Short Bouts Of Exercise Boost Self Control

Short bouts of moderately intense exercise seem to boost self control, indicates an analysis of the published evidence in the British Journal of Sports Medicine.

The resulting increased blood and oxygen flow to the pre-frontal cortex may explain the effects, suggest the researchers.

They trawled medical research databases for studies looking at the impact of physical exercise on higher brain functions, such as memory, concentration, planning, and decision-making, in three groups: 6 to 12 year olds; 13 to 17 year olds; and 18 to 35 year olds.

They found 24 relevant studies published up to April 2012. Nineteen of these, involving 586 participants, addressed the impact of short bouts of exercise, and five, involving 358 participants, addressed the impact of regular exercise.

Regular exercise didn't seem to have much impact on higher brain functions, the analysis showed, but the studies were too few in number, and their results too inconsistent to enable firm conclusions to be drawn, caution the authors.

But short bouts of exercise did boost higher brain function in all three age groups. Only four studies looked at the impact of this type of exercise on working memory, but only in young adults, and the numbers were insufficient to draw conclusions on the impact.

But 12 of the 19 studies looked at self control, and the analysis indicated that short bouts of exercise did improve this higher brain function across all three age groups, registering a small to moderate impact.

This is particularly important for children and teens, because well developed higher brain functions are important for academic achievement and other aspect of daily life, say the authors.

"These positive effects of physical exercise on inhibition/interference control are encouraging and highly relevant, given the importance of inhibitory control and interference control in daily life," they write.

"Inhibition is essential for regulation of behaviour and emotions in social, academic, and sport settings," they add.

They speculate that short bouts of exercise may boost the cerebral blood flow to the pre-frontal areas of the brain, responsible for higher (executive) functions.

Exercise might be a useful treatment for conditions characterised by impaired higher brain functions, such as attention hyperactivity deficit disorder (ADHD) and autism, and may help delay the ravages of dementia, they suggest.

"Given the trend for a more sedentary lifestyle, worldwide ageing and the increasing prevalence of dementia, the results highlight the importance of engaging in physical exercise in the general population," they conclude.

A stimulating environment may protect against Alzheimer's Disease

"Use it or lose it." The saying could apply especially to the brain when it comes to protecting against Alzheimer's disease. Previous studies have shown that keeping the mind active, exercising and social interactions may help delay the onset of dementia in Alzheimer's disease.

Now, a new study led by Dennis Selkoe, MD, co-director of the Center for Neurologic Diseases in the BWH Department of Neurology, provides specific pre-clinical scientific evidence supporting the concept that prolonged and intensive stimulation by an enriched environment, especially regular exposure to new activities, may have beneficial effects in delaying one of the key negative factors in Alzheimer's disease.

The study will be published online on March 6, 2013 in Neuron.

Alzheimer's disease occurs when a protein called amyloid beta accumulates and forms "senile plaques" in the brain. This protein accumulation can block nerve cells in the brain from properly communicating with one another. This may gradually lead to an erosion of a person's mental processes, such as memory, attention, and the ability to learn, understand and process information.

The BWH researchers used a wild-type mouse model when evaluating how the environment might affect Alzheimer's disease. Unlike other pre-clinical models used in Alzheimer's disease research, wild-type mice tend to more closely mimic the scenario of average humans developing the disease under normal environmental conditions, rather than being strongly genetically pre-disposed to the disease.

Selkoe and his team found that prolonged exposure to an enriched environment activated certain adrenalin-related brain receptors which triggered a signaling pathway that prevented amyloid beta protein from weakening the communication between nerve cells in the brain's "memory center," the hippocampus. The hippocampus plays an important role in both short- and long-term memory.

The ability of an enriched, novel environment to prevent amyloid beta protein from affecting the signaling strength and communication between nerve cells was seen in both young and middle-aged wild-type mice.

"This part of our work suggests that prolonged exposure to a richer, more novel environment beginning even in middle age might help protect the hippocampus from the bad effects of amyloid beta, which builds up to toxic levels in one hundred percent of Alzheimer patients," said Selkoe.

