MONDAY, Feb. 11 (HealthDay News) -- Surprising research suggests a popular artificial sweetener has the unexpected and unwelcome effect of packing on the pounds.

Purdue researchers report that saccharin altered the ability of rats to control their appetites. However, the head of an artificial sweetener trade group scoffed at the findings, saying they don't necessarily translate to humans.

"We found that the rats that were getting artificially sweetened yogurt gained more weight and ate more food," said study author Susan Swithers, an associate professor of psychological sciences at the Ingestive Behavior Research Institute at Purdue University. "The take-home message is that consumption of artificially sweetened products may interfere with an automatic process."

That process, she said, involves the body's ability to detect that it will soon be full. "We often will stop eating before we've been able to absorb all of the calories that come from a meal. One of the reasons we might stop eating is that our experience has taught in the past that, 'After I eat this food, I'll feel this full for this long,' " she explained.

It seems to be a subconscious process based on automatic estimations of how much energy certain foods will provide, she said. For example, a sweet taste might be a sign that "calories are coming, and I should prepare my body for the arrival of those calories." However, when the sweetness is not followed by a lot of calories, the body's digestive system gets confused, and the metabolism rate does not gear up as much the next time sweetness is tasted.

To test this theory, the researchers fed two different types of plain Dannon yogurt to male rats. Some received yogurt sweetened with glucose, a form of sugar, while others ate saccharin-sweetened yogurt. All also ate unsweetened yogurt.

The rats who ate artificially sweetened yogurt consumed more food overall and gained more weight. The body temperatures of those rats also didn't rise as high as the others. "That might be a kind of measure of energy expenditure, suggesting not only are the animals eating more calories, they may be expending or burning up fewer calories," Swithers said.

The findings were published in the February issue of Behavioral Neuroscience.

Essentially, she said, it appears that the bodies of the rats are learning to not expect much in the way of calories from sweet foods. "The artificial sweetener provides the signal that not as many calories are going to come, and the animal responds by consuming more calories."

As for humans, she said, previous research has provided conflicting indications about whether obesity is a bigger problem among people who use artificial sweeteners.

According to her, launching a similar study among people would be difficult, because few have never encountered artificial sweeteners before. The next step, she said, is to do more research in rats.

Lyn Nabors, president of the Calorie Control Council trade group, lambasted the study, saying it has "no basis in science" and "no relation to the human experience whatsoever."

Artificial sweeteners can help people lose weight, she said. "The scientific community firmly believes that calories in, calories out is what makes a difference. The recommendation is that you reduce calories and exercise if you want to lose weight."

More information

Learn about cancer and artificial sweeteners from the National Cancer Institute.

FRIDAY, Feb. 8 (HealthDay News) - Having a heart attack is apparently not sufficient reason for most people to change to a heart-healthy diet, a new study finds.

"We found that diet quality is poor after a coronary heart disease event," said study author Dr. Yunsheng Ma, an assistant professor of medicine at the University of Massachusetts Medical School, in Worcester.

But he warned that patients' failure to eat healthier puts them at risk for another cardiac event.

"Coronary heart disease [CHD] is the number one cause of mortality in Americans," the study noted. An estimated 13 million Americans have survived a heart attack or have coronary heart disease symptoms, the researchers added.

The findings are published in the February issue of the Journal of the American Dietetic Association.

In the study, Ma's team surveyed 555 patients averaging 61 years of age, 60 percent of whom were men. All of the participants were diagnosed with coronary heart disease and had already experienced a heart attack, angina or arrhythmia. The researchers queried the patients on their diets one year after they had undergone coronary angiography linked to some kind of coronary event.

According to the researchers, only 12.4 percent of the patients met the recommended consumption of vegetables. Similarly, only about 8 percent met daily fruit intake recommendations and just 8 percent were getting a heart-healthy amount of cereal fiber. Little more than 5 percent were limiting their intake of dangerous trans fats to recommended levels, the team said.

Compounding this, the researchers found that worst diets were associated with smoking and obesity. Poor diets were also closely correlated with lower levels of education.

Research has confirmed that fruit and vegetable consumption is associated with a lowered risk of heart disease, the researchers noted. The American Heart Association currently recommends "an overall healthy diet" that is rich in fruits and vegetables, high-fiber foods and limited amounts of saturated fat and trans fats, with an eye to maintaining a healthy weight.

