Sucralose is an artificial sweetener known by the trade name Splenda and "Altern." In the European Union, it is also known under the E number (additive code) E955. It is 320–1,000 times as sweet as sucrose, making it roughly twice as sweet as saccharin and four times as sweet as aspartame. It is manufactured by the selective chlorination of sucrose, by which three of sucrose's hydroxyl groups are substituted with chlorine atoms to produce 1,6-dichloro-1,6-dideoxy-β-D-fructo-furanosyl 4-chloro-4-deoxy-α-D-galactopyranoside or C12H19Cl3O8. Unlike aspartame, it is stable under heat and over a broad range of pH conditions, and can be used in baking, or in products that require a longer shelf life.
Sucralose was discovered in 1976 by scientists from Tate & Lyle, working with researchers at Queen Elizabeth College (now part of King's College London). It was discovered by Leslie Hough and a young Indian chemist, Shashikant Phadnis. The duo were trying to test chlorinated sugars as chemical intermediates. On a late-summer day, Phadnis was told to test the powder. Phadnis thought that Hough asked him to taste it; so he did. He found the compound to be exceptionally sweet (the final formula was 600 times sweeter than sugar). They worked with Tate & Lyle for a year before settling down on the final formula.
It was first approved for use in Canada (marketed as Splenda) in 1991. Subsequent approvals came in Australia in 1993, in New Zealand in 1996, in the United States in 1998, and in the European Union in 2004. As of 2006, it had been approved in over 60 countries, including Brazil, China, India and Japan.
Tate & Lyle manufactures sucralose at a plant in McIntosh, Alabama, with additional capacity under construction in Jurong, Singapore. It is used in products such as candy, breakfast bars and soft drinks. Sucralose mixed with maltodextrin and dextrose (both made from corn) as a bulking agent is sold internationally by McNeil Nutritionals under the Splenda brand name. In the United States and Canada, this blend is increasingly found in restaurants in yellow packets, in contrast to the pink packets commonly used by saccharin sweeteners and the blue packets used by those containing aspartame; though in Canada yellow packets are also associated with the SugarTwin brand of cyclamate sweetener.
Though marketed in the U.S. as a “No calorie sweetener,” Splenda contains 96 calories per cup. This is one eighth the 770 calories in the same volume of sugar.
Note too that although the “nutritional facts” label on Splenda’s retail packaging state that a single serving (1 teaspoon = 0.5 g) contains zero calories, Splenda actually contains two calories per teaspoon. Such labeling is appropriate in the U.S. because the FDA’s regulations permit a product to be labeled as “zero calories” if the “food contains less than 5 calories per reference amount customarily consumed and per labeled serving.” Because Splenda contains a relatively small amount of sucralose (it’s an extremely sweet compound) and little of that is metabolized anyway since sucralose is a chlorocarbon, virtually all of Splenda’s caloric content derives from the highly fluffed dextrose and/or maltodextrin bulking agent, or carrier, that gives Splenda its volume. Like other carbohydrates, dextrose and maltodextrin have 4 calories per gram.
Most products that contain sucralose add bulking agents and additional sweetener to bring the product to the approximate volume and texture of an equivalent amount of sugar. This is because sucralose is nearly 600 times sweeter than sucrose (table sugar). Pure sucralose is sold in bulk, but not in quantities suitable for individual use. Pure dry sucralose undergoes some decomposition at elevated temperatures. When it is in solution or blended with maltodextrin it is slightly more stable.
Sucralose can be found in more than 4,500 food and beverage products. Sucralose is used as a replacement of, or in combination with other artificial sweeteners such as aspartame, acesulfame potassium or high-fructose corn syrup.
Sucralose is the most heat stable artificial sweetener available, allowing it to be used in many recipes without any use of sugar. Sucralose is available in granulated form so as to measure cup for cup like sugar.
Sucralose has been accepted by several national and international food safety regulatory bodies, including the U.S. Food and Drug Administration (FDA), Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives, The European Union's Scientific Committee on Food, Health Protection Branch of Health and Welfare Canada and Food Standards Australia-New Zealand (FSANZ). The acceptable daily intake for sucralose is 9 mg/kg of body weight per day.