Moreover, the scientists found that exposing the brain to novel activities in particular provided greater protection against Alzheimer's disease than did just aerobic exercise. According to the researchers, this observation may be due to stimulation that occurred not only physically, but also mentally, when the mice moved quickly from one novel object to another.

"This work helps provide a molecular mechanism for why a richer environment can help lessen the memory-eroding effects of the build-up of amyloid beta protein with age," said Selkoe. "They point to basic scientific reasons for the apparent lessening of AD risk in people with cognitively richer and more complex experiences during life."

Excess dietary salt may drive the development of autoimmune diseases

Increased dietary salt intake can induce a group of aggressive immune cells that are involved in triggering and sustaining autoimmune diseases. In autoimmune diseases, the immune system attacks healthy tissue instead of fighting pathogens.

In recent decades scientists have observed a steady rise in the incidence of autoimmune diseases in the Western world. Since this increase cannot be explained solely by genetic factors, researchers hypothesize that the sharp increase in these diseases is linked to environmental factors. Among the suspected culprits are changes in lifestyle and dietary habits in developed countries, where highly processed food and fast food are often on the daily menu. These foods tend to have substantially higher salt content than home-cooked meals. This study is the first to indicate that excess salt intake may be one of the environmental factors driving the increased incidence of autoimmune diseases.

A few years ago Jens Titze showed that excess dietary salt (sodium chloride) accumulates in tissue and can affect macrophages (a type of scavenger cells) of the immune system. Independent of this study, Markus Kleinewietfeld and David Hafler observed changes in CD4 positive T helper cells (Th) in humans, which were associated with specific dietary habits. The question arose whether salt might drive these changes and thus can also have an impact on other immune cells. Helper T cells are alerted of imminent danger by the cytokines of other cells of the immune system. They activate and "help" other effector cells to fight dangerous pathogens and to clear infections. A specific subset of T helper cells produces the cytokine interleukin 17 and is therefore called Th17 for short. Evidence is mounting that Th17 cells, apart from fighting infections, play a pivotal role in the pathogenesis of autoimmune diseases.

Salt dramatically boosts the induction of aggressive Th17 immune cells

In cell culture experiments the researchers showed that increased sodium chloride can lead to a dramatic induction of Th17 cells in a specific cytokine milieu. "In the presence of elevated salt concentrations this increase can be ten times higher than under usual conditions," Markus Kleinewietfeld and Dominik Müller explained. Under the new high salt conditions, the cells undergo further changes in their cytokine profile, resulting in particularly aggressive Th17 cells.

In mice, increased dietary salt intake resulted in a more severe form of experimental autoimmune encephalomyelitis, a model for multiple sclerosis. Multiple sclerosis is an autoimmune disease of the central nervous system in which the body's own immune system destroys the insulating myelin sheath around the axons of neurons and thus prevents the transduction of signals, which can lead to a variety of neurological deficits and permanent disability. Recently, researchers postulated that autoreactive Th17 cells play a pivotal role in the pathogenesis of multiple sclerosis.

Interestingly, according to the researchers, the number of pro-inflammatory Th17 cells in the nervous system of the mice increased dramatically under a high salt diet. The researchers showed that the high salt diet accelerated the development of helper T cells into pathogenic Th17 cells. The researchers also conducted a closer examination of these effects in cell culture experiments and showed that the increased induction of aggressive Th17 cells is regulated by salt on the molecular level. "These findings are an important contribution to the understanding of multiple sclerosis and may offer new targets for a better treatment of the disease, for which at present there is no known cure," said Ralf Linker, who as head of the Neuroimmunology Section and Attending Physician at the Department of Neurology, University Hospital Erlangen, seeks to utilize new laboratory findings for the benefit of patients.

