July 24, 2010

Diet Soda Linked To Risk Of Premature Birth

New research suggests that there may be a link between the consumption of artificially sweetened beverages and the increased risk of premature births.

Dr. Thorhallur I. Halldorsson of the Statens Serum Institute in Copenhagen, one of the researchers on the study, told Reuters Health that it may be "non-optional for pregnant women to have high consumption of these types of products."

"Diet" beverages have been widely promoted as a healthy alternative to sugary sodas and juices, but Halldorsson and his colleagues said that there has been little research on the safety of regular use of artificial sweeteners in humans.

Both artificially and sugar sweetened soft drinks have been recently linked to high blood pressure, the researchers add, which increases the risk of premature delivery.

To find whether there might be a direct link, the team looked at nearly 60,000 Danish women who reported on their diet, including how many soft drinks they consumed each day, at around 25 weeks in pregnancy.

About 5 percent of the women delivered their babies ahead of 37 weeks.

Women who reported having at least one serving of artificially sweetened soda a day while they were pregnant were 38 percent more likely to deliver prematurely than women who drank no diet soda at all, the researchers found.

Furthermore, women who consumed at least four soft drinks a day were nearly 80 percent more likely to deliver preterm. The association was the same for normal-weight and overweight women.

The researchers did not report the actual risk of premature babies in each group. However, according to the March of Dimes, one in eight babies is born prematurely. This means that if drinking diet soda does increase the risk, a woman who drank one diet soda daily would have a 17 percent risk, while being around 22 percent if she drank four or more a day.

The Calorie Control Council, a lobbying group for companies that make and distribute low-calorie foods, said in a statement that the study was "misleading."

"This study may unduly alarm pregnant women. While this study is counter to the weight of the scientific evidence demonstrating that low-calorie sweeteners are safe for use in pregnancy, research has shown that overweight and obesity can negatively affect pregnancy outcomes," Beth Hubrich, a dietitian with the council, said in the statement.

"Further, low-calorie sweeteners can help pregnant women enjoy the taste of sweets without excess calories, leaving room for nutritious foods and beverages without excess weight gain - something that has been shown to be harmful to both the mother and developing baby," she added.

Because only diet soda was linked to preterm delivery, the study findings suggested that artificial sweetener itself, not soda drinking, accounts for the link, said the researchers. They added, however, that other possible causes for the link shouldn't be ruled out.

The researchers didn't specifically look at all artificial sweeteners, and Halldorsson noted that there are a number of different sweeteners. However, the researchers say there is indirect evidence linking the sweetener aspartame to preterm delivery in animals.

Aspartame breaks down into methanol and other substances in the body, which can be converted to toxic substances such as formaldehyde and formic acid, the team explained. Studies in non-human primates have linked even very low exposure to methanol to shortened pregnancy and labor complications.

Halldorsson said the findings warrant further attention, and pregnant women who consume soft drinks shouldn't be alarmed by the findings.

According to the American College of Obstetricians and Gynecologists, women who normally use the artificial sweeteners can safely continue to do so "in moderation" during pregnancy.

The researchers reported their findings in the American Journal of Clinical Nutrition.

Artificial sweeteners include: saccharin (Sweet n' Low), aspartame (NutraSweet), sucralose (Splenda) or acesulfame K (Sunett, Sweet One).


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