SATURDAY, April 26 (HealthDay News) -- While enjoying a cola or two every day might seem harmless enough, recent research suggests that those tasty drinks could be compromising your bone health.

"There is enough evidence that high consumption of soda and carbonated beverages is associated with somewhat lower bone mass in children, and that's a real concern and people should be aware of it," said Dr. Lawrence Raisz, director of the University of Connecticut Center for Osteoporosis.

The exact mechanism behind the problem isn't clear, but experts believe that drinking soda -- particularly colas -- affects bone density in several ways. One reason may be that people who drink colas are simply less likely to get enough calcium and vitamin D in their diets, because the soda is replacing more nutritious beverages, such as milk or calcium-fortified juice.

Or, it could be related to the caffeine in colas, because caffeine has been linked to a higher risk of osteoporosis.

The third possible explanation focuses on one of the ingredients found in colas: phosphoric acid. Phosphoric acid can cause an imbalance in the body as the body seeks to neutralize the acid with calcium. If there isn't enough calcium in the diet, the body will take calcium from the bones.

"Phosphate is in milk, but milk also contains calcium and vitamin D. In soft drinks, there is just phosphoric acid and no calcium. Extra overzealous drinking may lead to a phosphoric acid imbalance, and if there's not enough calcium, the body goes to the bones to restore the balance," explained Dr. Primal Kaur, director of the Osteoporosis Center at Temple University Health Sciences Center in Philadelphia.

Low levels of calcium are associated with the development of osteoporosis, a disease that thins the bones so much that they're at risk of fracture. More than half of Americans, especially postmenopausal women, have an increased risk of developing osteoporosis, according to the National Osteoporosis Foundation.

In a study that included more than 2,500 people with an average age of about 60, researchers from Tufts University found that cola consumption by women was associated with lower bone mineral density at three hip sites, regardless of age, menopause, total calcium and vitamin D intake. The women reported drinking an average of five carbonated drinks a week, four of which were colas.

There was less of a problem with decaffeinated cola, but the findings were similar for diet soft drinks. The researchers didn't find an association between cola drinking and lower bone mass in men.

Results of the study were published recently in the American Journal of Clinical Nutrition.

"Moderation is really important. If you really like soft drinks, you don't need to take them out of your diet completely, but limit yourself to one or two glasses" a week, Kaur said.

And, she added, make sure you're getting enough calcium and vitamin D to protect your bone health. Vitamin D needs vary by age, and where you live, so check with your doctor to find out how much vitamin D you should be consuming each day. Kaur said that if you're not getting at least 1,000 to 1,200 milligrams of calcium daily from your diet, you should take a calcium supplement to ensure you're getting adequate amounts of the mineral.

Another important way to prevent osteoporosis, according to Raisz, is to exercise.

"The standard recommendation is a half an hour a day for adults and an hour a day for kids, but anything is better than nothing," he said. "Try to walk at least a half a mile a day, and engage in a weight-bearing exercise of some sort."

More information

To learn more about risk factors for osteoporosis, visit the National Osteoporosis Foundation  .

FRIDAY, April 25 (HealthDay News) Nearly two-thirds (65 percent) of young American women report disordered eating behaviors, and 10 percent report symptoms of eating disorders such as anorexia and bulimia nervosa or binge eating disorder, a new survey finds.

The findings -- from an online poll of more than 4,000 women between the ages of 25 and 45 -- found that 75 percent eat, think and behave abnormally around food. The survey was conducted by SELF magazine in partnership with the University of North Carolina at Chapel Hill.

"Our survey found that these behaviors cut across racial and ethnic lines and are not limited to any one group. Women who identified their ethnic backgrounds as Hispanic or Latina, white, black or African American and Asian were all represented among the women who reported unhealthy eating behaviors," Cynthia R. Bulik, a professor of eating disorders and director of the UNC Eating Disorders Program, said in a prepared statement.

"What we found most surprising was the unexpectedly high number of women who engage in unhealthy purging activities. More than 31 percent of women in the survey reported that in an attempt to lose weight, they had induced vomiting or had taken laxatives, diuretics or diet pills at some point in their lives. Among these women, more than 50 percent engaged in purging activities at least a few times a week, and many did so every day," Bulik said.