Besides multiple sclerosis, Dominik Müller and his colleagues want to study psoriasis, another autoimmune disease with strong Th17 components. The skin, as Jens Titze recently discovered, also plays a key role in salt storage and affects the immune system. "It would be interesting to find out if patients with psoriasis can alleviate their symptoms by reducing their salt intake," the researchers said. "However, the development of autoimmune diseases is a very complex process which depends on many genetic and environmental factors," the immunologist Markus Kleinewietfeld said. "Therefore, only further studies under less extreme conditions can show the extent to which increased salt intake actually contributes to the development of autoimmune diseases."

Exercise Key to Good Sleep

Exercise can affect your sleep. The results of the National Sleep Foundation’s 2013 Sleep in America® poll show a compelling association between exercise and better sleep. 

“Exercise is great for sleep. For the millions of people who want better sleep, exercise may help,” says David Cloud, CEO of the National Sleep Foundation (NSF). 

Exercisers say they sleep better
Self-described exercisers report better sleep than self-described non-exercisers even though they say they sleep the same amount each night (6 hours and 51 minutes, average on weeknights). Vigorous, moderate and light*exercisers are significantly more likely to say “I had a good night’s sleep” every night or almost every night on work nights than non-exercisers (67%-56% vs. 39%). Also, more than three-fourths of exercisers (76%-83%) say their sleep quality was very good or fairly good in the past two weeks, compared to slightly more than one-half of non-exercisers (56%).

“If you are inactive, adding a 10 minute walk every day could improve your likelihood of a good night’s sleep,” says Max Hirshkowitz, PhD, poll task force chair. “Making this small change and gradually working your way up to more intense activities like running or swimming could help you sleep better.”

“Our poll data certainly find strong relationships between good sleep and exercise,” adds Hirshkowitz. “While cause and effect can be tricky, I don’t think having good sleep necessarily compels us to exercise. I think it is much more likely that exercising improves sleep. And good sleep is fundamental for good health, productivity, and happiness.” 

Vigorous exercisers report the best sleep
Vigorous exercisers are almost twice as likely as non-exercisers to report “I had a good night’s sleep” every night or almost every night during the week. They also are the least likely to report sleep problems. More than two-thirds of vigorous exercisers say they rarely or never (in the past 2 weeks) had symptoms commonly associated with insomnia, including waking up too early and not being able to get back to sleep (72%) and difficulty falling asleep (69%). In contrast, one-half (50%) of non-exercisers say they woke up during the night and nearly one-fourth (24%) had difficulty falling asleep every night or almost every night.

“Poor sleep might lead to negative health partly because it makes people less inclined to exercise,” says Shawn Youngstedt, PhD, poll task force member. “More than one half (57%) of the total sample reported that their activity level will be less than usual after a night of poor sleep. Not exercising and not sleeping becomes a vicious cycle.”

Non-exercisers are the sleepiest and have the highest risk for sleep apnea
Non-exercisers tend toward being more excessively sleepy than exercisers. Nearly one-fourth of non-exercisers (24%) qualify as “sleepy” using a standard excessive sleepiness clinical screening measure. This sleepiness level occurs about twice as often than for exercisers (12-15%). Also, about six in ten of non-exercisers (61%) say they rarely or never have a good night’s sleep on work nights. 

Sleepiness clearly interferes with many non-exercisers’ safety and quality of life. One in seven non-exercisers (14%) report having trouble staying awake while driving, eating or engaging in social activity at least once a week in the past two weeks, almost three times the rate of those who exercise (4-6%).

“Sometimes we might feel tired, and that's normal,” says Matthew Buman, PhD, poll task force member, “but if excessive sleepiness is your normal state, it warrants a conversation with your doctor. It could be a red flag that something is wrong with your health.”

Indeed, non-exercisers have more symptoms of sleep apnea. Sleep apnea is a serious medical condition in which a person stops breathing during sleep. Its symptoms often include tiredness, snoring, and high blood pressure. It also increases the risk for heart disease and stroke. More than four in ten non-exercisers (44%) exhibit a moderate risk of sleep apnea, compared to between one in four and one in five of light exercisers (26%), moderate exercisers (22%) and vigorous exercisers (19%). 

