High Blood Pressure and Alzheimer’s Risk

blood pressure and alzheimer's

New research suggests there may be a link between hypertension or high blood pressure and Alzheimer’s disease (AD).

High blood pressure occurs when the force of blood pushing against blood vessels becomes too high.

This can cause harm because it stresses not only the blood vessels but the heart as well.

The blood vessels cease to function properly because they have to work harder than normal.

Over time, the arteries will become narrower which can result in problems such as stroke, kidney failure, or heart disease.

Damaged small blood vessels can also negatively affect the sections of the brain responsible for memory and thinking.

Blood Pressure and Alzheimer’s Risk

Persons with higher blood pressure are also more likely to have brain lesions. These are the areas of dead tissues that develop because of low blood supply.

AHA statistics report that about 46% of America’s adult population has blood pressure. Not to mention, 16% do not even know they have the condition.

Alzheimer’s disease is the most common cause of dementia.

Dementia is a general term for the progressive loss of memory and other cognitive abilities that can seriously interfere with a person’s day-to-day life.

High blood pressure can affect the brain

high blood pressure can affect the brain
Scientists believe that hypertension can also affect a person’s brain to the extent of developing some of the main markers for AD.

A study published in Neurology states that seniors who have higher average blood pressure compared to their age-mates are more likely to develop plaques and tangles in the brain which are both markers for Alzheimer’s.

The study had 1,288 participants who were 65 years and older. The researchers conducted annual cognitive testing and blood pressure checks on the subjects.

Moreover, experts also kept track of the medications the participants took and their medical histories. They also agreed to go through a brain autopsy after death to look for signs of brain aging like plaques and tangles.

Researchers discovered that persons who had higher than average blood pressure had more dead tissues resulting from strokes (blocked blood flow) as well as tangles and plaques.

Dr. Claudia Padilla, a neurologist, explained that plaques and tangles happen when proteins that the body produces break down into toxic forms which significantly affect neurons in the brain.

Director of global science initiatives at Alzheimer’s Association, James Hendrix, Ph.D. notes that damage that the toxic proteins cause is only part of the problem.

He said that lack of sufficient blood flow affects how the brain works around damaged tissue which can worsen symptoms of brain tissue damage.

Hypertension may not be the warning sign of AD

hypertension may not be the warning sign of AD
Padilla also stated that because this was an observational study on the relationship between blood pressure and Alzheimer’s disease, the results do not prove that hypertension causes warning signs of AD.

The study did not determine how higher average late-life blood pressure ends up increasing plaques and tangles in the brain.

However, she added that the study found a clear association between higher blood pressure in late life and the presence of protein plaques and tangles which are symptoms of Alzheimer’s disease.

Based on the findings of the study, Padilla considers it important to control blood pressure as a strategy for preventing cognitive decline.

In another interesting study on the relationship between blood pressure and Alzheimer’s, a Johns Hopkins analysis of formerly gathered data revealed that individuals who took prescribed blood pressure medication were half as likely to develop AD than those who did not.

The report established earlier work from researchers at Johns Hopkins who found that using potassium-sparing diuretics reduced the risk of Alzheimer’s by about 75%.

The risk was reduced by a third for persons who used any kind of antihypertensive drugs. Director of Johns Hopkins Memory and Alzheimer’s Treatment Constantine Lyketsos, M.D said that they found that if a person did not have Alzheimer’s and they were taking blood pressure medication, they were less likely to develop dementia.

He continues to say that if a person developed dementia from AD and was taking certain antihypertensive, the illness was less likely to progress.

They were not sure if this connection arises from better management of blood pressure or there are specific drugs that end up interfering with processes that relate to AD. Lyketsos suspected that both play a role.

Controlling your levels of blood pressure is important

controlling your levels of blood pressure is important
An in-depth examination of long-term data from 4 countries by a team of global scientists also supported the idea that controlling high blood pressure can reduce the risk of Alzheimer’s.

