Artificial Sweeteners and Pregnancy

Now that you’re pregnant, a healthy diet is doubly important. Whether you’re sitting down for a meal or grabbing a snack from a vending machine, you have to think about how your choices will affect your baby.

If you develop gestational diabetes, you’ll have still more choices to make. Your doctor may advise you, for example, to use an artificial sweetener that won’t increase the sugar levels in your blood. If you’re like many other women, you may be concerned about artificial sweeteners such as aspartame (NutraSweet, Equal), sucralose (Splenda), or saccharin (Sweet’N Low).

It’s only natural to worry. A study has raised some concerns about the safety of aspartame, and though there’s no conclusive evidence that saccharin is dangerous, some experts recommend that you avoid it during pregnancy (see below). There are no long-term studies on possible side effects of sucralose on humans, although at least one physicians’ group has stated that sucralose is safe during pregnancy, as long as it’s used in moderation.

The American Pregnancy Association recommends that women with gestational diabetes, diabetes mellitus, or insulin resistance should limit their exposure to nutritive sweeteners, which include both table sugar and some sugar-free sweeteners known as sugar alcohols (such as Sorbitol, Xylitol, Isomalt, and Mannitol). Although many women assume sugar alcohols don’t contribute to excess weight gain during pregnancy, they do contain calories that can be converted into fat.

As for artificial sweeteners, here’s a closer look at the big three and how they might affect pregnancy.


This newer sweetener is made from sugar, but it doesn’t add any calories because most of it can’t be digested. Sucralose now has approval from the Food and Drug Administration (FDA) to appear in every type of food, from cookies to chewing gum to fruit juices. The FDA has approved sucralose as a substitute for sugar, and according to the American Academy of Family Physicians, it’s all right to use sucralose while you’re pregnant, as long as you use it in moderation.

It’s not all good news for the new sweetener, however. A Japanese study published in a peer-reviewed journal found that sucralose and saccharin, among other additives, caused DNA damage in the gastrointestinal organs of mice. The authors conclude that researchers need to reinvestigate the safety of such common food additives.


This additive is 180 times sweeter than sugar, and it’s become the standard sweetener in diet sodas and many other products. You should avoid aspartame if you have phenylketonuria (PKU), a rare inherited disease that makes it difficult to metabolize phenylalanine (an amino acid in aspartame); if you have advanced liver disease; or if you are pregnant and have high levels of phenylalanine in your blood.

Whether aspartame is safe for people who don’t have these conditions has been a matter of debate. A report from the FDA called it “one of the most thoroughly tested and studied food additives that the agency has ever approved.” Of particular note to pregnant women, the FDA claims there is no evidence that even high doses of aspartame can cause birth defects.

However, early animal studies showed a possible link between aspartame and brain tumors, and given the increase in the percentage of brain tumors over the last two decades, some neuroscientists have called for a reassessment of the sweetener’s cancer-causing potential. In addition, an Italian study published in the European Journal of Oncology renewed concerns about aspartame’s safety in some quarters. The study was the first to find statistically significant increases in lymphomas and leukemias among female rats given aspartame, even at levels similar to those that people consume from food. The authors called for “an urgent re-examination of permissible exposure levels [of aspartame] in food and beverages, especially to protect children.”

The Italian study’s findings were provocative, since a substance confirmed to cause cancer in long-term animal studies is often classified as an “anticipated” human carcinogen. The fallout from the Italian study prompted the nonprofit Center for Science in the Public Interest to call on the FDA to immediately review the safety of aspartame and possibly ban it. CSPI also noted that the manufacturer sponsored almost all of the previous studies on aspartame, which is the case with most chemicals and supplements.

However, the largest human study ever conducted on aspartame failed to find an increased risk of cancer even among people who reported drinking many artificially sweetened drinks a day. While critics such as CSPI assert the methodology of this latest study is imprecise because it relies on food questionnaires, the scientists at the National Cancer Institute who examined the sweeteners’ effect on more than half a million men and women over 10 years found no link to cancer. CSPI officials say that the new study did not follow people into their 70s and 802, thus leaving open the question of a cancer risk, but concede that the new study significantly allays concerns about a cancer-aspartame connection.


This classic sweetener has largely been replaced by newer, better-tasting alternatives, but you can still find those pink packets on many restaurant tables. Saccharin has a worse reputation than aspartame, largely because tests in the 1970s found that megadoses of saccharin could cause bladder cancer in rats. Further studies by the National Cancer Institute (NCI) found some evidence of an increased risk of bladder cancer in rats who consume large amounts of saccharin a day, but only through a mechanism peculiar to rodents. The NCI has not found any consistent evidence that links saccharin to cancer in humans. The American Pregnancy Association says that saccharin crosses the placenta and may remain in fetal tissue, so “its use for pregnant women still remains in question.”

As for other artificial sweeteners, including those sold in health food stores: Consult with your doctor before using any of them. To take just one example: The FDA has not approved the popular supplement called Stevia, a sweetener made from a South American shrub, for use as a sweetener, and its safety for pregnant and nursing women is unknown.


U.S. Food and Drug Administration. Sugar substitutes: Americans opt for sweetness and lite. December 2004.

American Diabetes Association. Sweeteners and Desserts.

American Academy of Family Physicians. Pregnancy: Taking Care of You and Your Baby. July 2005.

American Pregnancy Association. Using Artificial Sweetener during Pregnancy. March 2007.

U.S. National Institute of Environmental Health Sciences. Panel Recommends That Saccharin Remain on U.S. List of Carcinogens. October 1997.

Soffritti, M, et al. Aspartame induces lymphomas and leukaemias in rats. European Journal of Oncology. Vol. 10 (2). 2005.

National Cancer Institute. Cancer Facts: Artificial Sweeteners.

Olney, J.W. et al. Increasing brain tumor rates: Is there a link to aspartame? Journal of Neuropathology and Experimental Neurology. 55(11):1115-23. November 1996.

Weihrauch, M.R. et al. Artificial sweeteners: Do they bear a carcinogenic risk? Annals of Oncology. 15(10):1460-5. October 2004.

Sasaki, Y.F., et al. The comet assay with 8 mouse organs: Results with 39 currently used food additives. Mutation Research. 519(1-2):103-19. August 2002.

Nemours Foundation. Is Aspartame Safe for My Child?

Center for Science in the Public Interest. Letter to Commissioner Lester Crawford. U.S. Food and Drug Administration. July 27, 2005.

Center for Science in the Public Interest. New Aspartame Study May Allay Cancer Concerns. April 2006.

National Cancer Institute. Artificial Sweeteners. October 2006.

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