How safe are sugar substitutes? From aspartame, maltose, sucralose, stevia and xylitol, know the benefits and risks

Scientists have recently found a way to extract the protein praseine, a sugar substitute that is 2,000 times sweeter and probably harmless. More studies are yet to be done on the new discovery, but sugar substitutes have been around for a while to ward off the harmful effects of sugar.

This has yet again brought back the looming question: Are sugar substitutes safe to use, if yes, how long?

Here is a look at the various sugar substitutes, the advantages and disadvantages and what doctors in UAE have to say.

Two types of sugar substitutes

Today, the terms ‘artificial sweeteners’ or ‘non-caloric sweeteners’ are touted as multiple orders of magnitude  ‘sweeter than sugar’.

Generally, there are two types of sugar substitutes: natural (plant-based) and synthetic.

Each one represents a multi-billion dollar industry (Aspartame market was estimated at $9 billion in 2021).

Artificial sweeteners

The idea is simple: with sweeter-than-sugar alternatives, we take smaller amounts, but get the same kick of sweetness.

However, concerns have been raised that these sugar substitute could increase insulin resistance and glucose intolerance.

Experts say it is best to consume these sugar replacements with caution.

‘Training’ the body to deal with sugar cravings is key

What you need to know about these 10 sugar substitutes:

Xylitol
Type: Natural (herbal)
Sweetness vs. sugar: 0.95

What is it?

Xylitol is known as a sugar-free sweetener, which is 5% less sweet than sugar, but has 40% less calories (9 calories versus sugar's 16) and a low glycemic index. Chemically, xylitol’s structure looks like a cross between a sugar and an alcohol, but it is neither. Many fruits and vegetables have xylitol, a naturally sweet sugary substance — a carbohydrate — found in plants, particularly birch tree and other hard wood.

Its sweetness is nearly as sweet as sugar (sucrose), but has fewer calories and is absorbed more slowly by the body. It is one of the most popular sugar substitutes.

What experts say about xylitol

There are at least two studies done on xylitol, known to inhibit S. pneumoniae, the pathogen that causes pneumonia. A trial involving 157 children found Xylitol was found to retard growth of S. mutans and S. sobrinus, inhibits acid production by these organisms. Another study on 875 children found that xylitol candy, pops, ice, gums, puddings, and cookies help in arresting dental caries. Digestive side effects had been reported with xylitol use. Some experts warn taking high doses of xylitol is ‘possibly unsafe’, and using very high doses long-term might cause tumours.

Stevia
Type: Natural
Sweetness vs. sugar: up to 300

What is it?

It is a natural substitute dubbed as ‘50 to 300 times sweeter’ than sugar — yet contains zero calories. The herb-based sweetener is derived from the leaves of the plant species Stevia rebaudiana, native to Brazil and Paraguay. The active compounds are steviol glycosides which are heat-stable, pH-stable, and not fermentable.

What experts say about stevia

Stevia, with fewer calories than sugar, may help in weight loss regimen. And because it's free of calories and carbs, it's a great sugar alternative for people on low-calorie or low-carb diets. Potential side effects linked to stevia consumption include kidney damage, gastrointestinal symptoms, allergic reaction, hypoglycemia or low blood sugar, low blood pressure, endocrine disruption.

Sacharine
Type: Artificial
Sweetness vs. sugar: 550

What is it?

Saccharin, an artificial sweetener discovered in the late 19th century, is up to 550 times as sweet as sucrose. Its use continues today, though not without controversy. Saccharin gives a sugary taste, but it kicks up a strong metallic after-taste, masked by combining it with cyclamate. Saccharin has no known nutritional value but sweetens certain products such as drinks, candies, cookies and medicines. It is also used by food manufacturers of baked goods, jams, chewing gum, drinks and tinned fruit. Saccharin is also known as Sweet and Low, Sweet Twin, Sweet'N Low, and Necta Sweet.