The experts cross-referenced data from 6 large longitudinal studies. They observed the heath of more than 31,000 adults who were 55 years and above.

The scientists analyzed data from community-based comprehensive health studies conducted between 1987 and 2008 in France, United States, Netherlands, and Iceland.

They looked into 5 primary types of blood pressure drugs diuretics, ACE inhibitors, calcium channel blockers, beta-blockers, and angiotensin II receptor blockers.

The data was divided into 2 groups; 15, 553 people with normal blood pressure, and 15,537 people with high blood pressure.

In all, there were 1,741 Alzheimer’s disease diagnoses over time.

The results showed that treating hypertension reduced the risk of developing Alzheimer’s by 16% regardless of the type of antihypertensive medication a person was on.

In other words, it is important to take the link between lowering blood pressure and Alzheimer’s risk seriously.

High blood pressure medication can boost blood flow to the brain

high blood pressure medication can boost blood flow to the brain
A small clinical trial also revealed that using blood pressure medication for treatment can enhance blood flow to key brain regions in persons with Alzheimer’s disease.

The research was part of a larger trial that was looking into whether nilvadipine could improve thinking and memory skills with persons with Alzheimer’s.

It involved a trial of 44 participants who had mild to moderate AD. The average age of the participants was 77 years.

They were randomly assigned to either use blood pressure medication nilvadipine or inactive placebo pills for 6 months. At the end of the trial, specialized MRI scans showed the persons on the drugs recorded a 20% increase in blood flow to the hippocampus.

This is the structure of the brain that is involved in learning and memory.

These are the first areas that Alzheimer’s damages.

Persons on the real drug also indicated that their blood pressure dropped by eleven points when compared to the group that was on the placebo.

Experts, however, acknowledged that the size of the study was too small and short.

Unfortunately, it is impossible to conclusively indicate whether enhanced blood flow could have effects on the symptoms.

The lead author Dr. Jurgen Claassen hoped that future research could give a better answer to the query and it should mostly focus on persons with early Alzheimer’s.

He, however, explained that persons with early-stage AD showed benefits.

Closing Remarks

Even though several studies have linked high blood pressure to Alzheimer’s symptoms more research is still required.

The findings of the studies affirm that what’s good for the heart is also good for the brain.

We can reduce hypertension through various lifestyle changes like physical exercise, eating a healthy diet, and reducing sodium. Some medications can also help lower blood pressure.

Dementia and High Blood Pressure

dementia and high blood pressure

Numerous research studies confirm that there is a link between dementia and high blood pressure.

High blood pressure also known as hypertension is a chronic condition where the force of blood against the artery walls becomes too high causing various health problems including strokes and heart attacks.

Hypertension is known to cause progressive brain damage.

Blood pressure usually measures the force that is applied to the arteries as blood is circulated by the heart around the body.

Normal blood pressure should read about 120/80 mmHg. Hypertension is constantly above 140/90 mmHg.

Common risk factors for high blood pressure include an unhealthy diet comprising mostly salty foods, lack of exercise, excessive alcohol consumption, being obese or overweight, taking steroid medication, drinking lots of caffeine and kidney disease.

Also, everyone in the family with a history of hypertension is at risk, as well as those of Caribbean or African descent.

Dementia is a general term that is used to describe problems with memory, problem-solving, language, and other thinking abilities that end up interfering with a person’s day-to-day life.

The disease is progressive implying that the symptoms will become worse over time.

Research on Dementia and High Blood Pressure

research on dementia and high blood pressure
The World Alzheimer Report 2014 states that several studies observing large groups of individuals demonstrated that people with hypertension especially in mid-life were at high risk of developing vascular dementia one of the most common kinds of dementia later on in life.

The subjects were between the ages of 15-40 while mid-life was characterized by people between the ages of 40-64.

Vascular dementia occurs when there is an inadequate flow of blood to the brain which denies the organ essential nutrients and oxygen it needs to function properly.

