Here’s the skinny on some calorie-free sugar substitutes, both famous and obscure, with safety comments from the Center for Science in the Public Interest:

Aspartame

Brands: Equal, NutraSweet

Back story: A synthetic derivative of amino acids discovered in 1965, about 200 times sweeter than sugar. The subject of more than 200 safety studies, it was FDA-approved for limited use in 1981 and general use in 1996, despite a study that suggested a link between aspartame and brain tumors. A government analysis, however, showed that the rise in brain and central nervous system cancers began eight years before aspartame’s approval and occurred mainly in people over 70, a group not exposed to the highest doses of aspartame. Studies linking aspartame with headaches, dizziness and vision problems have had mixed results, but it is possible that some people have heightened sensitivity to it. People with the rare metabolic disorder phenylketonuria should avoid it.

Find it in: Everything – more than 6,000 products including soda pop, powdered soft drinks, chewing gum, candy, gelatins, dessert mixes, puddings and fillings, frozen desserts, yogurt, tabletop sweeteners, and some pharmaceuticals such as vitamins and sugar-free cough drops.

CSPI says: Avoid – recent study links it to leukemia in lab rats.

Saccharin

Brand: Sweet ‘N Low, Hermesetas

Back story: Discovered in 1879, this synthetic chemical is famous for its warning label: “Use of this product may be hazardous to your health.” Although saccharin scared people in the 1970s when it was found to cause bladder cancer in male rats, Congress blocked an FDA-proposed saccharin ban eight times. The government eventually decided that the rat experiments did not reflect saccharin’s impact on humans. In 1991, the FDA formally withdrew its ban proposal, and warning labels were dropped from saccharin-sweetened products in 2000.

The National Cancer Institute has found some evidence of an increased risk of bladder cancer for heavy saccharin users who drink two or more diet sodas a day or ingest six or more servings of tabletop sweetener.

Find it in: Soft drinks, tabletop sweeteners, baked goods, jams, gum, canned fruit, candy, dessert toppings and salad dressings. Saccharin also is used in cosmetic products, vitamins and pharmaceuticals.

CSPI says: Avoid – the government’s own human study found a cancer link.

Acesulfame K

Brand: Sunett

Back story: A synthetic chemical discovered in 1967, it’s about 200 times sweeter than sucrose. The FDA approved acesulfame K for use in soft drinks in 1998 and expanded that to general use approval in 2003.

Find it in: Chewing gum, dry beverage mixes, dry dessert mixes, tabletop sweeteners, candy, baked goods, dairy products, soft drinks and alcohol.

CSPI says: Avoid – needs more and better testing.

Sucralose

Brand: Splenda

Back story: Discovered in 1976, it’s a synthetic non-caloric sweetener made from sugar combined with chlorine and is 600 times sweeter than sucrose. Approved for general use in 1999, it can be used as a spoon-for-spoon sugar replacement in cooking and baking. High demand has caused periodic shortages.

Find it in: Diet soda, canned fruit, low-calorie fruit drinks, baked goods, sauces, syrups, nutritional supplements.

CSPI says: Safe.

Polyols

Also called: Sugar alcohols including erythritol, sorbitol, xylitol, mannitol, maltitol, lacitol, isomalt, hydrogenated starch hydrolysates.

Back story: Neither sugar nor alcohol, they are made by combining hydrogen atoms with sugar. Some have minimal calorie content. They are often used to enhance other artificial sweeteners and can be used spoon-for-spoon as a replacement for sucrose. Because they can cause gas, bloating and diarrhea, the FDA requires a “laxative effect” warning label if consumers could ingest 50 grams of sorbitol or 20 grams of mannitol from the food in a day.

Find it in: Candy, low-carb products, baked goods, nutritional supplements, gum, ice cream, cough drops and throat lozenges.

CSPI says: Safe, but beware of stomach problems.