October 8, 2009 (EurekAlert) - Attention weekend warriors: the simple act of exercise and not fitness itself can convince you that you look better, a new University of Florida study finds.People who don't achieve workout milestones such as losing fat, gaining strength or boosting cardiovascular fitness feel just as good about their bodies as their more athletic counterparts, said Heather Hausenblas, a UF exercise psychologist. Her study is published in the September issue of the Journal of Health Psychology.

"You would think that if you become more fit that you would experience greater improvements in terms of body image, but that's not what we found," she said. "It may be that the requirements to receive the psychological benefits of exercise, including those relating to body image, differ substantially from the physical benefits."

The study by Hausenblas and graduate student Anna Campbell is the first to systematically analyze the wide-ranging effects of exercise on body image by examining all intervention studies on the subject until June 2008. From the 57 publications, the researchers found conclusively that exercise buffed up the way people see their bodies regardless of the actual benefits, but the results varied.

Negative body image has grown to almost epidemic proportions in the past 20 years, with as many as 60 percent of adults in national studies saying they don't like the way their bodies look, Hausenblas said.

Americans spend billions of dollars a year for products designed to change their body size and shape, including diet pills and various cosmetic procedures, she said.

"Body dissatisfaction is a huge problem in our society and is related to all sorts of negative behavior including yo-yo dieting, smoking, taking steroids and undergoing cosmetic surgery," she said. "It affects men and women and all ages, starting with kids who are as young as five years old saying they don't like how their bodies look."

The psychological advantages of exercise have been less explored, including the reduction of depression or confidence in body image, compared with the well-researched and understood physical benefits, she said.

The study found no difference in body image improvement between people who met the American College of Sports Medicine guidelines by exercising at least 30 minutes a day five days a week and those who did not, Hausenblas said. The guidelines are considered the minimum amount of exercise needed to receive the health related benefits of physical activity, she said.

"We would have thought that people exercising this amount would have felt better about their bodies than those who did not work out as much," she said.

In other results, the study showed slightly larger benefits from exercise in terms of improving body image for women than men, Hausenblas said.

"We believed the gap would be much bigger, but what could be coming into play is the rise of body image issues among men," she said. "We're seeing more media portrayals of the ideal physique for men rather than the overriding emphasis on women we did in the past."

Age presented another difference, with older people most likely to report enhanced body images from exercise, Hausenblas said. The gap may be explained by the older generation having more concerns about their body image than young people, who tend to exercise more, she said.

While the frequency of exercise mattered for boosting body perceptions, there were no differences for the duration, intensity, length or type of exercise, the study found.

"People who say they have high body dissatisfaction tend to exercise the least, so we wanted to take it a step further and see whether exercise causes people's body image to improve," she said.

Kathleen Martin Ginis, a kinesiology professor at McMaster University in Ontario, Canada, and exercise expert, praised the research. "This is an important study because it shows that doing virtually any type of exercise, on a regular basis, can help people feel better about their bodies," she said. "With such a large segment of the population dissatisfied with their physiques, it's encouraging to know that even short, frequent bouts of lower intensity exercise can improve body image."

October 6, 2009 (Newswise) - St. Jude Children's Research Hospital investigators have discovered how destructive immune cells gain access to insulin-producing cells and help cause diabetes.The finding points to possible new strategies to halt or prevent type I diabetes.

Working in mice, researchers demonstrated that to enter key areas of the pancreas known as the islets of Langerhans, immune cells known as T cells must recognize a marker on the surface of insulin-producing cells housed there. T cells play a key role in regulating immune response. Once inside the islets, T cells trigger the inflammation that can lead to destruction of the insulin-producing beta cells.

The result is type I diabetes.

The report answers a fundamental question about the role of T cell entry and accumulation in the islets in development of type I disease, a disease that affects as many as 3 million Americans. The research appears in the October 16 edition of the journal Immunity. Dario Vignali, Ph.D., is the paper's senior author and vice chair of the St. Jude Immunology department.

The St. Jude results contradict a widely held theory that only a small percentage of T cells that infiltrate the islets were actively involved in causing type I diabetes. The old scenario held that most of the T cells found in the islets were recruited to the site by a small number of specialized T cells. Those recruited or bystander T cells were thought to play no role in causing diabetes. Furthermore, it was thought that any T cell could gain access to the islets.

