The truth about artificial sweeteners

Depending on who you talk to, artificial sweeteners are a useful alternative to sugar or a chemical minefield. So what are the facts?

Food is sweetened using a wide variety of ingredients, including sucrose (cane sugar), fructose (fruit sugar), lactose (milk sugar), glucose, honey, brown sugar, icing sugar, raw sugar and sweet syrups (maple, golden). These sweeteners all have an energy value (17kJ per gram).

‘Artificial sweeteners’ should really be called ‘alternative sweeteners’ as many of the latest types are not artificial but made from sugars that have been altered.

Alternative sweeteners provide a sweet taste with few or no kilojoules so are often added to food and beverages. Often these sweeteners have a very intense sweetness, which results in very small amounts being used in food.

NZ Food Safety

Food Standards Australia New Zealand (FSANZ) undertakes safety assessments before any food additive can be used. It checks the safety of the additive at the levels requested to be permitted in a food and that there are good reasons for the use of the additive.

As part of the safety assessment, the likely level of consumption of the additive for different groups of people if the additive were permitted is looked at. This is then compared to the acceptable daily intake. If it is well within safe limits, FSANZ then defines the maximum level of the additive that can be used in particular foods. Aspartame and sucralose are the only sweeteners recommended during pregnancy.

For more information on the Food Standards Code and the food additives permitted in New Zealand, go to the Food Safety website.

What about Stevia?

Stevia is a sweetener extracted from the leaves of the Stevia rebaudiana Bertoni plant. Stevia has been used for centuries in Argentina, Brazil and Paraguay to sweeten foods and drinks and is widely cultivated in Asia. While fresh leaves are reported to be 15-20 times sweeter than sugar, extracts from the leaves can be up to 300 times sweeter.

In New Zealand stevia may be sold as a dietary supplement but is not approved for use as a food additive. The key issue is the relatively limited research data about stevia.

The Food and Agriculture Organisation/World Health Organisation (FAO/WHO) Joint Expert Committee on Food Additives (JECFA) met in 2004 to review the scientific evidence about the safety of stevia. One of the problems they highlighted was there are not common specifications for the stevia that is traded. In other words, the amount of active constituents in stevia can vary. They also said more information was needed about the metabolism and pharmacological effects of stevioside (a major constituent of stevia) in people.

An application to Food Standards Australia New Zealand (FSANZ) is under consideration to permit the use of Steviol Glycoside (leaf extract) as a food additive in New Zealand.

Sugar alcohols

Sugar alcohols include mannitol, sorbitol, isomalt and xylitol. They are used as sweeteners in products like chewing gums, sweets, chocolate bars and mints.

Unlike sugar, the sugar alcohols have either a low or no ‘cariogenic effect’, that is they don’t cause dental caries. (Dental caries is an infectious disease which damages the structures of teeth. Tooth decay or cavities are consequences of caries.) 

Sugar alcohols are found naturally in many fruits and vegetables but are commercially produced from carbohydrates like glucose, sucrose and starch.

During the recent low-carb diet trend, sugar alcohols were added to many foods to lower their total carbohydrate content yet still provide a sweet taste.

Sugar alcohols do contain energy (between 32-64kJ compared to sugar at 70kJ per teaspoon) but they are absorbed more slowly and have little or no effect on blood glucose levels. They have little advantage for weight loss, so check the kilojoule content of any ‘no sugar added’ products.

Acceptable daily intake

The acceptable daily intake (ADI)* is an estimate of the amount that could be consumed every day over a lifetime without adverse effects. It’s worth noting that the ADI is set at a very conservative level. And usual intake is well below the acceptable daily intake.

* These volumes are related to the safety of the sweetener and do not imply that such large daily volumes of carbonated drinks are appropriate in a balanced diet. 

Benefits of alternative sweeteners

Alternative sweeteners are useful to help people satisfy a desire for sweet foods or the sweet taste without the extra kilojoules. There is no evidence to suggest using alternative sweeteners creates a sweet tooth or promotes a greater intake of sweet foods.

Eating chewing gums and sweets with low- or no-kilojoule alternative sweeteners between meals is also kinder to teeth.

Diet cordials and fizzy drinks have a much lower energy value than the sweetened original, making them useful for those wishing to limit sugar in their diet. Of course, it is worth remembering that water is the most economical non-sweetened beverage available.

You can have too much

High intakes of sugar alcohols are known to have a laxative effect and in some cases can cause diarrhoea. Excessive intake of sweets, mints or gum with other alternative sweeteners can cause gastrointestinal discomfort such as bloating, increased wind or diarrhoea.

While acknowledging they play a useful role, Diabetes New Zealand advises against using large amounts of alternative sweeteners. Regular users are advised to vary the sweetener used to avoid excessive intake of any one.

Inappropriate use

If you are using moderate amounts of alternative sweeteners then you can be assured they are safe, but it is unwise to consume excessive amounts or misuse products containing these sweeteners.

Eating disorders

People who suffer from disordered eating sometimes consume large amounts of diet products to lower their energy intake or provide bulk in the diet without energy. Typical foods include diet cordials and sodas, low sugar or no sugar chewing gums, diet jams, diet jelly and diet desserts. I have known young girls with eating disorders to drink up to 12 cans of diet soda a day to buffer the effects of hunger. Fortunately this sort of behaviour is rare.

High intake in children

Young people who have large intakes of diet cordials, diet soda and diet jelly could be at risk of consuming very high levels of alternative sweeteners. These foods should only be used as treats and for special occasions rather than on a regular basis. Because of their smaller size, children should not consume the same amount of these sweeteners as adults.

The diet trap

Some people mistakenly believe the use of alternative sweeteners promotes weight loss. These sweeteners can be effective when replacing the energy content of sugar and sweet foods but they can’t melt away the kilos.

Using an alternative sweetener will not guarantee weight loss or prevent weight gain by itself. Remember ‘sugar-free’ does not translate into ‘eat a larger serving’, ‘have an extra scoop’ or ‘eat as much as you like’. Drinking diet cordials and sodas while eating a candy or chocolate bar is not going to cancel the other kilojoules out. Using an alternative sweetener may be part of your weight control strategy but physical activity, energy balance, portion control and good food choices are all needed as well.

The bottom line

Alternative sweeteners have their place when used sensibly. They are useful to help satisfy a desire for sweet foods without adding the kilojoules. Used in moderation, alternative sweeteners are safe and effective for reducing the energy value in food and beverages that would otherwise contain sugar.