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Published on Leave a comment on Gut Bacteria Associated With Strokes

After writing about Lactobacillus sakei in the sinuses for several years (present in healthy sinuses, absent or less in those with chronic sinusitis, and also a treatment for chronic sinusitis), I wondered whether L. sakei is found anywhere else in the body. Today I read a study (conducted in Japan) about gut microbes and strokes and there it was - the presence of L. sakei in the gut.

Specifically, a study found that people who have ischemic strokes tend to have lower amounts ("depletion") of L. sakei in the gut than healthy people, even though it was detected in 80% of both groups.

The study found that in people with ischemic strokes there was evidence for the gut microbes being out of whack (dysbiosis), as well as more inflammation, and more of certain bacteria species (Atopobium cluster and Lactobacillus ruminis), and depletion of L. sakei bacteria.

The researchers took samples of stool (fecal samples) from each person of both groups (ischemic stroke group and healthy group) and analyzed the stool with modern tests (genetic sequencing) to see whether 22 groups of bacteria were in it. (Note that there are normally hundreds of species of bacteria living in a healthy person's gut, as well as viruses, fungi, etc.).

So once again it looks like L. sakei may be beneficial bacteria, even in the gut. The researchers were careful to point out that they couldn't say that certain bacteria caused the strokes - just that there was an association.

And what diet is associated with lower levels of inflammation in the body? Once again - a diet with lots of fruits, vegetables, whole grains, nuts, seeds, and legumes (think Mediterranean style diet). You want to feed the beneficial bacteria in the gut.

Excerpts from a research article by Yamashiro et al in PLoS One: Gut dysbiosis is associated with metabolism and systemic inflammation in patients with ischemic stroke

The role of metabolic diseases in ischemic stroke has become a primary concern in both research and clinical practice. Increasing evidence suggests that dysbiosis is associated with metabolic diseases. The aim of this study was to investigate whether the gut microbiota, as well as concentrations of organic acids, the major products of dietary fiber fermentation by the gut microbiota, are altered in patients with ischemic stroke, and to examine the association between these changes and host metabolism and inflammation.

We analyzed the composition of the fecal gut microbiota and the concentrations of fecal organic acids in 41 ischemic stroke patients and 40 control subjects via 16S and 23S rRNA-targeted quantitative reverse transcription (qRT)-PCR and high-performance liquid chromatography analyses..... Although only the bacterial counts of Lactobacillus ruminis were significantly higher in stroke patients compared to controls, multivariable analysis showed that ischemic stroke was independently associated with increased bacterial counts of Atopobium cluster and Lactobacillus ruminis, and decreased numbers of Lactobacillus sakei subgroup, independent of age, hypertension, and type 2 diabetes....Together, our findings suggest that gut dysbiosis in patients with ischemic stroke is associated with host metabolism and inflammation.   ...continue reading "Gut Bacteria Associated With Strokes"

Published on Leave a comment on Should Pregnant Women Be Warned To Avoid Licorice?

Avoid eating licorice during pregnancy? That licorice is a food to avoid during pregnancy (or only eat in tiny amounts) will be news to many. Most people think of licorice (or liquorice) as a candy, but it can also be used as a herbal medicine that can have negative health effects, especially in large doses (e.g, high blood pressure, loss of potassium). The licorice flavor comes from the root of the plant (licorice root). Licorice contains glycyrrhizin, which is in black licorice candy, and in some chewing gums, ice creams, syrups, soft drinks, supplements, herbal teas, and other products.

In 2016, the government of Finland warned against consuming licorice (including black licorice and salty licorice) during pregnancy. In the United States, the FDA does not warn pregnant women about eating licorice or licorice root. The National Institutes of Health (NIH) recommends that pregnant women avoid consuming large amounts of licorice root in food or taking it as a supplement. But how about small amounts of licorice? And what are possible effects during pregnancy?

A recent study in Finland compared children (average age of 12 1/2 years) whose mothers had either consumed little to no licorice during pregnancy or had consumed large amounts of licorice (high glycyrrhizin levels were calculated as more than 500 milligrams per week). Note that 500 mg glycyrrhizin is equal to 250 grams or 8.8 oz licorice. The researchers found that children whose mothers ate large amounts of licorice during pregnancy  were about 7 points lower on IQ tests, had poorer memory, and had higher rates of attention deficit/hyperactivity disorder problems than those whose mothers had eaten little or no licorice during pregnancy. High-consumption group girls had earlier and more advanced puberty, and were taller and heavier than those in the low-licorice group.

