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Category: brain

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The link between pesticide exposure (pesticides used in the home or in the garden or lawn) and childhood brain tumors has been known for years. From Science Daily:

Factors associated with childhood brain tumors identified

Older parents, birth defects, maternal nutrition and childhood exposure to CT scans and pesticides are increasingly being associated with brain tumors in children, according to new research. Brain and central nervous system tumors are the second leading cause of cancer death in children.

A team of researchers, led by Kimberly Johnson, PhD, assistant professor of social work at the Brown School, a member of the Institute for Public Health and a research member of Siteman Cancer Center, examined studies published since 2004 that analyzed the incidence of childhood brain tumors and survival in different parts of the world.

In this research, binge drinking was defined as drinking four or more units of alcohol in a day on at least one occasion during the pregnancy.From Science Daily:

Binge drinking in pregnancy can affect child's mental health, school results

Binge drinking during pregnancy can increase the risk of mental health problems (particularly hyperactivity and inattention) in children aged 11 and can have a negative effect on their school examination results, according to new research on more than 4,000 participants.  This builds on earlier research on the same children that found a link between binge drinking in pregnancy and their mental health when aged four and seven, suggesting that problems can persist as a child gets older. Other effects, such as on academic performance, may only become apparent later in a child's life.

Women who are pregnant or who are planning to become pregnant should be aware of the possible risks associated with episodes of heavier drinking during pregnancy, even if this only occurs on an occasional basis.'The consumption of four or more drinks in a day may increase the risk for hyperactivity and inattention problems and lower academic attainment even if daily average levels of alcohol consumption during pregnancy are low.

From Science Daily: Healthy lifestyle could prevent nearly half of all diabetic pregnancies

Nearly half of all cases of diabetes during pregnancy, known as gestational diabetes, could be prevented if young women eat well, exercise regularly and stop smoking before and during pregnancy, finds a study.

Several modifiable risk factors before pregnancy have been identified over the past decade. These include maintaining a healthy weight, consuming a healthy diet, regular physical activity, and not smoking.So a team of researchers based in the United States set out to examine the effect of these "low risk" lifestyle factors on the risk of gestational diabetes -- and measure the portion of the condition that may be preventable through adhering to them.

The strongest individual risk factor for gestational diabetes was pre-existing overweight or obesity -- having a body mass index (BMI) above 25 before pregnancy. Women with a BMI above 33 were over four times more likely to develop gestational diabetes than women who had a normal BMI before pregnancy. ..Compared with women who did not meet any of the low risk lifestyle factors, those meeting all four criteria had an 83% lower risk of developing gestational diabetes.

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A small, but interesting study of 46 young adults (about 20 to 21 years old).

From Medical Xpress: Lift weights, improve your memory

Here's another reason why it's a good idea to hit the gym: it can improve memory. A new Georgia Institute of Technology study shows that an intense workout of as little as 20 minutes can enhance episodic memory, also known as long-term memory for previous events, by about 10 percent in healthy young adults.

While many existing studies have demonstrated that months of aerobic exercises such as running can improve memory, the current study had participants lift weights just once two days before testing them. The Georgia Tech researchers also had participants study events just before the exercise rather than after workout. They did this because of extensive animal research suggesting that the period after learning (or consolidation) is when the arousal or stress caused by exercise is most likely to benefit memory.

"Our study indicates that people don't have to dedicate large amounts of time to give their brain a boost," said Lisa Weinberg, the Georgia Tech graduate student who led the project.

But why does it work? Existing, non-Georgia Tech human research has linked memory enhancements to acute stress responses, usually from psychological stressors such as public speaking. Other studies have also tied specific hormonal and norepinephrine releases in rodent brains to better memory. Interestingly, the current study found that exercise participants had increased saliva measures of alpha amylase, a marker of central norepinephrine.