What experts say about saccharine

As a compound, it does not contain any calories, nor does it raise blood sugar levels. However, in 1977, the US Food and Drug Administration (FDA) sought to ban saccharine after studies found that high doses could cause bladder cancer in rats. The move was unsuccessful. In 1995, the European Scientific Committee for Food concluded that saccharin does not pose a cancer risk to humans. Saccharin is third most used artificial sweeteners, after sucralose and aspartame. A 2019 study show that long-term saccharin consumption raises obesity and diabetes risk, as well as liver and renal impairment. The results also suggest an increased risk of brain carcinogenesis.

Aspertame
Type: Artificial
Sweetness vs. sugar: 200

What is it?

Chemically, it is known as a methyl ester of the aspartic acid/phenylalanine dipeptide, an artificial non-saccharide sweetener 200 times sweeter than sucrose (table sugar). Aspartame is often used as a sugar substitute in foods and beverages. The global aspartame market was estimated at $9 billion in 2021, predicted to hit $12 billion by 2027.

What experts say about aspartame:

In 2017, researchers published in the journal Nutritional Neuroscience a study linking aspartame to behavioural and cognitive problems including learning problems, headache, seizure, migraines, irritable moods, anxiety, depression, and insomnia. There’s also some evidence suggesting negative impact of aspartame on weight management, and potential risk for preterm delivery and certain cancers.

Mannitol
Type: Natural
Sweetness vs. sugar: 0.50

What is it?

Mannitol, also known as ‘manna’ sugar, is a colourless, sweet substance. The natural sweetener is produced by plants, and are found in fresh mushrooms, brown algae, tree bark and most fruits and vegetables. It is produced for use in chocolate coatings, confections and chewing gum.

While mannitol is made from fructose and hydrogen, it can also be produced artificially as a low-calorie sweetener. As a medication, it is used to decrease pressure in the eyes, as in glaucoma, and to lower increased intracranial pressure. Medically, it is given by injection. The Mannitol market was estimated at $267 million in 2019, estimated to reach $339 million in 2025.

What experts say about mannitol:

Mannitol is used both as a sweetener and medication. It is also used to prevent or treat kidney failure. As a diuretic, mannitol can help reduce pressure and swelling around the brain and in the eyes. It can be filtered through the kidneys but not reabsorbed into them, creating osmotic pressure that restores a healthy flow of blood through the kidneys. Israeli scientists are studying mannitol to treat Parkinson’s in a randomised, controlled Phase 2a clinical study (trial code NCT03823638).

Sorbitol
Type: Natural
Sweetness vs. sugar: 0.60

What is it?

Sorbitol is a type of carbohydrate called a sugar alcohol, or polyol, a water-soluble compound. It contains about one-third fewer calories than sugar and is 60% as sweet. Sorbitol occurs naturally in a variety of berries and fruits (apples and blackberries). It is also commercially produced and is the most commonly used polyol in the US.

What experts say about sorbitol:

Studies on sorbitol metabolism date back as far as the 1920s, when researchers began testing sorbitol as a potential carbohydrate substitute in people with diabetes. Sorbitol’s safety has been reviewed and confirmed by health authorities around the world. When eaten in excessive amounts, however, sorbitol may cause gastrointestinal discomfort, including gas, bloating and diarrhoea. Sorbitol is commercially produced to help reduce calories from sugars in baked goods, chocolates, frozen desserts, hard candies, sugar-free chewing gum and snack bars. The FDA requires a label regarding its potential laxative effects.

Maltose
Type: Natural
Sweetness vs. sugar: 0.33 to 0.45

What is it?

Maltose is honey’s less sweet cousin. It is a natural sweeter made out of two glucose molecules bound together.

Maltose or malt sugar is the least common disaccharide derived from hydrolysis by enzymes (α-amylase and β-amylase, from the amylose homologous series) of starch found in nature. Maltose is used in many foods and beverages you likely know and possibly like. Malt sugar or maltose (also known as maltobiose) is a product of the hydrolysis of starch (from germinating grains), catalysed by the enzyme amylase. Maltose is less sweet than sugar (55% less) and is soluble in water.