The researchers wrote that glycyrrhizin results in "glucocorticoid overexposure", which may affect the developing fetus, and the effects persist into early adolescence. The study researchers concluded that pregnant women should be informed that consumption of licorice and other food products containing glycyrrhizin may be associated with harm to their developing baby. A little licorice candy here and there during pregnancy seems to be OK (so don't panic!), but licorice or licorice root is not something that should be eaten or drunk (e.g.,in a tea) regularly. From Science Daily:

Pregnant women should avoid liquorice

A new Finnish study supports food recommendations for families with children in that women should avoid consuming large amounts of liquorice during pregnancy. The limit for safe consumption is not known. In the study, youths that were exposed to large amounts of liquorice in the womb performed less well than others in cognitive reasoning tests carried out by a psychologist. The difference was equivalent to approximately seven IQ points. Those exposed to liquorice also performed less well in tasks measuring memory capacity, and according to parental estimates, they had more ADHD-type problems than others. With girls, puberty had started earlier and advanced further.

The Glaku study carried out by the University of Helsinki, the National Institute for Health and Welfare and the Helsinki and Uusimaa hospital districts compared 378 youths of about 13 years whose mothers had consumed "large amounts" or "little/no" liquorice during pregnancy. In this study a large amount was defined as over 500 mg and little/no as less than 249 mg glycyrrhizin per week. These cutoffs are not based on health effects. 500 mg glycyrrhizin corresponds on average to 250 g liquorice.

Researchers suggest that pregnant women and women planning pregnancy should be informed of the harmful effects that products containing glycyrrhizin -- such as liquorice and salty liquorice -- may have on the fetus. In Finland, this is already reality. In January 2016, the National Institute for Health and Welfare published food recommendations for families with children, in which liquorice was placed in the 'not recommended' category for pregnant women. According to the recommendations, occasional consumption of small amounts such as a portion of liquorice ice cream or a few liquorice sweets is not dangerous.

As a result of animal experiments, the biological mechanism of the effects of liquorice is well known. Glycyrrhizin intensifies the effects of stress hormone cortisol by inhibiting the enzyme that inactivates cortisol. While cortisol is essential to the development of a fetus, it is detrimental in large amounts. It has long been known that glycyrrhizin causes higher blood pressure and shorter pregnancies in humans, but such long-lasting effects on the fetus have not been proven before. [Original study.]

Published on Leave a comment on Eating An Egg A Day May Be Beneficial?

Remember all the dietary advice that for years told us to avoid or limit consumption of eggs - that since they were high in cholesterol, they were bad for us and would increase our risk for heart disease? And the nonsense that we should only eat the egg whites while throwing out the yolks? Hah...That advice was wrong, which another recent study confirms.

Eggs are an amazingly nutritious food. They’re loaded with high quality protein, healthy fats, vitamins, minerals, high in choline (a brain nutrient), biotin, antioxidants, lutein, and zeaxanthin. One review of studies (involving millions of people) looked at whole egg consumption  and found that high egg consumption (up to one egg per day) is not associated with increased risk of coronary heart disease or stroke, and in fact there was a reduced risk of hemorrhagic stroke. Only among diabetics was there an elevated risk of coronary heart disease with high egg consumption (up to 1 egg per day). Another study found a lower risk of type 2 diabetes in middle-aged men (see post).

A recent study from Finland found that neither cholesterol nor egg intake (eating one egg per day) was associated with an increased risk of dementia or Alzheimer's disease in Finnish men who were followed for 22 years. Instead, eating eggs was associated with better cognitive performance in certain areas such as executive function, which includes memory, problem solving, and planning (they were given neuropsychological tests). From Science Daily:

High cholesterol intake and eggs do not increase risk of memory disorders

A new study from the University of Eastern Finland shows that a relatively high intake of dietary cholesterol, or eating one egg every day, are not associated with an elevated risk of dementia or Alzheimer's disease. Furthermore, no association was found in persons carrying the APOE4 gene variant that affects cholesterol metabolism and increases the risk of memory disorders. APOE4 is common in Finland.