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Two related stories that look at children, exercise, and academic performance. Boys, in general, have higher activity levels than girls, and they need exercise and recess to be able to get through the rest of the school day. Sitting quietly in class and doing classwork is hard when one has lots of excess energy. In fact, sitting still for hours on end is NOT healthy in any way for anyone! Fidget, fidget, fidget... From Science Daily:

High levels of physical activity linked to better academic performance in boys

Higher levels of physical activity are related to better academic achievement during the first three school years, particularly in boys, research shows. For instance, boys with higher levels of physical activity, and especially walking and bicycling to and from school, had better reading skills than less active boys....The findings of the present study highlight the potential of physical activity during recess and participation in organized sports in the improvement of academic achievement in children. 

 Instead of medicine, why aren't doctors prescibing exercise? From The Atlantic:

Exercise Is ADHD Medication

Physical movement improves mental focus, memory, and cognitive flexibility; new research shows just how critical it is to academic performance.

...More insipid but also more clearly critical to addressing what's being called the ADHD epidemic is plain old physical activity.

This morning the medical journal Pediatrics published research that found kids who took part in a regular physical activity program showed important enhancement of cognitive performance and brain function. The findings, according to University of Illinois professor Charles Hillman and colleagues, "demonstrate a causal effect of a physical program on executive control, and provide support for physical activity for improving childhood cognition and brain health." If it seems odd that this is something that still needs support, that's because it is odd, yes. Physical activity is clearly a high, high-yield investment for all kids, but especially those attentive or hyperactive. This brand of research is still published and written about as though it were a novel finding, in part because exercise programs for kids remain underfunded and underprioritized in many school curricula, even though exercise is clearly integral to maximizing the utility of time spent in class.

Earlier this month, another study found that a 12-week exercise program improved math and reading test scores in all kids, but especially in those with signs of ADHD.

Last year a very similar study in the Journal of Attention Disorders found that just 26 minutes of daily physical activity for eight weeks significantly allayed ADHD symptoms in grade-school kids. The modest conclusion of the study was that "physical activity shows promise for addressing ADHD symptoms in young children." 

"If physical activity is established as an effective intervention for ADHD," they continued, "it will also be important to address possible complementary effects of physical activity and existing treatment strategies ..." Which is a kind of phenomenal degree of reservation compared to the haste with which millions of kids have been introduced to amphetamines and other stimulants to address said ADHD. The number of prescriptions increased from 34.8 to 48.4 million between 2007 and 2011 alone. The pharmaceutical market around the disorder has grown to several billion dollars in recent years while school exercise initiatives have enjoyed no such spoils of entrepreneurialism. 

Over all, the pandemic of physical inactivity, as Hillman and colleagues put it in their Pediatrics journal article today, is "a serious threat to global health" responsible for around 10 percent of premature deaths from noncommincable diseases. 

John Ratey, an associate professor of psychiatry at Harvard, suggests that people think of exercise as medication for ADHD. Even very light physical activity improves mood and cognitive performance by triggering the brain to release dopamine and serotonin, similar to the way that stimulant medications like Adderall do. 

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Once again, research finds that eating highly processed foods is not the best, this time for cognitive performance of 17 year olds. From Medical Xpress:

Western diet leads to poorer performance

Higher intake of a western diet by 14-year-olds has been linked with diminished cognitive performance at age 17.

Researchers found that participants with a western dietary pattern—characterised by high intakes of takeaway food, red and processed meat, soft drink, fried and refined food—scored lower in cognitive tasks, particularly those involving reaction time/psychomotor function, visual attention, learning and memory.

Chips and crisps came in for a particular drubbing: their high consumption was significantly associated with longer reaction times on detection tasks. In contrast to their peers, study participants with a high intake of fruits and leafy vegetables had better cognitive performance, which lead researcher Dr Anett Nyaradi says could be due to increased micronutrient content. This includes folate from leafy green vegetables, which previous research has linked to enhanced cognitive development.

Led by UWA and the Telethon Kids Institute, the study involved 602 members of the Western Australian Pregnancy Cohort (Raine) Study....Dr Nyaradi says several factors may be at play in this diet-related decline in cognitive skills, including the level of omega-6 fatty acids in fried foods and red meat.

