Today we’re going to talk about the sugar substitutes – after having recently dealt with the subject of hidden sugar. What are sugar substitutes, what’s involved and how should we handle them? We can distinguish between: pseudo-sugars, natural sugar substitutes and sweeteners.
Pseudo-sugars are things like: fructose, corn syrup, honey, maple syrup, agave nectar and date sugar. They are called fake sugar substitutes because they also contain sugar. Sugar substitutes are compounds which are said to have a lower or similar sweetening power compared to household sugar. They contain fewer calories and are said to have less influence on the blood sugar level. Sugar substitutes are polyols in the narrower sense, socalled sugar alcohols. Some of the substitutes are: erythritol, xylitol, sorbitol, mannitol, isomaltose, maltitol, maltitol syrup and lactitol.
Erythritol (E968) is often used in the food industry as it is apparently more easily digested than other sugar alcohols. Around 90% of the Erythritol is absorbed through the small intestine and then excreted again with the urine – almost unchanged. However, if more than 1g per 1 kg body weight is ingested it can lead to abdominal pain, diarrhoea and flatulence. There are small amounts of it in some types of fruit, fungi and fermented foodstuffs. The sugar substitute is generally obtained through a fermentation process. Saccharose is transformed into erythritol with the help of yeasts and fungi. Erythritol has a sweetening power of 70 %, tastes mildly sweet and leaves a cool sensation in the mouth. That is the reason why it is used in the manufacturing of chewing gum and sweets, above all. But erythritol can also be used for baking or to sweeten hot drinks. It doesn’t dissolve so well in cold drinks. With a glycaemic index of zero, erythritol has no influence on the blood sugar level and is metabolised independently of insulin. Therefore, this sugar substitute is suitable for diabetics. It is also a good alternative for fructose intolerance, as it does not affect glycogen metabolism. A further advantage is that the sugar substitute is not supposed to promote caries.
Xylitol (E967), sometimes called birch sugar, is a sugar alcohol, which can be found in small amounts in some types of vegetables and fruits. Likewise, it can also be found in the bark of certain types of trees e.g. birch or beech. It is obtained from xylanes (vegetable polysaccharide) in technically complex processes. We find these in hardwoods, straw, cereal bran and corncob residues. Birch sugar is a more expensive sugar substitute due to the complex technological processes. Xylitol is similar to household sugar with a sweetening power of 100%. It is used as a table sweetener or in the production of chewing gums and sweets. Xylitol can be used in calorie-reduced products as a sugar substitute, since xylitol, with approx. 240 kilocalories per 100 grams, has about 40 % fewer calories than sucrose (400 kcal per 100 g). It is also suitable for diabetics, as the blood sugar level rises less after eating foods and drinks sweetened with xylitol. An additional plus point is that xylitol is said to help maintain tooth mineralization. It is generally easily digested but can have a laxative effect in the initial phase of conversion from household sugar – especially in larger quantities. Xylitol is not only suitable for baking and making jam, but is also used to sweeten food and drinks.
Sorbit (E420) was originally obtained from the fruits of the rowanberry, which contain up to 12 % sorbitol. However, we also find it in pomaceous fruits such as pears, plums, peaches, apricots and apples. In dried fruit the concentration of sorbitol is even higher due to the loss of water. For example, dried apricots contain about 4.6 g/100 g of sorbitol. It is also produced industrially from glucose. The sweetening power of sorbitol is about 40-60% compared to household sugar and provides less energy with 2.4 kcal per gram. The body does not use insulin to break down sorbitol and therefore it is suitable for sweetening foods for diabetics. Sorbitol is used as a moisturizer in the production of chewing-gum, cakes and chocolate-fillings. Also used in cosmetics and toothpaste, sorbitol protects against dehydration. It is authorised for use in almost all foodstuffs in any desired quantity – with the exception of drinks. But, if you consume more than 50g per day, it can lead to flatulence, abdominal pain and diarrhoea. These symptoms can also occur in case of intolerance because the utilization of sorbitol in the small intestine is completely or partially suspended.
Mannitol (E421), is also a sugar substitute and is found in algae, fungi, figs and olives as well as in the juice of the manna ash tree. Since mannitol is relatively expensive, it is only used as a sugar substitute to a limited extent. Mannitol is also used as an auxiliary and medicinal substance in the pharmaceutical industry.
