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Category: brain

Published on Leave a comment on Loss of Smell from A COVID Infection Can Linger For At Least Two Years

Millions of us have had a least one COVID infection. Many suffered a loss of smell during the infection. A recent study by NYU Langone researchers found that the loss of smell can linger for at least 2 years after the infection. And even if you thought that your smell was never impacted or that it has recovered, it actually may not have fully recovered, but only partially recovered.

Among the 3525 participants in the study that reported a loss of smell during a COVID infection - 80% still  had not fully recovered their sense of smell 2 years later, and for 23% it was severely diminished or lost. Interestingly, 66% of persons who originally had a COVID infection, but did not notice any smelling issues, also scored abnormally low on the evaluation done 2 years after the infection.

It can be said that their sense of smell has dulled (olfactory dysfunction). This reduced ability to smell is called hyposmia. Researchers administer a 40-odor test to persons to determine their smelling ability. To help recover the sense of smell, vitamin A supplementation and olfactory training are being tried.

From Science Daily: Millions could be living with hidden smell loss after COVID without knowing

People who suspect that their sense of smell has been dulled after a bout of COVID-19 are likely correct, a new study using an objective, 40-odor test shows. Even those who do not notice any olfactory issues may be impaired. ...continue reading "Loss of Smell from A COVID Infection Can Linger For At Least Two Years"

Published on Leave a comment on Commonly Used Chemical and Parkinson’s Disease

Over and over studies have found links with certain toxic chemicals (some pesticides and the chemical trichloroethylene) and Parkinson's disease. Another recent study found that long-term exposure to high levels of the chemical trichloroethylene (TCE) in the outside air increases the risk of developing Parkinson's disease.

TCE is an industrial solvent used in numerous industrial (as a degreaser), consumer, military, and medical applications. For example, it is used in dry cleaning clothes, removing paint, as a degreaser, carpet cleaner, and engine cleaner. Unfortunately, since it is environmentally persistent, it lingers in the air, water (e.g., in the military base Camp Lejeune), and soil across the US.

Bottom line: Outdoor air pollution also matters, not just the chemicals you are directly exposed to (e.g., in your job). TCE is a hazardous air pollutant, so avoid living (if you can) near a TCE emitting facility (especially in Lebanon, Oregon and Corydon, IN) because the risk of developing Parkinson's disease is the highest for people living near there.

From Science Daily: The invisible chemical in the air that could be raising Parkinson’s risk

Long-term exposure to the industrial solvent trichloroethylene (TCE) outdoors may be linked to an increased risk of Parkinson's disease, according to a large nationwide study published in the October 1, 2025, issue of Neurology, the medical journal of the American Academy of Neurology. ...continue reading "Commonly Used Chemical and Parkinson’s Disease"

Published on Leave a comment on Lifestyle Changes That Benefit the Aging Brain

As people age, they frequently start wondering what they can do to prevent memory and thinking problems, and especially dementia. The good news is that several large studies found that there are a number of lifestyle changes that one can do to have a healthier (memory! thinking!) brain in later years. Even if you are already in your 60s and 70s.

The evidence points to diet (e.g., Mediterranean style diet, ), exercise, and socializing being all important for brain health. In fact, it can result in keeping brains several years "younger" than in those with unhealthy lifestyles. Also, studies find that challenging your brain by learning something new, such as learning a new language or musical instrument or online cognitive training, is beneficial for the brain.

Adopting a lifestyle that promotes brain health is so very important, because it is NORMAL that as we age, there are brain changes, including brain shrinkage (volume of the brain). Therefore you want to slow down or delay these age related changes as much as possible. Researchers feel that adopting these lifestyle changes are so effective that they should be medically prescribed.

Excerpts from NPR: Trying to keep your brain young? A big new study finds these lifestyle changes help

Scientists have unveiled the strongest evidence yet that a combination of diet, exercise and brain training can improve thinking and memory in older Americans.

A study of more than 2,100 sedentary people in their 60s and 70s found that those who spent two years on the intensive regimen not only improved their mental abilities but appeared to reduce the usual declines associated with aging. ...continue reading "Lifestyle Changes That Benefit the Aging Brain"

Published on Leave a comment on Subtle Brain Changes From Heading Soccer Balls
Soccer ball Credit: Wikipedia

Many studies have discussed the short-term and long-term harm to the brain from both concussions and sub-concussions in athletes playing tackle football. But relatively little has been said about the possibility of similar harm from soccer. A recent study found that heading a soccer ball results in subtle brain changes, even when there isn't a concussion.

The well-done study of 15 adult male soccer players looked whether there are brain changes after a routine "heading" task (heading the ball 20 times in 20 minutes) and after a routine "kicking" task (the tasks were routine soccer exercises). Blood samples and MRIs of the brain were taken after each task, as well as cognitive function assessments.