The study concluded that "it may be helpful for physicians and health-care providers to refer CHD patients to behavioral interventions that include both diet and physical activity components, such as cardiac rehabilitation." Rehab by itself might not be enough, the study adds, urging consultation with registered dieticians to learn about how to make the necessary changes in diet.

Ma said that currently about 80 percent of patients do not go to rehabilitation after a coronary heart disease event such as angina, arrhythmia or heart attack. But even if patients do enter rehabilitation, many of these programs do not include dietary modifications, he added.

Dr. Alice Lichtenstein, of Tufts University, helped craft the American Heart Association's dietary recommendations. She questioned whether the new study produced truly conclusive results, noting that the study subjects may have under-reported their consumption of unhealthy foods. That's because the participants' mean calorie intake was a relatively healthy 1,775 calories but their average body-mass index was 30, which is in the obese range, Lichtenstein noted.

She said that instead of trying to calculate the exact amount of fat or saturated fat in their diet, it may be easier for people to simply concentrate in the types of healthy foods they should be eating -- items such as fruits, vegetables, grains, beans and fish. Americans have a wide range of such foods to choose from, so "it is easier now to consume a diet consistent with a heart-healthy pattern than it's ever been before," Lichtenstein said.

More information

There's more on heart-healthy eating at the American Heart Association  .

THURSDAY, Jan. 31 (HealthDay News) -- Consumption of sugar-sweetened soft drinks and fructose is strongly associated with increased risk of gout in men, a new study says.

Gout, caused by excess uric acid in the blood, is a joint disease that causes extreme pain and swelling. Cases of gout, which is most common in men, have doubled in the United States over the past few decades.

In this study, published in BMJ Online First, researchers looked at more than 46,000 men, aged 40 and older, with no history of gout. Information on the men's food and beverage intake was collected at the start of the study, and details about their weight, medication use and medical conditions were recorded every two years during the 12-year study.

During that time, 755 of the men were diagnosed with gout. The risk was much higher in men who drank five to six servings of sugar-sweetened soft drinks per week and was 85 percent higher in those who drank two or more of the beverages a day, compared to those who had less than one serving per month.

The increased risk was independent of other gout risk factors such as body-mass index, age, diuretic use, high blood pressure, alcohol intake and dietary habits. Diet soft drinks did not increase gout risk.

The study also found that fruit juice and fructose-rich fruits such as apples and oranges were associated with increased gout risk. But the researchers said this higher risk of gout needs to be balanced against the many health benefits provided by fresh fruits and vegetables.

More information

The American Academy of Family Physicians has more about gout  .

TUESDAY, Jan. 15 (HealthDay News) -- Foodborne illness can strike at any time and be caused by any number of different pathogens. Here is a rundown of the most common bacterial offenders, and what you can do to protect yourself:

E. COLI 0157:H7

There are many strains of the bacteria known as Escherichia coli, or E. coli. Most are harmless, four or five can cause disease, and one, in particular, can be fatal.

E. Coli 0157:H7 has been implicated in several deadly outbreaks. The U.S. Centers for Disease Control and Prevention estimates that 73,000 infections and 61 deaths are attributable to E. coli 0157:H7 each year in the United States, not as much as other pathogens, but infinitely more high-profile.

"E. coli 0157:H7 is the media star, but it's actually not that many cases per year," said Helene Andrews-Polymenis, an assistant professor of microbial and molecular pathogenesis at Texas A&M Health Science Center College of Medicine.

Most human infections result from eating uncooked ground beef (cattle carry the pathogen in their intestines without getting sick). It can also be acquired from consuming contaminated dairy products, vegetables, unpasteurized juice, person-to-person contact, and swimming in or drinking water contaminated with sewage. The bacteria also lives in deer, goats and sheep and is a permanent resident of many petting zoos.

Infection with E. coli 0157:H7 can result in bloody diarrhea lasting two to eight days and sometimes even kidney failure. There are ways to prevent transmission of the bacteria, namely good food hygiene.

"There's always going to be a small risk, but practicing good food hygiene is your best defense," said Andrews-Polymenis.

SALMONELLA

Salmonella, another bacteria, can cause bloody diarrhea in humans. Some 40,000 cases of salmonellosis are reported in the United States each year, although the CDC estimates that, because milder cases are not diagnosed or reported, the actual number of infections may be 30 or more times greater. Approximately 600 people die each year after being infected.

The risk of infection is greater in the summer than winter, and children, the elderly and immuno-compromised individuals are most at risk for serious complications.

