Health foods or functional foods have no universally accepted definition. Functional foods are those whole, fortified, enriched or enhanced foods that provide health benefits beyond provision of essential nutrients such as vitamins and minerals. They may do more than supply the macronutrients and micronutrients the body needs for normal biochemical reactions.

Functional foods have bioactive components that can potentially enhance health when eaten on a regular basis as part of a varied diet. The simplest examples of functional foods are fruits and vegetables. These not only offer life-essential vitamins and minerals, but also contain an array of phytochemicals that may fight certain diseases.

The concept was first developed in Japan in the 1980s when, faced with escalating health care costs, the Ministry of Health and Family Welfare initiated a regulatory system to approve certain foods with documented health benefits in hopes of improving the health of the nation’s ageing population. These foods which are eligible to bear a special seal are now recognized as foods for specified health use (FOSHU). As of July 2002, nearly 300 food products had been granted FOSHU status in Japan.

Nutraceutical is a term used interchangeably with functional food. It refers to those diet supplements that deliver a concentrated form of a presumed bioactive agent from a food, presented in a non-food matrix and used to enhance health in dosages that exceed those that could be obtained from normal food.

Dietary supplements are defined as any product that is intended to supplement the diet and contains one or more of the following: vitamins, minerals, herbs or other botanicals, aminoacids and other dietary substances intended to supplement the diet by increasing the total dietary intake or as any concentrate, metabolite, constituent, extract or combination of these ingredients.

The term dietary supplement means products intended for ingestion in a form (tablet, capsule, powder, softgel, gelcap and liquid) that is not represented as conventional food or as the sole item of a meal or of diet and that are labelled as dietary supplements.

In view of the increasing awareness of the health benefits of plant-based diets and the general perception that plant-derived drugs provide better and safer health care than pure chemical drugs, there is a huge demand for these drug/dietary botanicals. Several medicinal plant-based formulations are today flooding the market in various forms such as tablets, capsules, gels, syrups etc. Depending on the local regulations they are available as drugs, health foods, dietary supplements, nutraceuticals etc. While some of them are direct adaptations of traditional recipes taken from classic medical treatises, many are new or research-based proprietary products developed according to the need of the medical condition they claim to cater to. For e.g., antiobesity, hypolipidemic herbal drugs either single or in combination with other anti-oxidant/anti-inflammatory herbs are promoted for use in cardiovascular ailments. While such ad hoc new combinations seem appealing and marketable, safety and efficacy of such newer herbal cocktails are very much questionable and cannot be considered equivalent to time-tested traditional drugs. This is a cause of concern for regulating bodies world over especially in view of the ready availability of such concoctions under the name of herbal remedies, drugs, health supplements etc.

According to the Department of Health and Human Services, USA, diet plays a role in 5% to 10% of the leading causes of death, including coronary heart disease (CHD), certain types of cancer, stroke, diabetes type 2 and atherosclerosis. The dietary pattern that has been linked with major causes of death in developed countries is characterized as relatively high in total and saturated fat, cholesterol, sodium and refined sugars and relatively low in unsaturated fat, grains, legumes, fruits and vegetables. An accumulating body of research now suggests that consumption of certain foods or their associated physiologically active components may be linked to disease risk reduction. There are also many classes of physiologically active functional food ingredients of plant, animal or microbial origin with a great majority of them derived from plants.

Probiotics are a class of biologically active animal-derived components and defined as viable microorganisms that are beneficial to human health. Examples include Lactobacillus acidophilus and other strains of lactobacillus being incorporated into functional food products now on the market.

Prebiotics are non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of beneficial bacteria in the colon, thus improving host health. Synbiotics are mixtures of probiotics and prebiotics that beneficially affect the host by improving the survival and implantation of live microbial dietary supplements in the gastrointestinal tract, by selectively stimulating the growth and/or by activating the metabolism of one or a limited number of health-promoting bacteria, thus improving host welfare.