The dietary habits of 2,497 men aged between 42 and 60 years and with no baseline diagnosis of a memory disorder were assessed at the onset the Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, in 1984-1989 at the University of Eastern Finland. During a follow-up of 22 years, 337 men were diagnosed with a memory disorder, 266 of them with Alzheimer's disease. 32.5 per cent of the study participants were carriers of APOE4.

The study found that a high intake of dietary cholesterol was not associated with the risk of dementia or Alzheimer's disease -- not in the entire study population nor in the carriers of APOE4. Moreover, the consumption of eggs, which are a significant source of dietary cholesterol, was not associated with the risk of dementia or Alzheimer's disease. On the contrary, the consumption of eggs was associated with better results in certain tests measuring cognitive performance. 

Published on Leave a comment on Older Adults, Exercise, and the Brain

 Once again, research supports that you should get off your butt and exercise! Or do a moderate to vigorous physical activity at least several times a week, which can include housework, gardening, dancing, swimming, or walking briskly. Most important is to MOVE. And why is this so important? Not just for physical health and prevention of certain diseases, but also for the health of your brain, especially as it ages.

The research looked at both 31 young healthy adults (18 to 31 years old) and 26 older healthy adults (55 to 74 years old), assessed their cardiorespiratory (heart/lung) fitness on the treadmill, gave them a number of neurological tests, and also a memory task while their brain activity was observed during functional Magnetic Resonance Imaging (fMRI). They found that the older adults with higher heart/lung fitness had better performance on the memory task and greater brain activity in multiple regions than the older adults with low heart/lung fitness. The increased brain activity in those with higher levels of heart/lung fitness occurred in brain regions typically affected by age-related decline - in other words, higher fitness in older adults reduced some age-related differences.

The researchers thought these and other study results indicate that heart/lung fitness (cardiorespiratory fitness) may keep the brain younger (that is, it preserves neurological function and "neuroplasticity") as people age. They pointed out that some recent studies have revealed that lower cardiorespiratory (heart/lung) fitness was associated with accelerated cognitive decline and that older adults with lower heart/lung fitness had an increased risk for dementia.

From Health Day: Fitter Seniors May Have Healthier Brains

Good heart and lung fitness can benefit older adults' brains, researchers report.They assessed the heart/lung fitness of healthy young adults (aged 18 to 31) and older adults (aged 55 to 74), and compared their ability to learn and remember the names of strangers in photos. MRI scans recorded images of their brain activity as they learned the names.

The older adults had more difficulty with the memory test than the young adults. But older adults with high levels of heart/lung fitness did better on the test and showed more brain activity when learning new names than those of their peers with lower levels of heart/lung fitness. The increased brain activity in those with higher levels of heart/lung fitness occurred in regions typically affected by age-related decline. The findings suggest that heart/lung fitness may also help keep the brain healthy as people get older, according to the researchers. But the study did not prove a cause-and-effect link.

"Importantly, [heart/lung fitness] is a modifiable health factor that can be improved through regular engagement in moderate to vigorous sustained physical activity such as walking, jogging, swimming or dancing," said study corresponding author Scott Hayes....The researchers said high levels of fitness will not prevent brain decline, but may slow it.

An excerpt from the original study, from Cortex: FMRI activity during associative encoding is correlated with cardiorespiratory fitness and source memory performance in older adults

For brain regions in which older adults showed reduced activation relative to young adults, including left inferior frontal gyrus, medial frontal gyrus, bilateral thalamus, and fusiform gyrus, we observed a step-wise pattern, with the greatest activation in young adults, followed by high CRF [cardiorespiratory fitness] older adults and then low CRF older adults, indicating that higher fitness in older adults reduced age-related differences. These findings suggest that CRF supports successful brain maintenance in aging, in that it promotes the preservation of neural function seen in young adults (Nyberg, Lovden et al., 2012). 

Published on Leave a comment on Air Pollution, the Aging Brain, and Dementia

Another study finding a link between air pollution and negative health effects - this time a higher incidence of decline in cognitive functioning  and dementia in older women (65 and older) exposed to fine particles (PM2.5 ). These extremely small particles from vehicle emissions are a major source of urban air pollution throughout the world. These results match other studies finding a link with urban air pollution, especially vehicle traffic, to negative effects on the brain (dementia, cognitive decline, shrinking of the brain, etc.). The researchers also exposed mice to this air pollution for 15 weeks and then studied their brains for evidence of degenerative effects in their brains - and yes, they did find them.

