How Deadly Is Sucralose? What Does Research Say?

Medically reviewed by Addie Abohosh, MS, RD, LD Addie Abohosh Addie AbohoshMS, RD, LD facebook_iconinsta_icon
Written by , BSc, Professional Certificate in Food, Nutrition and Health Ravi Teja Tadimalla BSc, Professional Certificate in Food, Nutrition and Health Experience: 8 years
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Sucralose is over 600 times sweeter than sugar (1). And it has zero calories. But does this mean you should eat it?

Do you drink diet sodas or flavored iced teas? Ever considered picking up a pack of frozen dessert? Chewing gum? Or wait, how about meal replacement bars or ready-to-drink protein smoothies?

All of these contain sucralose. Sucralose is an artificial sweetener and a sugar substitute. It is hundreds of times sweeter than sugar, without the calories. Which is why it has been marketed as an ultra-healthy alternative to sugar. Even the US Food and Drug Administration has concluded it to be safe for use in food as a sweetener (2).

But is it?

An Israeli study tells us that ingesting sucralose may alter the levels of intestinal microbes in humans (3). Other studies also say it might alter glucose levels in humans (4).

So, what’s the verdict? Scroll down to find out.

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The Science Behind Sucralose

Sucralose is made from sugar, involving a multi-step chemical process. Three hydrogen-oxygen groups are replaced with three chlorine atoms. Though the process begins with sugar, the final product is a different form of sugar. Simply put, sucralose is not sugar. It is a chlorinated artificial sweetener. And since it has zero calories and zero grams of sugar and carbohydrates, its glycemic index is zero.

Some of the most popular commercial sucralose brands include Splenda, Zerocal, Sukrana, SucraPlus, and Candys. Of them all, Splenda is the most popular.

The American Heart Association and American Diabetes Association have given the nod to sucralose, although only cautiously. Sucralose is not a magic bullet. Of course, using non-nutritive sweeteners like sucralose can help you reduce sugars in your diet. This lowers your calorie intake and contributes to health. It can also be a great option for diabetics who are having trouble controlling their blood sugar. Seems quite logical, right?

But logic can only take you so far. There is more to the sucralose story.

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The Sucralose Story – How Sucralose Can Fool Your Brain

Experts from the Harvard Medical School are concerned that people using artificial sweeteners can replace the lost calories from other sources (5). This is psychological. I am taking zero-calorie sugar, so it is okay to have cake. Rings a bell? Now, this is a serious concern.

And there’s more. How your brain responds to artificial sweeteners is complex. Artificial sweeteners can change the way you taste food. A minuscule amount of sucralose produces a potent sweet taste. Taking it too frequently can make you find other less intensely sweet foods, like fruits or even vegetables, extremely unappealing.

This means taking artificial sweeteners, like sucralose, may make you keep off from healthy and nutritious foods and consume more artificially flavored foods with no nutritious value.

Sucralose can have another downside. Since you are ingesting something too sweet that has no calories, over time, you will tend to associate sweet foods with no calorific value. You may take more sweets and pastries, thinking that they have no calories and are healthy. Which is, of course, a lie.

Also, artificial sweeteners can be addictive – similar to regular sugar, drugs and alcohol. If you think you will be able to give up the desire for the sweet taste, think again.

Does this mean sucralose is bad? Not really.

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Does Sucralose Have Any Advantages?

1. Sucralose Can Be An Ideal Sugar Substitute

It’s 600 times sweeter than sugar – without the calories. This means you can take a minute amount of it, and you are good to go.

2. May Be Beneficial For Diabetics

Sucralose doesn’t have effects on blood sugar levels. Most of it passes through your body without getting absorbed by your system. In fact, less than 20% of it enters your blood. The remaining is excreted.

3. May Aid Weight Loss

Consider this with caution, though. Of course, taking sucralose in the place of actual sugar means you are taking fewer calories. But some studies suggest low-calorie sweeteners promote fat formation and even impact metabolism negatively. So, please talk to your doctor about how much artifical sugar you should be ingesting.

And from a psychological standpoint, you may think it is more acceptable to consume high-calorie foods because you made a “healthier choice” previously by choosing the low-calorie sugar substitute.

These could be the advantages sucralose has. But there is more validation and research required.

