Diet soda takes a hit in U study

University of Minnesota researchers have found another reason to cut back on red meat, fried foods and diet soda.

They all appear to raise the risk of developing metabolic syndrome, a condition that often paves the way for diabetes and heart disease.

The study, released Tuesday in the journal Circulation, sheds new light on a medical condition that few people had heard of only a few years ago. But metabolic syndrome is increasingly seen as a major health problem.

It's also the second big study in a year to suggest that diet pop may be part of the problem.

What is metabolic syndrome?

It's a cluster of symptoms that predispose people to diabetes, heart disease and stroke, such as fatty buildup at the waistline, high blood pressure, and abnormal levels of triglycerides, blood sugar and cholesterol.

What did the latest study find?

Why diet soda?

That was a surprise, said Lyn Steffen, the university nutritionist who led the study. It may be that people who drink lots of diet pop think they can splurge on other foods, because of the calories they're saving. Or there could be another reason they haven't found yet, she said.

Last year, a Boston study found that diet soda raised the risk of metabolic syndrome by nearly 50 percent.

Other surprises?

The Minnesota researchers expected that refined grains (such as pasta and white rice) would be associated with a higher risk of metabolic syndrome, as previous studies have found. But they found no such result in this study. They also thought that eating fruit and vegetables would lower the risk; but again, not in this study.

The scientists followed 9,500 healthy middle-aged adults in four states, including Minnesota, for at least nine years. They tracked their eating habits through extensive questionnaires.

What happened to the people in the study?

Within nine years, nearly 40 percent developed metabolic syndrome. "That's a lot," said Steffen, who noted that thousands of other subjects were excluded from the study because they already had metabolic syndrome when the research began.

The take-home message?

"Eat a variety of foods in moderation," said Steffen. "I'm not telling people not to eat meat. Just moderate amounts."