Eating habits that some women think are normal -- such as skipping meals, avoiding carbohydrates and, in some cases, extreme dieting -- may actually be signs of disordered eating, which is often linked with emotional and physical distress.

While there's a widespread belief that eating disorders affect mostly young women, the survey found that women in the 30s and 40s had about the same rates of disordered eating as younger women.

Among the other findings:

• 67 percent of the women (excluding those with actual eating disorders) are trying to lose weight.
• 53 percent of dieters are already at a healthy weight and are still trying to lose weight.
• 39 percent of the women said concerns about what they eat or weigh interfere with their happiness.
• 37 percent of respondents said they regularly skip meals to try to lose weight.
• 27 percent said they'd be "extremely upset" if they gained just five pounds.
• 26 percent have eliminated entire food groups from their diet.
• 16 percent have dieted on 1,000 or fewer calories a day.
• 13 percent smoke to lose weight.
• 12 percent often eat when they're not hungry, and 49 percent sometimes do.

The survey was expected to be published in the May issue of SELF and to be presented May 17 at the Academy for Eating Disorders' International Conference on Eating Disorders, in Seattle.

More information

The U.S. National Institute of Mental Health has more about eating disorders.

FRIDAY, April 18 (HealthDay News) -- Exercise may help improve fatigue caused by cancer and its treatments, new research says.

"A lot of time, the medical response to patients is that they should expect to be fatigued, that it is a normal side effect. If patients are told that fatigue is just a side effect and to accept it, what they are not getting is any advice or support to help them cope," review lead author Fiona Camp, a lecturer at the University of the West of England in Bristol, said in a prepared statement.

Camp and her colleagues examined data on more than 2,000 cancer patients in 28 studies, which tested exercise programs that lasted from three weeks to eight months. The typical duration was 12 weeks. Walking and stationary bike riding were the most common types of exercise in the studies.

The researchers found that exercise is more effective at combating cancer-related fatigue than the usual care provided to patients.

"Exercise shouldn't be used in isolation but should definitely be included as one of the components in the package of interventions used during and after treatment," Camp said.

She said a clearer "exercise prescription" for cancer patients can be developed after experts learn more about what intensity, frequency, duration and kinds of exercise best suit cancer patients. Until then, available evidence shows that exercise therapists, physical therapists and exercise physiologists need to part of cancer patients' treatment teams, she added.

The review was published in the current issue of The Cochrane Library.

The first step in treating cancer-related fatigue is to check for any underlying medical conditions (such as anemia or an underactive thyroid) that can cause fatigue-like symptoms, said exercise researcher Karen Mustian, an assistant professor in the department of radiation oncology at the University of Rochester School of Medicine. She was not involved in the review.

"There will still be a fair amount of patients dealing with fatigue after we get other situations under control," Mustian said in a prepared statement.

"I think it's safe to say at this point that the sort of generalized guidelines of walking 30 minutes a day three to five times a week generally help patients. We can't say what specific doses are best. With the evidence currently out there, we can't say much beyond that," she said.

More information

The U.S. National Cancer Institute has more about cancer-related fatigue.

TUESDAY, April 15 (HealthDay News) -- Prolonged fasting may increase the risk of a rare type of stroke almost three-fold, according to a new study.

The research focused on five years of data from three hospitals in Iran, a Muslim country where fasting is a religious practice followed during the month of Ramadan. During the month, the average number of people admitted for cerebral venous sinus thrombosis (CVST), was 5.5, compared with 2.0 during the rest of the year.

CVST is a rare type of stroke that most often affects young adults and children and is more common in women. However, the study results showed that the average age and percentage of men versus women was the same in the two groups of patients.

The study was to be presented Tuesday at the American Academy of Neurology annual meeting, in Chicago.

"These results need to be confirmed by other studies, but they should be looked at carefully," study author Dr. Mohammad Saadatnia, of Isfahan University of Medical Sciences, said in a prepared statement. "Coexistence of usual risk factors, such as oral contraceptive and coagulopathic disorders, along with dehydration in patients while prolonged fasting can be the reason for increased susceptibility to CVST. People and their physicians need to be aware of possible complications of prolonged fasting."

Previous studies have shown that fasting during Ramadan does not affect the rate of arterial stroke. More than one billion Muslims fast worldwide during Ramadan.

More information

The National Stroke Association has more about strokes  .