The Artificial Sweeteners' Side Effects List Revealed

By Bob Fear

The Artificial Sweeteners' Side Effects List Revealed

Artificial sweeteners have become a popular choice for replacing actual sugar in drinks such as tea, coffee and iced drinks. But are they really healthy? In this article we’ll find the truth about artificial sweeteners’ side effects.

What are artificial sweeteners?

Artificial sweeteners are chemical substances we can use to sweeten our food and drink instead of sugar. They are sold as a healthier alternative to sugar and are either low in calories or free from calories altogether.

Artificial sweeteners list: what different types are there?

Acesulfame K

Also known as Ace-K and E number E950, acesulfame potassium is a calorie-free sugar substitute that’s 200 times sweeter than sugar. It’s known for having a slightly bitter after taste. To counteract that, it’s often blended with other sweeteners. As it doesn’t break down under heat, it’s commonly used in low-sugar baked goods, sweets, beverages and ready meals.

The European Food Standards Agency (EFSA) says that the Acceptable Daily Intake (ADI) of Acesulfame K is 9mg per kg of your body weight. ADI levels are based on lots of scientific research to establish how much of a substance we can safely consume on a daily basis for the whole of our lives and experience no side effects.

If you’re worried that artificial sweeteners are bad for you, we take a look at all artificial sweeteners’ side effects below.


Aspartame (or E951) is the low-calorie sweetener that comes the closest to the taste of sugar. It’s the most widely used sweetener, it’s around 200 times sweeter than sugar and that sweetness lasts longer. Aspartame is sold under the brand names of Canderel, Hermesetas and Nutrasweet and is found in Diet Coke, Coke Zero, Diet Pepsi, Pepsi Max and lots of other diet or low-calorie drinks.

A can of Diet Coke contains 180mg of aspartame. According to the World Health Organization and the EU’s Scientific Committee on Food, the ADI of aspartame is 40mg per kg of your body weight. The average body weight being 70kg, the amount of aspartame we can supposedly safely consume in one day, on average, is 2,800mg - or 15 and a half cans of Diet Coke. Although we wouldn’t advise that!

Aspartame is a controversial artificial sweetener that many believe is bad for you. Read on to find out more about artificial sweeteners’ side effects.


Saccharin (or E954) has been used as an artificial sweetener for over 100 years. It’s around 300-400 times sweeter than sugar, hence the word ‘saccharin’ being used to describe something as sickly sweet. But it has a very bitter or metallic aftertaste so it’s usually combined with other sweeteners when used in food and drink production.

Historically, it’s been a popular sugar alternative as it doesn’t contain any calories or carbohydrates. Our bodies can’t break it down so it leaves unchanged. It has a long shelf life and stands up to heat, all of which adds up to its long-term wide use as an artificial sweetener. It has an ADI of 5mg per kg of your body weight.


Sorbitol (or E420) is a carbohydrate that’s about 40% less sweet than sugar and often used in diet foods. In its natural form, it’s a sugar alcohol - meaning that it contains sugar molecules as well as alcohol molecules. Sugar alcohols naturally occur in fruit and vegetables and are lower in calories than normal sugar. However, most food and drink products contain manufactured sorbitol to sweeten them. It’s often used in sugar-free chewing gum.

While sorbitol doesn’t currently have an ADI, it does carry a warning that anything more than 50g a day could have a laxative effect. Find out more aboutartificial sweeteners’ side effects below.


Sucralose (or E955) is a calorie-free artificial sweetener and the main constituent of the Splenda range of diet products. Although sucralose itself is calorie-free, the Splenda products also contain carbohydrates which slightly ups their calorie count, but only by a tiny amount.

Sucralose is the sweetest among this list of artificial sweeteners, at around 400-700 times sweeter than sugar. It also has none of the bitter aftertaste of most other sweeteners. The EU’s ADI of sucralose is 15mg per kg of body weight.


Stevia is a natural sweetener derived from plant leaves native to South America, where it’s been used for centuries to sweeten beverages and make tea. It has almost no calories and is 300 times sweeter than sugar. While it takes longer for it to hit our taste buds, once there, the taste lasts longer than sugar. For some it has a bitter, licorice taste. Stevia has an ADI of 4mg per kg of body weight.

Stevia-based sweeteners were relatively recently approved in the EU in 2011. Lots of them do not contain the whole leaf of the plant, but a highly refined extract called rebaudioside A (Reb-A) which is around 200 times sweeter than sugar and is less bitter than the Stevia leaves themselves. Most Reb-A products also contain other sweeteners such as sugar alcohol and glucose.


Xylitol (or E967), like Sorbitol, is a sugar alcohol that occurs naturally in plants. It has the same sweetness as sugar but contains 40% less calories and is absorbed more slowly in our systems. It’s commonly used in chewing gums and sweets as well as in dental care products. Like Sorbitol, again, it doesn’t have a specified ADI. This means, in theory, it’s safe to consume in unlimited quantities as a sweetener.

Are artificial sweeteners bad for you?

All of the sweeteners listed above are currently deemed as safe for us to consume, as long as it’s in an amount within each product’s ADI level - if it has one. This means that the authorities responsible for the safety of our food and drink say that none of these sweeteners, in moderation, are bad for you.

All sweeteners are heavily regulated by the EU, but it just remains to be seen if the UK now varies from EU guidelines. Artificial sweeteners remain controversial due to conflicting research around long-term health impacts and differing interpretations of those studies. In most cases, more research is needed.