Metabolic pathways function best with a balanced 1:1 ratio of omega-3 and omega-6 fatty acids, but the western diet can shift this to a 1:20 or 1:25 ratio.High intake of saturated fat and simple carbohydrates has been linked to impairment in the functioning of the hippocampus, a brain structure centrally involved in learning and memory that increases its volume during adolescence, Dr Nyaradi says.

"Adolescence represents a critical time period for brain development. It is possible that poor diet is a significant risk factor during this period…indeed, our findings support this proposition."

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This research involved 14,000 male and female participants in England, aged 16 or over. From Science Daily:

Fruit and vegetable consumption could be as good for your mental as your physical health

Fruit and vegetable consumption could be as good for your mental as your physical health, new research suggests. The research, conducted by the University of Warwick's Medical School using data from the Health Survey for England, and published by BMJ Open focused on mental wellbeing and found that high and low mental wellbeing were consistently associated with an individual's fruit and vegetable consumption.

33.5% of respondents with high mental wellbeing ate five or more portions of fruit and vegetables a day, compared with only 6.8% who ate less than one portion. Commenting on the findings Dr Saverio Stranges, the research paper's lead author, said: "The data suggest that higher an individual's fruit and vegetable intake the lower the chance of their having low mental wellbeing." 31.4% of those with high mental wellbeing ate three-four portions and 28.4% ate one-two.

Low mental wellbeing is strongly linked to mental illness and mental health problems, but high mental wellbeing is more than the absence of symptoms or illness; it is a state in which people feel good and function well. Optimism, happiness, self-esteem, resilience and good relationships with others are all part of this state. Mental wellbeing is important not just to protect people from mental illness but because it protects people against common and serious physical diseases.

"Our findings add to the mounting evidence that fruit and vegetable intake could be one such factor and mean that people are likely to be able to enhance their mental wellbeing at the same time as preventing heart disease and cancer."

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Well DUH ! Of course children need to run, run, run or somehow exercise to get rid of excess energy. That's why recess is so important (but unfortunately so many schools are eliminating it). It is incredibly hard for children to quietly sit for many, many hours straight like little robots working tirelessly on schoolwork, especially those with high energy levels to start with. From Medscape:

Before-School Exercise May Reduce ADHD Symptoms

Moderate to vigorous aerobic exercise in the morning may reduce symptoms of attention-deficit/hyperactivity disorder (ADHD) in young children at risk for the illness, new research suggests.

A randomized study of 202 kindergarteners, 1st graders, and 2nd graders showed that those who completed 12 weeks of before-school physical activity had significantly higher reductions in inattention and moodiness than those who completed a sedentary classroom-based intervention.In addition, the subgroup of children with elevated ADHD symptoms who went through the before-school exercise program showed reduced impairment associated with ADHD risk in both their school and home settings.

"We need more studies to replicate the results, but I think the take-home message is that aerobic exercise is a health-producing activity ― and there are really no negative side effects from it," added Dr. Hoza.

Past research has shown some positive effects from exercise on patients with ADHD, providing evidence that it may be "a viable strategy for improving symptoms, behavior, achievement, inhibitory control, and neurocognitive function in youth with elevated ADHD symptoms," write the investigators.

In the current study, the researchers enrolled 94 children at risk for ADHD and 108 children deemed "typically developing" to act as their control group....The physical activity involved continuous movement requiring children to breathe hard and included a variety of age-appropriate activities and games.

"Although our findings indicated that all participants showed improvements, children with ADHD risk receiving exercise benefited across a broader range of outcomes than those receiving the sedentary activities," said coinvestigator Alan Smith, PhD, chair of the Department of Kinesiology at Michigan State University in East Lansing, in a release.

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A banana a day keeps the doctor away? A recent large study found that older women who eat foods with higher amounts of potassium may be at lower risk of stroke and death, when compared to women who eat fewer potassium rich foods. The association was with ischemic stroke (caused by clot) and not hemorrhagic stroke.

