Functional foods: opportunities and challenges

Functional foods are defined as foods and food components that provide a health benefit beyond basic nutrition (for the intended population). These substances provide essential nutrients often beyond quantities necessary for normal maintenance, growth and development, and/or biologically active components that impart health benefits or desirable physiological effects.

The intersection of food and genes

Diet is one of the key environmental factors to which genes are exposed. Nutrients affect gene expression and formation of various proteins at discrete points in the processes of their formation. Discoveries in genetics make it possible to understand the effects of nutrients in processes at the molecular level and also the variable effects of dietary components on each individual. Disciplines such as nutrigenomics (study of interaction of dietary components with genes); proteomics (study of the proteins encoded and expressed by a genome); and metabolomics or metabonomics (metabolite profiling, measuring potential outcome of changes suggested by genomics and proteomics) have and will continue to contribute to the rapid development of functional foods.

Bioinformatics, a tool that uses computer database technology to integrate data from multiple disciplines, also plays an important role in this development. Early functional studies have focused on single genes; however, many common diseases are influenced by complex interactions among multiple genes, combined with environmental and lifestyle factors. There is a need for researchers to simultaneously study the functional interactions, networks and pathways. This research will reveal the effects of nutrients on the molecular-level processes in the body and document variable effects of nutrients under different conditions. IFT suggests that some changes in FDA’s policies are necessary to facilitate these accomplishments.

Limitations of current policies

Current policies limit addressing the full scope of benefits and potential developments for functional foods. The existing terminology and regulatory frameworks limit the scope and accuracy of consumer information and hinders development and marketing of functional foods. Convoluted wording of claims designed to avoid drug classification may lead to inaccurate conveyance of the actual effect of the food or result in misleading statements of the underlying science.

Current FDA policy requires that health benefits attributed to a food be derived from its ‘nutritive value’ in order for the food to be exempt from regulation as a drug. This policy unduly restricts the health effects of foods to the limited concept of nutritive value and appears to be inconsistent with the courts’ interpretation of the Federal Food, Drug and Cosmetic Act (FDC Act). The FDC Act defines a drug to exclude ‘food’ intended to affect the structure or any function of the body of man. The courts have held that this exclusion from the drug definition applies to ‘food’ broadly, not just to the nutritive components or nutritive value of a food.

Foods are defined in the statute as articles, including their components, used for food or drink for man or animals. In Nutrilab, Inc. versus Schweiker, the court concluded that foods are articles used by people in the ordinary way most people use food – primarily for taste, aroma or nutritive value. The court stressed that: “[t]o hold… that articles used as food are articles used solely for taste, aroma or nutritive value is unduly restrictive.” The court noted that: “some products such as coffee or prune juice are undoubtedly food but may be consumed… for reasons other than taste, aroma or nutritive value.”

Other courts have accepted this broad interpretation of ‘food’ as including articles consumed for reasons other than taste, aroma or nutritive value. In American Health Products Co. versus Hayes, the court determined that if an article affects bodily structure or function by way of its consumption as a food, the ‘food’ exemption to the drug definition precludes its regulation as a drug notwithstanding a manufacturer’s representations as to the physiological effect. The court reasoned that Congress did not want to inhibit the dissemination of useful information about a food’s physiological properties by subjecting the food to drug regulation. Thus, under the courts’ interpretation of the statute, truthful and non-misleading claims about the beneficial physiological effect of a food or a food component on the structure or function of the human body, need not be limited to foods that derive such benefits from nutritive value.

The IFT Expert Panel recommends that FDA policy not require claims about health effects of foods on normal health structure or function of the body to be based on the very limited concept of nutritive value. Rather, the Expert Panel supports basing structure/function health claims on broad-based scientific criteria that address the underlying link between health and nutrition and meet the need for sound scientific substantiation supporting the structure/function effect.

With regard to health claims, the FDC Act describes a health claim in terms of the relationship between a particular ‘nutrient’ and disease or other health-related condition. FDA policy requires that substances intended to be consumed at other than decreased levels contribute taste, aroma, nutritive value or a technical effect to the food in order to be eligible for a health claim. For this purpose, FDA defines nutritive value as “value in sustaining human existence by such processes as promoting growth, replacing loss of essential nutrients or providing energy.” While the Agency acknowledged that this definition was intended to be flexible, past application of the nutritive value criterion has varied and at times been very confining.

The IFT Expert Panel recommends that FDA not restrict the health effects of foods to the very limited concept of nutritive value. As noted in the IFT Expert Panel Report, our understanding of the interconnections between nutrition and other scientific disciplines such as physiology, endocrinology, biochemistry, neurology and genetics is rapidly evolving. The concept of traditional ‘nutritive value’ is too narrow to accommodate increasing comprehension and advances in functional food research. The IFT Expert Panel recommends that FDA apply a more appropriate policy that health claim benefits for functional foods be based on “nutritive value or through the provision of a physical or physiological effect that has been scientifically documented or for which a substantial body of evidence exists for plausibility.”

The FDC Act provides that, in general, express or implied claims that a food can cure, mitigate, treat or prevent any disease are drug claims that make the food subject to regulation as a drug. Traditionally, what constitutes an implied drug claim has been interpreted very broadly by FDA. For example, FDA took the position that a claim that a food lowers cholesterol would be considered a drug claim because it implies treatment of abnormal cholesterol levels, which the agency considers to be a ‘disease’. Therefore, functional foods that affect cholesterol levels could only state that the food “maintains normal cholesterol levels,” which is a permissible structure/function claim. However, such a statement is potentially misleading if the food in fact lowers cholesterol levels. A petition for a health claim was filed linking consumption of phytostanol and phytosterol esters to a reduced risk of heart disease. After the time-consuming and costly health claim petition was approved, the cholesterol-lowering ‘disease’ claim was allowed, but only in general terms of coronary heart disease risk reduction. The IFT Expert Panel recommends that product labelling be allowed to accurately reflect the scientific evidence. As long as claims are scientifically valid, enormous public health benefits would result from consumers understanding and acting on the claimed product benefit.

