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More studies showing health benefits of moving and exercise. From Science Daily:

Dangers of ... sitting? Regardless of exercise, too much sedentary time is linked to major disability after 60

If you're 60 and older, every additional hour a day you spend sitting is linked to doubling the risk of being disabled -- regardless of how much moderate exercise you get, reports a new Northwestern Medicine study.

The study is the first to show sedentary behavior is its own risk factor for disability, separate from lack of moderate vigorous physical activity. In fact, sedentary behavior is almost as strong a risk factor for disability as lack of moderate exercise.

If there are two 65-year-old women, one sedentary for 12 hours a day and another sedentary for 13 hours a day, the second one is 50 percent more likely to be disabled, the study found.

"This is the first time we've shown sedentary behavior was related to increased disability regardless of the amount of moderate exercise," said Dorothy Dunlop, professor of medicine at Northwestern University Feinberg School of Medicine and lead author of the study. "Being sedentary is not just a synonym for inadequate physical activity."

Disability affects more than 56 million Americans. It's defined by limitations in being able to do basic activities such as eating, dressing or bathing oneself, getting in and out of bed and walking across a room. Disability increases the risk of hospitalization and institutionalization and is a leading source of health care costs, accounting for $1 in $4 spent.

The study focused on a sample of 2,286 adults aged 60 and older from the National Health and Nutrition Examination Survey. It compared people in similar health with the same amount of moderate vigorous activity. Moderate activity is walking briskly, as if you are late to an appointment.

The participants wore accelerometers from 2002 to 2005 to measure their sedentary time and moderate vigorous physical activity. The accelerometer monitoring is significant because it is objective.

From Science Daily:

Exercise may slow progression of retinal degeneration

Moderate aerobic exercise helps to preserve the structure and function of nerve cells in the retina after damage, according to an animal study appearing February 12 in The Journal of Neuroscience. The findings suggest exercise may be able to slow the progression of retinal degenerative diseases.

Age-related macular degeneration, one of the leading causes of blindness in the elderly, is caused by the death of light-sensing nerve cells in the retina called photoreceptors. Although several studies in animals and humans point to the protective effects of exercise in neurodegenerative diseases or injury, less is known about how exercise affects vision.

This is the first report of simple exercise having a direct effect on retinal health and vision," Pardue said. "This research may one day lead to tailored exercise regimens or combination therapies in treatments of blinding diseases."

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Two studies about food and health benefits.  From Science Daily:

Can citrus ward off your risk of stroke?

Eating foods that contain vitamin C may reduce your risk of the most common type of hemorrhagic stroke, according to a study released today that will be presented at the American Academy of Neurology's 66th Annual Meeting in Philadelphia, April 26 to May 3, 2014.

Vitamin C is found in fruits and vegetables such as oranges, papaya, peppers, broccoli and strawberries. Hemorrhagic stroke is less common than ischemic stroke, but is more often deadly.

The study involved 65 people who had experienced an intracerebral hemorrhagic stroke, or a blood vessel rupture inside the brain. They were compared to 65 healthy people. Participants were tested for the levels of vitamin C in their blood. Forty-one percent of cases had normal levels of vitamin C, 45 percent showed depleted levels of vitamin C and 14 percent were considered deficient of the vitamin.

On average, the people who had a stroke had depleted levels of vitamin C, while those who had not had a stroke had normal levels of the vitamin.

"Our results show that vitamin C deficiency should be considered a risk factor for this severe type of stroke, as were high blood pressure, drinking alcohol and being overweight in our study," said study author Stéphane Vannier, MD, with Pontchaillou University Hospital in Rennes, France. "More research is needed to explore specifically how vitamin C may help to reduce stroke risk. For example, the vitamin may regulate blood pressure."

From Science Daily:

Eat spinach or eggs for faster reflexes: Tyrosine helps you stop faster

A child suddenly runs out into the road. Brake!! A driver who has recently eaten spinach or eggs will stop faster, thanks to the amino acid tyrosine found in these and other food products. Leiden cognitive psychologist Lorenza Colzato publishes her findings in the journal Neuropsychologia.

