Health benefits of functional foods

Food is made up of chemical compounds called nutrients. The six basic nutrients include proteins, carbohydrates, fats, vitamins, minerals and water. Different foods contain different amounts of nutrients. Most foods contain all three energy providers (carbohydrates, fats and proteins) as well as vitamins, minerals (body regulators), water and other substances. The amount of energy a food provides depends on how much carbohydrate, fat and protein it contains. Food and nutrition play a great role in maintaining and improving overall health. Healthy and balanced nutrition develop our immune system to prevent illnesses as well as contributes to the health of all parts of our body. The benefits of good nutrition can be found in our physical and mental health because a healthy diet provides adequate energy, promotes good sleep and prevents illness. All food is essentially functional as it provides energy and nutrients (nutritional function).Different foods have different tastes (sensory function). However functional foods (healthy foods) perform specific ‘physiological function.’

What are functional foods?

Functional food is any fresh or processed food claimed to have a health – promoting or disease preventing property beyond the basic function of supplying nutrients. Functional food is defined as “any modified food or food ingredient that may provide a health benefit beyond the traditional nutrient it contains" (American Dietetic Association 1995). Functional foods provide essential nutrients necessary for normal maintenance, growth and development and/or provide other biologically active components that impart health benefits or desirable physiological effects.Fruits and vegetables contain many different phytochemicals which reduce risk for cancer and heart disease. Polyphenolic compounds in purple grape juice support normal, healthy cardiovascular function. Sulforaphane in broccoli reduces cancer risk. Tomato is rich in lycophene, a compound that may reduce prostate cancer risk. Soy protein reduces cholesterol levels. Omega-3 fatty acids in fish or flaxseed reduce risk of heart disease and strengthen bone joints. Garlic has sulfur compounds that reduce risk for cancer and heart disease. Oats and oat-containing foods, with soluble fiber beta glucan, reduce cholesterol level. Yogurt and fermented dairy products contain probiotics which may improve gastrointestinal health. Catechins in black and green tea reduce risk of cancer.

Kinds of functional foods

Functional foods can be whole or fortified foods, enriched, or enhanced foods or dietary components that may reduce the risk of chronic disease and provide a health and physiological benefit beyond the traditional nutrients it contains.

Conventional foods are the most basic of the functional foods because they haven't been modified by enrichment or fortification; they're still in their natural state. Most whole fruits and vegetables fall into this category because they're rich in phytochemicals such as lycophene and lutein as well as other beneficial compounds. E.g., "Diets rich in whole grain foods and other plant foods and low in total fat, saturated fat, and cholesterol may reduce the risk of heart disease and some cancers.”

Modified foods have been enriched, fortified or enhanced with nutrients or other beneficial ingredients. Calcium fortified orange juice, folic acid enriched breads and margarine enhanced with plant sterols are functional foods that have been modified. Energy drinks that have been enhanced with herbs such as ginseng and guarana, as well as other potentially controversial foods, also fall into this category.

Fortified foods are foods that have nutrients added to them to boost the levels that are naturally present or to restore nutrients lost during processing e.g., white bread enriched with vitamins and minerals. Super fortified foods include orange juice with Echinacea or salad dressing with PUFAs. A food that is rich in a particular nutrient or some bioactive substance is called super foods.

Dietary supplements are defined as any product (other than tobacco) that is intended to supplement the diet and contains one or more of the following: a vitamin, mineral, herb or other botanical; an amino acid or metabolite; an extract; or any combination of the previously mentioned items. It is not represented as a conventional food or as sole item of meal/diet; and labeled as a dietary supplement. E.g., Calcium, vitamin D, and osteoporosis: Adequate calcium throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis e.g., sodium and hypertension: Diets low in sodium may reduce the risk of high blood pressure, a disease associated with many factors.

Nutraceuticals

A nutraceutical is a bioactive material isolated or purified from foods that is generally sold in medicinal forms not usually associated with foods. Stephen DeFelice, founder of the Foundation for Innovation in Medicine coined the term “nutraceutical” in 1979. Nutraceuticals are naturally – derived, bioactive (usually phytochemical) compounds that have health promoting, disease preventing or medicinal properties (Lachance and Saba2002).A nutraceutical is claimed to have a physiological benefit or provide protection against chronic disease. Thus, nutraceuticals are more correctly defined as parts of a food or a whole food that have a medical or health benefit, including the prevention and treatment of disease. The difference between a nutraceutical and functional food is that nutraceutical refers to nearly any bioactive component that delivers a health benefit, commonly in supplemental form and functional foods are only in food form e.g., linumlife is a lignan extract of flax which may protects prostate health. Fenulife is another product of fenugreek galactomannon that controls blood sugar. Marinol with mega 3 –fattyacid, DHA and EPA may protect heart health. Nutraceuticals can be prepared by manipulating the diet to get maximum level of active components or by combining food ingredients rich in nutraceuticals or by fortifying food with active ingredients or by fermentation of food products. Concentration, time and duration of supply of nutraceuticals influence human health. By manipulating the foods, the concentration of active ingredients can be increased. Diet rich in nutraceuticals along with regular exercise, stress reduction and maintenance of healthy body weight will maximize health and reduce disease risk.

