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Taller men have a lower rate of dementia? Apparently a number of studies have found a link between height of men and risk of dementia.

The latest is an interesting Danish study that measured the height of more than 666,000 young adult men (at the physical exam for the draft) and then looked at the rates of dementia decades later when they were between 55 to 77 years of age. They found that young men that were above average in height had about a 10% lower rate of dementia more than four decades later.

The researchers thought that the early adulthood height was an indicator of early life environment (such as nutrition and childhood diseases).

What were some of the height differences? "Above average in height" was being at least 1 standard deviation above average height. For example, the researchers found that Danish men born in 1959 who had a mean (average) height of 185.6 cm (73.07") had a 10% lower rate of dementia than men of average height (179.1 cm or 70.5").

From Medical Xpress: Study suggests taller young men may have lower dementia risk

Men who are taller in young adulthood, as an indicator of early-life circumstances, may have a lower risk of dementia in old age, suggests a study published today in eLife.   ...continue reading "Tall Men Have A Lower Rate Of Dementia?"

Air pollution is a killer, but it also does damage in subtle ways - such as having effects on the brain. A recent study found that early childhood exposure to high amounts of traffic-related air pollution (city life, living next to a highway) resulted in the brain having structural changes (differences in brain volume and cortical thickness) at the age of 12 when compared to children who did not have such high exposure to traffic-related air pollution. This means that the changes were permanent.

The study was conducted in Cincinnati, Ohio, but traffic-related air pollution (TRAP) is a problem throughout the world. This type of air pollution has all sorts of gaseous pollutants, fine and ultrafine particles, heavy metals, carbon, and polycyclic aromatic hydrocarbons. Diesel exhaust may be even worse - it has more than 40 toxic pollutants. When people breathe in the pollutants, the pollutants then can travel to the brain where they can cause damage.

What will it take for governments to really accept the dangers of air pollution and to take the hard steps necessary to toughen standards? Instead of loosening all sorts of pollution standards, which is what is going on in the United States today.

[More studies about air pollution and the brain, including higher risks of dementia, millions of ultra-fine particles getting to the heart and brain and lodging there, and shrinking of brain volume.]

From Science Daily: High air pollution exposure in 1-year-olds linked to structural brain changes at age 12   ...continue reading "What Is Air Pollution From Traffic Doing To Your Brain?"

Notice that the carbon dioxide levels in the air keep rising and rising? Along with the world getting hotter, the carbon dioxide levels are rising, and last year it hit 414.7 parts per million (ppm). This is the highest it has been in at least 800,000 years, and maybe for millions of years! (It's from the burning of fossil fuels.) Soo... the big question is: What will increasingly higher CO2 levels mean for our brains - for our thinking and cognition?

Ever notice that in rooms filled with people, that the air gets stuffier over time? Well, that's the effect of carbon dioxide - as the carbon dioxide levels rise (from us simply exhaling), the air in the room feels stuffier. It can already feel stuffy at 600 ppm. Rooms with people in them (classrooms, office meetings, etc) easily hit over 1000 ppm of carbon dioxide.

Studies suggest that at certain levels of carbon dioxide our thinking gets worse. While study results vary, there does seem to be agreement that "mental processes in the domain of decision making and planning appear to be robustly affected".  And yes, a growing number of studies do find pretty scary results.

For example, one 2016 study that looked at indoor air in office buildings found that: "...seven of nine cognitive function domains tested in a strategic management simulation decreased as CO2 increased. Employee scores were 15 percent lower in a day spent working at 945 ppm, and 50 percent lower at 1,400 ppm." It means that the people weren't thinking all that well as the CO2 levels rose in the air they were breathing.

Research looking at carbon dioxide effects have generally studied the problem as an "indoor pollutant" and used the outdoor air as a comparison. But what happens when the outdoor air of the future is the "high CO2" level studied today?

Some physical effects of rising carbon dioxide exposure in humans: increased CO2 in the lungs, in the blood, and in the brain (which is associated with reduced oxygen and brain activity), increased sleepiness and anxiety (both of which harm cognitive function), and acidosis (lowered blood pH - which leads to symptoms such as restlessness and a rise in blood pressure). One study in juvenile rats found "reduced levels of neuroprotective growth factor", which harmed brain development and impaired learning and memory.

What about babies and children? Developing fetuses? The elderly? The sick?  All unknown. Also, studies looking at effects are short term, but our future (if not changed) will have us exposed to higher and higher levels of CO2 all the time.

Keep in mind that as outdoor carbon dioxide levels rise, indoor levels will also rise.  Think about it - opening a window to let in some fresh air will only give you the CO2 levels in the outside air. If that is high and feels stuffy, that's what you'll get. All the time. Why isn't everyone discussing this issue? 

Excerpts from Robinson Meyer's article at The Atlantic: The Human Brain Evolved When Carbon Dioxide Was Lower   ...continue reading "What Will Rising Carbon Dioxide Levels Do To Our Brains and Thinking Abilities?"

Are you exercising frequently? No? Perhaps you need a good motivating reason. Recent study results provide a good reason (brain health!) for all of us to exercise or do some form of of moderate physical activity for at least 2 1/2 hours per week.