Also, there are other artificial sweeteners in the market. How does sucralose fare against them? How is it any different?

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Sucralose Vs. Aspartame Vs. Stevia

These three are the popular forms of sugar substitutes in the market today. Let’s see how they are different from each other.


Sucralose, as we saw, is almost 600 times sweeter than sugar. The FDA has approved it after reviewing more than 100 case studies. And as it is heat-stable, you can also use sucralose in baking.


Aspartame is a combination of two amino acids that offer sweetness with almost zero calories. It also is exhaustively studied, and the FDA has approved its use after reviewing close to 100 studies.

However, some individuals have reported headaches and dizziness after consuming products containing aspartame. So, you might want to be careful here if you are already prone to such symptoms.


This is a natural zero-calorie sweetener. Stevia is made from a South American plant and has been used for over centuries. It is now used in most sodas and sports drinks and baking blends and is also available in the form of liquid drops and dissolvable tablets.

Purified stevia extracts that you find in the market are usually considered safe. Some individuals experience a metallic taste after consuming stevia. And crude stevia extracts are not approved by the FDA.

Though the composition and the methods of production could be different – all of these serve one purpose. And that is to help you attain sweet taste without piling up on calories.

Coming back to sucralose, even though it may not have incredible advantages, you sure can use it in various ways. You can mix it with the dough while making baked foods. You can also add it to beverages in the place of sugar. You might also want to mix a bit of sucralose while preparing desserts.

But before you do any of that, you must keep in mind a few things.

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What Are The Side Effects Of Sucralose?

  • It May Not Be As Inert

Sucralose is often considered biologically inert, which means it can pass through the body completely unabsorbed. In fact, this is the reason sucralose is claimed to be harmless. But some studies show that some part of this sweetener does get metabolized – and this can cause problems.

  • It Might Interfere With Gut Microbes

We have already seen this. Sucralose can alter the composition of intestinal microbes. When your gut microbes get out of whack, this can affect many different parts of your body. It is even thought that your gut can regulate mood, the immune system, energy levels, and much more! Dysregulation of the microbes may also impair your appetite regulation or lead to weight gain.

  • Issues With Cooking

Though studies have proven that sucralose is heat-stable, some sources say cooking with sucralose may produce toxic compounds called chloropropanols.

  • May Elevate Blood Sugar

This sounds counterintuitive based on what we mentioned earlier – sucralose being a good alternative for diabetics. But some studies suggest that artificial sweeteners may alter metabolism and spike blood sugar levels.

  • May Affect Cancer Incidence

The research in this area is very inconclusive. Some studies see a trend of more malignant cancer incidence in mice over their lifetime when fed sucralose, but other studies do not (6).

Of course, the risk of cancer posed by sugar and high-fructose corn syrup outweigh the risk posed by sucralose – but though the chances are quite dim, sucralose may have an impact on cancer occurrence as well, although research does not prove that.

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The potential harm of sucralose is more psychological. Of course, biologically it is quite safe, which is why even the FDA has approved it. But from a psychological standpoint, we don’t recommend you get used to relying on sucralose – or any artificial sweetener for that matter. These products are still artificial. And while they may help limit overall sugar intake, we should be consuming less artificial and processed foods whenever possible.

Cut down on sugar. Go for more nutritious foods. Stay active. Feed your body and mind with the good stuff. That’s the best way to go.

If you have any feedback, suggestions, or questions regarding this article, please post a comment in the box below.


1. “Sensory characteristics of sucralose and other…”. Wiley Online Library.
2. “Additional information about high-intensity…”. US Food & Drug Administration.
3. “Non-caloric artificial sweeteners and the…”. US National Library of Medicine.
4. “Artificial sweeteners produce the…”. US National Library of Medicine.
5. “Artificial sweeteners: sugar-free, but…” Harvard Medical School.
6. “Sucralose administered in feed…”. US National Library of Medicine.


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Addie Abohosh
Addie AbohoshMS, RD, LD
Addie Abohosh is a registered dietitian with 7 years of experience. She believes in real food, scientific research, and the power of food as medicine. Her aim is to simplify healthy cooking, making overall wellness achievable, encouraging physical activity, and giving truthful nutrition advice to all.

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