TL;DR: Whether or not a sweetener is “healthy” has more to do with quantity and how it gets handled by our gut bacteria than if it’s “natural” or a sugar-substitute. (about 8 min read)

Metabolic tips for healthy sweeteners:

• Get adequate fiber in your diet to protect your gut and reduce the amount of bacteria that can cause inflammation.

• Stay hydrated and eat sweet things slowly to reduce GI distress from unabsorbed sugar or sugar-substitutes

• The rate of gut absorption is going to play a much larger role in health than the sweetener.

Natural sweeteners are things that taste sweet and are technically found in nature. This doesn’t mean that they aren’t heavily processed or that the ones sold to us in processed foods aren’t made in a lab, it just means that you can find naturally occurring versions of the same molecule outside of a lab.

Natural sweeteners are promoted as being “healthier” for marketing. Especially for people with diabetes, who have to manually check their blood glucose levels (BGLs). Processed foods need to be palatable, people will eat sweet food. If a Business is making money off of selling people sweet food, why leave out a group of people just because they can’t eat sugar? Hello, non-sugar substitutes.

Some non-sugar substitutes still raise blood glucose levels (BGLs). These include saccharin and sucralose. Raising BGLs will also raise insulin levels, which is not what someone wants when they are trying to maintain metabolic balance. Other non-sugar substitutes induce GI distress. However, too much regular sugar will ALSO induce GI distress!! This is important when we ask “is this healthier than sugar”? If both are causing GI distress, maybe the solution is not to avoid non-sugar substitutes. Maybe instead it’s to increase our fiber intake, reduce processed foods, and stay hydrated.

Sugar alcohols don’t raise BGLs or insulin levels. Sugar alcohols don’t raise BGLs or insulin levels because we can’t absorb them across our guts. However, there are two consequences of not being able to absorb sugar alcohols: (1) not absorbing something changes the osmotic pressure in our guts and water moves from your blood into your intestines (you don’t have to pull out the notecards you made to get through chemistry class, just know that the change in osmotic pressure = watery stools and then constipation). And (2) the bacteria in our gut can digest these sugar alcohols and that produces a lot of gas that builds up in our intestines. Anyone who has eaten sugar-free gummy bears or other sugar substitutes before monkfruit or stevia became popular knows about this firsthand.

Bloating, gas cramps, and changes in bowel movements are a sign that we have eaten something that cannot be absorbed by our guts. Like when we eat other foods with “rare” sugars like raffinose (found in Brussels sprouts, cabbage, and beans). Contrary to popular belief, it’s not the fiber that causes bloating, gas, or changes in bowel movements, it’s an influx of a simple sugar that gets broken down quickly by gut bacteria. We can avoid this by eating slower and staying hydrated.

Anyone who is (or knows someone who is) lactose-intolerant knows the effects of eating something and then not absorbing it. Lactose isn’t absorbed across the gut by anyone; there is an enzyme in (some of) our guts that breaks lactose into glucose and galactose. Those glucose and galactose molecules are absorbed. Any lactose that is not broken down cannot be absorbed.

We can reduce bloating and GI distress by eating sugars (all sugars!) more slowly. This is because gut bacteria that feed on fiber will produce gas less quickly than gut bacteria that feed on sugar. Here’s where we get to talk about timing – even if we can absorb a sugar, like glucose or fructose, we can only absorb that sugar at a certain rate.

Let’s say that your gut has 10 little doors to let sugar through. If you eat foods with 6 sugar molecules, then they can all go through a door when they hit your gut. If you eat a food with 12 sugar molecules, the first 10 will go through and the next 2 will have to wait their turn. If you eat a food with 50 sugar molecules, now there are 40 sugar molecules waiting their turn. Sugar molecules at the end of the line will be hanging out for a long time.

Except that the extra sugar molecules actually don’t hang out that long. Because in addition to the 10 little doors that our guts have for letting sugar molecules in, there are also hungry little gut microbes that will eat sugar molecules waiting their turn to enter your gut. So you probably do absorb sugar molecules 11-20, but not sugar molecules 41-50. 41-50 get eaten by bacteria and make you gassy and bloated. So even if you could have absorbed a certain type of sugar, you don’t absorb that sugar when you eat a large quantity of it at once (and the problem is made worse if you’re dehydrated).

Continuously eating foods that feed sugar-eating bacteria increases inflammation in our guts. When we eat sugars we don’t absorb - either because we can’t (lactose intolerance) or because we ate too much, too fast to absorb it effectively - we feed a certain type of that bacteria. There are two “main types” of bacteria in your gut: ones that break down fiber and have a good relationship with your gut’s immune cells, and ones that eat sugar like fiends and do not give any fucks at all. The sugar fiends literally fight with your immune system and cause gut inflammation.

Inflammed guts are “leaky” and end up getting more inflamed if we don’t stop eating the original sugar we aren’t absorbing. If we continue to stress our guts out by eating sugar faster than we can absorb it and feeding our sugar-loving bacteria, we will create inflammation in our gut lining. Inflammed guts get worse at absorbing everything. If this happens, we now have a hard time absorbing other nutrients, we reduce the number of little doors we have to let sugar in from 10 down to 6, or 4, or whatever, depending on the amount of damage.

Eventually, we cause little mini tears in our gut. Shredded guts = “leaky gut syndrome”, which causes IBS symptoms and other GI conditions. This is another reason why diets high in fiber and low in simple sugars are healthier for us. They don’t tear small shreds in our guts.

Soooooo…. are non-sugar, “natural” sweeteners healthier than sugar? It’s more important to keep our blood glucose levels stable and to not put things in our guts that will get eaten by sugar-fiend bacteria. Sweeteners that we don’t absorb OR get eaten by bacteria won’t raise BGLs or cause GI distress (e.g. like stevia or monkfruit), but they probably change the population of gut bacteria from fiber-friends to sugar-fiends. The healthiest thing to do is to eat sweet things in moderation, slowly, and with water.

Metabolic tips for healthy sweeteners:

• Get adequate fiber in your diet to protect your gut and reduce the amount of bacteria that can cause inflammation.

• Stay hydrated and eat sweet things slowly to reduce GI distress from unabsorbed sugar or sugar-substitutes

• The rate of gut absorption is going to play a much larger role in health than the sweetener.