As well as being one of the most used artificial sweeteners, aspartame is also one of the most controversial. While the EFSA cleared it for consumption in the EU, British food safety experts are calling for the UK to either ban aspartame or significantly reduce its ADI. These scientists contest the EFSA’s assessment of the research conducted on aspartame, saying that they shouldn’t have dismissed some of the documented side effects.

There are similar controversies with most other artificial sweeteners. We take a look at some of the reported side effects of artificial sweeteners below. 

What are artificial sweeteners’ possible side effects?

The side effects of artificial sweeteners may include: digestive issues, increased blood sugar levels, a higher risk of cancer, increased blood pressure and adverse effects on those with pre-existing mood disorders. Artificial sweeteners may also have an effect on some people’s immune systems.

Acesulfame K risks may include hormone disruption and cancer

Early tests on Ace-K remain controversial and various safety boards argue that existing research does not adequately prove its safety. Scientists argue that there is a risk to pregnant women and a risk of cancer and hormone disruption. Despite this, the EU’s consumer protection agency has given it an ADI level of 9mg/kg.

As with all artificial sweeteners, it’s best to be aware of all the arguments and research surrounding Ace-K so you can make your own decision around whether or not to avoid it. Look out for E950 on ingredients lists.

Aspartame’s side effects could affect mood disorders

Some scientists that tested on animals have long claimed that consuming aspartame could risk brain development and health, but these claims were refuted by food safety boards saying that aspartame would have to be consumed by humans in significant amounts, well above the ADI, to pose any health risk.

Further studies have since been made and, according to all the latest published research, aspartame may have an adverse effect on those with pre-existing mood disorders. It may also have an effect on some people’s immune systems. People with phenylketonuria, a rare hereditary disease, should avoid consuming aspartame due to this artificial sweetener’s side effects.

There is currently no solid, incontrovertible scientific evidence that proves aspartame can cause cancer, MS, seizures, lupus, or other illnesses. But as there is ongoing concern and disputes over data, many consumers and manufacturers have now chosen to avoid using aspartame. Look out for E951 on ingredients lists.

Saccharin’s risks are still being investigated

Research in the 1970s suggested a link to bladder cancer, but as these tests were performed on rats it was decided that there was no proof that saccharine could cause cancer in humans. Saccharin is now classed as safe for consumption by the world’s leading authorities, but many are still dubious about its safety and recommend we avoid it. Look out for E954 on ingredients lists.

Sorbitol Artificial sweetener’s side effects could lead to digestive issues

As with other sugar alcohols, consuming lots of sorbitol may cause bloating and diarrhoea. It’s worth remembering that sorbitol is used as a laxative so best not to overdo it. Taking too much could cause severe digestive problems and an electrolyte imbalance.

Sucralose may increase blood sugar in certain cases. Cancer could also be a side effectg of this artificial sweetner.

In anyone that doesn’t usually consume artificial sweeteners, it’s suggested that sucralose may raise blood sugar and insulin levels. Yet it’s said to unlikely have any effect on those whose regular diet already contains artificial sweeteners.

Despite some Splenda products being designed for baking, recent research has cast doubt on the safety of sucralose when heated to high temperatures. Although more research is needed for definitive proof, one study has highlighted a risk of cancer. Maybe best avoid cooking anything with sucralose in it. Look out for E955 on ingredients lists.

Stevia’s possible effects on blood pressure and the digestive system

Whereas Reb-A is generally considered to be safe, raw, whole-leaf and crude extract stevia haven’t been approved by safety boards for consumption because of the lack of research. Some suggest that raw stevia might have an adverse effect on our blood pressure, kidneys, and on our cardiovascular and reproductive systems. Where Reb-A is used alongside sugar alcohols, it may cause bloating and diarrhoea in some people.

As with other substances relatively new to the market that require more research to be done, it’s best to check with your doctor before introducing it into your diet if you have any underlying conditions.

Xylitol may lead to digestive trouble when consumed in large quantities

As with other sugar alcohols, consuming lots of xylitol may cause digestive issues, but our bodies tend to build up a tolerance over time if we slowly build our intake.

Whereas most other sweeteners carry some potentially adverse side effects, xylitol actually has some positive side effects. It doesn’t raise blood sugar levels, it combats plaque in your mouth and can even benefit your digestive system. So, if you’re looking for the best sweetener out there, it seems like that xylitol may be the best option. Look out for E967 on ingredients lists.

How do I avoid artificial sweeteners?

The best way to avoid artificial sweeteners is to go for the natural ones. Even though we’ve included stevia in our list of artificial sweeteners, technically it’s not artificial. It’s a novel sweetener, meaning that it’s highly refined from a natural source. So, you may prefer to give that a go, bearing in mind the potential side effects we’ve also mentioned. Xylitol, as a sugar alcohol, is technically not artificial so that also may be a preferred option, particularly for diabetics.

Natural sweeteners such as maple syrup and honey are also good to use instead of artificial sweeteners, although these are high in calories so should be used sparingly. Coconut sugar and agave nectar are also great natural sweeteners relatively new to the market, but these are both high in calories and contain lots of fructose so are not good for anyone with diabetes.

We’ve taken a look at all of the common sweeteners on the market, some artificial, some not. We’ve also highlighted some of the reported (and disputed) side effects. Navigating to find the best sweetener for you can be tricky, depending on your personal circumstances but, hopefully, armed with all the information here, we may have been of some help.

Next, find out more about why we get sugar cravings . Plus, we’ve also taken a look at the different types of sugar , so you know what to avoid. Discover everything you need to know in our handy articles.


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