What experts say:

Maltose has high fiber and iron content as well as some proteins, and contains no fructose and is used as a substitute for high-fructose corn syrup. Since ancient times, the Chinese used maltose as a light medicinal treatment for better digestion and a healthier immune system even to this day. Maltose is an intermediate in the intestinal digestion (i.e., hydrolysis) of glycogen and starch. When added to foods like candies, maltose can work as a preservative, increasing their shelf life.


Erythritol
Type: Natural
Sweetness vs. sugar: 0.70

What is it?

Erythritol is an organic compound in the form of white crystal granules. As a sugar substitute, this naturally-occurring substance contains almost no calories, and doesn't raise blood sugar or insulin levels. While sugar has 4 calories per gram, erythritol has zero. It is also made when cheese ferment. Besides its natural form, erythritol has also been a man-made sweetener since 1990. Erythritol has 70% of the sweetness of sugar.

What experts say about erythritol:

After studies on erythritol in animals and humans, the WHO approved erythritol in 1999, and the FDA did the same in 2001. Erythritol side effects typically include digestive problems and diarrhoea. It may also cause bloating, cramps, and gas. Nausea and headaches may occur as well. Healthline reported that since erythritol does not raise blood sugar levels, this makes it an excellent sugar replacement for diabetics.

Sucralose
Type: Artificial (synthetic)
Sweetness vs. sugar: up to 700 times

What is it?

Sucralose is a zero-calorie artificial sweetener. It has no bitter aftertaste, and is commonly used in both cooking and baking. It’s added to thousands of food products worldwide, with a market seen rising to $6.15 billion by 2027, one estimate shows. Sucralose is a by-product of sugar following a multi-step chemical process in which three hydrogen-oxygen groups are replaced with chlorine atoms.

What experts say about sucralose:

Authorities claim that sucralose is safe to eat, some studies have linked it to health problems. One small study in 17 people with severe obesity who didn’t regularly consume these sweeteners reported that sucralose elevated blood sugar levels by 14% and insulin levels by 20%. Sucralose is considered to be heat resistant and good for cooking and baking, though recent studies have challenged this. At high temperatures, sucralose starts to break down and interact with other ingredients. Another study found that heating sucralose with glycerol, a compound found in fat molecules, produced harmful substances called chloropropanols, which may raise cancer risk. One rat study found that sucralose may have negative effects on gut bacteria. After 12 weeks, rats that consumed it had 47–80% fewer anaerobes (bacteria that don’t require oxygen) in their guts, while beneficial bacteria like bifidobacteria and lactic acid bacteria were significantly reduced, even as more harmful bacteria seemed to be less affected. More studies are needed.

Tagatose
Type: Natural
Sweetness vs. sugar: 1.90

What is it?

In terms of chemical structure, tagatose is very similar to fructose and is a popular low-carbohydrate sweetener. It is used in chewing gum, and can be extracted from lactose (milk sugar), though the end product contains no further traces of lactose.

It is also found in some fruits (apples, oranges, and pineapple) and sterilised milk at levels ranging from 1 to 3.5 g/kg. Tagatose, a crystalline ketohexose sugar is also known as D-Tagatose, or D-tag — about 90% sweeter than table sugar (sucrose). It is also found naturally in the D-form gum from Sterculia setigera (an evergreen tree) endemic in Western Africa. Tagatose, though a monosaccharide similar in sweetness and physical bulk to sugar (sucrose), is metabolised like other high-intensity sweeteners.

What experts say:

Tagatose is claimed to be prebiotic, as it influences intestinal flora not only in animals but also in humans. Lactic acid bacteria and related organisms increased and pathogenic bacteria decreased. Studies show tagatose is non-cariogenic, so it is seen as suitable to directly replace sucrose or monosaccharides in chocolate, fondant, fudge, caramel and chewing gum, beverages, especially low-calorie soft drinks.

A 2002 study proposed the use of tagatose in pharmaceuticals — for lozenges, syrups and effervescent and chewable tablets. In the US, tagatose has GRAS (generally accepted as safe) status. Australia, New Zealand and South Korea permit tagatose as a food or novel food. The EU allowed tagatose as a novel food ingredient in 2005.

Finally, long-term use of sugar substitutes are not advised by doctors and scientists, so tread carefully.