The Sweetest Things in Life May Be Counterintuitive

April 2017

Writer / Janelle Morrison       Photo/ JJ Kaplan

“The question I frequently get is, ‘Should I drink diet soda or regular soda?’ and my answer is that it’s a terrible question. The answer is ‘no.’ You shouldn’t drink either one of those.” Susan E. Swithers, PhD

Perhaps you have heard the joke about ordering a “biggie-size” meal with large fries and a diet soda? Many people wrongly believe that if a product has “diet” stamped on its label or has nonnutritive sweeteners in the ingredients, it must be better than natural sugar and, therefore, healthier.

As it turns out, nonnutritive sweetened foods and drinks may not help with weight loss, but instead may be a problematic factor that contributes to obesity and other health issues, according to Susan E. Swithers, a Zionsville resident and local expert on the subject.
As a professor in the Department of Psychological Sciences at Purdue University, she studies ingestive behavior, body weight, and the roles that nonnutritive sweeteners play in weight management. Swithers reviewed and evaluated research on whether consuming nonnutritive sweeteners contributes to obesity or other health problems. Her findings were published in an opinion article in Trends in Endocrinology & Metabolism.

“As the negative impact of consuming sugar-sweetened beverages on weight and other health outcomes has been increasingly recognized, many people have turned to high-intensity sweeteners like aspartame, sucralose and saccharin as way to reduce risk of these consequences,” Swithers explained. “However, accumulating evidence suggests that frequent consumers of these sugar substitutes may also be at increased risk for excessive weight gain, metabolic syndrome, Type 2 diabetes (T2D) and cardiovascular disease.”

Swithers’s work is funded by the National Institutes of Health, and she strongly believes that as someone who gets government money to do science, she has an obligation to let people know if she discovers something that affects their lives.
“When we first started to try to understand if nonnutritive sweeteners help people and started to get some evidence that presented reasons to think they might not be so great, I needed to tell people that,” she said. Swithers refers to the sweeteners as “nonnutritive” sweeteners, which means that they don’t provide energy. They provide low to zero calories when consumed.

In the U.S. the FDA allows seven sweeteners in food and beverages. “They’re all slightly different from one another, but the main thing that they do is they activate the sweet taste receptors at really low concentrations,” Swithers explained. “For example, Sucralose, the sweetener in Splenda, is somewhere around two to three hundred times as sweet as sugar so you just use tiny amounts. Other sweeteners like Aspartame, which is in Equal and NutraSweet, are about 600 times as sweet as sugar. You only need such a tiny amount so when you look at the sweetener packet it contains such a tiny amount of the sweetener and then filler is added in to have enough that you can actually see it and know that you are putting it in your beverage or food.”

Most people believe that if they switch to the diet version of a drink, then it must be better for them. “But that is not necessarily based on any evidence. Sometimes commonsense and science don’t match up. If everything was just based on commonsense then we wouldn’t need science. But it’s not so; that’s why we have to start to look at what the evidence shows us.

She continues, “Diet soda is more likely to be consumed by people who are overweight or obese. The explanation has always been some people drink these because they are overweight or obese. You can’t rule out the possibility that something about drinking those sodas is contributing to their obesity. If you look at the data, you see with the intake of diet sodas start to go up before overweight and obesity start to go up.”

However, she doesn’t believe that nonnutritive sweeteners are necessarily the only cause of the obesity epidemic. “There is not a single cause that that anybody can point to and say this is how we got here, but we can look at things like nonnutritive sweeteners as components of the way that we eat and drink that are extremely unhealthy and a big part of the overall pattern of how we live,” she explains.

“We know that the intake of nonnutritive sweeteners had been rising dramatically in the mid- eighties when Aspartame was approved. We saw another big spike with the introduction of Sucralose. We’ve known for a long time that regular soda intake has gone up dramatically since the mid-sixties and we know that overweight and obesity have also gone up over the same period of time,” she explains.

“We think that what’s going on is not necessarily what a sweetener itself is doing, but how it’s affecting the ability to handle the sugars that are in the rest of the diet. The question I frequently get is, ‘Should I drink diet soda or regular soda?’ and my answer is that it’s a terrible question. The answer is ‘no.’ You shouldn’t drink either one of those every day. It’s not a healthy choice, and that’s the bottom line. There’s no evidence that it’s going to help.”

Swithens says she doesn’t want to be part of the “food police.” Her goal, she says, “is to make sure that people are aware of what they are doing and understand that this stuff may not actually help you and could be contributing to the same outcomes that you were trying to avoid.”

Swithers offers alternatives to people who are looking to ween off diet sodas or the nonnutritive sweeteners, such as taking a few sips of the soda and then tossing it. “After a while, you’ll get tired of wasting the money. Drink unsweetened teas or sweeten your own teas and coffees. You are less likely to put nine teaspoons of sugar or sweetener in your beverage but by drinking pre-sweetened beverages or diet beverages, you’re consuming that without conscious thought. Drink water. She recommended using frozen fruit-pineapples, melons, etc., to naturally sweeten the water to make it more appealing.

“No one should be drinking a sweetened beverage every single day,” Swithers concluded. “It is not healthy, and water is really phenomenal.”

7 Nonnutritive sweeteners approved for use in the USA Acesulfame K (Brand Names): Sunette, Sweet One Aspartame (Brand Names): NutraSweet, Equal Neotame (Brand Names): Newtame
Luo Han Guo Fruit Extracts (Brand Names): Nectresse, Monk Fruit, PureLO Saccharin (Brand Names): Sweet Twin, Sweet’N Low, Sweet and Low, NectaSweet Stevia (Brand Names): Truvia, Pure Via, Sun Crystals, Enliten
Sucralose (Brand Names): Splenda