“The poll data suggest that the risk of sleep apnea in exercisers is half that of non-exercisers,” says Christopher Kline, PhD, poll task force member. “People with sleep apnea are often overweight. Exercise can be part of the treatment.”

Less time sitting is associated with better sleep and health
Separate from exercise, spending less time sitting may improve sleep quality and health. Those who sit for less than eight hours per day sitting are significantly more likely to say they have “very good” sleep quality than those who sit for eight hours or more (22%-25% compared to 12%-15%). Furthermore, significantly more of those who spend less than 10 hours per day sitting mention excellent health, compared to those who spend 10 hours or more sitting (25-30% compared to 16%). 

“This poll is the first to show that simply spending too much time sitting might negatively affect our sleep quality,” says Prof. Marco Tulio de Mello, poll task force member. “In addition to exercise, standing at your desk, getting up for short breaks, and moving around as much as possible are important healthy behaviors to include in our lives.”

Exercise at any time of day appears to be good for sleep
Those who report exercising close to bedtime and earlier in the day do not demonstrate a difference in self-reported sleep quality. In fact, for most people exercise at any time seems to be better for sleep than no exercise at all. 

This finding contradicts long-standing “sleep hygiene” tips that advise everyone not to exercise close to bedtime. The National Sleep Foundation has amended its sleep recommendations for “normal” sleepers to encourage exercise without any caveat to time of day as long as it’s not at the expense of sleep. (However, people with chronic insomnia should continue to restrict late evening and night exercise, if this is part of their treatment regimen.) 

“Exercise is beneficial to sleep. It's time to revise global recommendations for improving sleep and put exercise—any time—at the top of our list for healthy sleep habits,” says Dr. Barbara Phillips, poll task force member. 

Healthy Sleep Advice
To improve your sleep, try the following sleep tips:

• Exercise regularly. Vigorous exercise is best, but even light exercise is better than no activity. Exercise at any time of day, but not at the expense of your sleep.
• Create an environment that is conducive to sleep that is quiet, dark and cool with a comfortable mattress and pillows.
• Practice a relaxing bedtime ritual, like a warm bath or listening to calming music.
• Go to sleep and wake at the same time every day, and avoid spending more time in bed than needed.
• Use bright light to help manage your "body clock." Avoid bright light in the evening and expose yourself to sunlight in the morning.
• Use your bedroom only for sleep to strengthen the association between your bed and sleep. It may help to remove work materials, computers and televisions from your bedroom.
• Save your worries for the daytime. If concerns come to mind, write them in a "worry book" so you can address those issues the next day.
• If you can't sleep, go into another room and do something relaxing until you feel tired.
• If you are experiencing excessive daytime sleepiness, snoring, or “stop breathing” episodes in your sleep, contact your health care professional for a sleep apnea screening.

Poll Methodology and Definitions
The 2013 Sleep in America® annual poll was conducted for the National Sleep Foundation by WB&A Market Research, using a sample of 1,000 adults between the ages of 23 and 60. The number of completes needed for both age groups and regions was determined using the most current U.S. Census data from 2010.

The maximum sampling error of the data for the total sample is +/- 3.1 percentage points at the 95% confidence level. The sampling error will vary depending on the sample size and the percentages being examined in the sample.

* Using a self-reported measure of physical activity, for which respondents considered physical activity they did for at least 10 minutes in the past 7 days, participants were classified into four different activity levels:  vigorous, moderate, light and no activity.  In this self-report measure, vigorous was defined as activities which require hard physical effort such as:  running, cycling, swimming or competitive sports.  The next level, moderate, was defined as activities which require more effort than normal such as:  yoga, tai chi and weight lifting.  Light activity was defined as walking, while those who do not do any activity classified themselves into the no activity level.  Segments are often referred to as vigorous exercisers, moderate exercisers, light exercisers and non-exercisers based on this measure of self-categorization.

