Artificial sweeteners are a perennial concern. Once every few months, we will hear a terrifying story that they are out to get us, like a silent assassin in the night who breaks into your house to give you diabetes.
Fortunately for Diet Coke lovers like myself, most of these stories are wrong.
Artificial sweeteners don’t cause cancer, they don’t make you gain weight, and there’s no good evidence that they cause diabetes or metabolic disease. And, despite recent headlines, there’s definitely no reason to believe that they are bad for your gut microbiome.
You can keep drinking that sweet, sweet diet drink.
Our gut is a wonderfully complex place, made up of a huge array of organisms that can both help and hinder digestion, and have a big impact on our health. This ecosystem is known as the ‘gut microbiome’, and a lot of research is currently underway to try and understand how we can promote health in this weird and wacky world.
A lot of the work is being done on bacteria, because we know that a lot of bacteria in our gut are important for good health.
The recent study that all the news is about was in this area: basically, the scientists took some bacterial cells, poured artificial sweeteners over them, and observed what happened. At high concentrations, most of the bacteria started to get ‘stressed’, which the scientists concluded was because of the “toxic effect” of the artificial sweeteners.
According to an astonishing number of news sources, this means that artificial sweeteners are bad for your health.
There are a few major holes in this theory. Firstly, the study that we’re talking about actually only looked at a single bacteria — E. Coli — and only a few strains. There are literally millions of different bacteria living in your gut, so extrapolating from this one to all of the others is…problematic.
The study also only found that artificial sweeteners were ‘toxic’ at very high concentrations. For example, the study found that the bacteria started getting stressed at a concentration of 4 grams per litre of aspartame. For reference, Diet Coke has a concentration of ~0.5 grams per litre. Equal — the artificial sweetener packets — has a concentration of 37 milligrams per gram. By my back-of-the-envelope calculation, to get the concentration that this study used in your gut, you’d have to eat about 100 packets of Equal, or boil down 8 litres of Diet Coke.
Not exactly representative.
It’s also really hard to extrapolate these conclusions to people. Remember, the study simply looked at E. Coli cells in petri dishes. Exposing cells to artificial sweeteners in a lab is very different to an actual person drinking diet soft drinks.
It looks like all of the media fuss was based on nothing but hot air. Instead of headlines saying “Artificial Sweeteners Are Bad For Your Gut Microbiome”, we should’ve been seeing “High Concentrations Of Artificial Sweeteners May Negatively Impact E. Coli In The Gut But We Aren’t Sure Yet About Any Of This”.
More wordy, but also more correct.
Ultimately, there’s some evidence that artificial sweeteners may cause negative changes in the gut microbiome, but we just aren’t sure yet. There’s certainly not much evidence linking such changes to actual, tangible effects in people. A systematic review of all the studies done on artificial sweeteners and the gut in 2016 found that there is currently not much evidence that they impact people, but it’s hard to tell either way because the evidence isn’t great.
Artificially sweetened drinks are probably not as good for you as water. But there’s no reason to believe that they are dangerous for your health.
Don’t believe the hype.
Artificial sweeteners still aren’t killing you.