People with hypertension are at higher risk

people with hypertension are at higher risk for dementia
A study published by Oxford University Press in Cardiovascular Research also reports that persons who have hypertension are at a higher risk of getting dementia.

For the first time, the research also reveals that doctors can conduct an MRI to detect neurological damage for persons with high blood pressure before dementia symptoms occur.

Researchers came to this conclusion after subjecting individuals between the ages of 40-65 to undergo a 3 Tesla MRI scan at the Regional Excellent Hypertension Centre of the Italian Society of Hypertension of the I.R.C.C.S.

The participants of the study did not have a dementia diagnosis or any structural damage.

The subjects also underwent clinical examinations to know their hypertensive status as well as damage to the target organ.

They were also subjected to an MRI scan to identify any microstructural damage.

The results indicated that hypersensitive participants had major alternations in 3 specific white matter fiber tracts.

The group also scored worse in cognitive tests and decreased performances in memory, speed, and learning-related tasks.

This goes to show that it is possible to detect changes before a person starts showcasing symptoms. Medics can then offer medication that will prevent further deterioration in regard to brain function.

Hypertension medication and dementia

hypertension medication and dementia
Another study worth mentioning about dementia and high blood pressure was conducted at the John Hopkins University.

Experts analyzed previously gathered data to report that persons taking hypertension medication were half as likely to end up with Alzheimer’s (the most common cause of dementia) when compared to the people who do not take the drugs.

Constantine Lyketsos, director of Memory and Alzheimer’s treatment at John Hopkins explained that people who do not have Alzheimer’s but are taking blood pressure drugs were less likely to develop dementia.

He went ahead to say that individuals who got dementia from Alzheimer’s and were taking specific antihypertensives were likely to experience slow or halt progress.

He concluded that it was still not clear where this connection arises.

It can either be from better management of blood pressure or some medications that may have some properties that interfere with some of the processes that relate to Alzheimer’s.

Women with high blood pressure are more like to get dementia

women with high blood pressure are more like to get dementia
A sex-specific study reveals that women who experience hypertension in their 40’s are 73% more likely to get dementia later in life when compared to the ladies who did not have high blood pressure.

This was in a bid to determine how dementia strikes women and men differently.

Experts who conducted the study said they adjusted the results for other risk factors that can also lead to dementia including diabetes, smoking, and obesity which held true for all races.

This, however, was not the same case for men even though hypertension was more common among the male fraternity. The study that was published in the American Academy of Neurology journal observed more than 7,000 individuals.

The participants went through blood pressure checks at the age of 33 and again at 44 in the 60s and 70s. Researchers began to follow up to see the persons who developed dementia in 1996.

The results indicated that ladies who had hypertension in their 30’s did not have a higher dementia risk as compared to those with high blood pressure in their 40’s.

How Hypertension Affects the Brain

how hypertension affects the brain
There are several ways high blood pressure affects the function of the brain. One of them is that over time, hypertension causes strain on the arteries.

This makes the artery walls become stiffer, thicker, and narrower a condition known as arteriosclerosis.

When this happens, the brain is deprived of important oxygen and nutrients which results in damaged brain cells that negatively affect the functioning of the brain.

Hypertension is also one of the major stroke risk factors.

One of the major reasons that cause strokes is the blockage of arteries in the brain which is usually a result of hardening arteries.

A stroke can also occur when an artery in the brain burst causing bleeding in the organ. Strokes can result in post-stroke or stroke-related vascular dementia.

When talking about dementia and high blood pressure, it is also important to mention that hypertension can damage small blood vessels in the brain.

This can affect the parts of the brain responsible for memory and thinking.

Closing Remarks

Even though the link between vascular dementia and high blood pressure is quite apparent, there is still no proof that lowering blood pressure can help to prevent the development of dementia.

More research needs to be done to identify the link between hypertension and dementia to see if anything can be done to prevent or treat dementia.

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