Seven Minutes of Vigorous Physical Activity A Must For Kids

A minimum of seven minutes of vigorous physical activity daily is a must for children to stay healthy, a recent study finds. "If you watch late-night television, or look in the backs of magazines, you'll see magical ads saying you need just 10 minutes a day or five minutes a day of exercise to stay fit. And for those of us in the medical field, we just rolled our eyes at that. But surprisingly, they may actually be right and that's what this research shows," says co-principal investigator Richard Lewanczuk, a researcher with the Faculty of Medicine & Dentistry at the U of A.
"Our research showed children don't need a lot of intense physical activity to get the health benefits of exercise – seven minutes or more of vigorous physical activity was all that was required. But the seven minutes had to be intense to prevent weight gain, obesity and its adverse health consequences. And most kids weren't getting that." Lewanczuk worked on this study with Jonathan McGavock, his co-principal investigator and former post-doctoral fellow, who now works with the Manitoba Institute of Child Health. They collaborated with Black Gold Regional Schools in Leduc and surrounding communities just south of Edmonton, as well as researchers from the University of Manitoba, Queen's University, the University of Newcastle, and U of A researchers from the Faculty of Medicine & Dentistry, the School of Public Health, Physical Education and Recreation, and Agricultural, Life and Environmental Sciences. The team's findings were recently published in the peer-reviewed journal Archives of Pediatrics & Adolescent Medicine. 
More than 600 children, between the ages of nine to 17 from Leduc and surrounding areas, wore monitors that tracked their physical activity levels for seven days. These children also had their weight, waist circumference and blood pressure regularly monitored. 
Researchers reviewed the data collected through the Healthy Hearts program via Black Gold Regional Schools and determined the children spent almost 70 per cent of their time doing sedentary activities; nearly 23 per cent was devoted to light physical activity; almost seven per cent to moderate physical activity and 0.6 per cent to vigorous physical activity. 
Overall, boys were less sedentary than girls. And the more vigorous the physical activity, the less apt the children were to be overweight. Children who were overweight had improved fitness levels and shrinking waist lines when they increased the amount of time spent doing vigorous activities. 
Lewanczuk said the team made some other notable findings including the following: there weren't the expected health benefits from doing only mild or moderate activity even if the time spent doing this type of activity increased. What seemed to be critical was taking part in intense physical activity. For kids who took part in vigorous physical activity that lasted longer than seven minutes, their health benefits were significantly better. And the whole notion of being overweight but fit? The team's data didn't support that finding in children. If children were overweight, they were also unhealthy, Lewanczuk says. 
"This research tells us that a brisk walk isn't good enough," says Lewanczuk, a professor in the Department of Medicine who has been studying this topic for eight years. "Kids have to get out and do a high-intensity activity in addition to maintaining a background of mild to moderate activity. There's a strong correlation between obesity, fitness and activity. Activity and fitness is linked to a reduction in obesity and good health outcomes." 
Getting young children to make vigorous physical activity part of their daily routines is important, especially considering activity levels in the teenage years drop right off, Lewanczuk says. And previously published research from the same group of children shows kids are more active at school than they are at home. 
"Quite often the activity levels on evenings or weekends would be almost flat," he says. "We made the presumption that kids were just sitting in front of a screen the whole time." 
Lewanczuk hopes the research findings will help schools decide what type of mandatory physical activity is needed. 
He praised the school district involved in the study, noting the research wouldn't have been possible without its support. 
Paul Wozny with Black Gold Regional Schools said physical activity is always worthwhile and noted that increased moderate to intense activity was closely associated with lower weights from year to year. He said the Healthy Hearts project has truly created "a school and community culture where regular physical activity and healthy nutrition are seen as essential ingredients for students' health, wellness and life-long learning. Everyone is involved – students, their parents, teachers, staff, researchers and the community as a whole. 
"We are always striving to improve, so we regularly review the research results to help us fine tune and develop future activity and wellness programming at all of our school communities. Black Gold Regional Schools' Health Hearts project has received both national and international recognition as a world-leading school and community initiative dedicated to the improvement of student cardiovascular health through regular physical activity and multi-stakeholder support." 
The primary funders of the research were: the Canadian Diabetes Association and the Alberta Center for Child, Family and Community Research. 
"The Canadian Diabetes Association is proud to be a leading supporter of diabetes research in Canada, investing more than $7 million annually in diabetes research," said Janet Hux, chief scientific advisor for the Canadian Diabetes Association. "The association encourages Canadians to pursue healthy lifestyles in order to prevent and manage diabetes. Dr. Lewanczuk's work provides important new insights that may make enhanced activity more feasible for children and youth." 
The Alberta Center for Child, Family and Community Research added: "Having this kind of evidence should make it easier for parents, schools and daycare programs to do activities with children that will help develop lifelong healthy attitudes towards exercise and activity," stated Alberta Center for Child, Family and Community Research President and CEO, Robyn Blackadar. 
 

