El lado amargo de los edulcorantes artificiales.

The Bitter Side of Artificial Sweeteners

Mohammed Alnamassi

Southern Illinois University Carbondale

Abstract

Sweet foods have been consumed by man since the beginning of its history and sucrose (table sugar) has been the most consumed natural sweetener and has been indispensable for the food industry due to its important functional properties. However there are public health problems that lead millions of people to limit their consumption: obesity, diabetes, tooth decay and behavioral disorders such as anxiety, frustration, and depression. In recent years biotechnology has introduced low-calorie artificial sweeteners based on chemical components into the world market, which emerged to meet the needs of people with limited sucrose and calorie consumption in their diet. However, the use of artificial sweeteners has been the subject of numerous controversies regarding its long-term safety or excessive use. In this article it was addressed how the patterns of sugar consumption have changed over time, what are the phenomenon that have influenced the man to develop non-nutritive sweeteners, and lastly, if there is evidence of secondary health effects of the most usually consumed non-nutritive sweeteners.

The Bitter Side of Artificial Sweeteners

Currently, the most popular topics of discussion at any social gathering is about health, figure and fitness. In recent years there has been a significant increase in consumer demand for low-calorie products. Consumers around the world have been paying more attention to the sugar content of foods than to any other component. Even though for many years sugar has been present in our diet, we perceive it today, as one of the worst nutrients. This change in perspective has been mainly due to harmful effects of sugar in our body and how it has contributed to the emergence of different and very serious diseases. Natural sweeteners are epidemiologically related to chronic diseases such as type 1 diabetes, cardiovascular disease, obesity, tooth decay (Edwards et al., 2016). On the other hand, several sugar substitutes have been widely evaluated and tested by the industry, among them low-calorie sweeteners appearing as a promising alternative. However, lately these have also been the subject of multiple controversies regarding their long-term safety or overuse. Therefore, in order to provide an accurate and current picture about this problematic, this article attempts to answer: How the patterns of sugar consumption have changed over time? What are the phenomenon that have influenced the man to develop artificial non-nutritive sweeteners? And lastly, is there evidence of secondary health effects of the most usually consumed non-nutritive sweeteners?

Sweeteners are used in foods for several reasons: to give a sweet flavor, to give body to the food, to provide an important caloric contribution, and to act as a preservative (Clifford & Maloney, 2016). The term "sugar" is defined as the sum of all mono and disaccharides and comprises glucose, fructose, lactose, galactose, sucrose and maltose (Edwards, Rossi, Corpe, Butterworth, & Ellis, 2016). Sugars can be found naturally in fruits and dairy, or it may be added by humans. From ancient times mankind has had a marked preference for sweet foods, in fact ADA (2004) states that “people are born liking the sensation of sweetness”. It is widely known that the human body requires glucose as a source of energy required for cellular processes. In earlier times, the exudates of certain trees like manna, were used in the Mediterranean as sweeteners in confectionery preparations because they were rich in mannitol (Keerthi Priya, 2011). The use of the manna was replaced by sucrose or common sugar, natural sweetener par excellence, which is extracted mainly from sugarcane (Sylvetsky & Rother, 2016). Sugarcane cultivation started in Southeast Asia, in India and China near the year 1000 BC (more than 3,000 years). Around the 8th century sugarcane was introduced by the Arabs to Europe, from where was consequently introduced to Central and South America by Spaniards (Fischer, Teixeira, Tothne, & van Velthuizen, 2008). The sweetness from sugar cane was eventually supplied, among others, by sorghum or corn (Parker, Salas, & Nwosu, 2010). Sweeteners derived from corn starch began their appearance in 1910. The slight sweetness of the sugars derived from corn starch, mainly glucose, was therefore referred to as substituting sweeteners (Clifford & Maloney, 2016), which generated restrictions on their use. Between 1960 and 1970 new chemical processes which could convert the glucose in corn starch to fructose were developed, causing the subsequent appearance of the famous high fructose corn syrup (HFCS) (Parker, Salas, & Nwosu, 2010). Basically, until the end of the nineteenth century man had only natural sweeteners such as sugar, honey, glucose, starch derivatives and lactose. However, as new pathways in the production of organic and biological molecules in the field of sucrochemistry were opened, a variety of sugar substitutes and artificial sweeteners were developed, these will be discussed below.

First, it is necessary to clarify how all these sweeteners are classified. There is a huge variety of types of sweeteners as well as classifications, they can be widely classified according to their calorie content (calorie or non-caloric), according to their origin (natural or artificial) or even according to their chemical structure (American Dietetic Association, 2004). In the most common classification, sweeteners are classified as nutritive sweeteners (NS) and non-nutritive sweeteners (NNS). NS provide calories or energy to the diet at a rate of about four calories per gram. They include sucrose sweeteners (e.g. refined sucrose, high fructose corn syrup, crystalline fructose, glucose, dextrose, honey, lactose, maltose, and concentrated fruit juice) (Clifford & Maloney, 2016).

On the other hand, NNS could be defined as food additives that are sweet yet contain considerably a lesser amount of calories than sugar (Clifford & Maloney, 2016). These were developed in the late nineteenth century, when saccharin was discovered by chance in the late 1800′s (Sylvetsky & Rother, 2016), and they may be derived from natural or artificial sources. Among naturally occurring sweeteners, the two most popular are thaumatin, stevia and sugar alcohols (E.g., sorbitol, mannitol, xylitol, isomaltitol, etc.) (Clifford & Maloney, 2016). One of the best known sugar alcohol is the xylitol. This has been known for over 90 years and has been used for a long time as a sweetener for diabetics in various countries in Europe and Asia (Clifford & Maloney, 2016). P. Shankar et al. (2013) state how few chemicals have been investigated as deeply as this in terms of safety for human consumption. This is commercially obtained from birch wood (Betula alba), and it is extensively used in products such as toothpastes and chewing gum, since it’s not fermented in acids by the bacteria present in the mouth and therefore, unlike sucrose, it is not cariogenic (Shankar, Ahuja, & Sriram, 2013). There are no known adverse effects due to its ingestion, but it is known that excessive consumption can lead to laxative effects. Another widely used natural NNS is the thaumatin, which represent a set of proteins (polypeptides) extracted from the pulp surrounding the seeds of a plant native to West Africa (Sierra Leone, Congo, Gabon, Sudan, Zaire and Angola), popularly known as the "Miraculous fruit of Sudan” (Davies, 2010). An interesting fact is that so far the thaumatin is considered the sweetest substance on the planet (1,600 times more than a 10% solution of sucrose).  Thaumatin is listed as GRAS (Generally recognized as safe) by the USDA since 1984 and it has been mainly used in chewing gums (Shankar, Ahuja, & Sriram, 2013). Finally, stevia plant (Stevia rebaundiana) has traditionally been used as a natural sweetener in South America, and for more than 20 years in Japan. As far as safety concerns regarding stevia, no adverse side effects have been described thus far.

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