What makes a functional food functional?

Functional foods are foods that, by nature or design, can deliver benefits beyond that of sustenance. They bridge the traditional gap between food and drugs, offering consumers greater opportunity to take their health care into their own hands. Rapidly increasing knowledge of the physiological effects of nutrients and their potential health benefits offers exciting prospects for the food industry and consumers alike. However, we must ensure that newly developed functional foods are indeed functional. The mere presence in a food of nutrients with well-publicised health attributes can infer that the food will deliver health benefits. We need to be certain that it will be efficacious for the indication specified and the nature and extent of benefit will be clearly understood by consumers. With the introduction of health claims, the onus will be on food manufacturers to provide scientific substantiation based not only on the literature related to an active nutrient, but also on intervention trials that demonstrate bioavailability and efficacy of the nutrient when delivered in a specific type of food. Such an approach, while demanding in terms of research and development investment, offers significant opportunities for product innovation. We can extend the variety of foods through which consumers may source a particular health-giving nutrient. Moreover, recognizing that a particular condition such as heart or bowel health may be influenced by more than one type of nutrient, manufacturers can design and evaluate unique foods with appropriate combinations of nutrients to optimise health status. Even though a new type of food may be shown to be efficacious in short-term, controlled clinical trials, can we be certain that consumers will derive long-term benefits free from adverse affects? Will food manufacturers undertake postmarketing surveillance or will this task be left to consumer watchdogs? The transition from traditional foods and herbal remedies of uncertain value to designer foods with guaranteed health benefits could be facilitated by adopting aspects of the pharmaceutical approach to substantiation and regulation.