Tuesday, July 31, 2007

Exercise, caffeine can fight skin cancer

By RANDOLPH E. SCHMID, AP Science Writer

WASHINGTON - Can adding a cup or two of coffee to the exercise routine increase protection from skin cancer? New research indicates that just might be the case.

The combination of exercise and caffeine increased destruction of precancerous cells that had been damaged by the sun's ultraviolet-B radiation, according to a team of researchers at Rutgers University.

Americans suffer a million new cases of skin cancer every year, according to the National Cancer Institute.

In mice there is a protective effect from both caffeine and voluntary exercise, and when both are combined the protection is even more than the sum of the two, said Dr. Allan H. Conney of the laboratory for cancer research at Rutgers.

"We think it likely that this will extrapolate to humans, but that has to be tested," Conney said in a telephone interview.

Nonetheless, he added, people should continue to use sunscreen.

Exposing the mice to ultraviolet-B light causes some skin cells to become precancerous.

Cells with damaged DNA are programmed to self-destruct, a process called apoptosis, but not all do that, and damaged cells can become cancerous.

The researchers report in Tuesday's issue of Proceedings of the National Academy of Sciences that they studied hairless mice in four groups. Some were fed water containing caffeine, some had wheels on which they could run, some had both and a control group had neither.

"The most dramatic and obvious difference between the groups came from the caffeine-drinking runners, a difference that can likely be attributed to some kind of synergy," Conney said.

Compared with the control animals, those drinking caffeine had a 95 percent increase in apoptosis in damaged cells. The exercisers showed a 120 percent increase, and the mice that were both drinking and running showed a nearly 400 percent increase.

Just what is causing that to happen is not yet clear, though the researchers have several theories.

"We need to dig deeper into how the combination of caffeine and exercise is exerting its influence at the cellular and molecular levels, identifying the underlying mechanisms," Conney said.

"With an understanding of these mechanisms we can then take this to the next level, going beyond mice in the lab to human trials," he said. "With the stronger levels of UVB radiation evident today and an upward trend in the incidence of skin cancer among Americans, there is a premium on finding novel ways to protect our bodies from sun damage."

Conney said the researchers were originally interested in the effects of green tea in preventing skin cancer and were doing tests on regular and decaffeinated teas.

They found the regular tea had an effect, but not the decaffeinated brew.

And, he said, researchers also observed that mice drinking caffeine were more active than those that didn't get it, so they decided to study the effects of exercise too.

They put running wheels into some of the cages. The mice "love to go on it," he said, and will jump on the wheels and run for several minutes, then get off for a while, and then get on and run some more.

And they found that both caffeine and exercise helped eliminate damaged skin cells, but the combination worked better than either alone.

"What we would like to see next is a clinical trial in people," Conney said.

Dr. Michael H. Gold, a Nashville, Tenn., dermatologist and a spokesman for the Skin Cancer Foundation, said he believes "the concept of systemic caffeine should be addressed further."

"I think the concept potentially has a lot of merit," he said in a telephone interview. But mice and humans are different and studies need to be done to be sure this also applies to people.

In the meantime, he said: "If you go outside, you have to wear a sunscreen ... it has to be caffeine and exercise with your sunscreen."


Read more!

Wednesday, July 25, 2007

WHO: Urban planning should promote active lifestyle

As obesity rates in Europe increase, the World Health Organization (WHO) deplores that only a few residential environment currently meet the recommended criteria to promote an active lifestyle.

A new WHO reportPdf external identifies the determinants that may encourage or impede physical activity in a residential environment and thereby have an impact on obesity. The study, published in June 2007, comes after two separate WHO reports, which highlighted evidence of the link between physical activity and health and the need to create opportunities for active living in urban environments (see EurActiv 16/11/06).

Even if the importance of the residential environment in promoting an active lifestyle is increasingly recognised, there is still a lack of integration of such concerns in urban planning. This is why WHO is now seeking to support this process by providing recommendations based on various case-studies.

The study argues that several characteristics of the residential environment - access to physical activity facilities, land-use mix, active transport opportunities and perceived safety in the neighbourhood - have an impact on people's physical activity level.

The WHO's recommendations with regard to urban planning differ according to the targeted population. Access to sport facilities close to home is, for example, a major prerequisite for promoting children's physical activity, whereas for older people it is important that public facilities are at walking distance. According to the report, national and local-level political commitment is crucial for successful and sustainable implementation.