Colzato and her colleagues created a situation in which test candidates had to interrupt a repetitive activity at a given instant. The participants had two sessions in the test lab. On one occasion they were given orange to drink that contained tyrosine, and on the other occasion the orange juice contained a placebo. The tests showed that the candidates performed better on the stopping task if they had drunk the juice with tyrosine.

The positive effect of tyrosine on our reaction speed can have benefits for road safety. But there are many more examples. Colzato: 'Tyrosine food supplements and tyrosine-rich food are a healthy and inexpensive way of improving our intellectual capabilities.

Tyrosine is found in such foods as spinach, eggs, cottage cheese and soya. 

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From Science Daily:

Impact of repetitive heading in soccer needs more research, say experts

Soccer is the most-popular and fastest-growing sport in the world and, like many contact sports, players are at risk of suffering concussions from collisions on the field. But researchers warned in a paper published today that not enough attention has been given to the unique aspect of soccer -- the purposeful use of the head to control the ball -- and the long-term consequences of repetitive heading.

The literature review by Dr. Tom Schweizer, director of the Neuroscience Research Program of St. Michael's Hospital, was published in the journal Brain Injury.

More than 265 million people play soccer worldwide, including 27 million in North America. Due to the nature of the sport, players are particularly vulnerable to head and neck injuries. Most are caused by unintentional or unexpected contact, such as when a player collides with teammates, opponents or the playing surface.

There is significant concern in the sporting and medical worlds about the potential long-term cognitive and behavioral consequences for athletes who suffer acute or repeat concussions or multiple "sub-concussive" head impacts -- blows to the head not causing symptoms of concussions.

"The practice of heading, which might occur thousands of times over a player's career, carries unknown risks, but may uniquely contribute to cognitive decline or impairment in the short- or long-term," said Dr. Schweizer, a neuroscientist. "Thus, soccer players present a unique opportunity to study whether cumulative sub-concussive impacts affect cognitive functioning, similar to that of concussions."

Research papers that looked at the mechanism of injury found 41.1 per cent of concussions resulted from contact by an elbow, arm or hand to the head. One found that 58.3 per cent of concussions occurred during a heading duel. More females suffered concussions from player-to-surface and player-to-ball contact than males who had more player-to-player contact than females.

Studies on the long-term effects of heading found greater memory, planning and perceptual deficits in forwards and defenders, players who execute more headers. One study found professional players reporting the highest prevalence of heading during their careers did poorest in tests of verbal and visual memory as well as attention. Another found older or retired soccer players were significantly impaired in conceptual thinking, reaction time and concentration. The few studies that used advanced imaging techniques found physical changes to the brains in players who had concussions.

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Children's brain development being harmed by chemicals in the environment - both before birth and in childhood -  is such an important topic that here are excerpts from two articles about the same report that was just released (in Lancet Neurology).  From Time:

Children Exposed to More Brain-Harming Chemicals Than Ever Before

In recent years, the prevalence of developmental disorders such as autism, attention deficit/hyperactivity disorder (ADHD) and dyslexia  have soared. While greater awareness and more sophisticated diagnoses are partly responsible for the rise, researchers say the changing environment in which youngsters grow up may also be playing a role.

In 2006, scientists from the Harvard School of Public Health and the Icahn School of Medicine at Mount Sinai identified five industrial chemicals responsible for causing harm to the brain — lead, methylmercury, polychlorinated biphenyls (found in electric transformers, motors and capacitors), arsenic (found in soil and water as well as in wood preservatives and pesticides) and toluene (used in processing gasoline as well as in paint thinner, fingernail polish and leather tanning). Exposure to these neurotoxins was associated with changes in neuron development in the fetus as well as among infants, and with lower school performance, delinquent behavior, neurological abnormalities and reduced IQ in school-age children.

