FRIDAY, Aug. 27 (HealthDay News) -- Nutritional supplements are popular among Americans but people need to educate themselves and use caution when using these products to try to reduce their risk of cancer, says a University of Texas expert.

"Researchers are still unsure about whether or not minerals, herbs and other plants taken in pill, capsule, tablet or liquid form actually prevent cancer," Sally Scroggs, health education manager at the Cancer Prevention Center at the University of Texas M.D. Anderson Medical Center, said in a news release from the center.

Vitamins E and C, for example, were found not to prevent cancer in the large-scale Women's Health Study and the Physicians' Health Study II. Findings from other studies suggest that some supplements may actually increase cancer risk by affecting the balance of nutrients in the body.

"If you eat lots of vegetables, fruits, whole grains and beans, you should get the nutrients, including fiber, vitamins and minerals, your body needs to lower your chances of getting diseases like cancer," Scroggs said. "Taking a pill can't replace a healthy diet."

She suggested eating plenty of foods loaded with cancer-fighting nutrients such as beta-carotene, selenium, lycopene, resveratrol and vitamins A, C and E.

While Scroggs does advise caution, there are some situations where taking supplements may benefit people, especially those who aren't getting enough nutrients due to food allergies, genetics or chronic illnesses, she said.

This includes women who are pregnant or breast-feeding; people at risk for vitamin D deficiency or osteoporosis; and people at risk for B-12 deficiency, including those aged 50 and older and vegans who consume no animal products.

Scroggs concluded that if you're considering taking supplements, consult with a doctor or registered dietician first.

More information

The U.S. Food and Drug Administration has more about dietary supplements.

MONDAY, Aug. 23 (HealthDay News) -- Close the diet books and skip the pills. The latest weight-loss trick may be as simple as gulping a couple of glasses of water before you eat.

A new study found that middle-aged and older adults who drank two cups of water before each meal consumed fewer calories and lost more weight than those who skipped drinking water.

Researchers divided two groups of overweight and obese men and women aged 55 to 75 into two groups: one group was told to follow a low-fat, low-calorie diet; the other group was told to follow the same diet and to drink two cups of water before breakfast, lunch and dinner.

After 12 weeks, those who drank water before meals had lost 15.5 pounds, compared to 11 pounds for the non-water drinkers, a nearly 30 percent difference.

The researchers got the idea for the weight-loss program from their prior research, which found that when middle-aged and older adults drank water before meals, they ate between 75 and 90 fewer calories at the meal.

What they weren't sure about, however, was if water drinkers would compensate by eating more throughout the rest of the day, said senior study author Brenda Davy, an associate professor in the department of human nutrition, foods and exercise at Virginia Tech. But after 12 weeks of dieting, that didn't happen.

"Drinking more water is a pretty simple strategy that may be helpful to people trying to lose weight," Davy said. "We're not saying, 'Drink more water and the body fat will melt away'. But for people who are trying to lose weight and trying to follow a low-cal diet, it's something they can do as part of that."

The research was to be presented Monday at the annual meeting of the American Chemical Society in Boston.

One of the most vexing issues with dieting is how difficult it is to keep the weight off long-term, Davy said. After the 12 weeks were up, Davy and her colleagues have continued to follow the participants.

After one year, preliminary data shows that those who continued to drink water before meals not only kept those pounds off, but have even continued to lose a bit more -- about 1.5 pounds on average.

Yet pre-meal water chugging comes with one caveat: it may only work if you're middle-aged or older, Davy said.

Prior research has shown that in those aged 18 to 35, drinking water before the meal did not cause them to eat fewer calories at the meal, Davy said.

In older people, it takes longer for the stomach to empty, which may be why the water helps them feel fuller and less hungry, while in younger people, water begins leaving the stomach almost immediately, Davy said.

Barry Popkin, director of the University of North Carolina Nutrition Obesity Research Center, called the findings "promising." His research has shown people who drinks lots of water drink fewer sugary beverages, eat more fruits and vegetables and overall consume fewer calories throughout the day.

One culprit in the obesity epidemic is that Americans consume some 300 calories more a day in sugary beverages than they did 30 years ago, Popkin added. That includes soda, punch and fruit juices with added sugar, sports drinks and sweetened tea.

"If you drink some more water right before a meal and fill up a little bit right before, there is the potential you may reduce your food intake," Popkin said. "But what we're concerned with is encouraging people to drink water to replace all the caloric beverages we're drinking."

