An unambiguous and agreed definition of what a functional food is does not exist. However, broadly speaking, a food is said to be functional if it contains a food component which affects one or more targeted functions of the body in a positive way. Functional foods often fall into the grey area between foods and medicine, but from a regulatory standpoint they are foods and consequently subject to food regulations. According to the food labelling directive, it is not permitted to label a food in such a way that, first, it will attribute the property of preventing, treating and curing human disease, or refer to such properties, and second, that it can mislead the consumer. The first aspect refers to the claims a food product may carry and specifically prohibits health claims - even if scientifically valid. It is argued that a claim on a food is a health claim if the consumer perceives it as such. The second aspect states that a given claim must be validated by sufficient scientific evidence, and far too often associations between food intake and disease risk have been misinterpreted as causal relations.