Now the same researchers have reviewed the literature and found six additional industrial chemicals that can hamper normal brain development. These are manganese, fluoride, chlorpyrifos, dichlorodiphenyltrichloroethane, tetrachloroethylene and polybrominated diphenyl ethers. Manganese, they say, is found in drinking water and can contribute to lower math scores and heightened hyperactivity, while exposure to high levels of fluoride from drinking water can contribute to a seven-point drop in IQ on average. The remaining chemicals, which are found in solvents and pesticides, have been linked to deficits in social development and increased aggressive behaviors.

But they say the growing body of research that is finding links between higher levels of these chemicals in expectant mothers’ blood and urine and brain disorders in their children should raise alarms about how damaging these chemicals can be. The developing brain in particular, they say, is vulnerable to the effects of these chemicals, and in many cases, the changes they trigger are permanent. “The consequence of such brain damage is impaired [central nervous system] function that lasts a lifetime and might result in reduced intelligence, as expressed in terms of lost IQ points, or disruption in behavior,” they write in their report, which was published in the journal Lancet Neurology.

Same report, from Science Daily: Growing number of chemicals linked with brain disorders in children

"The greatest concern is the large numbers of children who are affected by toxic damage to brain development in the absence of a formal diagnosis. They suffer reduced attention span, delayed development, and poor school performance. Industrial chemicals are now emerging as likely causes," said Philippe Grandjean, adjunct professor of environmental health at HSPH.

The study outlines possible links between these newly recognized neurotoxicants and negative health effects on children, including:  - Manganese is associated with diminished intellectual function and impaired motor skills  - Solvents are linked to hyperactivity and aggressive behavior - Certain types of pesticides may cause cognitive delays.

Grandjean and co-author Philip Landrigan, Dean for Global Health at Mount Sinai, also forecast that many more chemicals than the known dozen or so identified as neurotoxicants contribute to a "silent pandemic" of neurobehavioral deficits that is eroding intelligence, disrupting behaviors, and damaging societies. But controlling this pandemic is difficult because of a scarcity of data to guide prevention and the huge amount of proof needed for government regulation. "Very few chemicals have been regulated as a result of developmental neurotoxicity," they write.

The authors say it's crucial to control the use of these chemicals to protect children's brain development worldwide. They propose mandatory testing of industrial chemicals and the formation of a new international clearinghouse to evaluate industrial chemicals for potential developmental neurotoxicity.

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A feel good article. From Science Daily:

Love is good for the heart, cardiologist says

With Valentine's Day just one day away, Vanderbilt Heart and Vascular Institute cardiologist Julie Damp, M.D., says being involved in a healthy, loving relationship is good for the heart.  "There are different theories behind why that might be," Damp said.

A recent study from Finland showed that married men and women had a significantly lower risk of both having heart attacks and dying from a heart attack compared to people who were single.

There is also a theory that people who are in loving relationships may experience neuro-hormonal changes that have positive effects on the body, including the cardiovascular system," she said, explaining that there are certain hormone levels in the body that vary depending on the level of an individual's stress and anxiety.

Giving your loved one a box of dark chocolates and a bottle of red wine won't hurt either. Studies suggest they are good for the heart, as well.

Dark chocolate contains flavonoids, which are antioxidants. Antioxidants have positive effects on many different body systems including the cardiovascular system. The high concentration of cocoa in dark chocolate appears to be what offers the flavonoid benefit.

"Dark chocolate has been shown to be associated with lower blood pressure, lower blood sugar levels and improvement in the way your blood vessels dilate and relax," Damp said.

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It appears most of us sit too much. From Science Daily:

Obese Americans get less than one minute of vigorous activity per day, research shows

Researchers at the University of South Carolina’s Arnold School of Public Health have validated a new method for calculating physical activity, sedentary behavior, and the food energy requirements of Americans. The results suggest that as a nation, we spend more than 15 hours per day sleeping and sitting, and that obese men and women spend less than one minute per day in vigorous activity.