Like E. coli, people become infected by eating contaminated foods, usually ground beef, eggs, improperly pasteurized dairy products, undercooked pork and, increasingly, poultry products.

"We're seeing salmonella increasing in broiler chickens," said Dr. Robert Tauxe, the CDC's deputy director of the division of foodborne bacterial and mycotic disease.

Prevention methods are similar to those for E. coli, with the added caution not to eat raw eggs or anything containing raw eggs (even cookie dough) and to make sure all meat is cooked thoroughly. Breast-feeding infants can also prevent infection.

BOTULISM

Botulism is a disease caused by the bacterium Clostridium botulinum. The organism thrives in environments which lack oxygen, such as improperly canned goods, and produces a nerve toxin that can cause paralysis, including respiratory paralysis.

"It can be very, very dangerous," said Andrews-Polymenis. Often, botulism is found in home-canned foods with low acid content, such as asparagus, green beans, beets and corn, the CDC states.

Only about 25 cases of foodborne botulism are reported in the United States each year, but it's important that strict hygienic procedures be followed when canning at home. "If their canned food doesn't reach the proper heat or pressurization, then they're in danger," Andrews-Polymenis said.

Also, avoid giving raw honey to infants under the age of 1 as this can be a source of infection.

CAMPYLOBACTER

Campylobacter is one of the most common bacterial causes of diarrheal illness in the United States. More than 1 million people in the United States, or 0.5 percent of the population, are thought to be infected each year.

Again, the organism can cause diarrhea (including bloody diarrhea), cramping, abdominal pain and fever as well as nausea and vomiting. An estimated 100 people die each year, and others may develop arthritis or Guillain-Barre syndrome, an autoimmune disease which can lead to paralysis.

Campylobacter tends to strike in single, sporadic cases rather than large outbreaks. Most cases are associated with handling raw poultry or eating raw or undercooked poultry meat. Some 80 percent to 100 percent of chickens in the United States are carriers of this bacterium.

"There's nothing glamorous or high-tech about preventing these things," said Andrews-Polymenis. "It's all about good preventive maintenance."

LISTERIA

The incidence of Listeria infection, caused by eating food contaminated with the bacterium Listeria monocytogenes, is on the wane, said Tauxe.

Pregnant women, newborns and adults with compromised immune system are more vulnerable to this infection, characterized by fever, muscle aches and sometimes nausea or diarrhea. The infection can spread to the nervous system, resulting in headache, confusion, loss of balance or convulsions.

Some 2,500 people in the United States become ill each year with listeriosis, and about 500 die.

Listeria is usually killed by cooking and pasteurization but can be present in certain ready-to-eat foods such as hot dogs and deli meats.

VIBRIO VULNIFICUS

Infection with this bacterium, which is in the same family as the bugs that cause cholera, usually comes from eating contaminated seafood. Infection can cause vomiting, diarrhea and abdominal pain in healthy people. In immuno-compromised people, it can infect the bloodstream, resulting in septic shock. About half of the people who develop a bloodstream infection will die. From 1988 to 1995, there were 300 reported cases of infection from the Gulf Coast states, where most of the cases occur. Infection can be prevented by avoiding raw oysters or other raw shellfish, and avoiding cross-contamination of cooked seafood and other foods with raw seafood and juices from raw seafood.

OTHER OFFENDERS

Shigella is a bacteria found naturally in the intestinal tracts of humans and other primates. But people who eat food or drink water contaminated by Shigella can become ill with shigellosis. Food contaminated with Shigella usually comes from water polluted by human sewage or if handled by a person infected with Shigella or by cross-contamination.

Hepatitis A is a virus that causes illness characterized by sudden onset of fever, malaise, nausea, anorexia, and abdominal discomfort, followed in several days by jaundice. Cold cuts and sandwiches, fruits and fruit juices, milk and milk products, vegetables, salads, shellfish, and iced drinks are commonly implicated in outbreaks, according to the U.S. Food and Drug Administration. Water, shellfish, and salads are the most frequent sources. Infected workers in food processing plants and restaurants are a common source of the food contamination as well.

Norwalk virus is a virus that can cause viral gastroenteritis, acute nonbacterial gastroenteritis, food poisoning, and food infection and is transmitted mostly by contaminated water, sometimes by contaminated food. Shellfish, particularly raw clams and oysters, and salad ingredients, are the foods most often implicated in Norwalk outbreaks.