Dopamine Improves Long Term Memory

 - the feel good hormone boosts long term memory, say scientists. A team led by Emrah Duzel, neuroscientist at the German Center for Neurodegenerative Diseases (DZNE) and the University of Magdeburg have made the findings. 
The researchers investigated test subjects ranging in age from 65 to 75 years, who were given a precursor of dopamine.
 Treated subjects performed better in a memory test than a comparison group, who had taken a placebo. 
The study provides new insights into the formation of long lasting memories and also has implications for understanding why memories fade more rapidly following the onset of Alzheimer's disease. 
"Our investigations for the first time prove that dopamine has an effect on episodic memory. This is the part of long-term memory, which allows us to recall actual events. Occurrences in which we were personally involved," Duzel said. 
"Episodic memory is that part of our capacity to remember, which is first affected in Alzheimer's dementia. This is why our results can contribute to a better understanding of the disease," he said. 
The results have been published in the "Journal of Neuroscience."
Source-ANI

 

Exercise can Reduce Appetite

Hitting the gym for half an hour can suppress your hunger, find studies. 
One recently published study found that perceived fullness was higher among participants after 12 weeks of aerobic training, the Daily Mail reported.According to Men's health, another study showed that women appeared less hungry on mornings when they walked on a treadmill for 45 minutes compared with mornings they didn't. 
"Exercise can definitely suppress hunger," Barry Braun, director of the Energy Metabolism Laboratory at the University of Massachusetts, Amherst, told the publication.
Source-ANI
 

Sperm length variation is not a good sign

A new study published online in the journal Human Reproduction finds that the greater the inconsistency in the length of sperm, particularly in the tail (flagellum), the lower the concentration of sperm that can swim well. The finding offers fertility clinicians a potential new marker for fertility trouble that might trace back to how a patient’s sperm are being made.

Perhaps variety is the very spice of life, but as a matter of producing human life, it could be the bane of existence. That’s the indication of a new study in the journal Human Reproduction that found men with wider variation in sperm length, particularly in the flagellum, had lower concentrations of sperm that could swim well. Those with more consistently made sperm seemed to have more capable ones.“Our study reveals that men who produce higher concentrations of competent swimming sperm also demonstrate less variation in the size and shape of those sperm,” said Jim Mossman, a postdoctoral scholar at Brown University and lead author of the paper published in advance online Oct. 28. “It suggests that in some cases, testes are working more optimally to produce high numbers of consistently manufactured sperm, and vice versa.”At the University of Sheffield, where Mossman did his doctoral studies, he and his co-authors measured the heads, midpieces, and flagella of 30 sperm per man, from 103 men randomly selected from a pool of about 500 who were recruited for a larger fertility study. They also measured other characteristics of each man’s semen, such as sperm concentration and motility, that the World Health Organization recognizes as important markers of fertility.

