A less-known target of anxiety is a sweetener called acesulfame potassium, also known as acesulfame K or Ace K, and marketed as Sweet One or Sunnett.
In 1996, Karstadt and Michael Jacobson, executive director of the Washington-based consumer group Center for Science in the Public Interest, began urging the FDA and the National Toxicology Program to conduct long-term studies on the chemical. What data there are, Karstadt and Jacobson say, suggest that Ace K causes cancer in rodents.
In the last few years, Ace K has steadily gained shelf space as an add-on to products containing sucralose. The Splenda-Ace K blend has become a popular ingredient in baked goods because of the combination's taste and because it retains its sweetness when heated to high temperatures. Ace K also appears in products such as puddings, frozen meals and fruity drinks. But most consumers don't know it's there because, unlike other sweeteners, Ace K is never advertised on the fronts of food packaging.
Repeatedly, Huff adds, the FDA has turned down proposals to further test aspartame, Ace K and other sweeteners.
"There should be more studies," Jacobson says, but he's not holding his breath. "The only ones with the incentive to study them are the companies marketing them. If they say it causes cancer, they're out of business."
No matter which type of cookies and soda people choose, one thing is clear: We are a nation pulled in opposite directions by two conflicting desires. We crave sweets, yet we are obsessed with our weight and anything that claims to be a magic elixir for weight loss.
Artificial sweeteners, Katz says, have been around for a long time. If we were going to see an epidemic of cancer, he says, we would already have done so.
He opposes artificial sweeteners for a different reason -- there is no convincing evidence, he says, that products containing them help people lose weight.
They may do the opposite. For every study that suggests eating low-calorie foods leads to a short-term reduction in calorie consumption, another finds that people who consume diet foods and beverages add just as many calories -- if not more -- to other parts of their diet, he says.
Katz adds that eating large amounts of sweets -- regular or diet -- increases our tolerance for, and addiction to, sweetness. Bathe your taste buds in Diet Coke all day long and you may be more likely than someone consuming fewer sweets to need a sickeningly sweet dessert or sugar-enhanced pasta sauce or salad dressing to feel satisfied.
"The word 'diet' [in diet food products] is a misnomer," Katz says. "At this point, I am thoroughly convinced that they undermine that goal."