The researchers found that the adverse effects of fine particulate air pollution was stronger in both women and mice who had the APOE4 gene, a genetic variation that increases the risk for Alzheimer's disease. They said that while the air pollution has negative effects in general, that having the APOE4 gene interacted with the air pollution. The researchers also wrote that the mice studies they did showed that "...exposure to urban airborne particulates can intensify amyloid accumulation and neurodegeneration". Medical Xpress:

Air pollution may lead to dementia in older women

Tiny air pollution particles—the type that mainly comes from power plants and automobiles—may greatly increase the chance of dementia, including Alzheimer's disease, according to USC-led research. Scientists and engineers found that older women who live in places with fine particulate matter exceeding the U.S. Environmental Protection Agency's standard are 81 percent more at risk for global cognitive decline and 92 percent more likely to develop dementia, including Alzheimer's.

If their findings hold up in the general population, air pollution could be responsible for about 21 percent of dementia cases, according to the study. "Microscopic particles generated by fossil fuels get into our body directly through the nose into the brain," said University Professor Caleb Finch at the USC Leonard Davis School of Gerontology and co-senior author of the study. "Cells in the brain treat these particles as invaders and react with inflammatory responses, which over the course of time, appear to exacerbate and promote Alzheimer's disease.

The adverse effects were stronger in women who had the APOE4 gene, a genetic variation that increases the risk for Alzheimer's. "Our study .....provides the inaugural scientific evidence of a critical Alzheimer's risk gene possibly interacting with air particles to accelerate brain aging," said Jiu-Chiuan Chen, co-senior author of the study....[Their study] adds to an emerging body of research from around the world that links air pollution to dementia. The offending pollutants—known as PM2.5—are fine, inhalable particles with diameters 2.5 micrometers or smaller. A human hair is about 70 micrometers in diameter, making it 30 times larger than the largest PM2.5. The researchers analyzed data of 3,647 65- to 79-year-old women from the Women's Health Initiative Memory Study (WHIMS). These women lived across 48 states and did not have dementia when they enrolled.

USC scientists chronically exposed female mice carrying the APOE4 gene to nano-sized air pollution for 15 weeks. Compared to the control group, mice predisposed to Alzheimer's disease accumulated as much as 60 percent more amyloid plaque, the toxic clusters of protein fragments that further the progression of Alzheimer's.

In other studies, Chen and his colleagues linked long-term exposure to high PM2.5 levels to smaller gray and white matter volumes in important areas such as the frontal lobe, which carries out thinking, decision-making and planning. For every 3.5 micrograms of PM2.5 per cubic meter of air, white matter (insulated nerve fibers that connect different brain regions) decreased by 6 cubic centimeters, according to one earlier study. [see post]

Published on Leave a comment on Vitamin D and Frequent Headaches

I saw mention of this study in a number of places - that low vitamin D levels are linked to chronic headaches. A little too soon to know if that is really true -  the researchers in this study looked at the blood vitamin D levels of 2601 men just one time, and did not give vitamin D supplements to the men to see if this changed the frequency of migraine headaches. The researchers themselves pointed out that other studies looking at this same issue have had mixed results. And they themselves pointed out that low blood levels of vitamin D (serum 25(OH)D concentration) was associated with a markedly higher risk of frequent headache in men. Associated does not mean caused.

Yes, low vitamin D levels is linked to a number of health problems (see all vitamin D posts). But at this point I think that it's a case of "wait and see" to see if vitamin D levels have something to do with headache frequency. Perhaps other micronutrients are important, perhaps something else. Note that in the study they used below 50 nmol as the measure for low vitamin D levels. In the USA, that translates into below 20 ng/ml, which everyone agrees is too low (a deficiency). The best source of vitamin D is sunlight - which is why it's called the "sunshine vitamin". From Science Daily:

Vitamin D deficiency increases risk of chronic headache

Vitamin D deficiency may increase the risk of chronic headache, according to a new study from the University of Eastern Finland....The Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, analysed the serum vitamin D levels and occurrence of headache in approximately 2,600 men aged between 42 and 60 years in 1984-1989. In 68% of these men, the serum vitamin D level was below 50 nmol/l, which is generally considered the threshold for vitamin D deficiency. Chronic headache occurring at least on a weekly basis was reported by 250 men, and men reporting chronic headache had lower serum vitamin D levels than others.