A study conducted in Germany found evidence of an association between cardiorespiratory fitness and brain health, particularly in gray matter volume and total brain volume. The researchers found that higher cardiorespiratory fitness is associated with larger brain volumes in several brain regions that are involved with cognitive functioning.

The study found that exercise (which improves cardiorespiratory fitness) was especially beneficial for older adults. This is because there is some shrinkage of brain volume in normal aging, as well as in some diseases - thus want to prevent brain volume shrinkage as much as possible.

For example, one of the areas of the brain that that had greater volume with cardiorespiratory fitness was the hippocampus. The hippocampus plays a central role in memory-related functions and in stress regulation. This is an important finding because shrinking of the hippocampus (atrophy) is associated with several diseases and disorders, such as Alzheimer disease, depression, and schizophrenia.

What exactly is cardiorespiratory fitness? Cardiorespiratory fitness refers to the ability of the circulatory and respiratory systems to supply oxygen during physical activity. It is a big part of physical fitness and can be improved through regular physical activity, such as exercise. Higher cardiorespiratory fitness is associated with lower risk of heart disease and metabolic syndrome.

Bottom line: Get out and move, move, move to improve your cardiorespiratory fitness and so also benefit the brain. After all, we all want to prevent brain volume shrinkage (and cognitive decline) if at all possible. By the way, other studies also find beneficial brain effects from regular physical activity and exercise, even light physical activity.

...continue reading "Physical Activity Is Beneficial For The Brain"

Adding fluoride to municipal drinking water has been controversial for years, with much debate over benefits (prevention of tooth decay) vs health concerns. Especially worrisome are recent studies finding that fluoride in drinking water may have negative effects on children's IQ, whether the fluoride exposure occurs during pregnancy or infancy.

Canadian researchers found that babies that drank formula mixed with fluoridated water had a lower IQ at age 3 to 4 than exclusively breastfed children. [Breastfeeding results in much lower levels of fluoride exposure, even when the mothers drink fluoridated tap water. This is because only limited amounts wind up in breast milk.]

As in the USA, some Canadian communities fluoridate their water while others don't. Exposure to increasing levels of fluoride in tap water (even at government recommended "optimal" levels) was associated with lower IQ scores (especially non-verbal intellectual abilities) in the children. The more the fluoride exposure, the bigger the effect. In other words, studies suggest that fluoride is a neurotoxicant in that it negatively affects the developing brain.

What to do? Try to breastfeed your baby for 6 months. But if using formula and your municipal water has added fluoride - try to mix the formula with unfluoridated bottled water, especially water in glass bottles (because plastic leaches and has more microplastics in it.

From Beyond Pesticides: Fluoride In Science News Again, This Time For Effects On Children's IQ  ...continue reading "Time To Reconsider Adding Fluoride To Drinking Water?"

Several recent studies have highlighted the negative effects of air pollution on the brain, specifically from the tiniest particles in polluted air (called PM 2.5). These tiny particles get to the human brain and cause all sorts of damage. Even at levels within government guidelines.

Two studies found that with higher chronic (daily) exposure to PM2.5 air pollution there were structural changes to the brain. Which is negative to brain health, of course.

With chronic exposure to higher levels of  PM2.5 air pollution: one study found greater declines in memory and more Alzheimer's-like brain atrophy in older women in the USA; and the second study found that higher prenatal exposure was associated with a smaller corpus callosum (a part of the brain) later in childhood. Thus structural changes in the brain!

The tiniest particles are 2.5 micrometers or less in diameter, about 1/30th the width of human hair - and referred to as PM2.5. These fine particles are produced by all sorts of combustion, including motor vehicles, power plants, residential wood burning, agricultural burning, some industrial processes, and forest fires. Typically there is much more exposure to PM2.5 in busy urban streets, and less in quiet suburban streets.

Researchers in Barcelona, Spain found that long-term higher prenatal exposure to PM2.5 particulate matter, especially during the last trimester of pregnancy, is associated with a smaller corpus callosum in children between the ages of 8 and 12 years. This is an important finding because a smaller (reduced volume) corpus callosum is found in ADHD (attention deficit hyperactivity disorder), ASD (autism spectrum disorder), and hyperactivity. So here we see a structural change in the brain from air pollution at PM2.5 levels that are considered acceptable (within guidelines) by the European Union!

A report called The State of Global Air/2018 stated that studies show that long-term exposure to PM2.5  particles in the air "is the most consistent and robust predictor" of death from heart disease and stroke, lung cancer, and respiratory illnesses. And then there are nitrogen oxides and ozone, which are also linked to death. There are also nanoparticles (e.g., from friction of tires being used) that penetrate deep into the human body.

A 2018 The Guardian article called air pollution "the new tobacco". And that it's time to tackle this epidemic. Yup. Unfortunately, current air pollution standards are being relaxed in all sorts of ways under the current U.S. administration. Beware!

