Sweet scare is tempered

Last week was full of sour news on sweeteners. First came reports that mice get fatter when you spike their water with fructose. Second, we learned that rats consuming aspartame suffered an increased incidence of two types of cancer, lymphoma and leukemia.

Question: What is fructose?

Answer: Often called fruit sugar, it is naturally high in most fruits and makes up half of the content of white sugar and a little more than half of high-fructose corn syrup.

Q: Does the mouse study prove that fructose is causing increased obesity?

A: No. Mice do not handle sugars in their body exactly as humans do. Small rodents are more likely to convert sugars into the fatty acid components of fats. Converting carbohydrate into fat releases a significant amount of heat that helps small animals maintain their body temperature.

A number of theories support the connection between the rising consumption of fructose and the growth in obesity during the last 30 years, but decreased physical activity over the decades has had a far greater impact.

Still, it is clear that a 150-calorie can of soda goes down rather easily. And the 32-ounce fast-food bargain size provides one-fourth of the daily calorie needs for some people.

Q: Does the rat study prove that aspartame is causing cancer in people?

A: No. The study did not show a statistically significant increase in the incidence of lymphoma or leukemia in the rats studied overall. What the study showed is that female rats consuming higher levels of aspartame had a greater incidence of these cancers. The lowest level of aspartame intake associated with a significant increase in cancer incidence in the female rats was equivalent to about four 12-ounce diet sodas per day for a 110-pound person.

Four of the six experimental groups of male rats actually had less cancer than those consuming no aspartame. So, the results are not as convincing as some have reported.

It is important to remember that this study is only one out of more than 200 conducted over the years showing that aspartame is safe. Aspartame, one of the most thoroughly studied substances in our food supply, is composed of amino acids found in most every food that contains protein.

Which sweetener is safest? No one can say. Based on the evidence, all sweeteners seem reasonably safe when consumed in moderation.

See the Columnists section for some past articles.

Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S. are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, UH-Manoa. Dr. Dobbs also works with the University Health Services and prepares the nutritional analyses marked with an asterisk in this section.

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