Jim Mossman
“No one’s ever looked at this before across sperm components. What we show is that measurements on other sperm parts, such as the flagellum that propels the sperm, can provide additional information about the quality and consistency of sperm manufacture.”Credit: David Orenstein/Brown University“The WHO suggests that measurements should be made on multiple components of sperm, but generally it’s only the sperm head that is considered,” Mossman said. “No one’s ever looked at this before across sperm components. What we show is that measurements on other sperm parts, such as the flagellum that propels the sperm, can provide additional information about the quality and consistency of sperm manufacture.”The result of the novel analysis yielded two overall findings. One was that men who had higher mean flagellum length, total sperm length, and flagellum-to-head length ratios had higher concentrations of motile sperm. But perhaps the more interesting finding was that the greater the inconsistency of length in the sperm a man manufactures, particularly with regard to the flagellum, the lower his concentration of sperm that could swim well.“The finding could give clinicians new insight into the diagnosis and treatment of male fertility problems, which accounts for up to 50 percent of the cases where couples struggle to conceive,” Mossman said. The research suggests that at least in some men, measurable inconsistency in sperm length may be a sign of trouble with his process of making sperm, a process known as spermatogenesis. That trouble, akin to a manufacturing line with poor quality control, could result in a lower concentration of good swimmers.“This could be an indirect marker of testis function,” Mossman said.Mossman acknowledged that there is nothing in the study that suggests what might cause spermatogenesis problems that would result in either inconsistent lengths or low concentrations of motile sperm.“There are so many factors that govern sperm production, including environmental factors, genetic factors, and their interaction,” Mossman said. “As an andrologist and evolutionary biologist, I am very interested in what causes this variation and how that affects the phenotype of the sperm and its fertility potential.”At Brown since earning his Ph.D. at Sheffield, Mossman has been working in the lab of David Rand, professor of biology in the Department of Ecology and Evolutionary Biolog, using fruit flies to study the influence of genetics on male fertility.In addition to Mossman, the paper’s other authors are Jack Pearson, Harry Moore, and Allan Pacey, all of the University of Sheffield, which funded the research.

Source:Brown University

New Study Examines How Health Affects Happiness

A new study published in the Journal of Happiness Studies found that the degree to which a disease disrupts daily functioning is associated with reduced happiness.Lead author Erik Angner, associate professor of philosophy, economics and public policy at George Mason University, worked with an interdisciplinary team of researchers from the University of Alabama at Birmingham, the University of Chicago and the University of Massachusetts Medical School. The full study is available online.Previous research found that many serious medical conditions, including cancer, have a surprisingly small impact on happiness, while certain other conditions, such as urinary incontinence, seem to have a lasting negative effect on happiness.In their study, Angner and his co-authors explored the difference. They developed a measure called the “freedom-from-debility score” based on four health survey questions explicitly designed to represent limitations in physical activities and in usual role activities because of health problems.This study is the first to use a direct measure of the degree to which disease disrupts daily functioning.The authors found that when controlling for demographic and socioeconomic factors in addition to objective and subjective health status, a one-point increase in the freedom-from-debility score (on a scale from 0 to 100) was associated with a three-percent reduction in the odds of reported unhappiness.For example, a patient with prostate cancer, whose daily functioning is not affected by his condition, might score higher on a happiness scale than a patient with urinary incontinence, whose condition imposes dramatic limitations in daily functioning. Indeed, in an earlier study, the authors found that participants with a history of cancer reported being significantly happier than those with urinary incontinence.The study was conducted using a sample of 383 older adults recruited from the practices of 39 primary care physicians in Alabama.“These new results support the notion that health status is one of the most important predictors of happiness,” Angner said. “A better understanding of the complex relationship between health status and subjective well-being could have important implications for the care and treatment of patients and could lead to interventions that could dramatically improve patient quality of life.”Angner has separate PhDs in economics and in history and philosophy of science and has written extensively on the philosophy and economics of health, happiness and well-being. He is the author of A Course in Behavioral Economics.

