Research on food and nutrition has been an important topic in all Framework Programmes for Research and Technological Development of the European Commission. From the Second Framework Programme (ECU 2 million for four projects on functional foods) to the Fifth Framework Programme (€51 million for thirty-three projects on functional foods), the investment in research projects on functional foods has been increasing by quite an extent. In the early 1990s, the topics were fibres, pro-, pre- and synbiotics. Nowadays, the range of subjects has been broadened to antioxidative effects, vitamins, phyto-oestrogens and the socio-economic area.

In the context of this presentation, European means the European scientific community, which, over the last decade, has been working on the concepts for functional foods, producing a number of documents including a consensus paper, guidelines and scientific publications. The Functional Food Science in Europe (FUFOSE) project has been quite a unique attempt to establish a strong scientific framework to justify the functional food concept, to discover and develop new functional foods that are primarily function-driven, and to substantiate claims scientifically. Being clearly positioned as part of nutrition, the functional food concept is, however, quite distinct from other approaches like food supplementation or food fortification, and functional foods are different from nutraceuticals, pharmafoods, vitafoods and ‘alicaments’, all terms that are not defined conceptually. Functional foods are food products to be taken as part of the usual diet in order to have beneficial effects that go beyond what are known as traditional nutritional effects. Moreover, these beneficial effects have to be demonstrated scientifically to justify two specific types of claim: the enhanced function claim or the reduction of disease risk claim.

Functional food is a key concept for the future of nutrition as a science because it results from the implementation in nutrition of all the basic scientific knowledge that has accumulated over the past two or three decades. To the benefit of public health this progress cannot be ignored, it needs to be recognized fully and used. But, today, functional food is still mainly a scientific concept that serves to stimulate research and the development of new products.

There is an old Chinese thought meaning that medicine and food are isogenic. In Japan, a national research project started to endorse the thought scientifically, with the birth of functional foods that are now known to function to reduce the risk of life-style related diseases. The science gave rise to a national policy in which some functional foods were legally approved in terms of Foods for Specified Health Use. China has also constructed a unique system for approving some functional foods. This paper pinpoints a recent trend of functional foods characteristic to Asia, with special reference to relevant topics in Japan.

The perspectives of Latin America as a potential producer and consumer of functional foods will depend largely on the level of information and income of the population, credibility of the products, research investments and regulatory practices. The characteristics of Latin America are diverse at the regional and sub-regional levels. However, as part of the demographic and epidemiological transition currently underway, common trends can be identified such as increasing urbanization and life expectancy, the occurrence of obesity and malnutrition, increasing incidences of chronic diseases and causes of mortality rates, all of which suggests the importance of diet and functional foods in public health policies. The Latin American population in general has no knowledge of functional foods, but in the more urbanized areas there is an increasingly health-conscious consumer, aware of the importance of food for health, due to the media and local traditions. More investment in research is important to explore the existing plant biodiversity that is a rich source of new foods and bioactive compounds, some of which are already used for health improvement and wellbeing. Clinical validation of functional foods should consider functional food science concepts and also the diverse cultural and genetic background of the local population. In Latin American scientific and regulatory communities, the functional foods concept has been associated with foods having health benefits beyond those of basic nutrition but is not defined officially in the emerging regulatory codes. Regulation existing in some countries is focused on safety and efficacy; both functional and health claims are allowed (risk reduction) provided they have scientific validation. This allowed introduction on the market of several products with health claims, some of them submitted to post-marketing surveillance.

Linkages between diet habits and the quality of life continue to surface on numerous fronts. Collectively these epidemiological, pre-clinical and clinical studies provide rather compelling evidence that numerous essential and non-essential dietary components are capable of influencing growth, development and performance and disease prevention. Scientific discoveries and widespread interest in the potential medicinal benefits of foods and food components have fostered a variety of content, health and structure–function claims. Unfortunately, defining the ideal diet is complicated by the numerous and diverse components that may influence biological processes. Inconsistencies in the literature may reflect the multi-factorial nature of these processes and the specificity that individual dietary constituents have in modifying genetic and epigenetic events. New and emerging genomic and proteonomic approaches and technologies offer exciting opportunities for identifying molecular targets for dietary components and thus determining mechanisms by which they influence the quality of life. All cells have unique ‘signatures’ that are characterized by active and inactive genes and cellular products. It is plausible that bridging knowledge about unique cellular characteristics with molecular targets for nutrients can be used to develop strategies to optimize nutrition and minimize disease risk.

