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THURSDAY, Feb. 7 (HealthDay News) -- A diet low in carbohydrates but high in animal fat and protein doesn't seem to increase the risk of type 2 diabetes in women, a new study claims.

"One study is never enough to change a recommendation, but this study is interesting in that it shows that a low-fat diet is no better than a low-carbohydrate diet in preventing type 2 diabetes," said Thomas Halton, lead author of a study in the current issue of the American Journal of Clinical Nutrition. "The one diet that did seem to show a protective effect was a vegetable-based, low-carb diet which consisted of higher amounts of vegetable fat and vegetable protein, and lower amounts of carbohydrate."

The findings, Halton added, were a bit surprising in that most doctors and nutritionists recommend a low-fat diet to prevent type 2 diabetes. "This study showed that a low-fat diet didn't really prevent type 2 diabetes in our cohort when compared to a low-carb diet. I was also surprised that total carbohydrate consumption was associated with type 2 diabetes, and that the relative risk for the glycemic load was so high."

Halton is a recent graduate of the Harvard School of Public Health and has founded his own nutrition consulting company, Fitness Plus, in Boston.

Type 2 diabetes, which is associated with overweight and obesity, is a pressing health problem around the world. In the United States, two-thirds of adults weigh more than they should.

And, according to background information in the study, some 45 percent of women and 30 percent of men in the United States are trying to lose weight at any one time.

While low-fat, high-carb diets are often recommended, the long-term effects of such a regimen are not known.

People who reduce their carb intake generally take in more total and saturated fat and less whole grains, cereal fiber, fruit and vegetables, which can heighten the risk of type 2 diabetes.

For this study, Halton and his colleagues examined the association between low-carb diets and the risk of diabetes among 85,059 women participating in the Nurse's Health Study. The data included 20 years of follow-up.

Women were ranked according to what they ate. "We calculated a low-carbohydrate diet score based on the women's percent consumption of fat, protein and carbohydrate," Halton explained. "A higher score reflected a higher intake of fat and protein and a lower intake of carbohydrate. Therefore, the higher a woman's score, the more closely she followed a low carb-diet, and the lower her score, the more closely she followed a low-fat diet."

Women with a higher score did not have a heightened risk of diabetes. In fact, they seemed to have a small decreased risk when they derived their fat and protein from vegetable rather than animal sources.

Such a low-carb diet is similar to a healthy Atkins diet, meaning one which does not include large amounts of animal fat and animal protein, Halton said.

"When focusing on vegetable sources of fat and protein, this version of Atkins is similar to a low-glycemic Mediterranean diet," he said.

How easy will it be for people to follow such a diet?

"It's probably a very good thing to do . . . [but] people don't understand how to eat well. People don't know what simple and complex carbohydrates are and what it takes to have a good, balanced diet. People go to extremes," said Dr. Stuart Weiss, a clinical assistant professor of medicine at New York University School of Medicine in New York City. "In general, carbs should be limited just like saturated fat needs to be limited. . . If you eat too much of anything, you're bound to get into trouble."

More information

Learn more about healthy eating at the American Dietetic Association  .

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.

WEDNESDAY, Feb. 6 (HealthDay News) -- A large North American trial designed to aggressively lower the blood sugar of type 2 diabetics at risk of heart disease has been halted because of an unexpected number of deaths among those receiving the drug therapy.

Federal health officials announced Wednesday that 257 people who received the intensive therapy had died, compared with 203 in patients in a standard treatment group. But they could not pinpoint the reason for the heightened risk, and they appeared to rule out any of the diabetes drugs that were used.

A segment of the trial, called the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, was stopped 18 months early because of the findings.

"After thoroughly reviewing the data collected to date, ACCORD investigators found that among these adults with type 2 diabetes who are at especially high risk of cardiovascular disease, a medical treatment strategy to intensively lower their blood sugar levels below the current guidelines increased the risk of death compared to standard blood sugar lowering treatment." Dr. Elizabeth G. Nabel, director of the U.S. National Heart, Lung, and Blood Institute (NHLBI), said during a teleconference.

