Among the countries of South America, Brazil was the first one to develop legislation on functional food, in 1999. The regulation prohibited the use of therapeutic claims and permitted the adoption of claims on the reduction of generic disease risk and on the structure/function of certain foods [14]. Although in Brazil the concept of functional foods has not been defined, rules have been based on the idea that functional food is part of a normal diet (therefore not a drug) and may produce benefits beyond basic nutrition [13]. The Brazilian authority in charge of approving functional properties claims, bioactive substances, and isolated products is the National Health Surveillance Agency (ANVISA).

Chile has a regulation on food claims, which dates back to 2005. All food products must report in their labels the nutritional claim, as set forth by the Food Sanitation Regulation. All medical-type indications are forbidden. The Health Properties Claim must be recognized scientifically, or it must have been agreed globally, and must be part of the Technical Regulations on Nutritional Guidelines approved by the resolution of the Ministry of Health. According to Chile’s regulation, neither the Health Properties in Food Claim nor the Nutritional Properties Claim of a certain food product can include false associations with health benefits. It is also forbidden to induce unnecessary consumption of a product, suggesting the idea of protection against illness [15]. The technical regulation of food claims on health properties reports a list of claims that must be used if a relation between a food product, nutrient or other substance and a health condition has been established. This list contains a definition of the association, the essential characteristics of food, and the required message framework. These associations are under constant revision by health authorities and may be modified depending on scientific progress [16].

In Argentina the definition of Functional Food is analysed by an ad hoc team created in 2009 by the National Food Commission (CONAL, Comisión Nacional de Alimentos). CONAL is a technical institution with the aim to assess, support and monitor the National Food Control System (SNCA, Sistema Nacional de Control de Alimentos). Among CONAL’s activities, there is the monitoring of SNCA members which must enforce Argentina's Food Code in Argentina's territory. Other groups belonging to CONAL made research in the field of probiotics and prebiotics, creating a protocol that establishes the necessary requirements and evaluations to include prebiotics or probiotics in specific food products. Such projects were incorporated to Argentina’s Food Code towards the end of 2011 through the following regulations: Joint resolution SPRel 229/2011, and SAGyP 731/2011, and Joint Resolution SPRel 261/2011, and SAGyP 22/2011. Within this framework, any representation that expresses/suggests or implies the existence of a relationship between a food product (or a constituent of such food product) and health is considered as a “Health Property Claim”. Three different categories have been distinguished: 1. Nutrient Function Property Claim; 2. Other Function Property Claim OR Enhanced Function Property Claim; and 3. Health Risk Reduction Property Claim. Currently Argentina’s Food Code prohibits overtly all indications ­on labels or notices, advertising on radio, or TV as well as written advertising­ which refer to medical [17] or therapeutic properties of a food product, or which advise its consumption on the basis of health reasons (Section 235 of Argentina's Food Code, adopted by Joint Resolution SPRyRS 149/05 and SAGPyA 683/05).

The implementation of this regulation with additional information, the wide variety of criteria adopted and other issues, such as the inclusion of these indications in a regulation framework, is an important matter, still under debate at CONAL [18].

“Mate” is the infusion prepared with Yerba Mate leaves (Ilex Paraguaiensis), a popular plant especially in Argentina, Brazil, Paraguay and Uruguay. The infusion of Yerba Mate seems to have several health benefits, including a digestive and purifying effect due to the large amount of water used for its consumption [19]. Based on the results of extensive research, Yerba Mate consumption appears to reduce LDL (low-density lipoprotein) cholesterol, stimulating the increase of HDL (high-density lipoprotein) cholesterol both in vitro and in vivo [20, 21], and to protect LDL cholesterol from oxidation, stimulating the activity of important antioxidant body enzymes. It has been shown that the consumption of extracts of Yerba Mate may contribute to increase antioxidant defense against free radicals. Yerba Mate has been reported to have high levels of xantines (which stimulate the central nervous system) and up to 12 powerful polyphenols, among which, chlorogenic acid and quercitin seem to have an anti-adipogenic effect, down-regulating the expression of genes involved in the adipogenesis [22]. The inhibitory effect on lipase activity and on obesity has been reported in obese mice treated with 1-2 g/kg of Mate tea, after 8 weeks of high-fat diet. The results showed that Mate suppressed the increase of body weight, decreasing the serum triglycerides and LDL cholesterol concentrations, and the liver lipid content [23]. These findings suggest that Mate may be useful in the treatment of obesity caused by a high-fat diet.

In a study conducted on postmenopausal women by Conforti et al. [24], Yerba Mate consumption seems to be associated also with an high bone mineral density (BMD) at the lumbar spine and femoral neck, suggesting a potentially protective effect of this plant on bone mass of postmenopausal women involved in the study.

Beyond functional properties, also the nutritional content of Yerba Mate is notable. Potassium, magnesium, vitamins B1, B2, C, A, riboflavin, carotene, choline, pantothenic acid, inositol, and 15 types of amino acids [25] present in this plant may make Yerba Mate a good source of nutrients, representing a good alternative to coffee or tea.

Quinoa belongs to the Chenopodioideae family (together with spinach, Swiss chard, and beetroot), but it can be compared to cereals due to its chemical composition and the form in which it is normally consumed. Quinoa represents an excellent example of functional food that aims at lowering the risk of various diseases. Its beneficial effects are related to its nutritional composition: minerals, vitamins and fatty acids give an important contribution to human nutrition and physiology, particularly for what concern cell membranes’ protection and brain neuronal functions.

Furthermore, quinoa is considered the only element among vegetables to contain all essential amino acids [26]. The content of linoleic acid is very high [27], giving quinoa an important role in the reduction of LDL cholesterol and in the increase of HDL. Several studies conducted on quinoa and other pseudocereals have suggested a hypocholesterolemic effect of its seeds, rich in fibers, saponins, and squalene. Particularly, the action of these substances appears to lead to the absorption of dietary cholesterol [28] and to the reduction of cholesterol synthesis in liver, suppressing the expression of HMG-CoA reductase, the enzyme involved in the mechanism of synthesis of cholesterol [28]. Additionally, Quinoa seems to have an antioxidant effect, which is related to the high quality of its oil, rich in essential fatty acids, like linoleate and linolenate, and to natural antioxidants like α-tocopherol and γ-tocopherol [29]. Quinoa contains from 4.60 to 5.90 mg of Vitamin E/100g. which prevents lipid peroxidation, thus contributing to keep the stability of the cell membrane structures, and to protect the nervous system, muscles and retina from oxidation.

The consumption of food rich in nutrients having health benefits on physiological processes is widespread worldwide, and the existence of natural functional compounds is important for medical research, which may take advantage of these substances for the control of physiological mechanisms in humans.