Functional Food definition and health benefits, claims, risks, nutrients and ingredients
October 16 2016 by
Ray Sahelian, M.D.

Definitions of functional food vary but are essentially based on the foods' ability to enhance the quality of life, or physical and mental performance. Health benefits are best obtained through a varied diet containing fruits, vegetables, grains, legumes and seeds. However, fortified foods and dietary supplements have been marketed and the food industry have made functional food one of their current leading trends. Recently, the number of functional foods that have a potential benefit on health has hugely grown and scientific evidence is supporting the role of functional foods in prevention and treatment of several diseases. Cancer, diabetes, heart disease and hypertension are the most important diseases that can be treated or prevented by functional foods; other diseases are osteoporosis and arthritis. The majority of cancers in the USA have a nutrition / diet component suggesting a great impact of functional food and foods components on incidence and treatment of cancer. Numerous factors complicate the evaluation of scientific evidence regarding the benefit of functional foods such as the complexity of food substance, metabolic changes associated to dietary changes, the frequency of ingestion, combination of ingestion with other functional foods, and the lack of biological markers of disease development.

List of Functional Foods
Functional foods are the focus of many studies worldwide. This is justified by the effects they have on public health and thus interest in discovery of the mechanisms involved in their benefits.

Quite a number could be considered. Some of them include:

Berries including acai berry from South America and goji berry from Asia which are growing in popularity.

Buckwheat as a Functional Food and its effects on Health - a Comprehensive Review. Buckwheat grain is a highly nutritional food component that has been shown to provide a wide range of beneficial effects. Health benefits include plasma cholesterol levelsī reduction, neuroprotection, anticancer, anti-inflammatory, antidiabetic effects, and improvement of hypertension conditions. J Agric Food Chem. 2015 Aug 13.

Dark green leafy vegetables including kale and spinach.
Flaxseeds may lower the rate of prostate cancer and are a wonderful stool softener, reducing the risk for constipation.
Pomegranate, a fruit native to the Middle East, has gained widespread popularity as a functional food and nutraceutical source. The health effects of the whole fruit, as well as its juices and extracts, have been studied in relation to a variety of chronic diseases. Promising results against cardiovascular disease, diabetes, and prostate cancer have been reported from human clinical trials. The in vitro antioxidant activity of pomegranate has been attributed to its high polyphenolic content, specifically punicalagins, punicalins, gallagic acid, and ellagic acid. Anthocyanins and the unique fatty acid profile of the seed oil may also play a role in pomegranate's health effects.

Probiotics have good bacteria. Probiotics (live micro-organisms that confer health to the host) and prebiotics (nondigestible oligosaccharides that stimulate the growth of healthy bacteria) are functional foods known to mediate immune responses and modulate microbial populations in the gut.

Royal jelly is a functional food with lots of vitamins, minerals, protein, fatty acids, and other substances that have an influence on the immune system, energy, and well being.
Salmon roe has important fatty acids and phospholipids.
Soy sauce is used widely in Japan
Whey protein, derived from milk, is a good supplement for those who have a low intake of protein.

Functional foods stand for a new category of remarkably promising foods bearing properties (i.e., low cholesterol, antioxidant, anti-aging, anticancer, etc.) that have already rendered them quite appealing. There are many classes off functional foods (pro- and pre-biotics, dietary fiber, low fat, etc.), and their definition is occasionally confused with that of nutraceuticals. Consumers' main skepticism regarding functional foods resides in the veracity of health claims and in the low and often inadequate control of their claimed properties.  A survey in 2011 by the International Food Information Council (IFIC) showed more Americans say they are aware of their health benefits, but there has been no increase over the past five years in the number of people who are eating them on a regular basis.

Is Coffee a Functional Food?
The worldwide use of coffee for social engagement, leisure, enhancement of work performance and well-being is widely recognized. Depending on the quantities consumed, it can affect the intake of some minerals (K, Mg, Mn, Cr), niacin and antioxidant substances. Epidemiological and experimental studies have shown positive effects of regular coffee-drinking on various aspects of health, such as psychoactive responses (alertness, mood change), neurological (infant hyperactivity, Alzheimer's and Parkinson's diseases) and metabolic disorders (diabetes, gallstones, liver cirrhosis), and gonad and liver function. Despite this, most reviews do not mention coffee as fulfilling the criteria for a functional food. Unlike other functional foods that act on a defined population with a special effect, the wide use of coffee-drinking impacts a broad demographic (from children to the elderly), with a wide spectrum of health benefits. However, there is a down side to coffee drinking. Coffee can cause anxiety and blood pressure problems, and it could also cause or aggravate heart rhythm abnormalities. Hence, it is possible to claim that coffee, when limited to one cup a day could be a functional food, but not when 3 or more cups are drank a day, particularly if the coffee is ingested later in the day and causes insomnia.

Nutr Hosp. 2014 Mar 1. CONSUMPTION OF FUNCTIONAL FOODS IN EUROPE; A SYSTEMATIC REVIEW. Twenty two studies were identified to examine the differences in functional food consumption between European countries. Results: Figures on consumers of functional foods reveal differences across European countries. Functional foods are popular in most of European countries like Finland, Sweden, the Netherlands, Poland, Spain and Cyprus, but not so in other countries like Denmark, Italy and Belgium. A high percentage of adolescents in the European Mediterranean countries (Spain and Cyprus, but not Italy) consume functional foods. Evaluation of functional foods consumption according to gender is difficult, because results differ from one study to another.