When the study population was divided into four groups based on their serum vitamin D levels, the group with the lowest levels had over a twofold risk of chronic headache in comparison to the group with the highest levels. Chronic headache was also more frequently reported by men who were examined outside the summer months of June through September. Thanks to UVB radiation from the sun, the average serum vitamin D levels are higher during the summer months.

The study adds to the accumulating body of evidence linking a low intake of vitamin D to an increased risk of chronic diseases. Low vitamin D levels have been associated with the risk of headache also by some earlier, mainly considerably smaller studies.

Published on Leave a comment on Why Do Some Older Adults Have Youthful Brains?

The beginning of a new year is a time to think about the future, and perhaps think about healthy lifestyles and how to age well. One important issue to think about is: why do some older people have "young" minds while others do not? Can anything be done to improve our odds later in life of being a "superager" and having a youthful, sharp, clear mind?

Unfortunately, as humans age, memory and many other cognitive functions often decline. “Normal” performance on various cognitive tests may be substantially lower than that of a younger adult, but... there is substantial variation in the degree of cognitive decline with age. Some older adults—referred to by some as “superagers”—continue to perform mentally at a level similar to middle-aged adults and sometimes even young adults.

Earlier posts have examined some of the things that help people age well and keep their brains more "youthful" - from diet (here, here, and here), to daily coffee consumption, vitamin D levels (here and here), regular physical activity and exercise (here, here, and here), not living in polluted areas (here and here), civic engagement, higher education, learning new skills, doing arts or crafts, and using a computer (here). Also frequently mentioned are social activities, intellectual stimulation, and genetics.

One recent study (discussed below) found that doing something hard and really challenging (that means forget pleasant puzzles), something that tires you out (whether physically or mentally) is what is good for the brain. So go out and learn a new language or musical instrument, sign up for a course, or anything else that is really challenging - whether physical or mental. Excerpts from a piece written by Lisa F. Barrett, a professor of psychology at Northeastern University, from the NY Times:

How to Become a ‘Superager’

Think about the people in your life who are 65 or older. Some of them are experiencing the usual mental difficulties of old age, like forgetfulness or a dwindling attention span. Yet others somehow manage to remain mentally sharp....Why do some older people remain mentally nimble while others decline? “Superagers” (a term coined by the neurologist Marsel Mesulam) are those whose memory and attention isn’t merely above average for their age, but is actually on par with healthy, active 25-year-olds. My colleagues and I at Massachusetts General Hospital recently studied superagers to understand what made them tick.

Our lab used functional magnetic resonance imaging to scan and compare the brains of 17 superagers with those of other people of similar age. We succeeded in identifying a set of brain regions that distinguished the two groups. These regions were thinner for regular agers, a result of age-related atrophy, but in superagers they were indistinguishable from those of young adults, seemingly untouched by the ravages of time...... The thicker these regions of cortex are, the better a person’s performance on tests of memory and attention, such as memorizing a list of nouns and recalling it 20 minutes later.

Of course, the big question is: How do you become a superager? Which activities, if any, will increase your chances of remaining mentally sharp into old age? We’re still studying this question, but our best answer at the moment is: work hard at something. Many labs have observed that these critical brain regions increase in activity when people perform difficult tasks, whether the effort is physical or mental. You can therefore help keep these regions thick and healthy through vigorous exercise and bouts of strenuous mental effort. My father-in-law, for example, swims every day and plays tournament bridge.

The road to superaging is difficult, though, because these brain regions have another intriguing property: When they increase in activity, you tend to feel pretty bad — tired, stymied, frustrated. Think about the last time you grappled with a math problem or pushed yourself to your physical limits. Hard work makes you feel bad in the moment. The Marine Corps has a motto that embodies this principle: “Pain is weakness leaving the body.” That is, the discomfort of exertion means you’re building muscle and discipline. Superagers are like Marines: They excel at pushing past the temporary unpleasantness of intense effort. Studies suggest that the result is a more youthful brain that helps maintain a sharper memory and a greater ability to pay attention.

