Apart from artificial sweeteners, there are a few natural products with similar properties - they produce an intense sweet taste without carbohydrates and calories. The following are generally safe for consumption:
The main sweetener used in Japan - including in Coca Cola - is steviol glycoside, an extract from a naturally sweet leaf called stevia. Stevia has a long history of safe usage in herbal medicine in Asia and Central and South America. Scientific studies show that it has negligible effects on blood glucose levels and may even help glucose tolerance. It is thus potentially beneficial to people with diabetes.
Despite its safe record, stevia and steviol glycosides are banned or partially banned in several countries - not because it is known to be harmful but merely because it is "not known to be safe". Some people thus feel that the ban is politically motivated, to protect the interests of big companies that manufacture aspartame.
In the US, stevia is allowed to be sold as a food supplement, but steviol glycoside is banned as additives in food manufacturing - which is ironical since food supplements are supposed to be healthy. The European Union has only just approved the use of steviol glycoside in food manufacturing as of December 2011. Singapore previously banned stevia but in 2005 approved steviol glycoside for sweetening certain food products.
Stevia is now marketed under Equal®, the same brand as aspartame.
Luo Han Guo (Monk Fruit)
Also known as Buddha fruit or monk fruit, luo han guo is a palm-sized fruit whose extract is 300 times as sweet as sugar. The fruit is normally used dried. Fresh fruits can be eaten but they rot easily and produce an unpleasant smell.
The Chinese have long used luo han guo to prepare "cooling" herbal teas, which they would drink in hot weather and when they have "heaty" symptoms such as sore throat, dry cough and a feeling of "internal body heat". It is also used in traditional Chinese medicine to treat diabetes and obesity.
The fruit contains about 25 to 38 percent carbohydrates, including glucose and fructose. However, its intense sweetness comes from a class of phytonutrients called mogrosides. There have been no reports of toxic effects associated with luo han guo.
However, it has traces of bitter and astringent flavours and this limits its usage to sweetening drinks and soups. One or half a dried fruit is enough to sweeten a large pot of tea. The US company Proctor & Gamble has developed a version of luo han guo without its "interfering aromas", using solvents to remove the other aromas. It is not the same as the dried fruit and the long term safety of processed luo han guo is yet unknown.
Xylitol is a sugar alcohol that can be extracted from various plant products, including berries, mushroom, corn husks, sugar cane pulp and birch wood. Xylitol is about as sweet as regular sugar (sucrose) but contains only two-thirds the number of calories. It has a very low glycemic load (GL) - seven teaspoons of xylitol has the same GL as one teaspoon of sucrose. Xylitol thus will not have a big impact on blood glucose levels, making it suitable for people with diabetes. One drawback of xylitol, however, is that it is costly and hard to find.
Many chewing gums proclaim "Xylitol" on the labels. But if you read the ingredients list, you will see that it merely contains a bit of xylitol and the main sweetening agent is the artificial sweetener, aspartame. In any case, it is not a good idea to chew gum as the act of chewing sends false signals to the body, to indicate that you are "eating".
This content is adapted, with permission, from Book 1 of 2 : The Wonders of Nutrition by Dr Ang Poon Liat. MBBS, M.MED (PAED), MRCP (UK PAED), FAMS, MD.