Increasing obesity rates are a serious public health concern in Europe and lack of physical activity is a major determinant of this modern disease. The EU obesity White Paper, adopted in May 2007, highlights the importance of developing physical and social environments that are conducive to physical activity. The White Paper on Sport, adopted on 11 July 2007, includes proposals to enhance public health and tackle obesity through physical activity (see EurActiv 11/07/07).


Read more!

Monday, July 23, 2007

Simple Lifestyles Changes Can Produce Big Payoffs

The path to a better, longer life may be shorter than you think

FRIDAY, July 20 (HealthDay News) -- By now, everyone knows the drill: Quit smoking, eat better, exercise, and you'll get healthier.

Now, two new studies uncover the wisdom in that tried-and-true advice. And they find that success may come quicker than most people realize.

In one study, Christian Roberts and colleagues at the University of California, Los Angeles, found that lifestyle changes helped reverse serious heart disease risk factors in less than one month among 31 obese men they studied. That study was published online Jan. 10 in the Journal of Applied Physiology.

A second report -- this time by Stephanie Chiuve and colleagues at Harvard University -- found that men who followed five healthy habits had an 87 percent lower risk of getting heart disease than men who ignore these behaviors. The health habits included eating a prudent diet, exercising regularly, controlling weight, not smoking and drinking in moderation.

That study, which tracked more than 51,000 men for over 16 years, was published in the July 3 online edition of the journal Circulation

While both studies were done in men, the findings are expected to apply to women, said Chiuve. She noted that a separate study of women, published about five years ago, found that healthy behavior quickly reduced their risk of heart disease.

Following all five healthy habits is best, she says, but even if you change one or two habits, that's good, Chiuve said. The most important one to change: smoking.

"Not smoking was associated with the lowest risk for heart disease," Chiuve said. Next up was maintaining a healthy body weight -- that means sticking to a body mass index (BMI) below 25. For reference, a person 5 feet 5 inches tall who weighs 145 pounds has a BMI of 24, for instance. Statistical overweight begins at a BMI over 25.

"The other three [factors] -- exercise, eating a healthy diet, drinking in moderation were all equal," Chiuve said, in terms of reducing heart disease risks.

Some changes can reduce risks particularly quickly, she said. "Within two weeks, eating a healthy diet can reduce blood pressure."

Roberts' group found relatively speedy results from healthy changes, too. In his study, he followed men who had recently entered a residential program for improving their health. They ate a high-fiber, low-fat diet, taking in more than 40 grams a day and less than 15 percent of total calories from fat. They also walked for about 60 minutes a day.

After just three weeks of this behavior, about half the men reversed their tendency to type 2 diabetes or a cluster of other heart risk factors -- such as elevated blood pressure, insulin levels or high cholesterol -- that together are called the metabolic syndrome.

"We measured 15 or 20 different things," he said. "The lipids [such as cholesterol] tend to change very quickly," he said.

"Body weight [reduction] has a much longer course," he said. While many people focus on body weight reduction, thinking it's the prime factor driving health-related changes, that's not always so, Roberts said.

"Some people think the body weight [change] causes the cholesterol to drop. It's not the body weight per se, but many other mechanisms. The cholesterol can drop independent of body weight," he said.

Simply adding more fiber to the diet and taking out saturated fat, he said, could be beneficial for your lipid profile, as can regular exercise.

"An editorial written in concert with this paper suggests the concept that you have to change for several months is erroneous," he said.

What is needed, he said, is to consider the changes a new life plan, not a temporary fix.

More information

For more on heart-healthy lifestyles, visit the American Heart Association.

SOURCES: Stephanie Chiuve, Sc.D., research fellow, Harvard School of Public Health, Boston; Christian Roberts, Ph.D., adjunct assistant professor, physiological science, University of California, Los Angeles; July 3, 2006, online edition, Circulation; Jan. 10, 2006, online edition, Journal of Applied Physiology


Read more!

Wednesday, July 18, 2007

Losing Weight After Pregnancy: Diet And Exercise Better Than Diet Alone

Science Daily Preliminary evidence suggests that a combination of dieting and exercise is a more effective way of losing weight after pregnancy than dieting alone, concludes a Cochrane Systematic Review.

Women naturally gain weight during pregnancy and many gradually lose it afterwards, but some women find it difficult to lose this additional weight. This retained body weight may be one factor that contributes to obesity among women. Many women are keen to find ways of returning to, and maintaining, pre-pregnant weights, and there is plenty of competing advice on offer.