There were subtle brain changes seen in the MRIs, as well as inflammatory markers present in the blood after the soccer heading task, but not after the kicking task. As the researchers concluded: "non-concussive impacts, specifically those administered in the form of a controlled SHT, can alter select markers of brain function, chemistry and microstructure in male soccer players." Additionally, "heading decreased tissue conductivity in 11 areas of white matter of the brain".

The big question is what does heading of soccer balls, many times over a lifetime, do to the brain? Increased rates of dementia?

Bottom line: Heading soccer balls, even when done as part of soccer practice, causes subtle changes in certain areas of the brain. Be cautious!

From Medical Xpress: Heading soccer balls can cause changes in the brain even without concussion or symptoms

Heading a soccer ball alters the brain, new research spearheaded by the University of Sydney has found, despite having no immediate impact on cognition. ...continue reading "Subtle Brain Changes From Heading Soccer Balls"

Published on Leave a comment on Living Near A Golf Course Increases Risk of Parkinson’s Disease

Many people think that living next to a golf course is wonderful, thinking that it's lots of open space. But... it also comes with exposure to all the pesticides used on golf course lawns (pesticides drift through the air to neighboring properties and also get into water). Unfortunately, pesticides can cause health harms, including Parkinson's disease.

A recent study found that the closer a person lives next to a golf course, the higher the incidence of Parkinson's disease. In fact, living within a mile of a golf course is associated with a 126% increased risk for Parkinson's disease. The biggest risk was for individuals living 1 to 3 miles from a golf course.

Additionally, drinking water from groundwater that includes a water source from a golf course was associated with an almost two-fold increased risk for Parkinson's disease (due to drinking water contamination).

While this observational study showed an association with Parkinson's disease, other studies also show that exposure to certain pesticides increases the risk of Parkinson's disease. Some of the pesticides linked to increase risk of Parkinson's disease: 2,4-D, chlorpyrifos, MCPP, maneb, paraquat, and rotenone. (Note that pesticides such as 2,4-D are also commonly found in feed and weed products.)

Another disturbing thing to keep in mind is that American golf courses use greater amounts and more pesticides, including pesticides that are banned in Europe, compared to European golf courses. Just think of weed-free carpet-like lawns as poison lawns.

Excerpts from Medical Xpress: Golf course proximity linked to higher Parkinson's disease risk

Barrow Neurological Institute and Mayo Clinic-led researchers report an association between living near golf courses and increased Parkinson's disease (PD) risk in a study published in JAMA Network Open. ...continue reading "Living Near A Golf Course Increases Risk of Parkinson’s Disease"

Published on Leave a comment on The Sugar Substitute Erythritol And the Brain’s Blood Vessels

Once again artificial sweeteners are in the news, and not in a good way. New research found that the sugar substitute erythritol, at a concentration typically found in an artificially sweetened beverage, has harmful effects on the small blood vessels of the brain.

Erythritol crosses the blood brain barrier and interacts with the brain's cerebrovasculature (the blood vessels in the brain, including the arteries, veins, and capillaries that supply blood and nutrients to the brain tissue). This study focused on the smallest blood vessels (microvascular) in the brain. And yes, found that the amount or erythritol in 1 diet beverage has adverse effects at a cellular level on these blood vessels.

This study was done in a lab setting (and not directly on humans), but research results match up with other studies on erythritol. Other studies already found that erythritol increases the risk of heart attacks, heart disease, strokes, as well as blood clot formation. This study's results give an explanation for why there is a increased risk of these brain vascular (blood vessel) events happening.

Erythritol is found in some beverages advertised as low or zero calorie (e.g., Monster Zero energy drinks, Blue Sky Zero Sugar soda, Red Bull Zero) and in some low calorie foods (e.g., Halo Top low-calorie ice cream). Read ingredient lists on labels!

From Medical Xpress: Major sugar substitute found to impair brain blood vessel cell function, posing potential stroke risk

Erythritol may impair cellular functions essential to maintaining brain blood vessel health, according to researchers at the University of Colorado Boulder. Findings suggest that erythritol increases oxidative stress, disrupts nitric oxide signaling, raises vasoconstrictive peptide production, and diminishes clot-dissolving capacity in human brain microvascular endothelial cells. ...continue reading "The Sugar Substitute Erythritol And the Brain’s Blood Vessels"

Published on Leave a comment on Woman Dies After Using Contaminated Water For Nasal Rinses
Naegleria fowleri Credit: CDC

Saline nasal rinses have become very popular, usually to ease symptoms of nasal congestion during colds, allergies, or sinus infections. It is very important to only use boiled (and cooled), commercially bottled, sterile, or distilled water for nasal rinses to make sure any harmful microbes and organisms in the water are killed. One person in Texas ignored this advice and paid with her life.