Isomalt (E953) is produced from two substances that chemically belong to the sugar alcohols. Its sweetening power is about half that of household sugar. No insulin is required for its utilisation and at around 2.4 kcal/g the energy content is also slightly lower than that of sugar. The substitute is acid and heat stable. It can be easily combined with other sweeteners and sugar substitutes and is often used in energy-reduced foods. Isomalt is mainly found in sugar-free desserts, ice cream, sweets and chewing gum, in sauces, mustard and food supplements. It is also used as a carrier for vitamins and flavours.
Maltitol (E965) is produced from corn and wheat starch and has up to 90% of the sweetening power of household sugar. It is used in the production of sugar-reduced desserts and confectionery. As with the other substitutes, it can have a laxative effect and cause flatulence from a daily amount of 30-50 grams.
Lactitol (E966) is mainly used for the food of diabetics. However, since it has only a sweetening power of about 30-40%, we seldom find foods containing this sugar substitute. However, lactitol has a relatively strong laxative effect and is therefore often used therapeutically for the symptomatic treatment of constipation.
Sweeteners are the next category of sugar substitutes. In these sugar alternatives, a distinction is made between synthetic and natural sugar alternatives. Sweeteners are generally prohibited for baby food and organic products.
Among the synthetic alternatives are sweeteners such as aspartame, cyclamate or saccharin. They have a higher sweetening power than household sugar, contain no or only a few calories and do not raise the blood sugar level. They contain no carbohydrates and are therefore often used in low-carb recipes or even in "light" products. They are also not supposed to cause caries. However, there is evidence that sweeteners cause the release of insulin, which is then responsible for storing fat in the body. Studies also show that sweeteners can stimulate the appetite, arouse cravings for sweets and thus cause weight gain in the long term.
Aspartame (E951) has been approved in Germany since the 1990s and is frequently found in sweet beverages. It consists of the two amino acids L-aspartic acid and L-phenylalanine and contains 4 calories per gram. It is slightly sweeter than the same amount of sugar due to its high sweetening power. Aspartame is not suitable for cooking and baking as it loses its sweetening power when exposed to heat for a long time. All products sweetened with aspartame must bear the words "contains phenylalanine" on the label as a warning to persons suffering from the metabolic disease phenylketonuria.
Cyclamate (E952) has been approved in Germany since 1963. It has the lowest sweetening power of the sweeteners approved in the EU, but is said to be 35 times sweeter than sugar and to have a taste close to sugar. Cyclamate is heat-resistant and therefore also suitable for cooking and baking. However, cyclamate is suspected of being carcinogenic and has been banned in the USA since 1970. In Europe, it is permitted with a maximum quantity limit for energy-reduced and sugar-free drinks, desserts, spreads such as jams, marmalades or jellies and canned fruit. Cyclamate may no longer be used for ice cream, sweets and chewing gum.
Saccharin (E954) is the oldest synthetic sweetener and was discovered in the USA in 1878. It is said to be 300-700 times sweeter than sugar and can cause a bitter or metallic aftertaste, especially in higher concentrations. Saccharin is stable when heated as well as when using acids and does not react chemically with other substances. It can also be stored well. Saccharin is colourless, does not cause caries and is quickly absorbed by the body and excreted unchanged with the urine.
Stevia (E960) is a natural sweetener. The plant "Stevia Rebaudiana", or Stevia for short, originated in Paraguay and is now cultivated in many areas of South and Central America, Israel, Thailand and China. People from Paraguay and Brazil are said to use Stevia not only as a sweetener but also as a medicine to lower blood pressure. Stevia can be a good alternative as a sugar substitute for diabetics and for neurodermatitis sufferers. It is free of calories and, with a glycemic index of zero, has no effect on blood sugar and insulin levels. It can also be used in instances of fructose intolerance. In Germany it has been approved as a sweetener that is harmless to health since December 2, 2011. Stevia is 300 times sweeter than sugar. It can be used as powder, tablets or liquid in cooking and baking. The industry also uses Stevia for the production of sugar-free beverages and sweets such as chocolate and jam. However, Stevia is not approved by the EU for the production of cookies and pastries.
How should we deal with sugar substitutes?
According to a recent study, no final recommendation for or against sugar substitutes can be given yet. For diabetics and overweight people, substitutes can be helpful, but from a health point of view it is advisable to consume only small amounts of sugar or of these.
Mechthild Maiss /Katharina Stang