A researcher at the Washington University School of Medicine in St. Louis says she has found that sucralose does more than just taste sweet.

Research assistant professor M. Yanina Pepino, PhD with Washington University's School of Medicine in St. Louis.

Research assistant professor M. Yanina Pepino, PhD with Washington University’s School of Medicine in St. Louis.

Research Assistant Professor of Medicine M. Yanina Pepino, PH.D., says her study followed earlier research that established that when an animal is given glucose not only does the tongue’s taste receptors register sweetness, but similar receptors in their pancreas and gastrointestinal tract also react. That’s where her work began.

“The question was, is this the case for humans? If something tastes sweet to our tongue is it going to also taste sweet to other taste receptors in other areas, and will it also provoke physiological responses?”

The study involved 17 severely obese people who didn’t have diabetes and didn’t already use artificial sweeteners. The subjects were given either water or sucralose to drink before participating in a glucose challenge test.

The findings are that subjects’ blood sugar peaked at higher levels than when they drank only water before consuming glucose. Insulin levels also rose about 20 percent higher, so Pepino says sucralose is tied to an enhanced insulin and glucose response.

That tells her it is not inert, as many people believe, but it doesn’t indicate what it means for human health. She says more research is needed.

“We need to do other tests. We need to do tests where instead of giving it combined with a glucose shot we combine it with a meal, because that’s more relevant to what people do. Then we can talk about what it really means … if it affects your insulin levels and so forth.”

Pepino emphasizes that the implications of her findings are limited.

“We cannot say that if we do this test several times in a person we’ll always find that insulin is increased. We don’t know if maybe we adapt to this response and maybe it disappears after the first time they do this.”

The study focused on the sucralose product Splenda, so there is no data regarding products that use any of the other non-caloric sweeteners approved by the Food and Drug Administration, but Pepino hypothesizes that the results would be similar for them.

“Anything that activates a sweet taste receptor in the tongue should also activate the sweet taste receptors in the gut, so I would expect that they would be the same effects if you use other artificial sweeteners but we need to demonstrate that that’s the case.”

Other studies have found no effects from sucralose other than a sweet taste, but Pepino says to her knowledge, those did not screen to see if their subjects were already regular users of sucralose.

She says all she can say now is that sucralose is not inert, and she wants its users to know that.

“I think that if you drink it thinking it’s just the same as water, that may not be the case, and so I would think that we should drink it in moderation.”