Some good food sources of potassium are: bananas, cantaloupe, grapefruit, oranges, white and sweet potatoes, and white beans. The U.S. Department of Agriculture recommends that women eat at least 4700 mg of potassium daily, but in this study the average intake of the postmenopausal women was 2611 mg per day.

This study followed  90,137 postmenopausal women (aged 50 to 79 years at baseline), and followed them an average of 11 years. Now this same study needs to be done with men and women of all ages. From Science Daily:

Potassium-rich foods cut stroke, death risks among older women

Older women who eat foods with higher amounts of potassium may be at lower risk of stroke and death than women who consume less potassium-rich foods. The health benefits from potassium-rich foods are greater among older women who do not have high blood pressure. Most older American women do not eat the recommended amounts of potassium from foods.

"Our findings give women another reason to eat their fruits and vegetables. Fruits and vegetables are good sources of potassium, and potassium not only lowers postmenopausal women's risk of stroke, but also death."

Researchers studied 90,137 postmenopausal women, ages 50 to 79, for an average 11 years. They looked at how much potassium the women consumed, as well as if they had strokes, including ischemic and hemorrhagic strokes, or died during the study period. Women in the study were stroke-free at the start and their average dietary potassium intake was 2,611 mg/day. Results of this study are based on potassium from food, not supplements.

The researchers found: -Women who ate the most potassium were 12 percent less likely to suffer stroke in general and 16 percent less likely to suffer an ischemic stroke than women who ate the least. -Women who ate the most potassium were 10 percent less likely to die than those who ate the least. They also said there was no evidence of any association between potassium intake and hemorrhagic stroke, which could be related to the low number of hemorrhagic strokes in the study.

The U.S. Department of Agriculture recommends that women eat at least 4,700 mg of potassium daily. "Only 2.8 percent of women in our study met or exceeded this level. "Our findings suggest that women need to eat more potassium-rich foods. You won't find high potassium in junk food. Some foods high in potassium include white and sweet potatoes, bananas and white beans."

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The great effects (especially for hemorrhagic stroke) were found in people eating just 1 1/2 portions of fresh fruit daily. The amazing part is that 6.3% admitted to never consuming fruit. From Science Daily:

Fruit consumption cuts cardiovascular disease risk by up to 40 percent

Daily fruit consumption cuts the risk of cardiovascular disease (CVD) by up to 40 percent, according to research. The findings from the seven-year follow-up study of nearly a half million people in the China Kadoorie Biobank found that the more fruit people ate, the more their risk of CVD declined.

Dr Du said: "CVD, including ischaemic heart disease (IHD) and stroke, is the leading cause of death worldwide. Improving diet and lifestyle is critical for CVD risk reduction in the general population but the large majority of this evidence has come from western countries and hardly any from China."

The current study included 451 681 participants with no history of CVD and not on anti-hypertensive treatment at baseline from the China Kadoorie Biobank(1) conducted in 10 different areas of China, 5 rural and 5 urban. Habitual consumption of fruit was recorded at baseline according to five categories: never, monthly, 1-3 days per week, 4-6 days per week, daily.

Over the seven year follow up period there were 19 300 cases of IHD and 19 689 strokes (14 688 ischaemic and 3562 haemorrhagic). Some 18% of participants consumed fruit daily and 6.3% never consumed fruit. The average amount of fruit eaten by the daily consumers was 1.5 portions (~150g).

The researchers found that compared to people who never ate fruit, those who ate fruit daily cut their CVD risks by 25-40% (around 15% for IHD, around 25% for ischaemic stroke and 40% for haemorrhagic stroke). There was a dose response relationship between the frequency of fruit consumption and the risk of CVD.

Dr Du said: "Our data clearly shows that eating fresh fruit can reduce the risk of cardiovascular disease, including ischaemic heart disease and stroke (particularly haemorrhagic stroke). And not only that, the more fruit you eat the more your CVD risk goes down. It does suggest that eating more fruit is beneficial compared to less or no fruit."