"The new research argues that every T cell in the islet is important. What these T cells recognize that allowed them to gain access to the islets may provide us with clues as to what might be needed to prevent diabetes," Vignali said.

"Understanding the molecular differences between the T cells in the islets and the T cells in the periphery might also start to tell us a lot about what it takes to make a T cell attack the beta cells and cause diabetes."

Without insulin to turn food into fuel for cells, patients develop type I diabetes and are left dependent on insulin injections, an insulin pump or in rare cases a pancreas transplant. Unlike the more common form of the disease, known as type II diabetes, type I diabetes usually affects children and is sometimes called juvenile diabetes. About 15,000 new cases are diagnosed annually in the United States. Even with treatment, patients with type I diabetes are at risk for blindness, kidney failure and other complications.

"This paper also presents a new clinical intervention strategy-blocking T cells from even getting into the islet cells in the first place," Vignali added.

If any T cell could enter the islets, then it would be less likely that there were any "special rules" for entering islets and thus nothing unique about entry into the islets that might be targeted by treatment, he explained.

Understanding how T cell access to islets is controlled also raises hopes for developing a therapy to re-educate the immune system to tolerate rather than attack the beta cells. The St. Jude research points to a new route into islet cells.

For this study, scientists used a technique Vignali's laboratory developed in 2006. The technique allows researchers to quickly modify T cell production in mice. Normally mice make millions of T cells that can recognize many different cells and microorganisms. Each T cell carries on its surface a receptor that recognizes and binds to just one specific antigen, or marker, on the surface of the T cell's intended target.

The modification technique allowed researchers to create strains of mice with only two types of T cells, each with different receptors. One population carried a receptor that recognized the insulin-producing beta cells and could cause diabetes. The other group was programmed to recognize a different antigen. Researchers reported they could not induce the latter group of T cells to enter the islets.

Then investigators created and tracked T cells with three types of receptors-receptors from T cells with a proven ability to enter islet cells and cause diabetes, those able to enter islets and cause inflammation, but not diabetes, and a third group of receptors with no connection to type 1 diabetes or islet cells. The scientists reported that none of the T cells, even those with a demonstrated ability to cause diabetes in mice, could induce bystander T cells to enter the islet cells.

Finally, investigators tracked T cells carrying receptors from mice that naturally developed type I diabetes. They created mice with 17 new T cell receptors, five from the spleen of diabetic mice and 12 from T cells isolated in the islets of those diabetic mice. If the islets control T cells entry, then islets in the new mouse strains would be infiltrated by T cells with islet-derived, but not spleen-derived, receptors.

That is what happened. "About 70 percent of the receptors that came from the islets could mediate T cell migration back into the islets, while none of the receptors that came from the spleen could do likewise," Vignali said. The islet-derived receptors were also linked to rapid development of diabetes, with one-third causing diabetes during the 10-week study.

Vignali said it is unclear if the findings will hold true for other autoimmune diseases, such as rheumatoid arthritis or Crohn's disease. The authors noted that the structure, location and other factors might make the islet cells unique.

Greig Lennon, Maria Bettini and Amanda Burton, of St. Jude, shared first authorship on this study. The other authors were Erica Vincent and Paula Arnold of St. Jude, and Pere Santamaria of the University of Calgary, Alberta, Canada.

The work was supported in part by the Juvenile Diabetes Research Foundation International, the National Institutes of Health and ALSAC.

September 16, 2009 (Newswise) - Most Americans consume too much salt, contributing to the risk of heart disease and stroke, reports the September issue of Mayo Clinic Women's HealthSource."Many people probably are aware that too much sodium can cause or aggravate hypertension, a major risk factor for heart disease and stroke," says Gary Schwartz, M.D., a Mayo Clinic hypertension specialist. "They may be less aware that a high sodium intake can increase the risk of stroke even without an increase in blood pressure."

High sodium intake also can increase the risk of osteoporosis and kidney stones. Studies have shown a relationship between a high-salt diet and stomach cancer.

