Women who reach for fruit drinks, even some juices, instead of sugary sodas in an effort to improve their health may be in for a rude surprise, researchers said. Too many of those beverages can also raise the risk of diabetes.

Investigators led by Julie Palmer, an epidemiologist from Boston University, tracked 43,000 participants in the Black Women's Health Study for a decade to find out how drinking patterns affected diabetes risk. Both fruit drinks and soft drinks are high in calories and don't make people feel full, which may lead them to overimbibe, the researchers said.

Women who had at least two regular soft drinks a day were 24 percent more likely to develop type 2 diabetes than those who had less than one a month, almost entirely due to weight gain, the study found. Fruit drinks, a broad category that includes Kool- Aid, fruit punch, Snapple and juices other than orange and grapefruit, raised the risk 31 percent.

"Fruit drinks are just as bad as soda or soft drinks," Palmer said in a telephone interview July 18. "They are not a healthy alternative. Switching to diet soft drinks or water is a concrete, achievable goal that really makes a difference by itself."

Cutting out the drinks may be an easier way to lower the risk of diabetes than losing weight, she said. Not all doctors agree with that conclusion.

The comparable risk surfaced even though women drinking the fruit beverages had better overall eating and exercise habits, indicating they may be more health-conscious. Those who drank soda were more likely to smoke cigarettes and less likely in other ways to pursue a healthy lifestyle. The risk wasn't higher for women who drank real orange and grapefruit juice, perhaps because those are generally consumed with a meal, according to the report.

The study results were published in Monday's Archives of Internal Medicine.

Two additional studies in the journal found people who regularly ate fruits and vegetables were less likely to develop diabetes, while cutting back on fats without reducing calories seemed to offer no protection to women who have gone through menopause.

The fruits and vegetables may contain healthy ingredients, or they could simply help people avoid weight gain, said the researchers led by Anne-Helen Harding from Addenbrooke's Hospital in Cambridge, England. Eating even a small amount appeared protective, with a bigger benefit stemming from larger portions.

Fruit drinks were more popular than soft drinks in the beverages study. Among those were "fruit-fortified" drinks flavored with real fruit juice.

Overall, the amount of energy from fruit-fortified drinks in the U.S. doubled between 1977 and 2001. High fructose corn syrup used to sweeten almost all beverages in the U.S. accounts for 10 percent of total daily calories, according to a study in the American Journal of Clinical Nutrition.

About 24 million Americans, or 8 percent of the population, have diabetes, and more than 170 million people worldwide have the disease, according to the American Diabetes Association. About 90 percent of patients have the type 2 form linked to being overweight and inactive. Their cells don't properly use insulin to convert blood sugar into energy, leading to high levels that can damage the nerves and organs.

Two in three Americans are overweight or obese, fueling the rise in diabetes rates.

Researchers have too little evidence to determine if carbohydrates, fats, or high fructose corn syrup alone can raise the risk of diabetes or other health conditions, wrote Mark Feinglos from Duke University Medical Center in Durham, North Carolina, in an editorial. Until additional studies are done, doctors and patients should focus on weight.

"We know that, as a population, we eat too much for our level of activity, and we are growing fatter as a result," Feinglos said. "We have to assume that calories trump everything else, and that our No. 1 goal for the reduction of new cases of type 2 diabetes mellitus should be to reduce the intake of high- energy, low-benefit foods, particularly in young members of the most vulnerable populations."