The study of the Physical Activity Ratio (PAR) protocol is significant because it provides the first nationally representative estimates of total daily energy expenditure, physical activity and sedentary behavior for the U.S. population.

Data sets for the study were obtained from the National Health and Nutrition Examination Survey 2005-2006, a complex sample of the U.S. population conducted by the Centers for Disease Control and Prevention, and included adults age 20 to 74. The sample population was then divided into three Body Mass Index (BMI) categories: normal weight (18-25 kg/m2), overweight (25-29.9 kg/m2) and obese (30 kg/m2 or more) and took into account all factors contributing to energy expenditure, including sleep, and the digestion and metabolism of food.

The study found that the 1,272 men and 1,325 women that comprised the final sample exhibited key differences based on sex and BMI. Men were taller, heavier, and had greater resting energy expenditure than women. Men also spent more hours per day engaging in moderate and vigorous physical activity, and reported less sleep.

Not surprisingly, obese men and women were significantly less physically active and spent more time in sedentary behaviors than their normal weight counterparts. Obese men and women also reported less sleep and spent almost no time in more intense forms of physical activity. “Given that physical inactivity is now a leading cause of death and disability in the world, these data are essential in advancing the science of obesity and health,” Archer said.

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A recently released report from the American Academy of Microbiology explains the basics of the human microbiome (the collection of trillions of microbes living in and on the human body) and its role in human health in easy to understand language and illustrations. It's a primer for the general public that addresses questions about this growing area of research. There is also a section on the role of the microbiome in human conditions such as obesity and inflammatory bowel disease, and there are general tips on what can be done to maintain a healthy microbiome. It is well worth reading. Below is part of the answer to the question "How big is the microbiome?" The answer shows that it is amazingly big by all measures.

FAQ: HUMAN MICROBIOME

3) How big is the microbiome?

The microbiome is big by almost any measure — number of organisms, total volume, species diversity, and genetic diversity.

NUMBER OF ORGANISMS:
The microbiome includes approximately 100 trillion bacterial cells.                                                   That’s 100,000,000,000,000! You may have heard that there are 10 times more microbial cells than human cells in the human body, but that commonly cited ratio was based on an estimate of 10 trillion cells in the human body. More recent estimates suggest that the human body actually is made up of about 37 trillion human cells. Thus at any given time, the average human body is carrying around 3 times more bacterial cells than human ones. But the microbiome includes more than just bacteria. Remember that it also includes plenty of viruses, fungi, archaea, and single-celled eukaryotes. There is general agreement that viruses outnumber bacterial cells, maybe by as much as 5 to 1. There are thought to be about 10-fold fewer fungal cells than bacteria. All of these numbers are estimates and because the microbiome is a dynamic community, the numbers may change under different circumstances. 
TOTAL VOLUME:
The microbiome is also pretty big in terms of the space it occupies and its total weight. Even though each individual member is microscopic, those large numbers do add up. Most estimates put the weight of an average human microbiome at about 2.5 pounds. In volume, if consolidated, the microbiome would occupy about 3 pints. Keep in mind though, that the microbiome is not all consolidated in one place, and the density of the various microbial communities varies greatly from body site to body site. Blood and lymphatic fluids are practically sterile, while the intestines and colon contain one of the densest known microbial communities on Earth. What is the secret to that high density in the intestinal tract?
Surface area. The inner surfaces of the human intestine and colon are highly convoluted. If you were to flatten out the entire inner surface of the intestine, it would be the size of a tennis court! Dense microbial communities coat that entire surface and also fill the interior spaces of the intestines, resulting in a very dense community.

