Is Sucralose Bad For You? 4 Potential Side Effects Of Splenda, Explored


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The main reason that many people choose to consume sucralose vs sugar is to avoid the calories in sugar to potentially help with weight loss. 

Unlike natural sweeteners, such as honey, agave, molasses, or maple syrup, this artificial sweetener is manufactured in a lab using chemicals.

But, is sucralose safe, or is sucralose bad for you? Keep reading to find out!

In this guide, we will cover: 

  • What is Sucralose?
  • Is Splenda Safe, Or Is Sucralose Bad For You?
  • Potential Splenda or Sucralose Side Effects

Let’s jump in!

Sucralose in a spoon.

What is Sucralose?

Sucralose is an artificial sweetener or sugar alternative that contains zero calories, so it falls under the umbrella of noncaloric artificial sweeteners.

The most common brand name for a sucralose product is Splenda, which typically comes in yellow packets at a coffee shop or a sugar dish on the table at a restaurant.

Although regular table sugar is the starting ingredient, a series of chemical reactions occur to change the molecular structure of the sugar molecules to create sucralose.

The end result is that three of the hydrogen-oxygen groups on the sucrose (table sugar) molecule are replaced with chlorine atoms.

Sucralose is said to be 600 times sweeter than sugar. It is popular not only because it is a non-caloric sugar substitute but also because it is said to be free from the bitter aftertaste characteristic of many other zero-calorie sweeteners such as saccharin and Stevia.

Much like many products and chemicals, sucralose was created accidentally. The process and resultant product were discovered when a British scientist supposedly misunderstood a chemical testing process he was supposed to be conducting in a lab in 1976. He tasted the end product and discovered that it was extremely sweet.

A glass container of artificial sweeteners.

Then, the companies Tate & Lyle and Johnson & Johnson worked together to refine the process and develop Splenda products. 

Splenda and sucralose were introduced in the United States in 1999. Since its market introduction, Splenda has become one of the most popular sweeteners in the United States and certainly one of the most popular artificial sweeteners. 

Splenda is used as a 1:1 sugar substitute in baking.

Because sucralose is hundreds of times sweeter than sugar, in order to balance out the volume of substituting regular sugar for Splenda, some Splenda products are blends of noncaloric sucralose along with the carbohydrates dextrose (glucose) and maltodextrin.

The addition of these other carbohydrates does increase the caloric content.

Sucralose is also added to many different diet products because it can impart a lot of sweetness with a negligible number of calories, decreasing the total caloric content over a recipe that would use regular sugar.

For example, many protein bars, “light” or diet yogurts and ice creams, candy, “diet” juices, and flavored protein powders use sucralose instead of all or some of the regular sugar.

A chalkboard that reads blood sugar, and a stethoscope.

Is Splenda Safe, Or Is Sucralose Bad For You?

So, let’s get into our next big question, is sucralose good or bad for you?

According to the FDA, over 110 safety studies have been reviewed by the FDA in order to approve the use of sucralose as a general-purpose sweetener for food.

A review of many studies investigating the health effects of sucralose concluded that it is safe and is typically consumed well below toxic or problematic levels; of course, keep in mind, this doesn’t mean that sucralose is healthy, but rather that it’s not dangerous or toxic for your body. 

Potential Splenda or Sucralose Side Effects

Does Splenda Increase Blood Sugar?

Aside from the fact that sucralose and Splenda essentially contain no calories or carbohydrates, one of the primary reasons that people gravitate towards sucralose vs sugar is because sucralose is said to have little or no effect on your blood sugar and insulin levels.

Particularly for people with insulin resistance, pre-diabetes, obesity, or type 2 diabetes, this can make using Splenda vs sugar a much more attractive—and potentially healthier—alternative.

However, the results from actual scientific research studies investigating the effects of sucralose on blood sugar levels and insulin response have been mixed.

A blood sugar reading of 98.

There is some evidence to suggest that the impact of this artificial sweetener on your blood sugar levels and insulin levels actually depends on your own personal biochemistry as well as whether your body is accustomed to consuming and metabolizing artificial sweeteners.

Some studies have found that consuming sucralose does increase blood sugar levels, whereas others have not.