About George Mason UniversityGeorge Mason University is an innovative, entrepreneurial institution with global distinction in a range of academic fields. Located in Northern Virginia near Washington, D.C., Mason provides students access to diverse cultural experiences and the most sought-after internships and employers in the country.  Mason offers strong undergraduate and graduate degree programs in engineering and information technology, organizational psychology, health care and visual and performing arts. With Mason professors conducting groundbreaking research in areas such as climate change, public policy and the biosciences, George Mason University is a leading example of the modern, public university. George Mason University—Where Innovation Is Tradition.

Fast food menus still pack a lot of calories, Temple-led study finds

With increased scrutiny over the past decade by the mass media and several legislative efforts by local governments, you might think fast food has come a long way nutritionally. But has it really? You can now find some healthier choices on fast food menus such as oatmeal with fruit, fruit smoothies, side salads and grilled chicken sandwiches. However, a study led by Katherine W. Bauer, assistant professor in Temple University’s Department of Public Health andCenter for Obesity Research and Education, found that the average calorie content of foods offered by eight of the major U.S. fast food restaurants changed very little between 1997 and 2010.  In the study, results of which will be published in the November issue of the American Journal of Preventive Medicine, researchers analyzed menu offerings and nutrient composition information from leading fast food restaurant chains in the U.S. using archival versions of the University of Minnesota Nutrition Coordinating Center’s Food and Nutrient Database. McDonald’s, Burger King, Wendy’s, Taco Bell, KFC, Arby’s, Jack in the Box and Dairy Queen were chosen because they had been in the database since 1997, each has defined set of offerings on the menu and all standard menu items are included in the database.One striking finding was a 53 percent increase in the total number of offerings — 679 to 1036 items — over 14 years across the restaurants. Specific fast-growing additions to the menus include the number of entree salads, which increased from 11 to 51, and sweetened teas, which went from zero to 35. The study authors did not find any large changes in the median calorie content of entrees and drinks. A gradual increase in calories was found in condiments and desserts. Meanwhile, a decrease in the median calories of side items was observed — from 264 to 219 — which may be due to the addition of lower-calorie side salads and some restaurants limiting the portion sizes of side items like French fries.In the last years examined, 2009 and 2010, lunch and dinner entrees had 453 calories on average per item while side items had 263 calories on average. “You might order a lower-calorie entree, but then you get a drink, fries and a dessert,” said Bauer. “Calories can add up very quickly. A salad can be low calorie, but not when it includes fried chicken and ranch dressing. Sweetened teas are just empty calories.”Eating fast food becomes a concern when someone eats too much of it too often. Studies have consistently found associations between fast food intake and excess weight and weight gain among adults. A recent survey of adults found that 80 percent purchased fast food in the past month and 28 percent consumed it two or more times a week. On a typical day, nearly 40 percent of teens consume fast food. “We’re not saying you shouldn’t ever eat fast food, but you need to think about things like portion size, preparation method, condiments and the total caloric content of your meal,” said Bauer.In the near future, consumers will be able to see calories for all food items posted at restaurants and food vendors with more than 20 locations, as mandated by the Patient Protection and Affordable Care Act of 2010. McDonalds recently began posting calories on its menus.“Using this study as a start, we’ll be able to see if being required to post the calorie content of menu items — the primary aim of which is to inform consumers — prompts any changes by the fast food industry,” said Bauer. “While some localities such as Philadelphia and New York City already require menu labeling, when the effort is rolled out nation-wide fast food restaurants may modify the calorie content of the foods they sell so consumers can see a smaller number on the menu board.“Without massive changes by the fast food industry in the caloric content of food, the key is for consumers to try to educate themselves about calories and be aware that just because a restaurant promotes healthful options, does not mean that overall the foods sold are lower calorie,” she said. “Over time, with increased exposure to calorie information on menus, people may start to understand how many calories they should consume each day.”

Co-authors of the study are Mary O. Hearst, of St. Catherine University; and Alicia A. Earnest, Simone A. French, J. Michael Oakes and Lisa J. Harnack, of the University of Minnesota School of Public Health’s Division of Epidemiology and Community Health. The study was funded by the Robert Wood Johnson Foundation through the Healthy Eating Research program and by the National Institutes of Health.