This means that pleasant puzzles like Sudoku are not enough to provide the benefits of superaging. Neither are the popular diversions of various “brain game” websites. You must expend enough effort that you feel some “yuck.” Do it till it hurts, and then a bit more.

In the United States, we are obsessed with happiness. But as people get older, research shows, they cultivate happiness by avoiding unpleasant situations. This is sometimes a good idea, as when you avoid a rude neighbor. But if people consistently sidestep the discomfort of mental effort or physical exertion, this restraint can be detrimental to the brain. All brain tissue gets thinner from disuse. If you don’t use it, you lose it. So, make a New Year’s resolution to take up a challenging activity. Learn a foreign language. Take an online college course. Master a musical instrument. Work that brain. Make it a year to remember. [Original study]

Published on Leave a comment on Loss of Smell And Alzheimer’s Disease

Recently some studies have found that a diminished sense of smell occurs in persons with mild cognitive impairment and Alzheimer's disease. Doctors have long observed that patients with Alzheimer's frequently complain that food doesn't taste good anymore (because they can't smell what they are eating). This is because odor signals from the nose are processed in areas of the brain that are among the first to be affected by Alzheimer's disease. It is thought that as dementia starts and progresses, the parts of the brain that distinguish odors start to deteriorate.

This is why various odor tests have been devised. One such odor test (used in the following study) is called "Sniffin Sticks", which tests for 16 odors such as orange, peppermint, leather, banana, garlic, rose, fish, and coffee. However, note that other degenerative brain diseases (including Parkinson's) can also affect odor detection, and the ability to smell can be diminished by smoking, certain head injuries, and even normal aging. From Medical Xpress:

Study confirms 'sniff test' may be useful in diagnosing early Alzheimer's disease

Tests that measure the sense of smell may soon become common in neurologists' offices. Scientists have been finding increasing evidence that the sense of smell declines sharply in the early stages of Alzheimer's, and now a new study from the Perelman School of Medicine at the University of Pennsylvania published today in the Journal of Alzheimer's Disease confirms that administering a simple "sniff test" can enhance the accuracy of diagnosing this dreaded disease. The sniff test also appears to be useful for diagnosing a pre-dementia condition called mild cognitive impairment (MCI), which often progresses to Alzheimer's dementia within a few years.

Roalf and his colleagues used a simple, commercially available test known as the Sniffin' Sticks Odor Identification Test, in which subjects must try to identify 16 different odors. They administered the sniff test, and a standard cognitive test (the Montreal Cognitive Assessment), to 728 elderly people. The subjects had already been evaluated by doctors at Penn with an array of neurological methods, and according to expert consensus had been placed in one of three categories: "healthy older adult," "mild cognitive impairment," or "Alzheimer's dementia." Roalf and his team used the results from the cognitive test alone, or combined with the sniff test, to see how well they identified subjects in each category.

As researchers report, the sniff test added significantly to diagnostic accuracy when combined with the cognitive test. For example, the cognitive test alone correctly classified only 75 percent of people with MCI, but that figure rose to 87 percent when the sniff test results were added. Combining the two tests also enabled more accurate identification of healthy older adults and those with Alzheimer's dementia. The combination even boosted accuracy in assigning people to milder or more advanced categories of MCI.

Prompted by prior studies that have linked a weakening sense of smell to Alzheimer's, doctors in a few larger dementia clinics already have begun to use smell tests in their assessments of elderly patients. Part of the reason the practice has not yet become common is that the tests that seem most useful take too long to administer. 

Published on Leave a comment on Good Reason To Eat Vegetables Daily

New research further confirms a link between higher lutein levels (as measured in the blood) and the preservation of "crystallized intelligence" in older adults.  Crystallized intelligence is the ability to use the skills and knowledge one has acquired over a lifetime. Lutein is in foods such as leafy green vegetables, cruciferous vegetables (broccoli, brussels sprouts, cauliflower, and cabbage) and egg yolks. Lutein is also found in small amounts in other fruits and vegetables. Bottom line: eat a variety of fresh fruits and vegetables daily. [Original study.]Medical Xpress:

Study links nutrition to brain health and intelligence in older adults

A study of older adults links consumption of a pigment found in leafy greens to the preservation of "crystallized intelligence," the ability to use the skills and knowledge one has acquired over a lifetime.