“In determining the safety of sucralose, the FDA reviewed data from more than 110 studies in humans and animals. Many of the studies were designed to identify possible toxic effects including carcinogenic, reproductive and neurological effects. No such effects were found, and FDA's approval is based on the finding that sucralose is safe for human consumption.”
Concerns have also been raised about the effect of sucralose on the thymus gland, a gland that is important to the immune system. A report from NICNAS cites two studies on rats, both of which found "a significant decrease in mean thymus weight" at a certain dose. The sucralose dosages which caused the thymus gland effects referenced in the NICNAS report was 3000 mg/kg bw/day for 28 days. For an 80 kg (176 lb) human, this would mean a 28-day intake of 240 grams of sucralose, which is equivalent to more than 20000 individual Splenda packets/day for approximately one month. The dose required to provoke any immunological response was 750 mg/kg bw/day, or 60 grams of sucralose per day, which is more than 5000 Splenda packets/day (there are 11.9 mg of sucralose in a 1g retail packet of Splenda). These and other studies were considered by regulators before concluding that sucralose was safe. However, because some ingested sucralose is broken down and absorbed by the body there is concern that chronic consumption may lead to thymus shrinkage or other side-effects.
Chlorine atoms are covalently bonded to the carbon atoms in the sucralose molecule, making it a chlorocarbon. Many chlorocarbons are toxic; however, sucralose is unlike these chemicals because it is extremely insoluble in fat and does not accumulate in fat like most chlorinated hydrocarbons. In addition, sucralose does not break down or dechlorinate.
The bulk of sucralose ingested does not leave the gastrointestinal tract and is directly excreted in the feces while 11-27% of it is absorbed. The amount that is absorbed from the GI tract is largely removed from the blood stream by the kidneys and excreted in the urine with 20-30% of the absorbed sucralose being metabolized. Sucralose is digestible by a number of microorganisms and is broken down once released into the environment.
Critics of sucralose often favor natural alternatives, including xylitol (birch sugar widely used during World War II and in sugar-free chewing gum in Finland), maltitol, thaumatin, isomalt (popular in some European countries), and Stevia, which is widely used in Japan (in the U.S., it may be sold as a dietary supplement but not as a food additive). Stevia is controversial, however. The United States' FDA has not approved it as a food additive because of toxicity concerns. Xylitol and other sugar alcohols are non-toxic, but can only be consumed with careful restriction of quantity because of their laxative effects when the body's daily threshold has been reached.
Splenda usually contains 95% dextrose (an alternate name for glucose), which the body readily metabolizes. The safety information that many specialists and the media give to consumers is that Splenda is safe to ingest as a diabetic sugar substitute "free of problems".
The U.S. sugar industry has claimed that the advertising of Splenda is deceptive and has filed a formal complaint with the Federal Trade Commission. Taking issue with Splenda's advertising slogan “made from sugar so it tastes like sugar,” the Sugar Association states that: "Splenda is not a natural product. It is not cultivated or grown and it does not occur in nature." McNeil Nutritionals, the manufacturer of Splenda, has responded that its "advertising represents the products in an accurate and informative manner and complies with applicable advertising rules in the countries where Splenda brand products are marketed." The consumer advocacy group Citizens for Health has filed a petition with the FDA. They have asked the FDA to withdraw its approval of Splenda pending additional investigation of claimed side effects such as stomach pain and other digestion problems. The U.S. Sugar Association has also started a web site where they put forward their criticism of sucralose. The Sugar Association’s health-related concerns revolve around three essential points:
1. Sucralose is a chlorocarbon
2. Up to 27% of sucralose that is ingested is absorbed into the body by the digestive system
3. Long-term human studies with sucralose have not been performed.
The world's largest retailer of natural and organic foods (Whole Foods Market), made an official policy statement of not carrying products containing sucralose in any of its outlets. The retailer’s health-related concerns revolved around five essential points:
1. Sucralose is an artificial substance, some of which is absorbed by the body
2. Pre-approval tests indicated a potential for toxicity
3. Sucralose is a chlorinated compound (a chlorocarbon)
4. Independent, controlled human studies had not been performed
5. Long-term human studies with sucralose had not been performed.