SPECIES DIVERSITY:
The microbiome is also diverse — a normal microbiome includes around a thousand different species. Thinking back again to your high school biology class, you might recall learning about three basic kinds of bacteria: rods, spheres, and spirals. Certainly bacteriologists developed and used a much more detailed classification system that took into account bacterial physiology and metabolism, but until quite recently, known bacterial diversity was confined to the approximately 5,000 bacterial species that could be grown in the laboratory. Technological advances, especially the capacity to sequence genetic material from environmental samples, have allowed scientists to explore the bacterial world at much greater depth and resolution. 

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The following two articles discuss exercise and healthy aging. The first discusses Olga Kotelko and Bruce Grierson (author of the book "What Makes Olga Run").  From the Feb. 10, 2014 New York Times:

Seeking the Keys to Longevity in ‘What Makes Olga Run?’

No one would mistake Olga Kotelko for one of the Olympians competing in Sochi, Russia, but at age 94, she holds more world records than most: 26, to be exact, including age-group bests in the high jump, the hammer throw and the 200-meter run. Not bad for someone who took up track and field at age 77.

The result is this jolly book, which follows the pair as they consult researchers in fields like gerontology, exercise physiology and genetics for insights into Ms. Kotelko’s remarkable youthfulness.

What they find are countless opinions, but little definitive proof. Genes, diet, temperament, the theories abound. (Mr. Grierson rules out performance-enhancing drugs.) Or maybe it’s the exercise itself.

Research on twins suggests that heredity accounts for only about 25 percent to 30 percent of longevity, so it is not enough simply to label Ms. Kotelko a “genetic freak.” Besides, tests show she lacks at least one gene associated with longevity, and it turns out that her telomeres, chromosome caps that shorten with age, are merely average in length.

As for her diet, it is abundant and promiscuous. Her staples include red meat, sauerkraut, cottage cheese and sour milk, and she eats “immoderate amounts” of tapioca pudding. A centenarian friend of hers, the Australian shot-putter Ruth Frith, eschews vegetables altogether.

Among the potential anti-aging elixirs Mr. Grierson explores, exercise appears most potent. This old standby doesn’t just keep hearts pumping and muscles strong; studies suggest it may protect the mind too, by promoting the formation of neurons in the hippocampus — a part of the brain associated with memory.

Since she began her track and field career, Ms. Kotelko has rarely remained still, and that active lifestyle may be more important than her workouts at the track.

From the Feb. 7, 2014 Science Daily:

Exercise may slow progression of retinal degeneration

Moderate aerobic exercise helps to preserve the structure and function of nerve cells in the retina after damage, according to an animal study appearing February 12 in The Journal of Neuroscience. The findings suggest exercise may be able to slow the progression of retinal degenerative diseases.

Age-related macular degeneration, one of the leading causes of blindness in the elderly, is caused by the death of light-sensing nerve cells in the retina called photoreceptors. Although several studies in animals and humans point to the protective effects of exercise in neurodegenerative diseases or injury, less is known about how exercise affects vision.

Machelle Pardue, PhD, together with her colleagues Eric Lawson and Jeffrey H. Boatright, PhD, at the Atlanta VA Center for Visual and Neurocognitive Rehabilitation and Emory University, ran mice on a treadmill for two weeks before and after exposing the animals to bright light that causes retinal degeneration. The researchers found that treadmill training preserved photoreceptors and retinal cell function in the mice.

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From the Feb. 6, 2014 Science Daily:

Whole diet approach to lower cardiovascular risk has more evidence than low-fat diets

A study published in The American Journal of Medicine reveals that a whole diet approach, which focuses on increased intake of fruits, vegetables, nuts, and fish, has more evidence for reducing cardiovascular risk than strategies that focus exclusively on reduced dietary fat.

This new study explains that while strictly low-fat diets have the ability to lower cholesterol, they are not as conclusive in reducing cardiac deaths. By analyzing major diet and heart disease studies conducted over the last several decades, investigators found that participants directed to adopt a whole diet approach instead of limiting fat intake had a greater reduction in cardiovascular death and non-fatal myocardial infarction.