The researchers also found that people who consumed fruit more often had significantly lower blood pressure (BP). Eating fruit daily was associated with 3.4/4.1 mmHg lower systolic/diastolic BP compared to those who never ate fruit. 

In a separate analysis, the researchers examined the association of fruit consumption with total mortality and CV mortality in more than 61,000 patients from the China Kadoorie Biobank who had CVD or hypertension at baseline. They found that compared to those who never ate fruit, daily consumers of fruit cut their overall risk of death by 32%. They also reduced their risks of dying from IHD by 27% and from stroke by around 40%.

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An interesting article that discusses research that finds advantages to being dyslexic. Perhaps think in terms of cognitive diversity. From Scientific American:

The Advantages of Dyslexia

With reading difficulties can come other cognitive strengths.

In our laboratory at the Harvard-Smithsonian Center for Astrophysics we have carried out studies funded by the National Science Foundation to investigate talents for science among those with dyslexia. The dyslexic scientist Christopher Tonkin described to me his sense of this as a sensitivity to “things out of place.”  He’s easily bothered by the weeds among the flowers in his garden, and he felt that this sensitivity for visual anomalies was something he built on in his career as a professional scientist.  Such differences in sensitivity for causal perception may explain why people like Carole Greider and Baruj Benacerraf have been able to perform Nobel prize-winning science despite lifelong challenges with dyslexia.

Why are there advantages in dyslexia?  Is it something about the brains of people with dyslexia that predisposes them to causal thinking? Or, is it a form of compensation, differences in the brain that occur because people with dyslexia read less? Unfortunately, the answer to these questions is unknown.

One thing we do know for sure is that reading changes the structure of the brain. An avid reader might read for an hour or more a day, day in and day out for years on end. This highly specialized repetitive training, requiring an unnaturally precise, split-second control over eye movements, can quickly restructure the visual system so as to make some pathways more efficient than the others.

My colleagues and I suggested that one reason people with dyslexia may exhibit visual talents is that they have difficulty managing visual attention⁠. It may at first seem ironic that a difficulty can lead to an advantage, but it makes sense when you realize that what we call “advantages” and “disadvantages” have meaning only in the context of the task that needs to be performed.

For example, imagine you’re looking to hire a talented security guard. This person’s job will be to spot things that look odd and out of place, and call the police when something suspicious —say, an unexpected footprint in a flowerbed— is spotted. If this is the person’s task, would you rather hire a person who is an excellent reader, who has the ability to focus deeply and get lost in the text, or would you rather hire a person who is sensitive to changes in their visual environment, who is less apt to focus and block out the world?

Tasks such as reading require an ability to focus your attention on the words as your eyes scan a sentence, to quickly and accurately shift your attention in sequence from one word to the next.  But, to be a good security guard you need an opposite skill; you need to be able to be alert to everything all at once, and though this isn’t helpful for reading, this can lead to talents in other areas.

A series of studies by an Italian team led by Andrea Facoetti have shown that children with dyslexia often exhibit impairments in visual attention. In one study,Facoetti’s team measured visual attention in 82 preschool children who had not yet been taught to read. The researchers then waited a few years until these children finished second grade, and then examined how well each child had learned reading. They found that those who had difficulty focusing their visual attention in preschool had more difficulty learning to read.

These studies raise the possibility that visual attention deficits, present from a very early age, are responsible for the reading challenges that are characteristic of dyslexia. If this theory is upheld, it would also suggest that the observed advantages are not an incidental byproduct of experience with reading, but are instead the result of differences in the brain that were likely present from birth.

If this is indeed the case, given that attention affects perception in very general ways, any number of advantages should emerge.  While people with dyslexia may tend to miss details in their environment that require an attentional focus, they would be expected to be better at noticing things that are distributed more broadly.  To put this another way, while typical readers may tend to miss the forest because its view is blocked by all the trees, people with dyslexia may see things more holistically, and miss the trees, but see the forest.