By studying data from six different trials that involved a total of 245 women, a group of Cochrane Researchers found that women who did exercise did not lose significantly more than women who have a standard post-natal lifestyle. However, women who combined exercise and dieting did lose more weight than those with normal care.

Returning to body weight gradually after giving birth seems to be important, because women who regain their pre-pregnancy weight within six months have a lower risk of being overweight ten years later.

"As well as helping reduce body weight, exercise has the added advantage of improving the women's cardiovascular fitness and preserves fat-free mass -- dieting alone reduces fat-free mass," says Amanda Amorim, an epidemiologist working in Rio de Janeiro, Brazil.


Read more!

Tuesday, July 17, 2007

Overweight kids face early stigma, long-term problems

NEW HAVEN, Connecticut (AP) -- Overweight children are stigmatized by their peers as early as age 3 and even face bias from their parents and teachers, giving them a quality of life comparable to people with cancer, a new analysis concludes.

Youngsters who report teasing, rejection, bullying and other types of abuse because of their weight are two to three times more likely to report suicidal thoughts as well as to suffer from other health issues such as high blood pressure and eating disorders, researchers said.

"The stigmatization directed at obese children by their peers, parents, educators and others is pervasive and often unrelenting," researchers with Yale University and the University of Hawaii at Manatoa wrote in the July issue of Psychological Bulletin.

The paper was based on a review of all research on youth weight bias over the past 40 years, said lead author Rebecca M. Puhl of Yale's Rudd Center for Food Policy and Obesity.

It comes amid a growing worldwide epidemic of child obesity. By 2010, almost 50 percent of children in North America and 38 percent of children in the European Union will be overweight, the researchers said.

While programs to prevent childhood obesity are growing, more efforts are needed to protect overweight children from abuse, Puhl said.

"The quality of life for kids who are obese is comparable to the quality of life of kids who have cancer," Puhl said, citing one study. "These kids are facing stigma from everywhere they look in society, whether it's media, school or at home."

Even with a growing percentage of overweight people, the stigma shows no signs of subsiding, according to Puhl. She said television and other media continue to reinforce negative stereotypes.

"This is a form of bias that is very socially acceptable," Puhl said. "It is rarely challenged; it's often ignored."

The stigmatization of overweight children has been documented for decades. When children were asked to rank photos of children as friends in a 1961 study, the overweight child was ranked last.

Children as young as 3 are more likely to consider overweight peers to be mean, stupid, ugly and sloppy.

A growing body of research shows that parents and educators are also biased against heavy children. In a 1999 study of 115 middle and high school teachers, 20 percent said they believed obese people are untidy, less likely to succeed and more emotional.

"Perhaps the most surprising source of weight stigma toward youths is parents," the report says.

Several studies showed that overweight girls got less college financial support from their parents than average weight girls. Other studies showed teasing by parents was common.

"It is possible that parents may take out their frustration, anger and guilt on their overweight child by adopting stigmatizing attitudes and behavior, such as making critical and negative comments toward their child," the authors wrote, suggesting further research is needed.

Lynn McAfee, 58, of Stowe, Pennsylvania, said that as an overweight child she faced troubles on all fronts.

"It was constantly impressed upon me that I wasn't going to get anywhere in the world if I was fat," McAfee said. "You hear it so often, it becomes the truth."

Her mother, who also was overweight, offered to buy her a mink coat when she was 8 to try to get her to lose weight even though her family was poor.

"I felt I was letting everybody down," she said.

Other children would try to run her down on bikes to see if she would bounce. She had a hard time getting on teams in the playground.

"Teachers did not stand up for me when I was teased," McAfee said.

A study in 2003 found that obese children had much lower quality of life scores on issues such as health, emotional and social well-being, and school functioning.

"An alarming finding of this research was that obese children had (quality of life) scores comparable with those of children with cancer," the researchers reported.

Sylvia Rimm, author of "Rescuing the Emotional Lives of Overweight Children," said her surveys of more than 5,000 middle school children reached similar conclusions.

"The overweight children felt less intelligent," Rimm said. "They felt less popular. They struggled from early on. They feel they are a different species."

Parents should emphasize a child's strengths, she said, and teachers should pair up students for activities instead of letting children pick their partners.

McAfee, who now works for the Council on Size and Weight Discrimination, said her childhood experiences even made her reluctant to see a doctor when she needed one. She recalled one doctor who said she looked like a gorilla and another who gave her painkillers and diet pills for what turned out to be mononucleosis.