"Nearly all clinical trials in the 1960s, 70s and 80s compared usual diets to those characterized by low total fat, low saturated fat, low dietary cholesterol, and increased polyunsaturated fats," says study co-author James E. Dalen, MD, MPH, Weil Foundation, and University of Arizona College of Medicine. "These diets did reduce cholesterol levels. However they did not reduce the incidence of myocardial infarction or coronary heart disease deaths."

Carefully analyzing studies and trials from 1957 to the present, investigators found that the whole diet approach, and specifically Mediterranean-style diets, are effective in preventing heart disease, even though they may not lower total serum or LDL cholesterol. The Mediterranean-style diet is low in animal products and saturated fat, and encourages intake of monounsaturated fats found in nuts and olive oil. In particular, the diet emphasizes consumption of vegetables, fruit, legumes, whole grains, and fish.

"The potency of combining individual cardioprotective foods is substantial -- and perhaps even stronger than many of the medications and procedures that have been the focus of modern cardiology," explains co-author Stephen Devries, MD, FACC.

More evidence in support of Mediterranean style diet. From the Feb. 4, 2014 Science Daily:

Mediterranean diet linked with lower risk of heart disease among young U.S. workers

Among a large group of Midwestern firefighters, greater adherence to Mediterranean-style diet was associated with lower risk factors for cardiovascular disease (CVD), according to a new study led by researchers from Harvard School of Public Health (HSPH) and Cambridge Health Alliance (CHA). The study is the first to assess the effects of Mediterranean-style diet among a group of young, working U.S. adults.

The researchers analyzed medical and lifestyle data, including dietary habits, from an existing cohort of 780 male firefighters in the Midwest. They developed a modified Mediterranean diet score (mMDS) to assess the participants' dietary patterns.

The firefighter group with greatest adherence to Mediterranean-style diet showed a 35% decreased risk in metabolic syndrome, a condition with risk factors that include a large waistline, high triglyceride level, low HDL ("good") cholesterol level, high blood pressure, and high blood sugar. The group with the highest mMDS also had a 43% lower risk of weight gain compared with the lowest mMDS group. Additionally, greater adherence to a Mediterranean-style diet was significantly associated with higher HDL cholesterol and lower LDL ("bad") cholesterol. Consistent with previous investigations, obese participants in the firefighter study reported a higher intake of both fast foods and sugary drinks.

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Take note: all of us are exposed to these contaminants because they are in our environment.  The Inuit exposure is just more concentrated. From Feb. 7, 2014 Environmental Health News:

Contaminants have variety of effects on Arctic baby IQs

Babies in Arctic Canada are at risk of specific effects on their mental abilities, depending on which contaminants they are exposed to in the womb, according to a new study.While lead, methylmercury and polychlorinated biphenyls (PCBs) all are linked to neurological effects, each seems to have a different effect on infants, the scientists concluded. For example, PCBs seemed to impair the babies’ ability to recognize things they have seen.

The study involved 94 Inuit infants and their mothers from Nunavik, in northern Quebec. PCBs, mercury and other pollutants hitchhike north via prevailing winds and currents from industrialized areas, and then accumulate in food webs, predominantly in the eastern Arctic. Because the Inuit in Canada and Greenland eat top predators such as beluga whales and seals, they are among the world’s most contaminated human beings. The scientists measured the babies’ prenatal exposure to the three contaminants by testing cord blood, and then administered standard mental development tests at 6.5 months and 11 months. 

“Each contaminant was independently associated with impairment of distinct aspects of cognitive function with long-term implications for cognitive development – PCBs with visual recognition memory, methylmercury with working memory and an early precursor of executive function, lead with processing speed – deficits that can already be detected during the first year of life,” the authors wrote.

For the research, scientists at Quebec’s Centre de Recherche du CHUQ, who have been studying effects of contaminants on Inuit children for two decades, teamed up with Wayne State University scientists who conducted groundbreaking work in the Great Lakes linking PCBs to reduced IQs in the 1990s.