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Category: brain

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According to a recent large Swedish study, a healthy lifestyle lowers the risk of ischemic stroke (caused by a blood clot) - up to 54% lower risk. But unfortunately it does not lower the risk for a hemorrhagic stroke.

A healthy lifestyle was considered to be: healthy diet, moderate alcohol consumption, not smoking, being physically active, and being a normal weight (not overweight or obese). The more healthy life-style factors, the lower the risk for an ischemic stroke. In this study, healthy foods were considered to be: fruits, vegetables, legumes (beans), nuts, low-fat dairy foods, whole grain foods, and fish. 

From Science Daily: Healthy lifestyle may cut stroke risk in half for women

Women with a healthy diet and lifestyle may be less likely to have a stroke by more than half, according to a study. The study looked at five factors that make up a healthy lifestyle: healthy diet; moderate alcohol consumption; never smoking; physically active; and healthy body mass index (BMI). Compared with women with none of the five healthy factors, women with all five factors had a 54-percent lower risk of stroke.

For the study, 31,696 Swedish women with an average age of about 60 completed a 350-item questionnaire about their diet and lifestyle. They were then followed for an average of 10 years. A healthy diet was defined as within the top 50 percent of a recommended food score measuring how often the participants ate healthy foods such as fruits, vegetables and low-fat dairy products. Moderate alcohol consumption was defined as three to nine drinks per week. Physically active was defined as walking or biking at least 40 minutes a day along with more vigorous exercise at least one hour per week. Healthy BMI was considered below 25.

Most of the women had two or three of the healthy factors. Only 589 women had all five healthy factors, and 1,535 had none. There were 1,554 strokes among study participants. The risk of stroke steadily decreased with each additional healthy lifestyle factor.

Women who had a healthier diet were 13 percent less likely to have a type of stroke called a cerebral infarction than those whose diet was not as healthy. Women with healthier diets had a rate of 28 strokes per 10,000 women per year compared to 43 strokes per 10,000 women per year among those with a less healthy diet.

Cerebral infarction is the most common cause of stroke, accounting for up to 80 to 85 percent of all strokes. Cerebral infarction is caused by a blockage in a blood vessel preventing blood and oxygen from getting to an area of the brain.

There was no relationship between the healthy factors and the risk of hemorrhagic stroke. Hemorrhagic stroke, which is caused by bleeding in and around the brain, accounts for about 15 to 20 percent of all strokes.

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Different than my usual post, but oh so interesting. From Science Daily:

Near-death experiences? Results of the world's largest medical study of the human mind and consciousness at time of death

The results of a four-year international study of 2060 cardiac arrest cases across 15 hospitals concludes the following. The themes relating to the experience of death appear far broader than what has been understood so far, or what has been described as so called near-death experiences. In some cases of cardiac arrest, memories of visual awareness compatible with so called out-of-body experiences may correspond with actual events. A higher proportion of people may have vivid death experiences, but do not recall them due to the effects of brain injury or sedative drugs on memory circuits. Widely used yet scientifically imprecise terms such as near-death and out-of-body experiences may not be sufficient to describe the actual experience of death. The recalled experience surrounding death merits a genuine investigation without prejudice.

In 2008, a large-scale study involving 2060 patients from 15 hospitals in the United Kingdom, United States and Austria was launched. The AWARE (AWAreness during REsuscitation) study, sponsored by the University of Southampton in the UK, examined the broad range of mental experiences in relation to death. Researchers also tested the validity of conscious experiences using objective markers for the first time in a large study to determine whether claims of awareness compatible with out-of-body experiences correspond with real or hallucinatory events.

Dr Sam Parnia, Assistant Professor of Critical Care Medicine and Director of Resuscitation Research at The State University of New York at Stony Brook, USA, and the study's lead author, explained: "Contrary to perception, death is not a specific moment but a potentially reversible process that occurs after any severe illness or accident causes the heart, lungs and brain to cease functioning. If attempts are made to reverse this process, it is referred to as 'cardiac arrest'; however, if these attempts do not succeed it is called 'death'. In this study we wanted to go beyond the emotionally charged yet poorly defined term of NDEs to explore objectively what happens when we die."

Thirty-nine per cent of patients who survived cardiac arrest and were able to undergo structured interviews described a perception of awareness, but interestingly did not have any explicit recall of events. "This suggests more people may have mental activity initially but then lose their memories after recovery, either due to the effects of brain injury or sedative drugs on memory recall," explained Dr Parnia, who was an Honorary Research Fellow at the University of Southampton when he started the AWARE study.

Among those who reported a perception of awareness and completed further interviews, 46 per cent experienced a broad range of mental recollections in relation to death that were not compatible with the commonly used term of NDE's. These included fearful and persecutory experiences. Only 9 per cent had experiences compatible with NDEs and 2 per cent exhibited full awareness compatible with OBE's with explicit recall of 'seeing' and 'hearing' events.

One case was validated and timed using auditory stimuli during cardiac arrest. Dr Parnia concluded: "This is significant, since it has often been assumed that experiences in relation to death are likely hallucinations or illusions, occurring either before the heart stops or after the heart has been successfully restarted, but not an experience corresponding with 'real' events when the heart isn't beating. In this case, consciousness and awareness appeared to occur during a three-minute period when there was no heartbeat. This is paradoxical, since the brain typically ceases functioning within 20-30 seconds of the heart stopping and doesn't resume again until the heart has been restarted. Furthermore, the detailed recollections of visual awareness in this case were consistent with verified events.

Thus, while it was not possible to absolutely prove the reality or meaning of patients' experiences and claims of awareness, (due to the very low incidence (2 per cent) of explicit recall of visual awareness or so called OBE's), it was impossible to disclaim them either and more work is needed in this area.

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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%.