While the health benefit of a functional food may be a metabolic response that lowers risk for disease, the actual target for the food or food component may be on the functioning of the gastrointestinal tract (GIT). For example, slowing absorption from the intestine, as measured by examining the appearance of the nutrient or food component in the blood, the hormone response associated with absorption of the compound or excretion of the compound, may provide a health benefit. However, the food component may slow absorption by delaying gastric emptying, altering the mixing within the intestinal contents or decreasing the availability of digestive enzymes in the intestine. These measures of GIT function provide validation of the mechanisms by which the functional food or food components affect metabolism. Bioavailability of physiologically active compounds from foods will be determined by the digestibility of foods that contain these compounds, their subsequent absorption and utilization by tissues. The physical structure of foods contributes to the functional effects of foods as well as to the availability of compounds from foods. For example, recent studies have demonstrated that changing the viscosity of the gut contents alters absorption and GIT response. Additionally, food structures such as the plant cell wall change the availability of absorbable compounds along the gastrointestinal contents. The areas of probiotics and prebiotics have highlighted the potential importance of gut microflora in health. While evidence suggests biological activity relevant to disease risk reduction, the long-term implications of the microbial activity have yet to be established.

The immune system acts to protect the host from infectious agents that exist in the environment (bacteria, viruses, fungi, parasites) and from other noxious insults. The immune system is constantly active, acting to discriminate ‘non-self’ from ‘self’. The immune system has two functional divisions: the innate and the acquired. Both components involve various blood-borne factors (complement, antibodies, cytokines) and cells. A number of methodologies exist to assess aspects of immune function; many of these rely upon studying cells in culture ex vivo. There are large inter-individual variations in many immune functions even among the healthy. Genetics, age, gender, smoking habits, habitual levels of exercise, alcohol consumption, diet, stage in the female menstrual cycle, stress, history of infections and vaccinations, and early life experiences are likely to be important contributors to the observed variation. While it is clear that individuals with immune responses significantly below ‘normal’ are more susceptible to infectious agents and exhibit increased infectious morbidity and mortality, it is not clear how the variation in immune function among healthy individuals relates to variation in susceptibility to infection. Nutrient status is an important factor contributing to immune competence: undernutrition impairs the immune system, suppressing immune functions that are fundamental to host protection. Undernutrition leading to impairment of immune function can be due to insufficient intake of energy and macronutrients and/or due to deficiencies in specific micronutrients. Often these occur in combination. Nutrients that have been demonstrated (in either animal or human studies) to be required for the immune system to function efficiently include essential amino acids, the essential fatty acid linoleic acid, vitamin A, folic acid, vitamin B6, vitamin B12, vitamin C, vitamin E, Zn, Cu, Fe and Se. Practically all forms of immunity may be affected by deficiencies in one or more of these nutrients. Animal and human studies have demonstrated that adding the deficient nutrient back to the diet can restore immune function and resistance to infection. Among the nutrients studied most in this regard are vitamin E and Zn. Increasing intakes of some nutrients above habitual and recommended levels can enhance some aspects of immune function. However, excess amounts of some nutrients also impair immune function. There is increasing evidence that probiotic bacteria improve host immune function. The effect of enhancing immune function on host resistance to infection in healthy individuals is not clear.

The development of the sports food market and industrial involvement have led to numerous nutritional studies to define the type of nutrients that are most suited to support energy metabolism, fluid balance and muscle function. The key question in many of these studies was: ‘Does the product lead to a significant product/consumer benefit that can be used as a claim on the package?’ New methods and techniques have been developed, partly with sponsorship of the food industry, with the goal of measuring the effects of specific nutrients and supplements on athletic performance and metabolism. In line with this development, a wide variety of supplements and sports foods/drinks labelled with various performance or health benefit statements have been launched on the sports nutrition market. Although a variety of products have been tested clinically, there are also many products on the market with benefit claims that cannot be supported by sound nutritional and sports physiological science. The current short review highlights some of the methods and biomarkers that are used to substantiate product/consumer benefit claims for foods and drinks that are marketed as functional foods for athletes.

