Sugar substitutes have become commonplace in many low-calorie foods and diet beverages, but are artificial sweeteners bad for you? Currently, the use of them is tightly regulated by government authorities and only the ones that have been shown to be safe for consumption are allowed to be sold. At the same time, growing evidence suggests artificial sweeteners may have implications for many aspects of our health.
Artificial sweeteners should not be confused with nutritive sweeteners, such as sorbitol and xylitol, which can be found in the plant-based world. Synthetic sugar substitutes, such as acesulfame-K, aspartame and sucralose, are manmade and, as a result, are not absorbed and metabolized in the same ways as many other nutrients.
Here, we discuss what the science says about artificial sweeteners and their effects on human health.
Artificial sweeteners are sweeteners that contain few to no calories, yet have a higher intensity of sweetness per gram than sweeteners with calories (such as table sugar, honey or corn syrups). They may also be referred to as low-calorie sweeteners (LCS), non-nutritive sweeteners (NNS), sugar substitutes, and high-intensity sweeteners.
Artificial sweeteners are a common ingredient in many foods and beverages, including dairy products, frozen desserts, baked goods, candies, chewing gum, breakfast cereals and canned foods. Many products labeled as sugar-free or diet will contain one or more sugar substitutes. Some artificial sweeteners are also sold on their own, as general purpose sweeteners.
There are currently six artificial sweeteners approved as food additives by the US Food and Drug Administration (FDA):
Acesulfame-K – such as Sunett and Sweet One; 200 times sweeter than sugar
Aspartame – such as Equal, NutraSweet and Sugar Twin; 200 times sweeter than sugar
Neotame – such as Newtame; 7,000-13,000 times sweeter than sugar
Saccharin – such as Sweet’N Low, Sweet Twin and Necta Sweet; 200-700 times sweeter than sugar
Sucralose – such as Splenda; 600 times sweeter than sugar
Advantame – no brand names; 20,000 times sweeter than sugar
The role of artificial sweeteners is to trick our brain into believing that we’re eating sugar. Human beings are conditioned to seek and enjoy sweet foods, as they provide a high amount of calories. For thousands of years, energy-dense foods were essential for the survival of our species. To identify them, humans have developed tastebud receptors that detect sweetness. Artificial sweeteners bind to these receptors, creating a sensation similar to when we eat sugar.
But our bodies are not able to digest sugar substitutes. When ingested, these compounds tend to pass through our gastrointestinal system without being absorbed.
However, because they are not similar molecules, they are metabolized differently from each other. As scientists from Frontiers in Nutrition(opens in new tab) point out, these properties may explain why there is so much conflicting evidence about their health effects. Many studies look at artificial sweeteners as a whole, rather than test them individually.
There is also ongoing debate as to how sugar substitutes affect our brains. Scientists are particularly concerned that artificial sweeteners can interfere with parts of the brain related to energy metabolism and taste perception, potentially fuelling sugar cravings and problems with appetite regulation. According to a review published in Nutrients(opens in new tab), the evidence from fMRI(opens in new tab) studies is mixed, and more research is needed to fully understand this issue.
According to Dr. Simon Steenson, a nutrition scientist at the British Nutrition Foundation, it’s difficult to know exactly what effects artificial sweeteners have on our health. “Many of the studies that have looked at whether artificial sweeteners have a harmful effect on our health have been observational studies, which cannot tell us whether there is a cause and effect relationship,” he says.
“There have been conflicting results and controversy of the science around the effects of low- and no-calorie sweeteners on our health, including weight management and blood sugar control. What is well known is that excess added sugar is not good for our health, which has led to low- and no-calorie sweeteners being used to replace some, or all, the sugar in foods and beverages.”