Another challenge to the water-before-meals weight-loss strategy is getting people to do it, said Carla Wolper, an assistant professor in the Eating Disorders Center at Columbia University and a research faculty member at the New York Obesity Research Center at St. Luke's Hospital in New York City.

"The question is, do people continue to drink the water in a non-study situation?" Wolper said. "We know there are a lot of simple things people could do to lose weight. Clinical trials have shown if people write down what they eat, they lost twice as much weight. Yet it's very hard to get people to write down what they eat. Or, if people would reduce portions just a little bit, they would lose weight. But people don't do it."

The same goes for drinking more water. Even seemingly small changes require commitment. "Changing a pattern of behavior is complicated, and requires time and energy," Wolper said.

Still, it could be worth a try, she added. "Unless people overload on water, it's harmless, inexpensive. And if over the course of the entire day, it reduces the amount of food people take in, then of course it's a good idea," Wolper said.

Dieticians often will suggest a non-caloric drink such as club soda with lemon, diet soda or tea to help resist the urge to snack after dinner, Wolper said.

More information

The Harvard School of Public Health   has more on eating a healthy diet.

MONDAY, Aug. 23 (HealthDay News) -- When you buy a bottled tea, you may not be getting the health boost you expect.

A new study finds that these increasingly popular beverages may contain far lower levels of antioxidants called polyphenols than green or black tea that you brew at home. In fact, some commercial tea beverages contain such small amounts of polyphenols that you would have to drink 20 bottles to get an amount equal to what's in one cup of home-brewed tea.

Polyphenols are believed by scientists to have anti-cancer, anti-inflammatory and anti-diabetic properties.

"Consumers understand very well the concept of the health benefits from drinking tea or consuming other tea products," researcher Shiming Li said in an American Chemical Society news release. "However, there is a huge gap between the perception that tea consumption is healthy and the actual amount of the healthful nutrients -- polyphenols -- found in bottled tea beverages. Our analysis of tea beverages found that the polyphenol content is extremely low."

Li and colleagues measured the levels of polyphenols in six brands of bottled tea beverages purchased at supermarkets. Half of them contained virtually no antioxidants, while the polyphenol levels in others were so low that they would have little effect on health.

"Someone would have to drink bottle after bottle of these teas in some cases to receive health benefits. I was surprised at the low polyphenol content. I didn't expect it to be at such a low level," said Li, an analytical and natural product chemist at New Jersey-based biotechnology company WellGen Inc.

In fact, consumers buying commercially bottled teas may actually be spending money on substances detrimental to health, including sugar, high fructose corn syrup and sweeteners, Li said.

The study was presented Sunday at the American Chemical Society annual meeting in Boston.

More information

The American Dietetic Association has more about antioxidants  .

FRIDAY, July 16 (HealthDay News) -- New research indicates that major American fast food chains have substantially cut down on the use of unhealthful trans fats in their cooking oils.

The finding comes from the University of Minnesota's School of Public Health, and is being reported this week at the National Nutrient Database conference being held in Grand Forks, N. D.

"While it took time for major fast food chains to decrease trans fats in their foods, I'm pleased to see that they have done it," Lisa Harnack, director of the university's Nutrition Coordinating Center, said in a news release.

"I'm also pleased to see that they haven't raised levels of saturated fats to replace trans fats," she added. "This is good news, as the average American gets about 10 percent of calories from fast food. But moderation is still key when considering fast food. Calories and sodium are high and portion sizes are often too large."

The finding follows increasing pressure by global health authorities to reduce consumption of trans fats to trace amounts, along with a Congressional law passed in 2006 that mandates disclosure of trans fat content on American food labels.

Trans fats can upset the healthy balance of human cholesterol levels, boosting artery-clogging "bad" LDL cholesterol and reducing the levels of "good" HDL cholesterol. In fact, in terms of consumption, there is no safe level of trans fats, according to the U.S. National Academy of Sciences.

Relying on the school's proprietary database on the nutritional value of more than 18,000 foods, Harnack and her research team examined trans fat and saturated fat levels in the french fries sold at five popular nationwide fast food outlets: McDonald's, Burger King, Wendy's, Jack in the Box, and Dairy Queen.

The authors found that between 1997 and 2008, three major chains -- McDonald's, Burger King, and Wendy's -- significantly decreased the amount of trans fats in their french fries, with saturated fat levels either going down or staying the same.

Although Dairy Queen and Jack in the Box did not show similar decreases in the same time frame, the team noted that post-2008 data suggests that both have cut back on their trans and saturated fats use over the last couple of years.

The study was funded by the National Institutes of Health.

More information

For more on trans fats, visit the U.S. National Institutes of Health.