Artificial sweeteners are everywhere, but the jury is still out on whether these chemicals are harmless.
Also called non-nutritive sweeteners, these can be synthetic – such as saccharin and aspartame – or naturally derived, such as steviol, which comes from the Stevia plant.
Aspartame, for example, is found in more than 6,000 foods worldwide.
The American Diabetes Association officially recommends diet soda as an alternative to sugar-sweetened beverages.
However, recent medical studies suggest that these sweeteners may be contributing to chronic diabetes and cardiovascular diseases as well.
Why are these sweeteners calorie-free?
The key to these virtually calorie-free sweeteners is that they are not broken down during digestion into natural sugars like glucose, fructose and galactose, which are then either used for energy or converted into fat.
Non-nutritive sweeteners have different byproducts that are not converted into calories.
Aspartame, for example, undergoes a different metabolic process that doesn’t yield simple sugars.
Others such as saccharin and sucralose are not broken down at all, but instead are absorbed directly into the bloodstream and excreted in the urine.
Theoretically, these sweeteners should be a ‘better’ choice than sugar for diabetics. Glucose stimulates release of insulin, a hormone that regulates blood sugar levels.
Type 2 diabetes occurs when the body no longer responds as well to insulin as it should, leading to higher levels of glucose in the blood that damages the nerves, kidneys, blood vessels and heart. Since non-nutritive sweeteners aren’t actually sugar, they should sidestep this problem.
However, there is growing evidence over the last decade that these sweeteners can alter healthy metabolic processes in other ways, specifically in the gut.
Long-term use of these sweeteners has been associated with a higher risk of Type 2 diabetes.
Sweeteners, such as saccharin, have been shown to change the type and function of the gut microbiome, the community of microorganisms that live in the intestine.
Aspartame decreases the activity of a gut enzyme that is normally protective against Type 2 diabetes.
Furthermore, this response may be exacerbated by the ‘mismatch’ between the body perceiving something as tasting sweet and the expected associated calories.
The greater the discrepancy between the sweetness and actual caloric content, the greater the metabolic dysregulation.
Sweeteners have also been shown to change brain activity associated with eating sweet foods.
Another study revealed that longer-term and higher diet soda consumption are linked to lower activity in the brain’s ‘caudate head,’ a region that mediates the reward pathway and is necessary for generating a feeling of satisfaction.
Researchers have hypothesized that this decreased activity could lead a diet soda drinker to compensate for the lack of pleasure they now derive from the food by increasing their consumption of all foods, not just soda.
Together these cellular and brain studies may explain why people who consume sweeteners still have a higher risk of obesity than individuals who don’t consume these products.