Bring On the Hate Mail

We hate to say we told you so...

But for years, we've written about a topic that always brings the hate mail – sugar substitutes.

We get it. Most of us (at least here in America) are addicted to sugar and feel like we need our regular sugar hit. That's why sugar substitutes are so popular, and folks don't want to hear anything against them.

For decades, popular sugar substitutes were successfully marketed as a healthier, calorie-free way to satisfy a sweet tooth. Because these sweeteners lack carbohydrates, the belief was that they wouldn't trigger the same insulin response as sugar. So you could use these sweeteners without worrying about inflammation or illnesses, like diabetes.

We've long warned that this is a dangerous myth.

And last week, a new study published in Cell backed us up by demonstrating how alternative sweeteners aren't as safe as folks think.

Researchers looked at four popular sugar substitutes: saccharin, sucralose, aspartame, and stevia. They gave participants – all of whom were not consumers of these sweeteners, were not overweight, and were considered healthy – sachets of the four different sweeteners. There was also a control group that received no sweeteners and a group who received glucose.

Over 29 days, the researchers measured each participants' glycemic response and the changes in their oral and gut microbiomes. (Glycemic response measures glucose levels in your blood.)

Participants who consumed saccharin and sucralose saw a spike in their blood glucose levels. Folks in the aspartame and stevia groups didn't have a significant spike, but all four groups had changes in the gut microbiomes. The changes varied depending on the sweetener, but all were bad in different ways. For example, some of the changes looked similar to changes we see in people with diabetes.

This is just the latest study proving artificial sweeteners aren't harmless.

Let's take a look at everything we already know about the top sugar substitutes...


Saccharin is in artificial sweeteners like Sweet'N Low, as well as low-calorie or zero-calorie foods like jams, salad dressing, sugar-free gum, and many "diet" processed foods. Research shows saccharin disrupts gut bacteria and leads to high blood-sugar levels. It even causes you to gain weight compared with healthier, higher-calorie alternatives.


Sucralose is the main ingredient in Splenda. It's not easily broken down in your digestive system and may even stop your colon from breaking down glucose. A 2018 study from George Washington University took samples of fat tissue from participants in two groups: normal weight and obese. They exposed the tissues to different levels of sucralose.

What they saw was that the more sucralose the cells got, the more fat they wanted to create. Basically, the sucralose made the fat cells behave the same way as they did with sugar.


Aspartame, a main ingredient in Equal, is a common sugar substitute found in ice cream, diet soda, mints, hard candy, and chewing gum. Research from the journal Diabetes Care demonstrated that artificial sugar could raise insulin levels as well, even leading to type 2 diabetes.

Aspartame can also dampen your mood. With too much aspartame, your serotonin levels drop. Serotonin is a neurotransmitter we need to boost our moods. It also controls smooth muscle contraction, proper sleep, body temperature, and more. And guess what – depression (from low serotonin) and exhaustion factor heavily into low libido.

Lastly, aspartame is a well-documented source of inflammation, and several studies show that inflammation increases the joint pain in folks suffering from arthritis.


Xylitol is a type of sugar alcohol (and a common ingredient in sugar-free chewing gum). Sugar alcohols are partially broken-down carbohydrates. They taste sweet, but our small intestine can't absorb them well. That means they generally pass through our bodies without disturbing much. No studies point to increased blood sugar or higher insulin levels, for instance.

However, some folks report diarrhea, nausea, and similar bowel issues when eating large amounts of sugar alcohols. Researchers believe the inability of our intestines to absorb the sugar substitute means it passes through too quickly, which leads to loose stools. And any symptoms also depend on an individual's tolerance.


Longtime readers might recall that stevia is the sugar substitute we hate the least... Stevia is a natural, plant-based sweetener. It's in brand-name sweeteners Truvia and Pure Via.

A review published last year in EXCLI Journal looked at past research that found stevia extract has several potential health benefits, including controlling blood sugar, lowering hypertension, and fighting damage from free radicals with its antioxidant traits.

The problem with stevia, however, is blood pressure. Some research suggests that stevia lowers your blood pressure. This can be problematic if you're already on blood-pressure-lowering medication. Unfortunately, there aren't enough studies yet for us to know just how dangerous this is.

Monk fruit

Similar to stevia, monk fruit is an extract derived from a plant. But although it's more natural than the most popular artificial sweeteners, we don't know much about what monk fruit as a sweetener does to your health. We do know that it won't cause your blood sugar to spike, and some research points to potential antioxidant properties. The fact is, it's just not that well-researched yet.

Also, depending on the type you buy, it could be blended with a sweetener – dextrose – that does cause a spike in blood sugar. We should also mention that monk fruit sweetener isn't cheap and can be difficult to find. Some of our colleagues say it also has an unpleasant aftertaste, but others don't mind it.

Look, I know it's convenient to make something sweet by adding sugar or a sugar additive... The subject of artificial sweeteners is one of our most-requested topics.

But I've pounded the table on this for years.

Do what I do and avoid regularly consuming sugar or sugar alternatives.

Stick to fruit for your sugar fix. The fiber in the fruit helps to slow the absorption of sugar... And you'll get all of the health benefits of fruits, too.

Have you beaten an addiction to sweetness? Tell us your story... [email protected].

What We're Reading...

Here's to our health, wealth, and a great retirement,

Dr. David Eifrig and the Health & Wealth Bulletin Research Team
September 1, 2022