I got the idea for this topic after having an interesting conversation with a colleague about sugar and sugar substitutes, i.e. sweeteners, during our afternoon coffee break at work, talking about the implications sweetener consumption brings with it.
Although it’s known that sweeteners are safe to eat, one might wonder whether there are any ‘side effects’ they bring along with them?
First, let’s look at sugars: they belong to the family of carbohydrates, which is composed of four subgroups: monosaccharides, disaccharides oligo- and polysaccharides. The latter two are the more complex compounds also known as starch, and are found in potatoes, for example. The first two simple compounds are the common sugars and account for everything from fructose (fruit sugar) to lactose (milk sugar).
Now to sweeteners, aka the imposters: they are usually much sweeter than sugar (on average between 200-400x) and have a similar chemical structure to sugar, resulting in them binding to the same receptors as sugar on our tongues, however they’re not absorbed in downstream digestion in the gut (like sugars are).
This sounds awesome… but is it really?
When you eat sugars, the body responds mainly in 2 ways – via our taste receptors and the actual digestion/ post-ingestion pathway. Both of these responses elicit changes in neurochemical pathways in our brain (one reason why chocolate makes ‘happy’) and hormone release. They also involve metabolic ‘preparations’ for sugar digestion, including energy and insulin* release.
When someone consumes sweeteners however, the sensory (taste) pathway, alerts the brain that sugar is coming, fooling the post-ingestion pathway as they’re all prepared and excited for actual sugar to arrive – but all they get are the imposters. So after some time of sweetener consumption, the post-ingestion pathway gets tired of this, and doesn’t react as well, resulting in a reduced “anticipatory response”. Which unfortunately leads to an inadequate response when real sugar is eaten, as the body thinks you’re just ‘fooling’ it again. As a result of this, artificial sweetener consumption can, over time, mess with the energy metabolism and have a negative affect on appetite and energy levels.
Apart from changes in the energy metabolism, studies have shown that artificial sweetener consumption has a negative effect on the gut microbiome. (The gut microbe is a heterogenous population (a lot of different types) of bacteria that help us with digestion – they’re good for us.) They particularly looked at the gut microbiome of type II diabetes patients (which often rely on sweeteners) and showed a reduction of microbial heterogeneity ie. the variety of bacteria in their gut. A reduction of this variety can in turn have a negative effect on digestion.
In summary, as charming as the idea of “sugar without the actual energy” sounds, there are various negative effects sweeteners have on homeostasis, metabolism and digestion in our body, making us question how ‘awesome’ they really are.
The research behind the ‘reward phenomena’ and gut microbe implications is nicely, in more detail explained here (https://link.springer.com/article/10.1007/s11894-017-0602-9)
*insulin is the hormone released in response to sugar. It is implicated in diabetes when it’s not secreted properly.