Diuretics and Cognitive Health: Delaying Alzheimer's Disease?

Many different things can contribute to Alzheimer's disease or dementia. Old age is the most well-known. But other factors include:¹

1. Lack of sleep
2. Family history
3. Heart disease
4. High blood pressure (hypertension)

Researchers looking to address dementia in older people have recently been focusing on hypertension. Hypertension has been shown to cause changes in brain structure. These changes could possibly affect dementia. Compared with people whose blood pressure was well controlled, people with poorly controlled hypertension scored much lower on tests of:¹

• Thinking (cognition)
• Attention
• Executive function

Because of these differences, doctors have been looking into the best ways to fix hypertension while also helping to reduce the risk of dementia. One of these ways is by using a diuretic. Diuretics are a class of drugs that are commonly used to fight high blood pressure (antihypertensive drugs).¹

There are no current guidelines around using diuretics to possibly prevent dementia. The evidence is not entirely certain one way or the other. But doctors do agree that keeping your heart and blood vessels healthy (good cardiovascular health) is crucial for delaying Alzheimer's and dementia.^1-3

The effects of diuretics on cognition

Diuretics have a generally positive effect on cognition, though this is somewhat debated in studies. Many studies have found that people who use diuretics have improved verbal learning and memory compared to people who do not.¹

In particular, a type of diuretic called "potassium-sparing" was effective for improving verbal learning and memory. Potassium-sparing diuretics also have been shown to decrease Alzheimer's risk. It is possible that these drugs work best because having lower potassium levels has been linked to Alzheimer's and dementia.¹

Antihypertensives, in general, have a similar effect to potassium-sparing diuretics. But the effect of these other drugs is not necessarily as strong. The following antihypertensive drugs have been linked to lower Alzheimer's risk:¹

• Diuretics
• Angiotensin receptor blockers
• ACE (angiotensin-converting enzyme) inhibitors
• Beta blockers

People who took these drugs also had a higher rate of living free of Alzheimer's than people who did not. But there is disagreement about the usefulness of diuretics in connection to the disease. Some studies have found that diuretics can help to protect against Alzheimer's; other antihypertensive may not. Other studies question whether diuretics are even helpful.^1,2

There may be disagreement about whether antihypertensives are helpful. And though most studies found that diuretics can help reduce Alzheimer's risk, there may be other factors involved. Doctors are continuing to look into exactly how these drugs can be helpful for the most people possible.

The importance of heart health in delaying Alzheimer's and dementia

One of the things that doctors do agree on is the importance of cardiovascular health for slowing or stopping Alzheimer's and dementia. High blood pressure is one of the main risk factors for dementia. It is also one of the risk factors that are easier to control with the proper guidance of a doctor.²

Treatments to lower your blood pressure are readily available. Though there is conflicting evidence on which drug is best for cognition, heart health, in general, is still very important. Scientists are confident that people who control their hypertension and heart health are at lower risk of Alzheimer's and dementia.^1,2

White matter lesions

There are a few possible reasons why heart health is considered so crucial. One of the main theories is that a healthy heart is important for controlling "white matter lesions." These are small nicks in the pathways that transmit information in the brain. The lesions are known to contribute to dementia.^1-3

People with hypertension who have these lesions perform much worse in cognitive testing than people who have hypertension but without the lesions. This difference emphasizes the connection between hypertension, white matter lesions, and cognitive function.¹

The connection between heart health and dementia

The connection between cardiovascular health, Alzheimer's, dementia, and diuretics is still being explored. But in any case, keeping your heart healthy can be helpful for slowing the progression of Alzheimer's and dementia. If you have hypertension, talk to your doctor about what treatments may be right for you.