Hypertension can cause silent brain damage: Doctors share protection tips

Nearly half of Americans have hypertension, also known as high blood pressure. More than 119 million US adults have high blood pressure, according to the US Food & Drug Administration’s 2024 data. However, only one in four of those people has their condition under control. While many assume hypertension is harmless, the truth is far from it. A groundbreaking study has now found that hypertension damages the brain even before the fluctuations show up.

The new research from Weill Cornell Medicine found that hypertension damages the brain days before blood pressure increases. These findings could reshape how doctors treat the condition. The preclinical findings are published in Neuron.

Hypertension affects the brain much earlier than expected

The new preclinical study by Weill Cornell Medicine investigators found that hypertension impairs blood vessels, neurons, and white matter in the brain even before the condition causes a measurable rise in blood pressure. These findings help explain why hypertension is a major risk factor for developing cognitive disorders, such as vascular cognitive impairment and Alzheimer’s disease. The study also found that the condition may induce early gene expression changes in individual brain cells that could interfere with thinking and memory. These findings could pave the way for medications that both reduce blood pressure and prevent cognitive decline.

Though people with hypertension have a 1.2- to 1.5-fold higher risk of developing cognitive disorders than others, the reason behind this wasn’t known. While many medications successfully lower high blood pressure, they have little or no effect on brain function.

“We found that the major cells responsible for cognitive impairment were affected just three days after inducing hypertension in mice—before blood pressure increased. The bottom line is that something beyond the dysregulation of blood pressure is involved,” senior author Dr Costantino Iadecola, director of the Feil Family Brain and Mind Research Institute, professor of neuroscience and Anne Parrish Titzell Professor of Neurology at Weill Cornell, said.

Early cellular damage

The research team, co-led by postdoctoral associate Dr Anthony Pacholko, used advanced single-cell technology to examine how hypertension affects different brain cell types at the molecular level. The researchers induced hypertension in mice using angiotensin, a hormone that raises blood pressure in humans. On the third day, they analysed the brain cells—this was even before blood pressure increased. When they checked again on day 42, the blood pressure was elevated and cognitive function had declined.

At day three, gene expression changed dramatically in endothelial cells lining blood vessels, interneurons regulating nerve signals, and oligodendrocytes that maintain myelin sheaths around nerve fibres. They also noticed premature ageing in endothelial cells, with reduced energy metabolism and higher senescence markers. They observed early signs of a weakened blood–brain barrier, which potentially allows harmful molecules into the brain while restricting nutrients. They also observed changes similar to patterns seen in Alzheimer’s disease.

“The extent of the early alterations induced by hypertension was quite surprising. Understanding how hypertension affects the brain at the cellular and molecular levels during the earliest stages of the disease may provide clues to finding ways that can potentially block neurodegeneration,” Dr Pacholko said.

How to prevent brain damage from hypertension

The researchers tested losartan, an antihypertensive drug that inhibits angiotensin receptors. They found that the medication reversed early hypertension effects on endothelial cells and interneurons in mice.

“In some human studies, the data suggest that angiotensin receptor inhibitors may be more beneficial to cognitive health than other drugs that lower blood pressure,” Dr Iadecola said.

“Hypertension is a leading cause of damage to the heart and the kidneys, which can be prevented by antihypertensive drugs. So, independent of cognitive function, treating high blood pressure is a priority,” Dr Iadecola said.

Note: The information provided in this article is for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare professional before starting any new medication or treatment, or before changing your diet or supplement regimen.