Functional foods and dietary supplements: products at the interface between pharma and nutrition.

It is increasingly recognized that most chronic diseases of concern today are multifactorial in origin. To combat such diseases and adverse health conditions, a treatment approach where medicines and nutrition complement each other may prove to be the most successful. Within nutrition, apart from (disease-related) dietetic regimes, an increasing number of functional foods and dietary supplements, each with their own health claim, are marketed. These food items are considered to be positioned between traditional foods and medicines at the so-called 'Pharma-Nutrition Interface'. This paper encompasses aspects related to the regulatory framework and health claims of functional foods and dietary supplements. The use of functional foods or dietary supplements may offer opportunities to reduce health risk factors and risk of diseases, both as monotherapy and in combination with prescription drugs. Nevertheless, the potential caveats of these products should not be overlooked. These caveats include the increased risk for food-drug interactions due to the elevated amounts of specific functional ingredients in the diet, and the stimulation of self-medication potentially resulting in lower adherence to drug therapy. Health technology assessments should be used more to compare the cost-effectiveness and benefit-risk ratios of drugs, functional foods and dietary supplements, and to evaluate the added value of functional foods or dietary supplements to drug therapy.