Why fish is so good for you

Jena (Germany) Fish is healthy: easy to digest and with a high level of precious proteins, fish is considered an important part of a healthy diet. And with the so-called omega-3 fatty acids fish contains real 'fountains of youth'. These fatty acids – like docosahexaeonic acid (DHA) occur mostly in fatty fish like herring, salmon and mackerel. They are thought to lower the blood pressure, to strengthen the immune system and to have positive effects on the development on the nervous system and the cardiovascular system.

"Clinical studies about the intake of nutritional supplements containing omega-3 fatty acids haven't provided complete clarity so far," Prof. Dr. Stefan H. Heinemann from Friedrich Schiller University Jena (Germany) says. "The molecular impact of the omega-3 fatty acids isn't fully understood yet," the biophysicist continues. But now scientists of the DFG research group FOR 1738 based at Jena University are able to bring new facts to light: in two newly published articles for the well-known science magazine 'Proceedings of the National Academy of Sciences, USA' they describe how they analyzed the impact of omega-3 fatty acids on a systemic level and they also described the underlying molecular mechanisms for the first time.

The teams around Prof. Heinemann (Jena University), Prof. Dr. Michael Bauer (Jena University Hospital) and Prof. Dr. Toshinori Hoshi (University of Pennsylvania) were able to show that the so-called 'SLO1' potassium channel is an important component in the effectiveness of omega-3 fatty acids. "These ionic channels act like very specific receptors for DHA and are opened by the binding of the omega-3 fatty acids," Biophysicist Heinemann explains. In the case of other omega-3 fatty acids – like the shorter eicosapentaenoic acid (EPA) or the alpha-linolenic acid (ALA) extracted from plants – the impact is much weaker.

Prof. Bauer and his colleagues examined the effects of omega-3 fatty acids on SLO1 channels of the cardiovascular system by experimenting with mice. "Administration of DHA should result in an expansion of the blood vessels and consequently a drop in blood pressure," the physician says. The laboratory experiments confirmed exactly that. In genetically modified mice however, which were not able to produce the SLO1 channel, the antihypertensive impact of DHA failed to appear. "Thus we were able to show for the first time that DHA directly influences the blood pressure, which is being mediated through SLO1 channels," Bauer summarizes.

Beyond that, the scientists made another surprising discovery: a variant of DHA, which can often be found in nutritional supplements containing omega-3 fatty acids, doesn't show an antihypertensive effect. Moreover, it suppresses and even diminishes the effect of the natural DHA from fish oil. "The intake of non-natural omega-3 fatty acids can therefore also have counter-productive effects," Prof. Bauer stresses. This is of particular importance for the nutritional supplements of patients in intensive care who are being drip-fed: their supplements of omega-3 fatty acids should be specifically aimed at and adapted to the patients' clinical requirements.

Walking Away from Back Pain

Home aerobic program as effective as clinical therapy in treating lower back pain, finds TAU researcher

Lower back pain is a common complaint, and treatment often requires many hours of physical therapy over multiple weekly clinic visits — a costly commitment. Now Dr. Michal Katz-Leurer of Tel Aviv University's Stanley Steyer School of Health Professions at the Sackler Faculty of Medicine says that a simple aerobic walking program is as effective in alleviating lower back pain as muscle strengthening programs that require specialized equipment in rehabilitation clinics. The program includes walking two to three times a week for a period of 20 to 40 minutes.

Dr. Katz-Leurer and her colleague Ilana Shnayderman, a graduate student at the Department of Physical Therapy and a practicing physiotherapist at Maccabi Health Care, say that their treatment option fits easily into a daily routine and allows those with back pain to be more responsible for their own health.

Their study was published in the journal Clinical Rehabilitation.

According to Dr. Katz-Leurer, research has shown that when people walk actively, abdominal and back muscles work in much the same way as when they complete exercises that target these areas. And unlike muscle strengthening programs, which often call for specific equipment and can involve exercises that require expert supervision, walking is a simple activity that can be done alone.

For the study, the researchers recruited 52 patients with lower back pain to participate in a randomized control trial. Through questionnaires, they were initially assessed for pain levels, feelings of disability, and avoidance of daily activities, as well as muscle and walking endurance.