Medical foods

Generally medical foods and dietary supplements are not considered functional foods. Medical foods refer to a food formulated to be consumed or administered internally while under the supervision of a physician. Medical foods are not regular foods. They’re orally administered dietary products formulated for the management of diseases for which specific nutritional requirements have been established. Medical foods may be used to treat diabetes, obesity or heart disease. Some medical foods were designed for the unique nutritional needs of patients with inherited metabolic disorders. Medical foods are specially formulated and processed for partial or exclusive feeding of a patient orally or by enteral tube. It can be used for patients with limited/impaired capacity to ingest, digest, etc. Medical foods used for managing metabolic syndrome, type 2 diabetes, and cardiovascular disease are designed to improve lipid profiles and blood sugar levels, combat insulin resistance, and support favourable changes in body composition (i.e., increased lean body mass). These products generally have a low glycaemic index and often contain folic acid, vitamin B6, and soy fibre, nutrients that help normalize serum homocysteine levels, a known risk factor for cardiovascular disease. In addition to these nutrients, medical foods promoting cardio-metabolic health may contain formulated blends of plant sterols, dietary fibre, herbal extracts, and soy protein. Axona® (caprylic triglyceride) is marketed as for dietary management of Alzheimer disease. Limbrel® (flavocoxid™) is marketed for osteoarthritis.

  Natural functional foods

Fiber is a functional food because it may reduce the risk of chronic disease and provide a health and physiological benefit beyond the traditional nutrients it contains. There are three physiological effects of dietary fiber that currently have sufficient scientific evidence to be recognized as characteristics of dietary fiber—a positive effect on laxation, attenuation of blood cholesterol levels, and/or attenuation of blood glucose levels; increasing the water-binding capacity of the feces, and softening stools. Dietary Fiber consists of non-digestible carbohydrates and lignin that are intrinsic and intact in plants. The fiber in oat meal can help reduce the risk of heart diseases.

Blueberries are often referred to as a natural functional food/super-food. Blueberries contain anthocyanins (flavonoids), the antioxidant pigments and various phytochemicals possibly having a role in reducing risks of some diseases, including inflammation and certain cancers. Researchers have shown that blueberry anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins inhibit mechanisms of cancer cell development.

Herbal tea extracts is regarded as functional dietary food supplements due to their significant content of total polyphenols. These bioactive substances have significant radical scavenging capacity. Consumption of a diet rich in polyphenols has been linked with a reduced risk for cardiovascular diseases and certain types of cancer. These dietary natural antioxidants strengthen the endogenous antioxidant system by reducing oxidative stress and the risk of toxic diseases.

Soybean is in use for more than 5000 years in China and South East Asia as food. "Soybean is a treasure box of functionality." Dry soybean contain 36% protein, 19% oil, 35% carbohydrate (17% of which dietary fibre), 5% minerals and several other components including vitamins. The U.S. Food and Drug Administration (FDA) approved in 1999 a health claim for use on food labels which stated that daily diet containing 25 g/day of soy protein, which is also low in saturated fat and cholesterol, may reduce the risk of heart disease. Modest reductions in serum LDL cholesterol levels have been achieved with soy intake, especially for subjects with hypercholesterolemia. The major effects of soybean soluble fibres on serum lipoproteins appear to be related with bile acid binding and with a decrease in the reabsorption of bile acid. Soybean contains several components with anticancer activity, such as, isoflavones, protease inhibitors, phytosterols, saponins, phenolic acids, and phytates.

Honey contains about 0.5% proteins, mainly enzymes and amino acids (General Tonic). Fructose is the main sugar in most honeys. Three main honey enzymes are diastase (amylase), decomposing starch or glycogen into smaller sugar units, invertase (sucrase, glucosidase), decomposing sucrose into fructose and glucose, as well as glucose oxidase, producing hydrogen peroxide and gluconic acid from glucose. Honey contains a number of trace elements(chrome, manganese and selenium, sulphur, boron, cobalt, fluorine, iodine, molybdenum and silicon).Long term ingestion of honey (sweet medicine)can improve gut and gastroenterological health, improve the immunological reaction towards infections and cardiovascular health.

Fish oil is one of the most popular functional ingredients containing high omega 3 fatty acid and are used widely for various purposes such as cardiovascular health, vision acuity, anti-inflammation, mother and child health. Fish oils are used for their anti-inflammatory and hypolepidemic (lowers blood triglyceride levels) effects. Essential Fatty acids, particularly DHA and EPA, are 10 to 100 times more concentrated in fats from marine sources such as fish than from terrestrial sources. The US Food and Drug Administration (FDA) currently allow omega-3 fatty acid supplements to bear the following qualified health claim: “Consumption of omega-3 fatty acids may reduce the risk of coronary heart disease." Scientists recommend a daily intake of 2.0-4.0 gram fish oil containing about 25% Omega-3 or 30-60 gram of oily fish per day. Omega-3 fatty acids have shown benefits in rheumatoid arthritis, systemic lupus erythrematosus, Crohn disease, ulcerative colitis and immunoglobulin A nephropathy. There is also increasing evidence that diets high in fish may protect against the development of Alzheimer disease and prostate cancer.

Summary

Functional foods/foods for health are an important part of an overall healthful lifestyle that includes a balanced diet and physical activity. Health claims confirm a relationship between components in the diet and reduced risk of disease or health condition, as approved by FDA and supported by significant scientific agreement. The functional foods are thought to provide benefits beyond basic nutrition and may play a role in reducing or minimizing the risk of certain diseases and other health conditions. Examples of these foods include fruits and vegetables, whole grains, fortified foods and beverages and some dietary supplements.