Source:Temple University

Injectable sponge delivers drugs, cells, and structure

Bioengineers at Harvard have developed a gel-based sponge that can be molded to any shape, loaded with drugs or stem cells, compressed to a fraction of its size, and delivered via injection. Once inside the body, it pops back to its original shape and gradually releases its cargo, before safely degrading.

The biocompatible technology, revealed this week in the Proceedings of the National Academy of Sciences, amounts to a prefabricated healing kit for a range of minimally invasive therapeutic applications, including regenerative medicine.

“What we’ve created is a three-dimensional structure that you could use to influence the cells in the tissue surrounding it and perhaps promote tissue formation,” explains principal investigator David J. Mooney, Robert P. Pinkas Family Professor of Bioengineering at the Harvard School of Engineering and Applied Sciences (SEAS) and a Core Faculty Member at the Wyss Institute for Biologically Inspired Engineering at Harvard.

“The simplest application is when you want bulking,” Mooney explains. “If you want to introduce some material into the body to replace tissue that’s been lost or that is deficient, this would be ideal. In other situations, you could use it to transplant stem cells if you’re trying to promote tissue regeneration, or you might want to transplant immune cells, if you’re looking at immunotherapy.”

Consisting primarily of alginate, a seaweed-based jelly, the injectable sponge contains networks of large pores, which allow liquids and large molecules to easily flow through it. Mooney and his research team demonstrated that live cells can be attached to the walls of this network and delivered intact along with the sponge, through a small-bore needle. Mooney’s team also demonstrated that the sponge can hold large and small proteins and drugs within the alginate jelly itself, which are gradually released as the biocompatible matrix starts to break down inside the body.

Normally, a scaffold like this would have to be implanted surgically. Gels can also be injected, but until now those gels would not have carried any inherent structure; they would simply flow to fill whatever space was available.

Left: A fully collapsed square-shaped cryogel rapidly regains its original memorized shape, size, and volume upon hydration. Right: Photos show the placement of a cryogel inside a 1-mL syringe, and the recovery of a square gel after injection through a normal 16-gauge needle. (Images courtesy of Sidi Bencherif.)

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“Our scaffolds can be designed in any size and shape, and injected in situ as a safe, preformed, fully characterized, sterile, and controlled delivery device for cells and drugs,” says lead author Sidi Bencherif, a postdoctoral research associate in Mooney’s lab at SEAS and at the Wyss Institute.

Bencherif and his colleagues pushed pink squares, hearts, and stars through a syringe to demonstrate the versatility and robustness of their gel (seevideo).

The spongelike gel is formed through a freezing process called cryogelation. As the water in the alginate solution starts to freeze, pure ice crystals form, which makes the surrounding gel more concentrated as it sets. Later on, the ice crystals melt, leaving behind a network of pores. By carefully calibrating this mixture and the timing of the freezing process, Mooney, Bencherif, and their colleagues found that they could produce a gel that is extremely strong and compressible, unlike most alginate gels, which are brittle.

The resulting “cryogel” fills a gap that has previously been unmet in biomedical engineering.

“These injectable cryogels will be especially useful for a number of clinical applications including cell therapy, tissue engineering, dermal filler in cosmetics, drug delivery, and scaffold-based immunotherapy,” says Bencherif. “Furthermore, the ability of these materials to reassume specific, pre-defined shapes after injection is likely to be useful in applications such as tissue patches where one desires a patch of a specific size and shape, and when one desires to fill a large defect site with multiple smaller objects. These could pack in such a manner to leave voids that enhance diffusional transport to and from the objects and the host, and promote vascularization around each object.”

The next step in the team’s research is to perfect the degradation rate of the scaffold so that it breaks down at the same rate at which newly grown tissue replaces it. Harvard’s Office of Technology Development has filed patent applications on the invention and is actively pursuing licensing and commercialization opportunities.

Coauthors included R. Warren Sands, Deen Bhatta, and Catia S. Verbeke at SEAS; Praveen Arany at SEAS and the Wyss Institute; and David Edwards, who is Gordon McKay Professor of the Practice of Bioengineering at SEAS and a Core Faculty Member at the Wyss Institute.

