks to medication were about 13% less likely to get dementia.

“We found there was a significant effect of treatment in lowering the odds of dementia associated with a sustained reduction in blood pressure in this older population,” Peters said in a statement.

According to Peters, the findings imply a “broadly linear relationship” between blood pressure reduction and lower risk of dementia, regardless of which type of treatment was used.

“This is the strongest evidence yet to show that blood pressure lowering, in older adults, reduces dementia risk,” she said.

Dr. Bibhuti Mishra, chief of neurology at Long Island Jewish Forest Hills in Queens, part of Northwell Health in New York, explained that blood pressure has long been recognized as one of three or four major risk factors that lead to the development of a condition that narrows or blocks blood flow called lipohyalinosis.

“This is the name given to the deposition of fat (lipo) and protein (hyalin) mixture in the walls of small and medium-sized arterioles (little arteries),” explained Dr. Mishra.

He said that this condition causes narrowing and blockage of blood flow through these arteries.

“This process can give rise to multiple small strokes that are tiny and are called lacunar strokes,” said Mishra.

“If a sufficient number of arterioles become blocked, global brain network function is disordered by reduced brain blood supply, causing signs and symptoms of dementia,” he continued.

“Every drug has a different safety profile,” said Dr. Supreeti Behuria, director of nuclear cardiology at Staten Island University Hospital in New York.

She noted that there are many options for first-line medications to treat hypertension and it’s important for each person to work with their physician to find the safest and most efficacious drug for them.

Dr. Behuria emphasized that controlling hypertension “certainly” reduces the risk of developing diseases that are associated with it.

“A study from Lancet showed that a 5 mmHg (millimeter of mercury) reduction in systolic blood pressure lowered the relative risk of major cardiovascular events by 10 percent on an average of four years of follow up,” she said.

Behuria added that keeping blood pressure “at goal” also reduces stroke and kidney disease risk.

Elizabeth H. Dineen, DO, a cardiologist at the Susan Samueli Integrative Institute at UCI Health in Orange County, California, emphasized that lifestyle changes can significantly reduce blood pressure.

“Each lifestyle change has been shown to lower blood pressure at least a few mmHg if not more,” she said.

“Things like losing weight if overweight/obese, increasing physical activity, decreasing salt in the diet and focusing on the DASH diet (high in fruits and vegetables, increased potassium-containing foods, low in salt), limit alcohol,” Dr. Dineen continued.

“Age is the number one risk factor for Alzheimer’s disease,” said Betsy Mills, PhD, assistant director of aging and Alzheimer’s prevention at the Alzheimer’s Drug Discovery Foundation.

According to Dr. Mills, approximately one out of 10 people older than 65 has Alzheimer’s disease.

“Which goes up to about one third for those over age 80,” she said. “Aside from age, dementia risk comes from genetic (the ApoE4 gene) and environmental/lifestyle factors.”

She added that cardiometabolic diseases, such as diabetes, high cholesterol, hypertension, and heart disease have all been associated with increased risk for vascular dementia and/or Alzheimer’s disease.

“The risk appears to be strongest for those who develop these cardiovascular and metabolic conditions during middle age, particularly if they are not properly managed for a prolonged period of time,” said Mills.

Researchers analyzed data from clinical trials involving over 28,000 people to find whether people using high blood pressure drugs had a reduced risk of dementia compared to those that didn’t.

Experts say there are many safe drugs available to treat blood pressure, but lifestyle changes can help significantly.

They also say that the risk is strongest for people who develop diabetes or cardiovascular conditions during middle age.