The woman used nonboiled water from the RV faucet (in her RV vehicle), which was unfortunately contaminated with the amoeba Naegleria fowleri. This amoeba traveled to her brain and caused primary amebic meningoencephalitis (PAM), also known as Naegleriasis. Which is almost always fatal. In her case, she died within 8 days from the first symptoms.

Authorities were unable to determine if the amoeba was in the RV campsite drinking system or if it was picked up in another site when filling up her RV's water. But, they did point out that drinking water contaminated with Naegleria fowleri does not cause problems. It is only a problem when rinsing contaminated water into the nasal passages and sinuses - the amoeba can then travel to the brain.

As the CDC points out on its web-site (also see page on safe nasal rinsing):

"Germs such as the amebas Naegleria fowleri and Acanthamoeba can grow in public and private water tanks and pipes. They can also grow in the pipes and water heaters in some homes and buildings.

Naegleria fowleri and Acanthamoeba can pose a serious risk to your health if they are in the water you use to rinse your sinuses or nasal passages. If the amebas go up the nose and to the brain, they can cause nearly always fatal brain infections. Although rare, people have died from rinsing their sinuses with tap water containing Naegleria fowleri and Acanthamoeba."

From CIDRAP (The Center for Infectious Disease Research and Policy at the Univ. of Minnesota): Woman dies from brain ameba after flushing nose with RV water

A previously healthy 71-year-old woman in Texas died within 2 weeks of using tap water from a recreational vehicle (RV) for nasal irrigation. She was diagnosed as having primary amebic meningoencephalitis (PAM) a rare, often fatal brain infection caused by the ameba Naegleria fowleri, according to a report yesterday in Morbidity and Mortality Weekly Report. ...continue reading "Woman Dies After Using Contaminated Water For Nasal Rinses"

Published on Leave a comment on Herpes Simplex Virus and Alzheimer’s Disease

Over the past decade there has been as increasing amount of research suggesting that the herpes virus (cold sores!) is implicated in the development of Alzheimer's disease. (here, here, here).

A recent study suggests the same possibility - herpes simplex 1 (HSV-1) has a role in the development of Alzheimer's disease. And treating cold sores with antiviral therapy (antiherpetic medications) results in a reduced risk of developing Alzheimer's disease - thus the antivirals are protective.

The researchers found that having herpes virus type 2 (genital herpes) and varicella zoster virus (chicken pox, shingles) also resulted in increased risk of later developing Alzheimer's disease. But infection with cytomegalovirus was not.

From Medical Xpress: Cold sore viral infection implicated in development of  Alzheimer's disease

Symptomatic infection with the virus responsible for cold sores around the mouth–herpes simplex 1, or HSV-1 for short—may have a key role in the development of Alzheimer's disease, suggests a large US study published in BMJ Open. ...continue reading "Herpes Simplex Virus and Alzheimer’s Disease"

Published on Leave a comment on Exercise, Insulin, and the Brain

Studies find that exercise or physical activity improves the functioning of the brain, including memory and overall cognition. In a recent study, almost two weeks of exercise by older adults improved brain insulin signaling - that is, it improved the abilities of insulin to act on the brain by increasing "neuronal extracellular vesicles".

The study found these beneficial effects on a group of sedentary adults (average age 60) with prediabetes, who are at higher risk for Alzheimer's disease and dementia.

The participants exercised twelve times (60 minutes per day) by using a stationary bicycle (cycle ergometry exercise) over a 13 day period. So quick and simple, but it resulted in health benefits for the brain.

From Science Daily: Exercise improves brain function, possibly reducing dementia risk

A study led by scientists at Rutgers University-New Brunswick has shown that specialized cells involved in how the body responds to insulin are activated in the brain after exercise, suggesting that physical activity may directly improve brain function. ...continue reading "Exercise, Insulin, and the Brain"

Published on Leave a comment on Exercise Boosts Brain Function At All Ages

Exercise boosts brain function at all ages. This means that for both young and old, it is worth it to get out and engage in physical activity.

A large study reviewed other studies (for a total of 258,279 persons) on effects of exercise on brain functioning. They found that exercise, even light exercise, boosts brain function (specifically general cognition and executive function) and memory. Executive function refers to mental processes (executive functioning skills) that help you solve problems, make plans, set and carry out goals, and manage emotions.

The researchers concluded that most forms of exercise appear effective, including light-intensity activities, and even yoga, Tai Chi, and walking. The positive effects were found at all ages, and in all groups studied. There seemed to be an especially strong effect in persons with ADHD

From Science Daily: Exercise of any kind boosts brainpower at any age

Whether it's an early morning jog, or a touch of Tai Chi, groundbreaking research from the University of South Australia shows that any form of exercise can significantly boost brain function and memory across children, adults, and older adults. ...continue reading "Exercise Boosts Brain Function At All Ages"