From healthy foods to functional foods

A large body of evidence from epidemiological studies indicates that some foods and dietary patterns are beneficial for the prevention of non-communicable diseases as obesity, type 2 diabetes, cardiovascular diseases (CVD) and some types of cancer. This applies, in particular, to dietary fibre as well as to fruit, vegetables, nuts, wholegrain cereals and legumes. Moreover, mono- and n-6 polyunsaturated fatty acids, and in particular oleic and linoleic acid, n-3 long-chain polyunsaturated fatty acids, plant sterols, potassium, polyphenols, are associated to a lower risk of CVD (Assmann et al. 2014). The identification of the health benefits of some foods and nutrients have led the scientific community to search for food constituents that can influence specific body functions relevant for health thus characterising these foods as functional. Although the functional food market is constantly growing, to date no universally accepted definition for functional foods exists. According to the Concerted Action on Functional Food Science in Europe (FUFOSE) endorsed by the European Commission, a food can be regarded as 'functional' if it is 'satisfactorily demonstrated that it affects beneficially one or more target functions of the body, beyond adequate nutritional effects, in a way that is relevant to either an improved state of health and well-being and/or reduction of risk of disease'. A 'functional food' can be either a natural food (healthy food), or a food to which a component has been added, or a food from which a component has been removed by technological or biotechnological means. Functional foods, however, must remain foods and they must demonstrate their beneficial effects on health in clinical trials performed in humans utilising in amounts that can normally be expected to be consumed in the habitual diet: they are not pills or capsules, but part of a normal food pattern (Diplock et al. 1999). Consumers are informed about the health benefits of functional foods by health claims that are represented by any communication that states, suggests or implies by any means a relationship between a food or a food category and health; they include functional claims, reduction of disease risk claims, or claims referring to the growth and development of children. The European Food Safety Authority (EFSA) scientifically evaluates whether a food is able either to influence a biological function or to reduce the risk of disease. Examples of functional claims are 'sugar-free chewing gum helps reduce tooth demineralization' or 'plant sterols contribute to keep plasma cholesterol levels under control'. Reduction of disease risk claims are i.e. 'calcium reduces risk of osteoporotic fracture' (over 65 years) or 'dietary fibres contribute to decrease the risk of colon cancer'. A claim is the only guarantee for consumers of the health effects of a functional food and a necessary support to make the appropriate product's choice. To authorise a claim, EFSA requires the following conditions: 1. the food /constituent is well characterised; 2. the claimed effect is well defined and physiologically relevant; 3. a cause-effect relationship exists between the food/constituent and the claimed effect for the target group and for the proposed conditions of use. Benefits of functional foods have frequently been reproduced by providing isolated components of foods as supplements identified as nutraceuticals. It is mandatory that, before health claims for particular foods or nutraceuticals are authorised, clinical trials in humans are undertaken demonstrating their beneficial effects on human health. An example of a new potential functional food is represented by a rusk made with a flour enriched in amylose (a type of starch with a slower digestibility) that impro