It is easier to demonstrate the consistent effects of foods on satiety than on cognitive performance. This is understandable since the satiety system incorporates physiological signalling systems that mediate the effects of foods on function. Specific manipulations of proteins, carbohydrates and fats have the potential to act as functional foods for appetite control. Because of the importance of the optimal functioning of cognitions for survival, these functions are quite strongly protected against short-term dietary and physiological perturbances. Therefore, food manipulations may be better detected through the degree of effort exerted to maintain performance rather than via changes in the actual performance itself. This procedure has not been widely used hitherto. The concept of biomarkers may have to be interpreted differently from research on physiological systems or clinical endpoints. For satiety, adjustments in the profile of hunger could serve as a biomarker or surrogate endpoint. For cognitions, correlated physiological variables may be more difficult to measure than the functional endpoint itself. Changes related to unitary functions (such as tracking) could serve as biomarkers for more complex, integrated skills (such as car driving). Since food manipulations may affect multiple functions, the challenge is to design foods with good satiety control that do not impair mental performance; or alternatively to engineer foods that optimise cognitive performance without compromising satiety. This rapidly developing field has great potential for close collaboration between academia and industry in the production of commercially successful products that show clear improvements in human functioning with the capacity to protect against disease or impairment.

Obesity has reached epidemic proportions in many countries around the world. Because of the close relationship between obesity and type 2 diabetes, an epidemic of diabetes is close behind the obesity epidemic. Preventing and treating obesity is becoming an increasing priority. In the United States, over 60% of the adult population is overweight or obese and thus at increased risk of developing diabetes and cardiovascular disease. While the aetiology of obesity and diabetes is complex, diet clearly plays an important role both in the development and management of these diseases. There is interest in functional foods that could help in prevention and/or management of obesity and type 2 diabetes. This could involve food products that help management of ‘hunger’ or that increase ‘satiety’. It could also involve foods that contribute to more inefficient use of ingested energy (i.e. foods that stimulate energy expenditure more than would be expected from their energy content). As the concept of insulin sensitivity becomes generally more accepted by health care professionals and the public, foods may be targeted towards maximizing insulin sensitivity and towards ‘prevention’ of diabetes. In addition to foods that impact upon body weight, these may include foods that affect the glucose and/or insulin levels that are seen either following the ingestion of food or later in the day. The present paper reviews the complex aetiology of obesity and diabetes and considers a potential role for functional foods in prevention and treatment of obesity and diabetes.

One of the most promising areas for the development of functional foods lies in modification of the activity of the gastrointestinal tract by use of probiotics, prebiotics and synbiotics. While a myriad of healthful effects have been attributed to the probiotic lactic acid bacteria, perhaps the most controversial remains that of anticancer activity. However, it must be emphasised that, to date, there is no direct experimental evidence for cancer suppression in man as a result of consumption of lactic cultures in fermented or unfermented dairy products, although there is a wealth of indirect evidence, based largely on laboratory studies. Presently, there are a large number of biomarkers available for assessing colon cancer risk in dietary intervention studies, which are validated to varying degrees. These include colonic mucosal markers, faecal water markers and immunological markers. Overwhelming evidence from epidemiological, in vivo, in vitro and clinical trial data indicates that a plant-based diet can reduce the risk of chronic disease, particularly cancer. It is now clear that there are components in a plant-based diet other than traditional nutrients that can reduce cancer risk. More than a dozen classes of these biologically active plant chemicals, now known as ‘phytochemicals’, have been identified. Although the vast number of naturally occurring health-enhancing substances appear to be of plant origin, there are a number of physiologically active components in animal products (such as the probiotics referred to above) that deserve attention for their potential role in cancer prevention.

Osteoporosis is a growing global problem. The health care costs and decreased productivity and quality of life are staggering. Much research is invested in life-style approaches to build peak bone mass during growth to prevent osteoporosis as well as to treat the disease in later life. Functional foods have enjoyed a niche in bone health. Foods fortified with Ca are most popular. Other bone nutrients such as vitamin D, Mg and vitamin K are sometimes added. Future products are likely to include enhancers of Ca absorption such as inulin or whey proteins. Dietary factors that reduce urinary Ca loss (plant proteins) or suppress bone resorption (possibly phyto-oestrogens) are also gaining attention. Methodologies for evaluating the effectiveness of functional foods on bone health include measures of bone quality such as bone densitometry or measures of Ca metabolism, particularly absorption. Biochemical markers for bone turnover are less satisfactory for diet-related effects. Use of a rare isotope, 41Ca, and accelerator mass spectrometry offers a new approach for assessing the ability of functional foods to suppress bone resorption.