The IFT Expert Panel supports scientifically defensible health and nutrition messages in the marketplace and therefore supports the concept of qualified health claims. However, consumers may be misled if qualified health claims are not adequately differentiated from approved health claims. To promote consumer understanding, the wording of qualified health claims should clearly indicate the degree of scientific support or certainty associated with a biological effect or modification of disease risk. The IFT Expert Panel recommends that FDA prohibit claims relying on “very limited and preliminary studies” and develop guidelines that protect consumers from limited scientific information of no meaningful value. The current scientific standard applied by FDA in evaluating qualified health claims is the “weight of the scientific evidence (WOSE), tempered by credible evidence.” Properly applied, this standard should operate to preclude dissemination of misleading information based on poor science.

Process for bringing functional foods to market

The IFT Expert Panel identified a seven-step process that would address critical aspects in the design, development and marketing of functional foods. After identifying a potential new bioactive ingredient (step 1), the ingredient’s efficacy and safety must be evaluated (steps 2 and 3). When selecting an appropriate food vehicle for the bioactive substance (step 4), characteristics of the food, the ingredient and the intended consumer must be considered. An independent peer review and, if required, regulatory oversight (step 5) ensures the accuracy of health claims, which must be properly communicated to consumers (step 6). Finally, in-market surveillance confirms the findings of the pre-market assessments (step 7). Although all seven steps would be undertaken for each new bioactive substance and the resulting functional foods, the specific requirements within each step vary depending upon the physical, chemical and biological characteristics of the functional component, the applicable regulatory requirements and the health claims to be made.

Safety and efficacy of functional foods

In general, the safety of functional foods should be based on the long-standing principle that foods are safe. Further, the safety assessment should accept the safety of components already established through generally recognised as safe (GRAS) determinations and food additive approvals. That said, an objective, science-based evaluation process must establish that functional components are safe at their projected use levels. The safety assessment must also be sufficiently flexible to consider the many factors associated with consumer responses to food and food ingredients, including genetic predisposition, age, sex, nutrition status and lifestyle. The safety assessment would be concluded through current procedures for establishing GRAS status or as obtaining food additive approval.

A major recommendation in the report pertains to the demonstration of scientific sufficiency of evidence for efficacy. This recommendation if implemented, we believe, would encourage public confidence in the labelling of functional foods and would conserve government resources. It is recommended that independent expert panels be established to make generally recognised as efficacious (GRAE) determinations. These panels would be composed of respected scientists qualified to determine efficacy of the component under consideration. The multi-disciplinary nature of the panel would provide a broad context for data evaluation and assure that the resulting conclusions are scientifically defensible and relevant to consumer practices. The GRAE panel would apply the Hill criteria to determine if the proposed claims are supported by the available evidence. GRAE panels could be assembled and managed in a variety of ways as long as the panel’s independence is assured and conflicts of interest avoided. GRAE panels could be organised by a professional organisation, by a private consulting organisation or by the company developing the functional food (provided the panel is given complete autonomy).

The panel of independent experts with appropriate scientific expertise would be fully disclosed. The GRAE panel reports (accompanied by relevant scientific literature and data) would be submitted to FDA under a GRAE notification process similar to that used for GRAS notifications.

Role of research

The IFT Expert Panel discloses that functional foods currently on the market represent a small fraction of the possible products. Extensive research is needed to achieve vast potential as well as to ensure safety and efficacy of the product. The IFT Expert Panel has identified the following research areas as vital to the development of functional foods:

• Understanding the mechanisms of action, dose/response relationship, clinical outcomes and individual response for nutrient and bioactive substances.
• Identification and development of additional biomarkers and surrogate markers, as well as further defining acceptable ones.
• Identification and tailoring food vehicles for delivery of bioactive ingredients.
• Expansion and use of exiting food composition and dietary intake databases to identify relationships between diet and health.
• Use of nutrigenomics to provide nutrient plans and products based on interaction of genetics and diets for groups and individuals (mass customisation).

Further, research is needed in the areas of ethics, regulatory and legal implications of nutrigenomics. Appropriate incentives such as market exclusivity to the food industry for health and nutrition research would greatly enhance development of functional foods.

Conclusions

The IFT Expert Report identifies areas that need changes and further encourages development of functional foods. Overall the IFT Expert Panel recommends the following:

• Expanded research into traditional nutrients, other bioactive food components and the intersection of genomics and molecular nutrition.
• Expanded research on biomarkers and physiological endpoints.
• Use of GRAE panels to evaluate health claims and streamline regulatory process.
• Allowing structure/function and health claims in product labelling to accurately reflect the scientific data without triggering drug status.
• Modifying the current definition and application of the ‘nutritive value’ requirement.
• Allowing health claims based on SSA and qualified health claims based on WOSE.
• Indicating the degree of scientific certainty for approved and qualified health claims.
• Developing incentives for companies to invest in functional food research and development.
• Using health claims on food labels as foundation for consumer education regarding dietary components for health.

This article is based on testimony given in December 2006 by Barbara Petersen, PhD, during the FDA’s Public Hearing on Functional Foods. Dr Petersen was a panellist and contributor to the IFT Expert Report on Functional Foods (2005).