"The amount of cruelty I've seen in people has changed me forever," McAfee said.

The Yale-Hawaii research report recommends more research to determine whether negative stereotypes lead to discriminatory behavior, citing evidence that overweight adults face discrimination. It also calls for studying ways to reduce stigma and negative attitudes toward overweight children.

"Weight-based discrimination is as important a problem as racial discrimination or discrimination against children with physical disabilities," the report concludes. "Remedying it needs to be taken equally seriously..."


Read more!

Friday, July 13, 2007

Exercise may help delay inflammation

CHAMPAIGN, Ill., July 5 (UPI) -- A study may offer insight into whether regular exercise can fend off the onset of heart disease or diabetes, University of Illinois researchers said.

The researchers, in a news release, said this could lead to a better understanding of the link between exercise and inflammation, a condition predictive of cardiovascular conditions or other diseases.

Researchers examined parasympathetic tone and sympathetic tone on C-reactive protein -- a biomarker for inflammation -- by assessing heart-rate recovery after exercise. The sympathetic nervous system speeds things up during exercise and the parasympathetic nervous system slows things down when the exercise is finished.

"(When) you're exercising, your sympathetic nervous system will be on, increasing your heart rate, your respiration, etc. Once you stop ... the parasympathetic nervous system kicks in to get everything back down to baseline levels," said Victoria Vieira, a pre-doctoral fellow and the study's primary author and designer.

A notable finding related to post-exercise, heart-rate recovery, researchers said.

"The quicker the individuals were able to get back to their resting heart rate after a strenuous exercise test was inversely related to their CRP," Vieira said. "(Individuals) who had better parasympathetic tone had lower levels of inflammation."


Read more!

Tuesday, July 03, 2007

Scientists discover stress-obesity switch

WASHINGTON — Scientists reported Sunday that they have uncovered a biological switch by which stress can promote obesity, a discovery that could help explain the world's growing weight problem and lead to new ways to melt flab and manipulate fat for cosmetic purposes.

In a series of experiments on mice, researchers showed that the neurochemical pathway they identified promotes fat growth in chronically stressed animals that eat the equivalent of a junk-food diet.

The international team also showed that blocking those signals can prevent fat accumulation and shrink fat deposits, while stimulating the pathway can strategically create new ones, possibly offering new ways to remove fat as well as to mold youthful faces, firmer buttocks and bigger breasts.

"It's very exciting," said Zofia Zukowska of Georgetown University, who led the research published online by the journal Nature Medicine. "This could be revolutionary."

While cautioning that the safety and effectiveness of the approach remains to be proven in people, other researchers said the findings reveal new clues about the basic biology of fat and why obesity has been increasing so quickly, particularly in Western countries.

"There is a lot of uncontrollable stress right now in our societies. There's also a lot of inexpensive high-fat food," said Mary Dallman of the University of California, San Francisco, who co-wrote a commentary accompanying the research. "This could help explain the obesity epidemic."

The researchers have applied for a patent and begun negotiating with drug companies to license the technology. They predicted studies in people could begin within two years.

Previous studies have indicated that while acute stress can make some people lose weight, chronic stress, such as long-term job insecurity, might cause some to put on pounds.

To explore this, Zukowska and her colleagues subjected mice to chronic stress — either standing in cold water an hour a day or being caged with a more aggressive alpha mouse for 10 minutes a day — and then gave them standard feed or a high-fat, high-sugar diet similar to the junk-food fare that many people consume.

"By treating the mice the way humans are treated, which is introducing a chronic stress from which they cannot escape and introducing this abundance of food, we mimicked what happens in American society," Zukowska said.

After two weeks, only the mice that were both stressed and fed the junk-food diet gained a significant amount of weight, accumulating about twice as much fat in their bellies as non-stressed mice that consumed the same diet.

"This tells me it's not just the stress. It's the combination of stress and the high-fat, high-sugary rich diet ... There is some kind of interaction going on."

Moreover, the stressed-out junk-food eaters put on the worst kind of fat — deposited around their abdomens and laced with hormones and other chemical signals that promote illness. After three months, the animals developed the constellation of health problems obese humans often get: high blood pressure, early diabetes and high cholesterol.

When the researchers examined the animals' fat tissue, they discovered sharply elevated concentrations of a substance called neuropeptide Y (NPY), a chemical messenger produced by the nervous system. They also had far higher levels of a molecular partner that NPY needs to work, known as the neuropeptide Y2R receptor.