Among other advantages observed, Gadi Geiger and his colleagues at MIT found that people with dyslexia can distribute their attention far more broadly than do typical readers, successfully identifying letters flashed simultaneously in the center and the periphery for spacings that were much further apart. They also showed that such advantages are not just for things that are visual, but that they apply to sounds as well. In one study, simulating the sounds of a cocktail party, they found that people with dyslexia were able to pick out more words spoken by voices widely-distributed in the room, compared with people who were proficient readers.

Whether or not observations of such advantages —measured in the laboratory— have applications to talents in real life remains an open question. But, whatever the reason, a clear trend is beginning to emerge: People with dyslexia may exhibit strengths for seeing the big picture (both literally and figuratively) others tend to miss.  Thomas G. West has long-argued that out-of-the-box thinking is historically part and parcel of dyslexia, and more recently physicians Brock and Fernette Eide have advanced similar arguments. Sociologists, such as Julie Logan of the Cass Business School in London agree.  Logan found that dyslexia is relatively common among business entrepreneurs; people who tend to think differently and see the big picture in thinking creatively about a business.

Whatever the mechanism, one thing is clear: dyslexia is associated with differences in visual abilities, and these differences can be an advantage in many circumstances, such as those that occur in science, technology, engineering and mathematics. It’s only when everything is all the same that nothing productive can get done. Neurological differences similarly drive the engine of society, to create the contrasts between hot and cold that lead to productive work. Impairments in one area can lead to advantages in others, and it is these differences that drive progress in many fields, including science and math.

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Several more articles on the benefits of exercise. From Science Daily:

Train your heart to protect your mind

Exercising to improve our cardiovascular strength may protect us from cognitive impairment as we age, according to a new study. "Our body's arteries stiffen with age, and the vessel hardening is believed to begin in the aorta, the main vessel coming out of the heart, before reaching the brain. Indeed, the hardening may contribute to cognitive changes that occur during a similar time frame," explained the first author of the study. "We found that older adults whose aortas were in a better condition and who had greater aerobic fitness performed better on a cognitive test. We therefore think that the preservation of vessel elasticity may be one of the mechanisms that enables exercise to slow cognitive aging."

The researchers worked with 31 young people between the ages of 18 and 30 and 54 older participants aged between 55 and 75. This enabled the team to compare the older participants within their peer group and against the younger group who obviously have not begun the aging processes in question. None of the participants had physical or mental health issues that might influence the study outcome.

The results demonstrated age-related declines in executive function, aortic elasticity and cardiorespiratory fitness, a link between vascular health and brain function, and a positive association between aerobic fitness and brain function. "Although the impact of fitness on cerebral vasculature may however involve other, more complex mechanisms, overall these results support the hypothesis that lifestyle helps maintain the elasticity of arteries, thereby preventing downstream cerebrovascular damage and resulting in preserved cognitive abilities in later life."

From Science Daily:

Physically fit kids have beefier brain white matter than their less-fit peers

A new study of 9- and 10-year-olds finds that those who are more aerobically fit have more fibrous and compact white-matter tracts in the brain than their peers who are less fit. 'White matter' describes the bundles of axons that carry nerve signals from one brain region to another. More compact white matter is associated with faster and more efficient nerve activity.

The analysis revealed significant fitness-related differences in the integrity of several white-matter tracts in the brain: the corpus callosum, which connects the brain's left and right hemispheres; the superior longitudinal fasciculus, a pair of structures that connect the frontal and parietal lobes; and the superior corona radiata, which connect the cerebral cortex to the brain stem."All of these tracts have been found to play a role in attention and memory," Chaddock-Heyman said. 

From Science Daily:

Exercise may protect older women from irregular heartbeat

Increasing the amount or intensity of physical activity can cut the chances of older women developing a life-threatening irregular heartbeat, according to new research. Researchers found that post-menopausal women who were the most physically active had a 10 percent lower risk of developing atrial fibrillation (AF), compared to women with low levels of physical activity, even if they were obese. Obesity is an important risk factor for atrial fibrillation.