Friends of mine want to go sugar-free and avoid blood sugar spikes. This is generally something I welcome... even if it's not how I would want to live - at least not at the moment. After all, I'm writing this while enjoying a delicious tiramisu cake in my favourite café.

However, my friends asked me how they should deal with cravings for sweets. One option could be protein bars. These usually contain sweeteners and my friends were worried that they could cause blood sugar spikes.

First of all: sweeteners are safe. Why? Read on!

What can you expect from this article:

Do sweeteners affect blood sugar and insulin?
How do they affect the microbiome?
Are there risks like cancer or other side effects?
What my problem is with ‘natural is better’.

I make no claim to completeness. This article is more about my thoughts on the subject and is intended to dispel dangerous half-knowledge.

What are sweeteners anyway?

Sweeteners are calorie-free or low-calorie sugar substitutes with high sweetening power. Well-known sweeteners are aspartame, sucralose, saccharin and stevioglycosides. A total of 12 sweeteners are authorised in the EU (source: consumer advice centre). In other parts of the world, some other sweeteners are also authorised.

There are artificial sweeteners (e.g. aspartame) and natural sweeteners (e.g. stevioglycosides). Being natural does not mean that a product is better. By the way, this is true almost everywhere! Just because something is natural does not mean it is better or contains fewer chemicals. Everything consists of chemicals! EVERYTHING! In fact, the belief that natural is better is a logical fallacy. The venom of the black mamba (the snake, not Kobe) is extremely deadly... but natural. The quantity makes the poison. Basics of chemistry. 7th grade or so.

Sorry... little side rant. Back to the topic.

Are sweeteners detrimental to health?

Insulin and blood sugar levels

Unlike sugar, sweeteners cause no or only a negligible increase in blood sugar.

A few years ago, scientists such as Gary Taubes proposed the so-called carbohydrate-insulin hypothesis as a common explanation for obesity. I myself adhered to it for a very long time. The basic idea is that the consumption of refined carbohydrates such as sugar or starchy foods causes insulin levels to rise sharply. Insulin functions, among other things, as a storage hormone that regulates blood sugar by transporting carbohydrates into the cells where they are needed for energy production. Too much carbohydrate in the blood means a higher blood sugar level and therefore a higher insulin response. The excess sugar is then stored in the fat deposits. This is said to lead to weight gain and obesity.

The carbohydrate-insulin hypothesis was debunked a few years ago. Funnily enough, Gary Taubes had contributed a crucial study in which he wanted to prove his model once and for all... and impressively demonstrated the opposite. But he still sticks to his model... It's just unfortunate when the entire business model is built on a false foundation.

The mechanism of how insulin works is correct, but not so crucial for obesity. Carbohydrates, proteins, fats: all these nutrients increase blood sugar levels. However, the combination of fat and carbohydrates keeps it up for a long time. If you look at continuous glucose monitoring (CGM - devices developed for diabetics that display blood sugar levels in real time), you can see that literally every food causes blood sugar to rise. The extent of the increase depends on various (also) individual factors.

Good old calories are more relevant for weight gain. If you eat too many calories, you will gain weight. Foods that contain a lot of refined carbohydrates and fat are often very, very tasty, contain a lot of calories and are not particularly filling. I know what I'm talking about: the tiramisu cake has been eaten for a long time, I really want more and I'm not full.

Microbiome and metabolism

Another reservation about sweeteners is that they could negatively affect your gut microbiome.

There is not enough data available on this. In fact, a meta-analysis was published a few years ago which found that sweeteners

have no negative effect on the microbiome,
very probably have a neutral effect on the microbiome and
may have a positive effect on the microbiome.

This is just one analysis of many! But it clearly shows that there are no black and white statements in this context. What we can assume, however, is that sweeteners have an effect on our gut bacteria. But nobody can say whether this is good or bad. If it is bad, then probably only in absurdly high quantities of sweeteners consumed at one time. Furthermore, studies indicate that possible changes in the gastro-intestinal bacteria are even reversible.

It is important to realise that we do not yet know what constitutes good gut flora. Firstly, your own gut flora is highly individual and secondly, it is extremely adaptable. In his book ‘Diet Cults: The Surprising Fallacy at the Core of Nutrition Fads and a Guide to Healthy Eating for the Rest of Us’, Matt Fitzgerald describes how humans and their predecessors have stood out since they climbed down from the trees by being able to adapt to literally every possible food they encountered along the way. If you want to put it that way, this adaptability is something that makes us human. There are cultures that have been almost exclusively vegetarian for generations (and there are vegetarians and vegans). There are indigenous peoples who live almost exclusively on fish and seal babies (and there are carnivore dieters who ‘think’ their diet is the holy grail).

Cancer Risk

Aspartame has been categorised by the WHO as ‘possibly carcinogenic’. Pickled and fermented vegetables and aloe vera extract are also on the same list.

NEWS FLASH: PICKLED VEGETABLES CAUSE CANCER!!!

Joking aside. This is only an assessment of whether a substance harbours a potential cancer risk and not whether there is a real health risk. Studies that show such a risk come from animal experiments with unrealistically high doses. Remember: the dose makes the poison. The WHO and the European Food Safety Authority continue to regard aspartame as safe.

Conclusion

Sweeteners are a good calorie substitute and can help you lose weight. Diet cola is a good alternative to real cola!
They have no or a negligible effect on your blood sugar level.
Sweeteners still taste sweet and if you want to wean your taste buds, keep that in mind.
Humans have evolved to tolerate a wide variety of foods. That's what makes us so successful.
The dose makes the poison!

Eating less sugar is a good idea. But sugar is not evil. No food is evil. Not even sweeteners. There is no such thing as Big Sugar or Big Sweetener. Only Big Belly if you eat too much and Big Sick if you eat shit.

I'm going to order another croissant.

Ciao

Marco

Sweeteners: cancer, insulin & other fairy tales - a text written over a slice of tiramisu cake.