How much salt is too much? A report from the Centers for Disease Control and Prevention recommends a maximum of 1,500 milligrams (mg) daily for most Americans. That recommendation has been in place since 2005 for people with high blood pressure or at risk of high blood pressure. However, it's new -- and lower -- for most Americans. The previous guideline was 2,300 mg daily, the equivalent of about a teaspoon of salt.

Dr. Schwartz says the average American is eating at least two to three times the recommended daily amount of sodium, and most don't realize it. That's because most sodium isn't coming from the kitchen salt shaker. About 80 percent of consumed salt comes from foods that are processed, canned or purchased in restaurants.

The best way to reduce sodium intake is to eat more fresh foods and less canned and processed foods.

Other sodium-reducing tips include:
-- Cut back on eating in restaurants, especially fast-food restaurants.
-- Use unsalted spices in cooking, for example, garlic powder instead of garlic salt.
-- Rinse canned vegetables to remove sodium.
-- Check grocery labels for sodium content and opt for those products with low sodium.

September 16, 2009 (Newswise) - A health club membership isn't a prerequisite for staying in shape. The September issue of Mayo Clinic Women's HealthSource offers suggestions on free and low-cost options to help stay in shape without straining the budget.Buy used equipment: Some sporting good stores specialize in used equipment. Great deals can be found online too. But be aware that shipping costs might put the cost out of budget range. Shoppers should be cautious about responding to ads, since scams abound.

Buy affordable equipment (or make your own): Hand weights are reasonably priced, available in many sizes, and can be used to strengthen every muscle group. Home-improvised versions work well too. Milk jugs or water bottles filled with varying levels of water or sand work well as weights. (Secure the tops with duct tape.)

Check out the local recreation department: Many community recreation centers offer discounted fitness classes to local residents. High school or college fitness centers or swimming pools also may be open to community members.

Use exercise DVDs: Practice aerobics, yoga, strength training and tai chi with DVDs. They are available to buy or rent. Libraries are a good source, too.

Share costs with a friend: Trade exercise DVDs with a friend. Find a personal trainer who is open to you sharing sessions with a friend or two.

Know what to avoid: Some fitness products aren't worth buying, no matter how low the price. Avoid products that offer instant fitness benefits or promise to melt away pounds without diet and exercise. Avoid products that focus on one body part, such as abs or thighs.

Make the most of everyday activities: Walking, gardening, taking the stairs, and playing with children or grandchildren offer free fitness benefits.

September 2, 2009 (Newswise) - Exercise helps prevent weight regain after dieting by reducing appetite and by burning fat before burning carbohydrates, according to a new study with rats. Burning fat first and storing carbohydrates for use later in the day slows weight regain and may minimize overeating by signaling a feeling of fullness to the brain.The University of Colorado Denver study also found that exercise prevents the increase in the number of fat cells that occurs during weight regain, challenging the conventional wisdom that the number of fat cells is set and cannot be altered by dietary or lifestyle changes.

These coordinated physiological changes in the brain and the body lower the 'defended' weight, that is, the weight that our physiology drives us to achieve, and suggest that the effects of exercise on these physiological processes may make it easier to stay on a diet.

The study is "Regular exercise attenuates the metabolic drive to regain weight after long term weight loss." Paul S. MacLean, Janine A. Higgins, Holly R. Wyatt, Edward L. Melanson, Ginger C. Johnson, Matthew R. Jackman, Erin D. Giles, Ian E. Brown and James O. Hill, all of the University of Colorado Denver, conducted the study. The American Physiological Society published the research in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology.

How exercise works
Weight gain is, on the surface, remarkably simple, occurring when the calories consumed exceeds the calories expended. On closer examination, the process is remarkably complex. Laboratory, animals eat according to physiological signals that may suppress appetite or arouse the desire to eat. These signals are relatively weak in humans, as their intake is largely influenced by psychological, cognitive and lifestyle factors. After dieting, however, the physiological signals emerge to play a more substantial role in controlling intake. Being persistently hungry after losing weight with restricted diets is a big part of the weight regain problem. Most people are unable to ignore this physiological cue and are pushed by their biology to overeat and regain the weight they worked so hard to lose.

Some people are successful at keeping the weight off, and those tracked by The National Weight Control Registry share a number of common characteristics, including a program of regular exercise. The aim of this investigation was to uncover how exercise affects the body's physiology to minimize weight regain.