First study. Excerpts from Medical Xpress: Exposure to PM 2.5 pollution linked to brain atrophy, memory decline  ...continue reading "Air Pollution and the Brain, Part 1"

Generations of people were raised thinking that when a person sleeps, that the brain is also resting. Well.... that was then, but the new view is that when we are sleeping, a number of important things are occurring. A main activity during sleep is that the brain is flushing out the garbage, that is, waste products or toxins. [Some other stuff going on includes cell repair, building of bone and muscle, memory consolidation, and strengthening of the immune system.]

A team of Boston researchers found that first a wave of electrical signal in the neurons of the brain occurs (known as a slow wave), and seconds after that a pulse of cerebrospinal fluid washes through the brain. Cerebrospinal fluid (CSF) is the liquid that flows through the brain and spinal cord. The researchers, who studied sleeping humans, said that the waves were like a really slow wash cycle in the brain, and that this was happening every 20 seconds during deep sleep (non-rapid eye movement sleep). Their thinking is that the fluid washes away toxins associated with Alzheimer's disease.

Bottom line: Make sure to get enough sleep! Your health depends on it.

From NPR: How Deep Sleep May Help The Brain Clear Alzheimer's Toxins

The brain waves generated during deep sleep appear to trigger a cleaning system in the brain that protects it against Alzheimer's and other neurodegenerative diseases.  ...continue reading "The Brain Flushes Out Waste and Toxins During Deep Sleep"

The evidence is building, study by study, that we are all exposed to a mixture of hormone disrupting chemicals (endocrine disruptors) on a daily basis, and that these have serious health effects, including on the developing fetus during pregnancy. Researchers found that early prenatal exposure to a mixture of endocrine disrupting chemicals  was associated with lower levels of cognitive functioning (lower IQ scores) at age seven, particularly among boys.

Researchers in New York City and Sweden looked at the impact of 26 endocrine disrupting chemicals during pregnancy on 718 Swedish mother-child pairs. It appeared that the higher the exposure during pregnancy, the more of an effect at age 7. Especially harmful was the BPA replacement chemical BPF - this is because it is chemically related to BPA.

Endocrine disrupting chemicals (EDCs) include bisphenols (BPA and its replacement  chemicals, such as BPF - used in products called "BPA free"), phthalates (especially used in vinyl products), parabens, chemicals used in flame retardants and non-stick coatings,  and some pesticides (e.g. the commonly used chlorpyrifos).

Especially worrisome is that while scientists typically test chemicals one at a time to determine their safety, in the real world we are all exposed to mixtures of these chemicals in our food, consumer products (including personal care products and cosmetics), and environment. Some of these chemicals can cross the placenta during pregnancy and so have an effect on the developing the fetus, including brain and neurological development. Yes, some of these chemicals are only in the body for a short time, but during critical developmental  stages, the effects can be big - even at very low exposures.

Bottom line: If trying to conceive a child or during pregnancy, try to minimize exposure to plastics, pesticides, flame retardants, non-stick cookware, stain-proofing (in fabric and rugs), fragrances and scented products (including air fresheners and dryer sheets), and food stored in cans and plastic containers. Avoid triclosan, anti-odor, antibacterial, anti-germ products and clothing. Avoid parabens (in lotions, etc). Read labels. Glass and stainless steel is perfectly fine. Use unscented or fragrance free products as much as possible.

From Medical Xpress: Chemicals in consumer products during early pregnancy related to lower IQ   ...continue reading "Pregnancy, Endocrine Disrupting Chemicals, and Lower IQ"

Very depressing news about football. A study looking at those who played football long-term (as a career in adulthood) found that for every year of playing tackle football (lots of pounding and repeated head collisions), a person's risk of developing chronic traumatic encephalopathy (CTE) increases by 30%. The researchers from the Boston Univ. School of Medicine arrived at this conclusion after looking at 266 deceased former amateur and professional football players.

What was different about this study was that they compared football players who did not develop CTE with those who did - so the researchers thought it was representative of career football players.

The study results make total sense, but are horrifying because of all the children in the US growing up and playing tackle football from a young age. Other studies find brain changes from just playing some semesters in high school or college or before the age of 12.

From Futurity: CTE RISK GOES UP 30% FOR EACH YEAR OF PLAYING FOOTBALL  ...continue reading "Football May Not Be A Good Career Choice"

Walking is important for health, but walking speed is also important. It turns out that slow walking speed or gait (particularly when trying to walk as fast as possible) is a problem sign already in mid-life (the 40s). Researchers found that slow walking speed is a sign of "accelerated aging",  and that slow walkers exhibited such signs as reduced brain volume, cortical thinning, and reduced brain surface area.

The Duke University researchers found that a slow walking speed at midlife was associated with poorer mental functioning, and that there was an average difference of 16 IQ points between the slowest and fastest walkers. The researchers point out that this matches other studies showing that there is an association of slow walking speed of older adults and cognitive impairment and risk of dementia. The researchers viewed midlife gait speed as a summary of life-long aging, and felt that some differences were apparent already at the age of three. [This was a 5 decade long study in New Zealand of 904 persons.]

From Medical Xpress: Slower walkers have older brains and bodies at 45

The walking speed of 45-year-olds, particularly their fastest walking speed without running, can be used as a marker of their aging brains and bodies ...continue reading "Are You A Slow Or Fast Walker?"