Though based on the differences in the study designs, it might be reasonable to conclude that sucralose can increase blood sugar levels in those who are unaccustomed to consuming it, whereas the effect on blood sugar and insulin levels seems negligible for those who habitually consume artificial sweeteners.

For example, one small study with adults with obesity found that consuming sucralose elevated blood sugar levels by 14% and elevated insulin levels by 20% afterward. However, the participants in this study did not regularly consume artificial sweeteners.

In contrast, there have been numerous studies involving people of normal weight and no major medical conditions who do regularly use both in their diets. These studies have found that sucralose does not have any significant effect on blood sugar levels or insulin levels after consumption.

Therefore, your body may become accustomed to metabolizing this artificial sugar so it does not spike blood sugar levels afterward.

However, there is really not enough evidence to draw conclusions. If you have insulin resistance or need to control your blood sugar levels, you should speak with your healthcare provider about incorporating sucralose or Splenda into your diet for individualized guidance.

A variety of cookies.

Is It Safe to Bake With Splenda?

Although baking with Splenda is purported to be safe, there are some studies that raise questions about these claims.

Evidence from some recent scientific studies suggests that Splenda can start to break down at high temperatures, causing unfavorable interactions with other ingredients that can potentially result in the production of harmful compounds.

For example, one study found that when sucralose is heated in the presence of glycerol, a backbone of triglycerides or fat molecules, harmful substances called chloropropane are produced. These substances are considered carcinogenic, meaning that they may increase the risk of cancer.

Does Sucralose or Splenda Affect Gut Health?

One of the most potentially concerning issues with consuming sucralose is the deleterious effect that this artificial sweetener seems to have on the gut microbiome.

Research suggests that consuming artificial sweeteners such as sucralose can disrupt the composition of the gut bacteria, increasing the populations of pathogenic species and decreasing the counts of beneficial bacteria such as bifidobacteria and lactobacillus.

For example, one animal study found that consuming sucralose for 12 weeks resulted in gut dysbiosis and a significant shift in the composition of the gut microbes.

There were 47 to 80% fewer anaerobic bacteria (bacteria that do not require oxygen to survive), including some of the most beneficial microbes and a higher relative proportion of pathogenic bacteria.

Even more concerning was the fact that these deleterious changes did not reverse after the experiment was over, potentially signifying permanent disruption to the microbiome.

A person making a heart with their hands on their stomach.

Does Splenda Make You Gain Weight?

Of course, theoretically, it makes sense that if you are consuming a zero-calorie sweetener, you will not gain weight.

Furthermore, if you replace a caloric sweetener, such as sugar, honey, or syrup, with a calorie-free sweetener like Splenda, you will lose weight because you’ve cut calories; the actual evidence suggesting that this is true is weak at best.

Some observational studies have found that there doesn’t seem to be an association between artificial sweetener consumption and body weight or body fat percentage, whereas others have noted that artificial sweeteners may actually result in a small increase in body mass index (BMI).

With that said, the study designs are quite weak, so strong conclusions cannot be made. 

One review that looked at the collective results of observational studies did find that consumption of artificial sweeteners was associated with a slight decrease in body weight—about 1.7 pounds (0.8 kg) on average.

A scale.

More research in this area is needed.

One of the potential factors that may partially negate the anticipated weight loss from switching to sucralose is the notion that the extremely sweet nature of these artificial sweeteners triggers the same amount of craving for sugar, if not more so, than regular sugar.

This can cause people who eat food with Splenda or sucralose to seek out sweeter and sweeter foods and consume more calories.

Sugar is considered an addictive substance because it elicits a dopamine response in the pressure centers of the brain, causing the brain to crave more sugar to replicate the positive feelings.

Because artificial sweeteners are even sweeter than regular sugar, on the order of 600 to 700 times sweeter, the sugar cravings and sugar addiction may be even more intense. 

The noncaloric nature of these artificial sweeteners may also interfere with the body‘s ability to recognize that food has been consumed, meaning that your appetite may not be equally satiated by a Splenda-sweetened food versus a sugar-sweetened food, leading you to eat more and essentially compensate or undo whatever calorie savings you had.

So, is sucralose good or bad for you? Now that we have shared the studies, you be the judge!

What about Stevia? Is Stevia better for you than sugar? Take a look at the fact in our article: Stevia Vs Sugar Compared, Which Is Better For You?

A bowl of Stevia.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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