Lutein (LOO-teen) is one of several plant pigments that humans acquire through the diet, primarily by eating leafy green vegetables, cruciferous vegetables such as broccoli, or egg yolks, said University of Illinois graduate student Marta Zamroziewicz, who led the study with Illinois psychology professor Aron Barbey. Lutein accumulates in the brain, embedding in cell membranes, where it likely plays "a neuroprotective role," she said. "Previous studies have found that a person's lutein status is linked to cognitive performance across the lifespan," Zamroziewicz said. 

The study enrolled 122 healthy participants aged 65 to 75 who solved problems and answered questions on a standard test of crystallized intelligence. Researchers also collected blood samples to determine blood serum levels of lutein and imaged participants' brains using MRI to measure the volume of different brain structures. The team focused on parts of the temporal cortex, a brain region that other studies suggest plays a role in the preservation of crystallized intelligence.

The researchers found that participants with higher blood serum levels of lutein tended to do better on tests of crystallized intelligence. Serum lutein levels reflect only recent dietary intakes, Zamroziewicz said, but are associated with brain concentrations of lutein in older adults, which reflect long-term dietary intake. Those with higher serum lutein levels also tended to have thicker gray matter in the parahippocampal cortex, a brain region that, like crystallized intelligence, is preserved in healthy aging, the researchers report..... "Our findings do not demonstrate causality," Zamroziewicz said. "We did find that lutein is linked to crystallized intelligence through the parahippocampal cortex."

Published on Leave a comment on Is Autism Spectrum Disorder Linked To Pregnancy Flu Shots or The Flu?

A big concern nowadays is why some children develop autism, specifically autism spectrum disorder (ASD). Autism spectrum disorder is considered a life-long neurodevelopmental disorder that is thought to affect 1 out of 68 American children. While the causes of ASD are unknown in most cases, some studies report an association (higher risk) between a pregnant woman's infections and fever during pregnancy and risk of ASD in the baby, while other studies don't find such an association. Some studies also looked at the timing of infections during pregnancy, but again results have been mixed. A viral infection during the first trimester is associated with increased risk in some studies, while other studies report an increased risk with a second- or third-trimester bacterial infection.  So it has been unclear whether a flu (influenza) infection or flu vaccination during pregnancy is linked to autism spectrum disorder or not. Is there a link or not?

Why are pregnant women encouraged to get a flu shot (flu vaccine)? This is because pregnant women have an increased risk of complications from the flu infection. Studies also show that getting a flu vaccine during pregnancy reduces the risk of a preterm birth, a small-for gestational-age child, and a low-birth-weight child, and prevents influenza infection in newborns for up to 6 months.

The researchers of a large study done in California found no association between autism spectrum disorder (ASD) risk and flu (influenza) infection during pregnancy or flu (influenza) vaccination during the second to third trimester of pregnancy. However, there was a suggestion of increased ASD risk among children whose mothers received flu vaccinations during the first trimester (though the researchers say the association was perhaps due to "chance". Bottom line: the study results were reassuring for pregnant women, but if one wanted to be ultra-cautious, then delay getting a flu shot until the second trimester of pregnancy. From Science Daily:

No association between mother's flu in pregnancy, increased child autism risk

A study of more than 196,000 children found no association between a mother having an influenza infection anytime during pregnancy and an increased risk of autism spectrum disorders (ASDs) in children, according to a new study published online by JAMA Pediatrics. The study by Ousseny Zerbo, Ph.D., of Kaiser Permanente Northern California, Oakland, and coauthors included 196,929 children born in the health system from 2000 through 2010 at a gestational age of at least 24 weeks.

Within the group, there were 1,400 mothers (0.7 percent) diagnosed with influenza and 45,231 mothers (23 percent) who received an influenza vaccination during pregnancy. There were 3,101 children (1.6 percent) diagnosed with ASD. The authors report no association between increased risk of ASD and influenza vaccination during the second and third trimesters of pregnancy. There was a suggestion of increased risk of ASD with maternal vaccination in the first trimester but the authors explain the finding was likely due to chance because it was not statistically significant after adjusting for multiple comparisons. The study cannot establish causality and has several limitations, including ASD status determined by diagnoses on medical records and not validated by standardized clinical assessment for all cases. [Original study.]