Safety Assessment of Sugar Substitutes
The acceptable daily intake (ADI) of sweeteners is cautiously evaluated to ensure the safety aspects for human consumption. It is specified as milligrams per kg of the body weight. The Food and Drug Administration is in charge of controlling the acceptable daily intake in the United States. Distinguished organisations including the Joint FAO/WHO Expert Committee on Food Additives, have the international authorisation of ADI.
In 1977, the consumption of saccharin was forbidden in Canada when the animal research reported the increased risk of bladder cancers caused by saccharin precipitation. In the USA the manufacturers were legally obligated to label a warning (that saccharin may develop the risk of cancer in laboratory animal) on the packages of the Saccharin-content products. However, the possibility of the cancer induced by saccharin was ruled out based on the extensive research conducted by the National Institute for Environmental Health Sciences as it was stated that the cancer developing system in rats is quite different from that in human mechanisms. The major evaluation was concerned with the rats metabolism of sodium after saccharin ingestion which was found to be inconclusive as the same symptoms of cancer was diagnosed when animals fed with different sodium salts like sodium citrate.
As a result of the preliminary in vivo research (reported that aspartame can be carcinogenic in rodents, the consumption of this sweetener was banned in the US by the Food and Drug Administration. This was however ruled out by the international experts who noted that aspartame has no cancer-inducing factor and it is safe to be consumed by human. After the ingestion, aspartame is chemically decomposed into smaller components such as aspartic acid and phenylalanine. The latter may be harmful to those suffering phenylketonuria; a genetic disease with insufficient hepatic enzyme known as phenylalanine hydroxylase. The enzyme is able to metabolise phenylalanine. This can lead to the conversion of the accumulated phenylalanine into phenylketone which is detectable in the urine discharge. In this regard, aspartame is required to be clearly specified on the labels that "should not be used by phenylketonuria patients, contains phenylalanine". This specification is a legal obligation in some countries like in the United Kingdom.
Recent studies reported that neotame has no toxic effect and no adverse association with reproduction or offspring development. Researchers also detected no neurotoxic implication of neotame in their investigations. Furthermore, other studies also that neotame is not carcinogenic and it is quickly excreted from the body with no dangerous sedimentation. There is no legal obligation to label a warning or caution on the packages containing neotame. its suitability for everyone including pregnant women and diabetics has been approved.
Sucralose has been internationally approved to be used for human consumption and it has been legally confirmed that it has no contributory factor to cancer diseases. Numerous in vivo studies have found that the significant percentage of the ingested sucralose is unabsorbed in the gastrointestinal (GI) tract and is normally eliminated through the large intestine. Large amount of the absorbed sucralose from the GI tract is taken from the blood by means of kidneys and discharged from the bladder and urine. The remaining absorbed portion of the sucralose goes through the metabolising process. Sucralose has been found to be toxicologically safe and it does not stimulate immunological system. Animal experimentation found the correlation of sucralose intake with lowering the normal weight of thymus. This was considered as an inconclusive evidence due to the fact that animals were fed an extreme overdose of sucralose (750 mg/kg per day).
Cyclamate was forbidden for the food applications in 1969 as a result of the in vivo research; the laboratory animals were fed high quantities of cyclamate and saccharin combination that brought about the development of bladder cancer. At present, cyclamate as a sweetener is legally accepted in food products in over 55 countries including the UK and EU. The commercial products containing cyclamate include the Sweet’N Low products in which a few artificial sweeteners are used. Cyclamate is absent in the US products and saccharin is forbidden in Canada.
Acesulfame potassium (ace-K)
A number of in vivo studies have ruled out the carcinogenic implication of acesulfame potassium since the results from the animal tests demonstrated no relation of this sweetener to the cancer development. Some reports of animal experiments have indicated the ability of ace-K to encourage irregular secretion of insulin in rodents which may lead to a condition of hypoglycemia (a level of too low blood sugar). The application of ace-K in food industry has been approved by the US FDA. It is also legally acceptable in the UK and Europe.
Stevia sweeteners are derived from the leaves of Stevia rebaudiana plants. The sweet flavour of the stevia extract is attributable to the presence of Steviol glycosides; the active ingredients that primarily include rebaudioside and stevioside. The purified rebaudioside A as a favourable compound in the Stevia rebaudiana, contains the lowest degree of bitterness compared to other types of Steviol glycosides. The legal requirements of the stevia extracts are regulated differently in various countries. The ADI of Steviol glycosides to less than 4 mg/Kg body weight per day has been approved by the Joint Expert Committee on Food Additives (JECFA).