Drinking soda (or pop, or whatever you prefer to call it) may be going the way of cigarette smoking. Study after study appears to come to the same conclusion: drinking soda (regular or diet) is just plain bad for your health.

Danish researchers looked at the soda drinking habit of 60,000 women over 6 years, and found a link between drinking diet soda and delivering a baby early. Women who drank four or more diet sodas per day were 78% more likely to deliver early (before 37 weeks).

In another study published in the journal Diabetes Care, researchers at Louisiana State University found that drinking more than five servings per week of regular soda prior to pregnancy boosts the risk of developing gestational diabetes by 22%. The researchers speculate that the sugar-sweetened soft drinks may interfere with the proper functioning of the pancreas, and cause a high glycemic load which could lead to the development of insulin resistance.

Another study, by researchers in Singapore and funded by the National Cancer Institute, tracked over 60,000 people for 14 years and found that those who drank two sodas per week may raise their risk of developing pancreatic cancer by 87%. The study only looked at sugar-sweetened soft drinks, not diet sodas. The researchers suggested that the sugar in the beverages may spike insulin levels which sparked the development of the cancer cells. The news may not be all bad, though, as several prior studies that looked at this same link were inconclusive.

Several studies have already established the link between drinking more than one soda a day — regular or diet — and an increased risk of obesity and type 2 diabetes.

In another study, researchers at Boston University School of Medicine using data collected from 3,500 men and women in the Framingham Offspring Study (children of participants in the long-term Framingham Heart Study). The researchers found that participants who drank one or more sodas per day had a 44% higher risk of developing metabolic syndrome. They also noted a rise in their risk of developing high blood pressure among soda-drinking participants.

Metabolic syndrome is a collection of symptoms that includes high blood pressure, high blood sugar, high cholesterol, and abdominal fat. And according to the American Heart Association over 47 million Americans have it.

For the record, the American Beverage Association begs to differ. The industry association based in Washington, DC, represents producers of non-alcoholic beverages, and contends sodas are a perfectly fine addition to a healthy diet; however, moderation is essential. As far as they're concerned, the studies show possible links, but they don't establish a causal relationship.