Safety of sugar substitutes remains inconclusive

On a June day in 1878, Constantin Fahlberg, a research chemist conducting experiments in a Johns Hopkins University lab, sat down to eat, bit into a roll and found it amazingly sweet. Because he had forgotten to first wash his hands, he assumed something he’d touched in the lab had contaminated his food. He searched his workspace, tasting vials, beakers and dishes until he found it. A beaker had boiled over, mixing o-sulfobenzoic acid with phosphorus (V) chloride and ammonia.

The result was benzoic sulfimide – or, as we know it today, saccharin. Fahlberg’s discovery ushered in a burgeoning new industry that promised hope for millions struggling to lose weight, and for people with diabetes who needed to control their blood sugar.

Saccharin provided the sweetness they craved, but without the sugar or calories. Other sugar substitutes followed, including more than a half-dozen products approved by the Food and Drug Administration. (The use of sugar alcohols such as sorbitol and xylitol – also sweet, but which contain about half the calories as sugar - also became popular.)

Yet, if something seems too good to be true, maybe it is.

In recent years, studies have questioned the safety of sugar substitutes – collectively called artificial sweeteners, although some come from natural substances – and whether consuming them helps or harms the body. The research still is inconclusive. Even saccharin came under scrutiny during the 1970s after research suggested it might cause bladder cancer in rats, and the government attempted to ban it. Subsequent studies, however, could not prove the link in humans, and saccharin remains on the market.

Because of the ongoing confusion, experts suggest consumers use them with caution.

“I advise my patients to use them sparingly because we do not fully understand the scope of their impact on our bodies and our health,” says Jessica Murgueytio, a dietitian in Bethesda, Maryland. “I tell them to use them in moderation, so they don’t get used to consuming sweet foods in excessive quantities. The ‘poison’ is most likely in the dose, so while a pack of stevia in your coffee should be OK, I would suggest not having a large amount of diet soda routinely.”

Donald D. Hensrud, associate professor of preventive medicine and nutrition at the Mayo Clinic College of Medicine, suggests that the first goal for consumers should be to try to avoid the real thing – sugar – as much as they can.

“Sugars should be restricted in the diet as they are a ‘quadruple whammy,’” he says. “They provide extra calories, do not provide any nutritional value, have direct adverse effects on health – for example, dental cavities, inflammation and heart disease.”