Untreated High Blood Pressure May Increase Alzheimer's Risks

New research suggests that older adults may want to consider treating their high blood pressure to help lower the risk of developing Alzheimer's disease.

High blood pressure, or hypertension, is a highly treatable chronic health condition that impacts around 30% of adults in the United States. Still, according to the U.S. Centers for Disease Control and Prevention (CDC), only 63% of people with high blood pressure take medications to treat it.

While it is widely known that hypertension is a risk factor for heart disease and stroke, it can also increase the risk of vascular dementia by damaging tiny blood vessels in the brain. However, the links between hypertension and Alzheimer's disease are unclear.

Recently, scientists looked closer at the potential associations between hypertension and Alzheimer's. They found evidence that suggests treating high blood pressure may lower the risk of developing this neurodegenerative condition.

Can high blood pressure increase the risk of Alzheimer's?

The meta-analysis, published on August 14, 2024, in the online issue of Neurology, the medical journal of the American Academy of Neurology, involved 31,250 participants 60 years and older who were enrolled in one of 14 studies from around the world.

Each of the 14 studies measured the participants' cognitive changes and dementia diagnoses over time.

The research team examined blood pressure readings and identified which participants had a hypertension diagnosis and who had been or was currently taking medication for high blood pressure. They also included individuals without hypertension.

The data showed that 9% of the participants had untreated high blood pressure, 51% were taking medications for the condition, and 36% did not have hypertension. Blood pressure data was unclear in 4% of the participants.

After analyzing the data and adjusting for factors that could interfere with the results, the scientists found that individuals with untreated high blood pressure had a 36% higher risk of developing Alzheimer's disease than people without hypertension.

They also found that people not treated for hypertension had a 42% higher risk of Alzheimer's than individuals taking blood pressure medications.

While the study's findings are significant, the researchers say that the results only show an association between untreated hypertension and Alzheimer's and do not prove forgoing treatment for high blood pressure leads to the neurodegenerative condition.

Previous research found similar links

This latest study is not the only research to show potential associations between untreated hypertension and Alzheimer's or dementia.

For instance, a study published in 2014 found that the use of antihypertensive drugs to control high blood pressure was linked to a lower incidence of Alzheimer's disease. Moreover, the study identified that specific types of blood pressure medications — thiazide and potassium-sparing diuretics — were associated with the greatest reduction in Alzheimer's risk.

More recent research published in JAMA Network Open revealed that treating high blood pressure lowered the risk of dementia, and people who had their blood pressure under control via medication had the same risk for dementia as those without hypertension.

These findings and the results of the current meta-analysis add more weight to the notion that treating high blood pressure may help fend off dementia and other neurodegenerative conditions.

"Our meta-analysis that included people from around the world found that taking blood pressure medications was associated with decreased risk of Alzheimer's disease throughout later life," said study author Matthew J. Lennon, M.D., Ph.D., from the University of New South Wales in Australia, in a news release. "These results suggest that treating high blood pressure as a person ages continues to be a crucial factor in reducing their risk of Alzheimer's disease."