Functional foods can be widely described as processed food that provides medical or health benefits as well as a reduction in disease risk. There is no universal definition of functional food, but in the context of their benefits, a hallmark feature is their disease-preventing ability alongside their nutritional and health-promoting benefits. They are not considered preventative or curative by themselves and are typically not essential to the diet.
The history of the term functional foods
The term functional foods, and later “nutraceutical” was first coined in Japan in the early 1980s. Functional foods overlap with other terms alongside nutraceuticals, and include “vitafoods”, “medical foods”, “probiotics”, and “pharmafoods”.
Today, functional foods cover a wide variety of food types and are considered to be those that are fortified, enriched, or enhanced foods; it is by way of enhanced nutritional profiles that these foods provide health benefits that go beyond providing essential nutrients (vitamins and minerals) when they are consumed at a threshold amount as part of a varied diet, regularly.
Japan is also the first country to have devised a specific regulatory approval process for functional foods. The term food for specified health use (FOSHU) was coined and established in 1991. This concept then rapidly expanded to different parts of the world.
Subsequently, there is a great variation across the world with regards to the regulation of functional foods, and they have not been well established. There are also distinct differences in the approach to functional foods between legislators across the world.
Variations in functional food definitions and legislation across the world
The US Food and Drugs Administration (FDA) in the USA has a regulatory scheme that does not recognize functional foods to be a distinct category and does not provide a legal definition of functional foods. Despite this, several working definitions have been developed by organizations which include the American Dietetic Association (ADA), the International Food Information Council (IFIC), and the Institute of Food Technologists (IFT).
However, within the European Union, a regulation on nutrition and health claims came into force in 2007. Under the regulation, health claims are subject to preapproval, involving scientific assessment by the European Food Safety Authority (EFSA).
The adoption of regulation for the use of nutritional claims for foodstuffs harmonized EU-wide rules for the use of health and nutritional claims on foodstuffs. The main objective of this regulation ensure that food claims are substantiated by scientific evidence and are clear to the consumer.
The EFSA, Unlike the FDA, defines functional foods as “a food, which beneficially affects one or more target functions in the body, beyond adequate nutritional effects, in a way that is relevant to either an improved state of health and wellbeing and/or reduction in risk of disease.
A functional food can be a natural food or food to which a component has been added or removed by technological or biotechnological means, and it must demonstrate their effects in amounts that can normally be expected to be consumed in the diet.” However, they are as yet, not covered by any specific legislation except for general food legislation.
Japan is the only country in the world that recognizes functional foods as a distinct category and the Japanese functional food market is considered to be one of the most advanced, globally.
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Functional products – functions and benefits
Bioactive compounds are a typical hallmark present in significant quantities in functional foods. Broadly speaking, these include foods enriched with dietary fiber, omega-3 polyunsaturated fatty acids, carotenoids, as well as those supplemented with probiotics and prebiotics, those capable of lowering cholesterol, for example. The table below summarises a range of functional products and their effects on the body:
| Ingredient |
Functional product |
Functions |
|
Dietary fiber
|
Oat, brown, grits, and flour – including any products derived from them such as oatmeal, cereal, and bread; fruit jams, cured sausages, and fish products; fermented milk drinks contain Lactobacillus plantarum, and wholegrain oat; fruit drinks with oat β-glucans.
|
Lowers concentration of blood glucose (4 g/day of β-glucan from cereals) and cholesterol (3g of soluble dietary fiber from oats), reduces constipation symptoms (threshold quantities include those containing 8.3 g of fermentable fiber and 9.7 g of nonfermentable fiber per 100 g).
|
|
Omega-3 polyunsaturated fatty acids (PUFA)
|
Oil; margarine; bread; pasta; milk-based drinks; chocolate; and supplemented fruit juices (those supplemented with docosahexaenoic acid & eicosapentaenoic acid)
|
Omega-3 FA (>2 g/day) has been shown to lower the concentration of blood triglycerides as well as produce hypotensive and arhythmic effects. Supplementation of DHA and EPA may also improve health and aid in nerve cell membrane regeneration; This can slow down the aging of the brain and prevent dementia
|
|
Phytoestrogens
|
Miso; tempeh; tofu; soy-based products such as milk; oil; imitation meat; cereal bars; whole-grain cereal products; and bread that contain rye and flaxseed
|
Phytoestrogens have some weak estrogenic effects which can help aid symptoms of menopause; this can subsequently improve hyperglycemia, glucose tolerance as well as circulating insulin concentration
|
|
Natural antioxidants
|
Fortified breakfast cereals; milk-based drinks; margarine; and fortified pasta
|
Are thought today the onset of cardiovascular and neurological diseases, cataracts, some types of cancer, and some non-communicable diseases
|
|
Probiotics and prebiotics—fructans, inulin, and resistant starch
|
Vegetable juices; cheeses; ice cream; frozen dessert; fermented dairy products such as yogurt; kefir; and buttermilk; fermented fruit; kombucha; and fermented meats
|
Probiotics can influence and regulate the immune system as well as improve immune function. They are also instrumental in the treatment of constipation, diarrhea, and the management of irritable bowel diseases such as Crohn's disease as well as irritable bowel syndrome and diverticular disease. Prebiotics such as fructans can also facilitate the maintenance of good bacteria and facilitate absorption of calcium, iron, copper, magnesium, and phosphorus (4-8g/day of fructans)
|
|
Carotenoids—lutein and zeaxanthin
|
Eggs and eggs products; canned corn; cornmeal
|
Lutein can react with free radicals and protect low-density lipoproteins against oxidative processes. These are associated with the risk of atherosclerosis and ischemic heart disease; carotenoids, especially lutein (≥4 mg/day), are essential in the prevention (prophylaxis) of age-related sight deterioration
|
|
Plant sterols and stanols
|
Margarine, yogurt, cream cheese, yogurt drinks, mature cheeses, milk-based drinks, meat products, soy or rice-based drinks, sources for salads, rye bread, chocolate, and mayonnaise
|
Plant sterols (0.8 g/d) or stanols (1–3 g/d) decrease total blood cholesterol between 5-11% and LDL by 16%. Stanols can lower thrombocytes aggregation which is associated with the reduction of total cholesterol and LDL
|
A balanced diet is an optimal way to protect against nutrient deficiencies and maintain good health. Aging-related changes as well as the presence of other diseases can make this task a challenge. Consequently, supplementing the diet by consuming functional foods which contain an augmented quantity of a particular type of nutrient or bioactive compound can improve the state of health and well-being and/or reduction of risk of disease.
References:
- López-Varela S, González-Gross M, Marcos A. (2002) Functional foods and the immune system: a review. Eur J Clin Nutr. doi:10.1038/sj.ejcn.1601481.
- Hasler CM. (2002) Functional foods: benefits, concerns and challenges-a position paper from the american council on science and health. J Nutr. doi:10.1093/jn/132.12.3772.
Further Reading
Ultra-processed foods dominate children's diets from toddlerhood to middle childhood