Skip to content
My WebMD Sign In, Sign Up

Food & Recipes

Font Size

Rat Study Links Aspartame to Cancer

Lymphoma, Leukemia in Rats Fed Sweetener; Industry Group Says Aspartame Is Safe


"EFSA does not consider it appropriate to suggest any change in consumers' diets relative to aspartame on the basis of the information it currently has," the EFSA announced on July 14.

Low-Calorie Industry: No Cause for Alarm

The new findings fly in the face of all previous studies of aspartame safety, says the Calorie Control Council, an international association representing the low-calorie and reduced-fat food and beverage industry.

The Soffritti study findings "are not consistent with the extensive scientific research and regulatory reviews done on aspartame," the CCC says in a statement. "Aspartame has been used by hundreds of millions of consumers around the world for over 20 years. With billions of man-years of safe use, there is no indication of an association between aspartame and cancer in humans."

The CCC points to four long-term studies on aspartame that failed to find any relationship between aspartame and any form of cancer.

It's true that reports linking brain and breast cancer to aspartame had little merit, says blood-cancer specialist Martin R. Weihrauch, MD, of the University of Cologne, Germany. Last year, Weihrauch reported on his analysis of all published studies on artificial sweeteners in the Annals of Oncology.

"The entire stuff about brain tumors and breast cancer was really nonsense, Weihrauch tells WebMD.

So what does he think of the new study linking aspartame to leukemia and lymphoma?

"I think it is shocking news," he says. "However, the data have to be carefully reviewed and the study redone. Not because of their methods, probably they are fine. But for a study like this, which brings out data that would make a big change in what consumers do every day, it certainly has to be confirmed. It is worrisome."

What Happened to the Rats

Soffritti's study findings may be a first report, but the study was quite thorough. It looked at 1,800 rats fed various doses of aspartame -- or no aspartame at all -- from age 8 weeks until death. When the animals died, the researchers did a thorough autopsy.

They found that:

  • A daily dose of 20 milligrams of aspartame per kilogram of body weight was linked to lymphomas and leukemias in female -- but not male -- rats.
  • Rats that got daily doses of as little as 4 mg/kg aspartame got lymphomas and leukemias 62% more often than those that got no aspartame, but this finding could have been due to chance.
  • A few brain tumors were seen in rats fed aspartame, while those who did not get the sweetener did not get brain tumors. But this finding, too, could have been due to chance.

The findings are scheduled to appear in the European Journal of Oncology.


Today on WebMD

Four spoons with mustards
What condiments are made of and how much to use.
salmon and spinach
How to get what you need.
grilled veggies
Easy ideas for dinner tonight.
Greek Salad
Health benefits, what you can eat and more.

WebMD Recipe Finder

Browse our collection of healthy, delicious recipes, from WebMD and Eating Well magazine.

roasted chicken
grilled steak
vegetarian sandwich
fresh vegetables
Foods To Boost Mens Heath Slideshow