The researchers used obesity-prone rats. For the first 16 weeks, the rats ate a high-fat diet, as much as they wanted, and remained sedentary. They were then placed on a diet. For the following two weeks, the animals ate a low-fat and low-calorie diet, losing about 14% of their body weight. The rats maintained the weight loss by dieting for eight more weeks. Half the rats exercised regularly on a treadmill during this period while the other half remained sedentary.

In the final 8-weeks, the relapse phase of the study, the rats stopped dieting and ate as much low-fat food as they wanted. The rats in the exercise group continued to exercise and the sedentary rats remained sedentary.

Compared to the sedentary rats, the exercisers:

• regained less weight during the relapse period
• developed a lower 'defended' body weight
• burned more fat early in the day, and more carbohydrates later in the day
• accumulated fewer fat cells and less abdominal fat during relapse
• reduced the drive to overeat
• enhanced the ability to balance energy intake with energy expended

During feeding, the sedentary group preferentially burned carbohydrates while sending fat from the diet to fat tissue. This preferential fuel use stores more calories because it requires less energy to store fat than to store carbohydrates. In addition, burning away the body's carbohydrates may contribute to the persistent feeling of hunger and large appetite of the sedentary animals.

Exercise blunted this fuel preference, favoring the burning of fat for energy needs and saving ingested carbohydrates so that they could be used later in the day. Taken together, the exercise led to a much lower appetite and fewer calories ending up in fat tissue.

The researchers also found that exercise prevented the increase in the number of fat cells observed with weight regain in sedentary rats. In sedentary rats, a population of very small, presumably new, fat cells appears early in the relapse process. Small, new fat cells would not only accelerate the process of regain, but also increase fat storage capacity in the abdomen. It would also explain why sedentary rats overshoot their previous weight when they relapse.

Conventional wisdom holds that the number of fat cells is determined by genetics, rather than being regulated by diet or lifestyle. Because this effect of exercise is a novel finding, the team will do further research to demonstrate that exercise is, indeed, preventing the formation of new fat cells early in relapse and not simply altering the size of pre-existing fat cells.

To read the full study cut or paste the following link into your web browser: http://ajpregu.physiology.org/cgi/reprint/297/3/R793

Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS) has been an integral part of this scientific discovery process since it was established in 1887.

September 1, 2009 (EurekAlert) - Juice extracted from North American lowbush blueberries, biotransformed with bacteria from the skin of the fruit, holds great promise as an anti-obesity and anti-diabetic agent. The study, published in the International Journal of Obesity, was conducted by researchers from the Université de Montréal, the Institut Armand-Frappier and the Université de Moncton who tested the effects of biotransformed juices compared to regular blueberry drinks on mice."Results of this study clearly show that biotransformed blueberry juice has strong anti-obesity and anti-diabetic potential," says senior author Pierre S. Haddad, a pharmacology professor at the Université de Montréal's Faculty of Medicine. "Biotransformed blueberry juice may represent a novel therapeutic agent, since it decreases hyperglycemia in diabetic mice and can protect young pre-diabetic mice from developing obesity and diabetes."

The scientists tested the effect of biotransformed blueberry juice on a group of mice prone to obesity, insulin resistance, diabetes and hypertension. Incorporating biotransformed blueberry juice into the water of mice reduced their food intake and their body weight. "These mice were an excellent model that closely resembles obesity and obesity-linked type 2 diabetes in humans," says Dr. Haddad, who is also director of the CIHR Team in Aboriginal Anti-Diabetic Medicines at the Université de Montréal.

Biotransformation of the blueberry juice was achieved with a new strain of bacteria isolated from the blueberry flora, specifically called Serratia vaccinii, which increases the fruit's antioxidant effects. "The identification of the active compounds in biotransformed blueberry juice may result in the discovery of promising new antiobesity and antidiabetic molecules," says Dr. Haddad.

As for the impact of blueberry products on diabetes, says Tri Vuong, lead author and recent PhD graduate from the Université de Montréal's Department of Pharmacology: "Consumption of fermented blueberry juice gradually and significantly reduced high blood glucose levels in diabetic mice. After three days, our mice subjects reduced their glycemia levels by 35 percent."