The ACCORD trial, sponsored by the NHLBI, began in 2001 at 77 sites in the United States and Canada with the enrollment of 10,251 patients with type 2 diabetes who were at high risk for heart attack or stroke because they had at least two risk factors, including high blood pressure, high cholesterol or obesity. Those in the trial received either medications to aggressively lower their blood sugar below recommended levels, or standard treatment to control their disease.

Among the 257 deaths in the aggressive therapy group, 50 percent were due to heart attacks or other cardiovascular causes, said Dr. William Friedewald, a clinical professor of public health and medicine at Columbia University and the chairman of the ACCORD Steering Committee.

While these death rates were lower than those seen in similar groups in other studies, the NHLBI decided to follow the recommendation of the study's data safety monitoring board and stop the aggressive therapy part of the trial. Patients in that part of the trial will now receive standard care until the study ends in 2009, Nabel said.

Officials stressed that it's not clear why people in the intensive therapy group were at higher risk of death. But the researchers did not find that the combination of medications used for the trial -- and approved by the U.S. Food and Drug Administration to lower blood sugar -- was responsible for the increased risk.

The halting of the trial segment follows recent reports that one of those medications, Avandia (rosiglitazone), has been linked to an increased risk of heart attack. But Friedewalt said the drug was not responsible for the deaths.

"Because of the recent concerns raised with regard to rosiglitazone, we specifically analyzed the data to try and determine whether there was any link between this particular medication and the increased deaths we were seeing in the ACCORD intensive treatment group," Friedewald said. "At this time, we have found no link, and thus the use of rosiglitazone does not seem to explain the increased mortality."

Most of the people in the intensive treatment group were taking high doses of several medications to lower their blood sugar. Other drugs used in the trial included metformin, thiazolidinediones, insulins, sulfonylureas, exenatide, and acarbose.

Reaction to the news was generally cautious.

One federal health expert said the findings should not affect the current treatment of type 2 diabetes.

"The ACCORD findings are important, but will not change therapy for most patients with type 2 diabetes. Few patients with high cardiovascular risk like those studied in ACCORD are treated to blood sugar levels as low as those tested in this study, " Dr. Judith Fradkin, director of the National Institute of Diabetes and Digestive and Kidney Diseases' division of diabetes, endocrinology, and metabolic diseases, said in a prepared statement. "People with diabetes should never adjust their treatment plan or goals without consulting their health care providers."

Nabel also urged those with diabetes " to consult with their health-care professional before making any changes to their treatment."

And the American Diabetes Association echoed his words.

"The American Diabetes Association looks forward to more analysis of the data from ACCORD, as well as other ongoing studies that may shed more light on this issue," the group said in a prepared statement. "However, at this time, the American Diabetes Association advises people with diabetes who have existing cardiovascular disease (CVD), or multiple CVD risk factors, to consult with their health care team about their treatment goals and to ensure that their blood pressure and cholesterol are appropriately managed."

Wednesday's announcement stunned at least one doctor who specializes in diabetes treatment.

"This is a mindblower," said Dr. Mary Ann Banerji, a diabetes expert at SUNY Downstate Medical Center in New York City. "We absolutely did not expect this."

"If we do have an increase in mortality, then we absolutely have to stop it," said Banerji, who has nearly 100 patients in the trial. "Of course, nobody knows why it happened. And everybody would like to know why it happened.

"It may be that these patients were a very high risk group to start with, because every other study suggested that intensive glucose [blood sugar] control was actually better for you," Banerji added. "This study flies in the face of that."

Type 2 diabetes is the most common form of diabetes. An estimated 21 million Americans have type 2 diabetes and 284,000 die from it each year. Sixty-five percent of those deaths are related to cardiovascular causes. Type 2 diabetes increases the risk for heart disease two to four times, according to the NHLBI.

More information

For more on diabetes, visit the American Diabetes Association  .