Dementia represents a range of cognitive disorders that can cause memory loss, difficulty thinking, as well as problems with judgement, communication, and more. And while many of us falsely think of dementia as something that simply happens in old age, experts say there are several ways to lower your risk by practicing preventative measures long before symptoms arise. In fact, studies say there’s one simple thing you can do in mid-life that’s been shown to lower your dementia risk as much as 25 years later—and it’s important for other areas of your health, too. Read on to find out which mid-life decision can make or break your dementia risk, and why it’s so dangerous for your cognitive health if you fail to take action.
Though most people don’t think about their blood pressure in relation to their dementia risk, studies show that having untreated hypertension during mid-life can greatly raise your risk of cognitive decline. A 2000 study published in the journal Neurobiology of Aging was among the first to determine that “increased mid-life blood pressure [is] associated with an increased risk for dementia in old age.” The researchers added that while hypertensives who were never treated with medication were at higher risk of dementia, “there was no association of dementia to blood pressure in treated men.”
In particular, the team observed that untreated hypertension was significantly associated with increased likelihood of vascular dementia, the second most common type of dementia (after Alzheimer’s disease) which accounts for between 15 and 17 percent of all dementia cases.
Since that study’s release, many others have confirmed those findings, including a 2021 study published by StatPearls. “The one crucial risk factor that should be modified is hypertension. Countless studies show that the use of antihypertensive medications can reduce the risk of vascular dementia,” the research team wrote.
According to the health charity Blood Pressure U.K., uncontrolled high blood pressure can harm your brain in several ways by damaging your blood vessels. “This restricts the blood supply to parts of the brain, so not enough oxygen and nutrients can reach the brain cells,” the organization’s experts explain. Specifically, they say there are three key ways that hypertension can cause vascular dementia by affecting the blood supply to the brain.
The first and “most common cause of vascular dementia” is known as small vessel disease. When this occurs, the blood vessels become stiff and narrow, restricting blood flow to or within the brain.
The second is stroke, which occurs when “a blood vessel in the brain becomes blocked or bursts, cutting off the blood supply to part of the brain and causing damage.”
The third is called transient ischemic attack, also known as a TIA or mini-stroke. This causes similar damage to a stroke, but because they are smaller and can occur more frequently, the effects are more gradual.
The researchers behind the 2000 study made an additional discovery about hypertension and dementia that they found surprising. “Because of the known relation of blood pressure to stroke, an association of blood pressure to vascular dementia was not unexpected. However, we also find a strong relation of elevated diastolic mid-life blood pressure to Alzheimer’s disease,” they said.
The researchers noted that there are several reasons that hypertension may lead to increased risk of Alzheimer’s. “Hypertension has been associated with brain atrophy, large artery and small artery infarction, and white matter lesion progression, which are more common in Alzheimer’s disease cases compared to non-cases,” the team wrote. Specifically, they shared that they found “a strong relation of hypertension to the frequency of neurofibrillary tangles and neuritic plaques,” two types of brain lesions found in Alzheimer’s cases, which interfere with nerves within the brain tissue.
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Though most of the research has focused on the increased odds of dementia in those with high blood pressure, the 2000 study also determined that low blood pressure may also be a risk factor.
“In addition to high blood pressure, we also noted a tendency for subjects with low blood pressure in middle age to be at higher risk for subsequent dementia,” the researchers wrote. They added that in some individuals, low blood pressure can cause atherosclerosis (hardened arteries) and autonomic failure (according to the National Organization for Rare Disorders, controls “involuntary actions such as widening or narrowing of our blood vessels”). These two conditions can ultimately lead to hypoxia, or insufficient oxygen in bodily tissues.
If you suspect a problem with your blood pressure—whether you believe it to be high or low—it’s best to speak with your doctor about your concerns. Maintaining a healthy blood pressure now could make all the difference in your cognitive and overall health later in life.