Then, half of the participants completed a typical clinic-based muscle strengthening program, with two to three exercise sessions a week for six weeks. The other half completed a six-week aerobic walking program, walking two to three times weekly. Participants started with 20 minutes of walking, then progressed to 40 minutes as their endurance improved.

Results showed that both groups improved significantly in all areas of assessment, demonstrating that the walking program was "as effective as treatment that could have been received in the clinic," says Dr. Katz-Leurer.

The path to a healthier lifestyle

Dr. Katz-Leurer says that the walking program has the additional advantage of encouraging patients to follow a healthier lifestyle overall. In terms of physical fitness, those in the walking group were able to walk an average of 0.05 miles farther during a six-minute walking test at the end of the program compared to the pre-program assessments.

She also notes that that regularly active people are less likely to suffer typical aches and pains over their lifetime. Walking, a low-impact activity, also lowers blood pressure, boosts brain and immune system functioning, and reduces stress, she says.

The Importance Of Eating Your Greens

Eating your greens may be even more important that previously thought, with the discovery that an immune cell population essential for intestinal health could be controlled by leafy greens in your diet.

The immune cells, named innate lymphoid cells (ILCs), are found in the lining of the digestive system and protect the body from 'bad' bacteria in the intestine. They are also believed to play an important role in controlling food allergies, inflammatory diseases and obesity, and may even prevent the development of bowel cancers.

Dr Gabrielle Belz, Ms Lucie Rankin, Dr Joanna Groom and colleagues from the Walter and Eliza Hall Institute's Molecular Immunology division have discovered the gene T-bet is essential for producing a population of these critical immune cells and that the gene responds to signals in the food we eat.

Dr Belz said the research team revealed T-bet was essential for generating a subset of ILCs which is a newly discovered cell type that protects the body against infections entering through the digestive system. "In this study, we discovered that T-bet is the key gene that instructs precursor cells to develop into ILCs, which it does in response to signals in the food we eat and to bacteria in the gut," Dr Belz said. "ILCs are essential for immune surveillance of the digestive system and this is the first time that we have identified a gene responsible for the production of ILCs."

The research was published in the journal Nature Immunology.

Dr Belz said that the proteins in green leafy (cruciferous) vegetables are known to interact with a cell surface receptor that switches on T-bet, and might play a role in producing these critical immune cells. "Proteins in these leafy greens could be part of the same signalling pathway that is used by T-bet to produce ILCs," Dr Belz said. "We are very interested in looking at how the products of these vegetables are able to talk to T-bet to make ILCs, which will give us more insight into how the food we eat influences our immune system and gut bacteria."

ILCs are essential for maintaining the delicate balance between tolerance, immunity and inflammation. Ms Rankin said the discovery had given the research team further insight into external factors responsible for ILC activation. "Until recently, it has been difficult to isolate or produce ILCs," Ms Rankin said. "So we are very excited about the prospect for future research on these cells which are still poorly understood."

ILCs produce a hormone called interleukin-22 (IL-22), which can protect the body from invading bacteria, Dr Belz said. "Our research shows that, without the gene T-bet, the body is more susceptible to bacterial infections that enter through the digestive system. This suggests that boosting ILCs in the gut may aid in the treatment of these bacterial infections," she said.

ILCs help to maintain a 'healthy' environment in the intestine by promoting good bacteria and healing small wounds and abrasions that are common in the tissues of the gut. They may also have a role in resolving cancerous lesions. "The discovery of these immune cells has thrown open a completely new way of looking at gut biology," Dr Belz said. "We are just starting to understand how important these immune cells are in regulating allergy and inflammation, and the implications for bowel cancer and other gastrointestinal disorders such as Crohn's disease," she said.

"Understanding the biology of ILCs and the genes that are essential for generating them will help us to develop methods of targeting these cells," Dr Belz said. "This might include boosting ILCs in situations where they may not be active enough, such as infections or some cancers, or depleting them in situations where they are overactive, such as chronic inflammatory disease," she said.