September 1, 2009 (EurekAlert) -According to the National Center for Chronic Disease Prevention and Health Promotion, 46 million Americans have arthritis. Many of these people take over-the-counter anti-inflammatory medications that block production of certain molecules, known as bioactive lipids, to reduce pain and swelling. Yet, the role of these lipids is not yet understood completely, and medications may have adverse side effects. Recently, University of Missouri researchers completed the first comprehensive analysis of bioactive lipids in an inflammatory response triggered by the Lyme disease agent, Borrelia burgdorferi. This analysis could shed light on the role bioactive lipids play in inflammatory diseases."Many diseases, such as arthritis, cardiovascular disease and diabetes are associated with chronic inflammation," said Charles Brown, associate professor of veterinary pathobiology in the MU College of Veterinary Medicine. "The first step in finding an effective treatment is to understand the basics of an inflammatory response, including the role of bioactive lipids. Understanding how bioactive lipids regulate the disease processes will lead to the development of drugs that have more specific targets and less adverse side effects."

In the study, researchers investigated the role of certain bioactive lipids in mice infected with Borrelia burgdorferi, the bacteria responsible for Lyme disease. Eicosanoids, which are bioactive lipids that play an important role in inflammatory disease, were extracted from mice that displayed symptoms of Lyme arthritis and from mice who showed no symptoms. The researchers found differences in the amounts of specific eicosanoids in the samples, which correlated with the severity of arthritis in the mice.

"The process of inflammation is not a passive event, but instead is a coordinated, orderly process actively signaled by specific protein and lipid molecules," Brown said. "Previous studies investigating eicosanoids have focused on singular pathways or phases of the inflammatory response. These studies provided an incomplete picture and gave the impression that some bioactive lipids function in isolation. In our study, we were able to measure virtually all of the known eicosanoids at the same time and examine a more complete picture of the inflammatory response."

The findings from this study also could translate into a diagnostic tool for assessing individual patients, assist with the development of more disease-specific therapies, and facilitate the progress of individualized medicine, resulting in more effective treatments for inflammatory diseases with fewer side effects.

Lyme arthritis occurs in 60 to 80 percent of individuals not treated with antibiotics at the time of their infection, and patients are typically given anti-inflammatory drugs to treat their pain and swelling. Arthritis in mice caused by Lyme disease is a good model for how bioactive lipids regulate the process of inflammation, because researchers can observe the process from start to finish, Brown said.

August 28, 2009 (Newswise) - A moderate aerobic exercise program, without weight loss, can improve insulin sensitivity in both lean and obese sedentary adolescents, according to a new study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM). Insulin is a hormone produced in the pancreas that permits glucose to enter cells to be used for energy or stored for future use by the body.Because obese adolescents are resistant to insulin, in order to maintain normal blood sugar levels, they have to increase their production of insulin. Increased insulin production however, places higher demands on the pancreas. These higher demands can exhaust pancreatic beta cells to the point that they no longer produce sufficient amounts of insulin to keep blood sugar levels normal, which might subsequently lead to type 2 diabetes.

"Because weight loss can be difficult to achieve and maintain in obese sedentary children, the purpose of this study was to determine whether a controlled exercise program, without any diet intervention and with no intention of weight loss, would improve fat distribution and sensitivity to insulin," said Agneta Sunehag, MD, PhD, of Baylor College of Medicine and senior author of the study. "We found that a 12-week moderate aerobic exercise program consisting of four 30-minute workouts a week increased fitness and improved insulin sensitivity in both lean and obese adolescents."

In this study, 29 adolescents (14 lean and 15 obese) completed the 12-week moderate aerobic exercise program. During the exercise sessions, subjects worked out on a treadmill, elliptical or bicycle. The goal of each exercise session was to get the participants' heart rate to increase to at least 70 percent of their maximum capacity. Glucose and insulin concentrations were measured both before and after the exercise program. Cardiovascular fitness was determined using an oxygen consumption test which consists of measuring oxygen uptake of the participant during a treadmill exercise where speed and incline is increased every three minutes until the subject reaches his maximum exercise capacity.

"Many studies include both diet and exercise interventions, which makes it difficult to determine which intervention is most effective and best accepted by adolescents," said Sunehag. "Our findings show that exercise alone can increase fitness and improve insulin sensitivity, making an aerobic program like the one used in this study a potential useful tool in preventing obesity-related illnesses."