NPY induces the growth of immature fat cells, coaxes mature fat cells to get bigger, and promotes blood vessels necessary to sustain fat tissue.

Scientists also showed injecting a substance that blocks NPY prevented mice from accumulating fat even if they were stressed and ate a high-fat diet, and could shrink fat deposits by 40 percent to 50 percent within two weeks.

The technique could offer an alternative or supplement to liposuction, Zukowska said.

On the flip side, when the researchers inserted pellets containing NPY under the skin of mice and three monkeys, they were able to stimulate localized fat growth, suggesting the approach could replace skin fillers and other cosmetic and reconstructive surgical techniques.

"This has tremendous potential applications for both cosmetic and reconstructive surgery," said Stephen Baker, a Georgetown professor of plastic surgery who helped conduct the research.

Others cautioned that much more research would be needed to confirm that the same system works in people, and to learn whether blocking or stimulating NPY receptors is safe.

And they warned that it is unlikely that anything will ever be a panacea for weight gain or replace eating well and exercising regularly.

"I wouldn't want people to not to make an effort to control their weight or lose weight while waiting for this magical solution to fix the whole thing," said Louis Aronne of the Weill Medical College of Cornell University. "This is very promising, but the average person shouldn't say, 'I can eat whatever I want and wait for that shot to take it all away.' "


Read more!

Exercise key in control of type 2 diabetes

NEW YORK (Reuters Health) - People with type 2 diabetes may go a long way in managing their condition if they take up regular exercise, a new research review shows.

Researchers found that when they combined the results from 103 studies, there was clear evidence that lifestyle changes helped people with type 2 diabetes gain better control over their blood sugar.

But while diet, exercise and medication are all vital to diabetes management, exercise alone was effective in these studies.

In fact, the review found, studies that focused only on boosting exercise levels yielded greater benefits than those that tried to change patients' diets, exercise habits and medication adherence all at once.

The findings "could mean that it is easier for people to focus on one thing at a time," lead study author Dr. Vicki Conn said in a statement. "It is easy for people to get overwhelmed when asked to make too many changes."

Conn and her colleagues at the University of Missouri-Columbia report the findings in the journal Diabetologia.

For their study, the researchers combined the results of 103 studies that involved a total of 10,455 adults with type 2 diabetes, a disorder in which the body cannot properly use the blood-sugar-regulating hormone insulin.

Type 2 diabetes is closely linked to obesity, and diet, exercise and adherence to medication are the cornerstones of managing the disease. But Conn's team found that blood sugar improvements were twice as great in studies that focused on exercise alone than in those that tried to improve diet, exercise and medication adherence.

Importantly, the researchers point out, exercise helped study participants regardless of their weight or how poor their blood sugar control had been in the past.

"The improvements from exercise," Conn said, "were equal across the board."

SOURCE: Diabetologia May 2007.


Read more!

Monday, July 02, 2007

Exercise Grows New Brain Cells

Jeanna Bryner
LiveScience Staff Writer

Exercise stimulates the growth of new brain cells, a new study on rats finds. The new cells could be the key to why working out relieves depression.

Previous research showed physical exercise can have antidepressant effects, but until now scientists didn’t fully understand how it worked.

Astrid Bjornebekk of the Karolinska Institute in Sweden and her colleagues studied rats that had been genetically tweaked to show depressive behaviors, plus a second group of control rats. For 30 days, some of the rats had free access to running wheels and others did not.

Then, to figure out if running turned the down-and-out rats into happy campers, the scientists used a standard “swim test.” They measured the amount of time the rats spent immobile in the water and the time they spent swimming around in active mode. When depressed, rats spend most of the time not moving.

“In the depressed rats, running had an antidepressant-like effect after running for 30 days,” Bjornebekk told LiveScience. The once-slothful rodents spent much more time in active swimming compared with the non-running depressed rats.

The researchers also examined the hippocampus region of the brain, involved in learning and memory. Neurons there increased dramatically in the depressed rats after wheel-running.

Past studies have found that the human brain’s hippocampus shrinks in depressed individuals, a phenomenon thought to cause some of the mental problems often linked with depression.

“The hippocampus formation is one of the regions they have actually seen structural changes in depressed patients,” Bjornebekk said.

Running had a similar effect as common antidepressants called selective serotonin reuptake inhibitors (SSRIs) on lifting depression.

The research is published in the International Journal of Neuropsychopharmacology.


Read more!