El lado amargo de los edulcorantes artificiales.

...

Artificial sugar substitutes are usually calorie-free and they have high sweetening power -at least 30 times sweeter than table sugar- (Edwards et al., 2016). Currently, there are 6 artificial NNS are approved by the Food and Drug Administration (FDA) of the United States: acesulfame k (acesulfame potassium), aspartame, saccharin, sucralose, and most recently Neotame and advantame (American Dietetic Association, 2004). This is the group that arouses the greater interest in research, since it has been vital to demonstrate their safety and provide reliable data on the possible therapeutic effects in patients with diabetes or other specific health problems (Clifford & Maloney, 2016).

The first mass-distributed artificial sweetener was saccharin (Shankar, Ahuja, & Sriram, 2013). Its consumption was banned in in 1902 and 1910 in France and in the United States respectively because of its lack of nutritional value (American Dietetic Association, 2004). However, with sugar rationing during World War I, the authorities allowed the use of saccharin as a substitute for sugar, and its use was boosted in the food industry from 1950 (Shankar, Ahuja, & Sriram, 2013). When other sweeteners appeared it was suggested that saccharin could produce carcinogenic effects, therefore in 1977, USA and Canada banned its consumption, a measure that was lifted 20 years later because only bladder cancer was observed in male rats that ingest a very high amount of this substance throughout their life, which lead to conclude that there was a "lack of evidence to question its innocuousness" (American Dietetic Association, 2004). From this, the Acceptable Daily Intake (ADI) for saccharin was set at 2.5 mg/kg (Shankar, Ahuja, & Sriram, 2013).

Another of the most commonly used synthetic sweeteners is aspartame, discovered by James Slatter in 1965 (Shankar, Ahuja, & Sriram, 2013). This product was initially approved by the FDA in 1980, with some restrictions, which were annulled in 1986, leaving the product free of restraints for registration and sale. Aspartame is a constituent of more than 6000 products, and it’s approved in more than 90 countries, including the U.S. where is considered as GRAS with an ADI of 40-50 mg/kg/day (Clifford & Maloney, 2016). Regarding safety studies, it has been proved that administration of high doses produces changes in some biochemical parameters, including amino acid levels in plasma and neurotransmitters in the central nervous system, but safety studies in mice, rats, guinea pigs, dogs and humans, including infants, children, adolescents, lactating women and healthy adults, as well as individuals of these ages and conditions with obesity and diabetes, have not shown acute, subacute or chronic adverse effects or changes in body physiology even at doses as high as 4000 mg/kg/day (Shankar, Ahuja, & Sriram, 2013). Therefore it is considered that consumption of aspartame is safe in individuals of any age and its use as a non-caloric sweetener is acceptable, except for phenylketonuric patients.

One of the most recently introduced sweetening products is acesulfame potassium (K), which was discovered by K. Klauss in 1967 and approved by the FDA in 2001 (Clifford & Maloney, 2016). Currently, this additive is used in more than 4000 foods and beverages in approximately 90 countries around the world. Toxicity problems derived from acesulfame K are unknown (Shankar, Ahuja, & Sriram, 2013).

Finally, another synthetic sweetener widely used worldwide is the sucralose (obtained by chlorination of sucrose) which was discovered in 1976, approved by the FDA in 1988 and by the European Commission in 2002 (Clifford & Maloney, 2016). It would be thought that being bound to chlorine molecules could be harmful to health. However, research has concluded that the consumption of chlorine when consuming sucralose is lower than that observed when taking chlorinated drinking water, lettuce, tomatoes, mushrooms, melon, peanut butter and table salt (Edwards et al., 2016). Sucralose is 600 times sweeter than sugar so the maximum daily intake observed is 1 mg/kg/day (Davies, 2010). Studies of safety and efficacy for sucralose in humans, infants, children, adults, pregnant women, lactating women, and diabetics or obese people, have shown that the daily intake of sucralose three times the maximum dose for three months does not produce adverse metabolic reactions, do not cause bioaccumulation, does not cause carcinogenesis, has no effect on fetal or neonatal development, is not actively transported from the mammary gland to the milk and does not cause neurotoxicity because it does not cross the blood-brain barrier (Shankar, Ahuja, & Sriram, 2013). Therefore, its use has been approved in more than 80 countries and is used in more than 4,000 products worldwide, without any warning about nutritional safety in foods and beverages containing it.

The properties of sweeteners vary considerably, factors such as quality and type of sweetness can vary significantly between them. Sugar is described as a sweetener with a “clean” taste that keeps a slight sweetness sensation (Clifford & Maloney, 2016). However, for NNS taste is defined differently, for example, thaumatin has a sweet aftertaste and others such as saccharin or stevia have a bitter one. These differences create guidelines for the specific application that each individual sweetener can serve for. Sugar is in fact hard to replace, besides being a nutritive sweetener, sugar provides other attributes to products such as flavor, texture/structure, crystallization, hydration, solubility, low hygroscopicity, freezing point depression, osmotic effects, and thermal and acid stability. The relative importance of these remarkable features of sugar differs depending on the category of food or drink (Davies, 2010). Usually NNS can’t directly replace sugar in food manufacturing processes, except for diet soda, even though in some cases their technical characteristics can be improved by adding soluble filler agents (polyols in particular), thickeners, gelling agents or preservatives. In fact, following to Sylvetsky & Rother (2016), NNS are now found in several products such as condiments, bakery products (bread and granola bars), dairy products (flavored milk, sugar-free yogurts, no-sugar added ice cream), and even medications and hygiene products (mouthwash and toothpaste). Therefore, it is undeniable that NNS are today one of the most dynamic areas in the field of food additives, given the great expansion that the market for low-calorie or diabetic foods has experienced in recent years (Davies, 2010).

At a consumer level, in a quest for low-calorie products the interest in these products has increased considerably. According to recent figures published in the Calorie Control