The research was supported by the Wyss Institute for Biologically Inspired Engineering at Harvard, the National Institutes of Health, and the Juvenile Diabetes Research Foundation.

Source:Hravard School of Engineering and Applied Sciences

Vitamin D prevents clogged arteries in diabetics

People with diabetes often develop clogged arteries that cause heart disease, and new research at Washington University School of Medicine in St. Louis suggests that low vitamin D levels are to blame.

In a study published Nov. 9 in the Journal of Biological Chemistry, the researchers report that blood vessels are less like to clog in people with diabetes who get adequate vitamin D. But in patients with insufficient vitamin D, immune cells bind to blood vessels near the heart, then trap cholesterol to block those blood vessels.

BERNAL-MIZRACHI LAB

Low levels of vitamin D in people with diabetes appear to encourage cholesterol to build up in arteries, eventually blocking the flow of blood. In mice, immune cells adhering to the wall of a major blood vessel near the heart are loaded with cholesterol (shown in red).

“About 26 million Americans now have type 2 diabetes,” says principal investigator Carlos Bernal-Mizrachi, MD. “And as obesity rates rise, we expect even more people will develop diabetes. Those patients are more likely to experience heart problems due to an increase in vascular inflammation, so we have been investigating why this occurs.”

In earlier research, Bernal-Mizrachi, an assistant professor of medicine and of cell biology and physiology, and his colleagues found that vitamin D appears to play a key role in heart disease. This new study takes their work a step further, suggesting that when vitamin D levels are low, a particular class of white blood cell is more likely to adhere to cells in the walls of blood vessels.

Vitamin D conspires with immune cells called macrophages either to keep arteries clear or to clog them. The macrophages begin their existence as white blood cells called monocytes that circulate in the bloodstream. But when monocytes encounter inflammation, they are transformed into macrophages, which no longer circulate.

In the new study, researchers looked at vitamin D levels in 43 people with type 2 diabetes and in 25 others who were similar in age, sex and body weight but didn’t have diabetes.

Bernal-Mizrachi

They found that in diabetes patients with low vitamin D — less than 30 nanograms per milliliter of blood — the macrophage cells were more likely to adhere to the walls of blood vessels, which triggers cells to get loaded with cholesterol, eventually causing the vessels to stiffen and block blood flow.

“We took everything into account,” says first author Amy E. Riek, MD, instructor in medicine. “We looked at blood pressure, cholesterol, diabetes control, body weight and race. But only vitamin D levels correlated to whether these cells stuck to the blood vessel wall.”

Riek and Bernal-Mizrachi say what’s not yet clear is whether giving vitamin D to people with diabetes will reverse their risk of developing clogged arteries, a condition called atherosclerosis. They now are treating mice with vitamin D to see whether it can prevent monocytes from adhering to the walls of blood vessels near the heart, and they also are conducting two clinical trials in patients.

Riek

In one of those studies, the researchers are giving vitamin D to people with diabetes and hypertension to see whether the treatment may lower blood pressure. In the second study, African Americans with type 2 diabetes are getting vitamin D along with their other daily medications, and the research team is evaluating whether vitamin D supplements can slow or reverse the progression of heart disease.
Sometime in the next several months, the scientists hope to determine whether vitamin D treatment can reverse some of the risk factors associated with cardiovascular disease.

“In the future, we hope to generate medications, potentially even vitamin D itself, that help prevent the deposit of cholesterol in the blood vessels,” Bernal-Mizrachi explains. “Previous studies have linked vitamin D deficiency in these patients to increases in cardiovascular disease and in mortality. Other work has suggested that vitamin D may improve insulin release from the pancreas and insulin sensitivity. Our ultimate goal is to intervene in people with diabetes and to see whether vitamin D might decrease inflammation, reduce blood pressure and lessen the likelihood that they will develop atherosclerosis or other vascular complications.”

Source:Washington University in St.Louis