Other researchers working on the study include Gert-Jan van der Heijden of Baylor College of Medicine in Houston, Tex.; Gianna Toffolo and Erica Manesso of the University of Padova in Padua, Italy; and Pieter Sauer of the University of Groningen in The Netherlands.

The article, "Aerobic exercise increases peripheral and hepatic insulin sensitivity in sedentary adolescents," will appear in the November 2009 issue of JCEM.

August 27, 2009 (Newswise) - Much like an unwelcomed visitor who vows to return, swine flu is gearing up for another long visit this fall. Doctors say it's not time to panic, but it is time to be aware."The concern among researchers is that if the swine flu virus, mutates it could cause significant problems," said Dr. Ashley Drews, an infectious disease expert with The Methodist Hospital in Houston.

"With kids back in school, this opens up the possibility of the disease spreading rapidly."

H1N1, more commonly known as the swine flu, is a novel virus in the influenza A family. The symptoms: fever, body aches, nausea and abdominal pain are virtually the same as regular seasonal influenza. One major difference with swine flu is that it is showing up more in children than in adults. Normally, people age 65 and older are at high risk for contracting influenza and are encouraged to receive a flu shot. This time, experts are recommending children six months and older, health care workers, pregnant women and anyone who works with children, receive the swine flu vaccine when it becomes available.

"The good news is just like regular influenza, if you catch the virus you can use medications like Tamiflu within the first few days to treat it," Drews said. "It's also important for everyone to practice good hand hygiene. Wash your hands thoroughly before you eat and after you use the restroom or touch other people. Also, try and keep your hands away from your nose and mouth if you haven't washed your hands because that is how the disease is transmitted."

While swine flu is a big concern this fall, Drews hopes people do not forget about regular seasonal influenza. Flu season runs from November through March. It is important to get a flu shot as soon as possible because it takes about two weeks for the vaccine to take effect, she said. For children who are afraid of needles, a nasal-spray flu vaccine has been proven to provide protection against seasonal influenza. The flu virus is spread mainly from person-to-person when the infected person coughs or sneezes. Keep in mind, the possible swine flu vaccine is different from the seasonal vaccine.

Drews said between five and 20 percent of the population gets the flu every year. More than 200,000 people are hospitalized with flu-like symptoms and more than 35,000 people die every year from the seasonal influenza, far more than swine flu.

"We want people to be aware of both types of flu and take the necessary precautions," Drews said. "The flu will put you out of commission for about three to five days, but getting a shot and recognizing the symptoms early will help keep you healthy this fall and winter."

August 21, 2009 (University of Nottingham Communications) - Exciting research into Brown adipose tissue (BAT) - brown fat, which is found in abundance in hibernating animals and newborn babies - could lead to new ways of preventing obesity.Studies have already shown that BAT activity in adults is reduced with obesity. Therefore, promoting BAT function could prevent or reduce obesity in some people.

New research, led by Michael Symonds, Professor of Developmental Physiology in the School of Clinical Sciences at The University of Nottingham, has shown - for the first time - that daylight is a major factor in controlling BAT activity.

Professor Symonds said: "Our research has suggested a previously unknown mechanism for controlling BAT function in humans and this could potentially lead to new treatments for the prevention or reversal of obesity."

Winter was traditionally a time of the year that was accompanied with increased thermal demands and thus energy expenditure, but the body's requirements for BAT has been reduced in recent times by central heating plus global warming. BAT is capable of producing up to 300 times more heat per unit mass compared with all other tissues.

The research, published in the journal Diabetes, studied well over 3500 patients. The presence of BAT was documented and correlated with monthly changes in daylight and ambient temperature. Their results showed that BAT was more common in females and that changes in BAT activity were more closely associated with day light than ambient temperature.

BAT is activated by the cold and is unique in being able to produce very large amounts of heat - but little is known about the main factors that regulate the amount of BAT in our bodies. Professor Symonds said: "Our research demonstrates a very strong seasonal variation in the presence of BAT. The study focused on the impact of daylight and ambient temperature as these are two key factors in determining BAT function in small mammals. Our exciting new findings may help us find novel interventions aimed at promoting BAT activity particularly in the winter."