The United Kingdom Food Labelling Regulations (1994) make it an offence to claim that a food can prevent, treat or cure a human disease. For the food manufacturer the only way around this would be to present evidence thought to justify calling a particular food a medicine; and then apply for a product licence under the Medicines Act (1968).
However, articles in magazines and editorials are the opinion of the writer and do not constitute a claim. This is how a number of so-called health foods are promoted at present.
So-called Functional Foods (also known as designer foods, pharmafoods or nutraceuticals) are processed foods, developed in Japan in the 1980's. Some are enriched versions of familiar foods. Others are specially formulated foods, containing specific ingredients.
Occupying a position midway between food and over the counter medicines (and marketed in Japan by both food companies and pharmaceutical companies) it is claimed for them that they can neutralise harmful substances, prevent disease, promote recovery and delay the effects of aging.
In 1984 the Japanese government decided that, subject to official scrutiny, such a food could be designated as "Functional Food". This term was later changed to "Food with a Specific Health Claim."
Despite a vast literature claiming health virtues for some 100 naturally-occurring substances the supporting evidence is of doubtful validity. There always seems to be at least one study showing benefit, but the majority of reports (often not cited by proponents) fail to confirm the claims.
Dietary fibre, for example, reduced cholesterol, but only in those with abnormally high levels and the overall benefit is still controversial. Though the antioxidants in fruits and vegetables seem to have a general protective effect against cancer, recent trials of individual antioxidants in specific cancers have shown no benefit.
There are also potential risks with functional foods. There are toxins present in many natural substances which pose potential problems if the intake is unusually high.
In clinical trials of drugs the expected benefit may justify any potential risk but in trials of the active compounds of functional foods that are claimed to benefit apparently healthy, well-fed people the risk may outweigh any potential benefit. For example:
We know approximately how much of each of the nutrients will satisfy the requirements for growth, development and maintenance of health-that is the recommended daily amount or reference nutrient intake but apart from the antioxidant vitamins and minerals there is no evidence that an increased intake of any of these confers additional benefit. Nor is there evidence that meals rich in carbohydrate or protein or amino-acids affect mood or performance.
Two products exemplify old and new ingredients of functional foods:
1. The old product is soured milk - sometimes referred to as "lactic acid bacteria" - since Metchnikoff at the end of the 19th Century postulated that mild-souring bacteria in yogurt oust putrefactive bacteria from the intestine and confer health benefits. The modern approach is the use of a range of fermented products made from a variety of micro-organisms which are claimed to be beneficial in cancer of the colon, to stimulate the immune system, and reduce blood cholesterol levels. Groups of medical scientists in various countries do support such claims but a recent authoritative review of the subject dealing with 100 papers reporting human trials as distinct from animal experimentation, concluded that many of these claims are premature (Sanders. In: Goldberg I, ed. Functional Foods. Chapman and Hall, 1994: 294-322).
2. The new group of products consist of a range of about 15 sugar derivatives - mono- and oligosaccharides. They occur in small amounts in some foods and are made chemically or through the action of bacterial enzymes from various sugars and starch derivatives. Some of them are not digested but are fermented in the intestine, some are absorbed but not utilised, some are poorly absorbed but that portion is metabolised. The health properties claimed include the absence of stimulation of insulin, no damage to teeth, reduced energy content and "improvement" of intestinal flora. They are therefore claimed to be beneficial in obesity, heart disease, diabetes, colonic cancer and dental decay. While they are certainly of use in food processing as semisweet, low-energy bulking materials, the evidence of health benefits is not convincing.
There is sufficient evidence to suggest that some claims may eventually be shown to be valid. But the kind of marketing of functional foods now being practised in Japan and the USA must be viewed with considerable caution. Apparently healthy people are probably more likely to benefit from a change in lifestyle than they are from adding functional foods to their diet.
HealthWatch believes that there is a need for further regulation in this area based on the advice of a specially constituted expert committee, which will screen products and examine all claims from the point of view of both efficacy and safety. Each product and each claim must be treated individually.
This position paper by Professor Arnold Bender
endorsed by the Executive Committee, July 1995