Nutraceuticals: Definition, Types and sources

The nutraceuticals are the plant based foods that naturally provides medical value, which can even prevent and treat diseases. The Nutraceuticals is derived from the words nutrition and pharmaceuticals in 1989 by stephen DeFelice.

The oral bioavailability of a nutraceuticals (health-promoting dietary component ) may be limited by various physicochemical and physiological phenomena like solubility in gastrointestinal fluids, interaction with gastrointestinal components, chemical degradation or metabolism, and epithelium cell permeability.

Algae, Fungi, Bacteria, Animal & Plant origins comes under Nutraceuticals.

Foods That Comes Under Nutraceuticals

  • These are vitamins and minerals, amino acids, fatty acids.
  • These are herbal and botanical products.
  • Foods for viability or functional and medical foods, health foods, organic foods.
  • Sports and energy products and natural medical products with specific health benefits.


  • Antioxidants are the substances which prevents deterioration and damage caused by oxidation.
  • During oxidation, free radicals are generated. These antioxidants are powerful scavengers of free radicals.
  • Free radicals disrupt the equilibrium of biological system by damaging their major constituent molecules (lipids, proteins, DNA, carbohydrates). These eventually leads to cell damage.
  • Dietary antioxidants are zinc and certain antioxidants are important.
  • Antioxidants are found in oils like soya bean, canola oil, oats, wheat germ oil, palm oil, evening primrose oil.
  • Action of antioxidants- They reduce the action of free radicals, suppress the free radical formation and also repair the damaged cell and reconstitute membrane.

Types Of Foods Used In Nutraceuticals

  1. Probiotics
  2. Dietary Fiber
  3. Prebiotics
  4. Polyunsaturated fatty acids
  5. Antioxidant vitamins
  6. Polyphenols

1. Probiotics:

These are live microbial food ingredient which are beneficial to health. these are adhered to gastrointestinal tract and competitive exclusion of pathogens. The main aim to introduce probiotics is to transform the toxic flora of the large intestine into a host-friendly colony of Bacillus bulgaricus.

  Probiotic Species Includes:

Streptococcus, Enterococcus, Saccharomyces, Bacillus, Pediococcus.

  1. Lactobacilli – L. acidophilus, L.casei, L.delbrueckii subsp. bulgaricus, L.brevis, L.cellobiosus.
  2. Gram-positive cocci – Lactococcus lactis, Streptococcus salivarius subsp. thermophilus, Enterococcus faecium
  3. Bifidobacteria – B.bifidun, B.adolescentis, B.infantis, B.longum, B. thermophilum.

These also improve the health. The most dense probiotic populated area after GI tract. It has capacity to tie with pancreatic juice. It compete with bad bacteria to adhere on gut wall. To compete with nutrients and stimulate immunity. It alter the intestinal microflora balance. It inhibit the growth of harmful bacteria which promotes digestion, improves intestinal system.

Specific probiotics are generally used to treat gastrointestinal (GI) conditions such as lactose intolerance, acute diarrhea and antibiotic-associated GI side effects. Probiotic agents possess the properties of non-pathogenic, non-toxic, resistance to gastric acid, adherence to gut epithelial tissues producing antibacterial substances. There are evidences that administration of probiotics decreases the risk of systemic conditions, such as allergy, asthma, cancer and several other infections of the ear, urinary tract.

Probiotics are available in various forms like powder form, liquid form, gel or paste or granule forms, capsule forms etc.

Food Source:  Yogurt, kombucha, sauerkraut, pickles, kimchi, certain bread and some cheeses.

2. Dietary Fiber

Dietary fibre is the food material, found in the plant material that is not hydrolyzed by digestive tract enzymes, but can digested by microflora in the gut. Dietary fibres are mostly found in celluloses, hemicelluloses, gums and pectins, lignin, resistant dextrins and resistant starches.

Chemically, dietary fibre is said to be a carbohydrate polymers with a degree of polymerization not lower than 3, which can digested or not absorbed in the small intestine.

Dietary fibres are classified into two types based on their water solubility: –

  1. Water Insoluble Dietary Fiber and
  2. Water Soluble Dietary Fiber

Dietary Insoluble Fiber:

This insoluble fiber is not soluble in water. We know that, generally fiber is found in mostly plant based foods, which cannot be digested and absorbed by the body. Insoluble dietary fiber makes the food moves through the gastrointestinal tract more easily and make loosen the stools and reduce constipation. It also useful for the removal of bad cholesterol from the body.

Water insoluble fiber includes β-glucans, pectins, gums, mucilages and hemicelluloses that are fermented in the colon.

Food Source: Whole-wheat flour, wheat bran, nutsbeans and vegetables, such as cauliflower, green beans, onions, tomato, cucumbers and potatoes and fruits like apple, orange, pineapple, plum ,apricot

Water Soluble Dietary Fiber:

This fiber is soluble in water and forms a gel like texture which binds to the stools and inhibit non-propulsive colon contraction and also helps in bulking of stools and quick passage through digestive tract which reduce constipation or irregular stools. This fiber affects the rate of digestion and the uptake of nutrients. Soluble fibre lowers serum LDL cholesterol and to improve glucose tolerance. Fiber also decrease the appetite by feeling full longer.

 It is also found in psyllium, a common fiber supplement. Some types of soluble fiber may help lower risk of heart disease

Soluble fiber includes celluloses, some hemicelluloses and lignins which is fermented to a limited extend in the colon.

Food Source: Oats, dried beans, legumes, apple, nuts, seeds, peas, lentils, barley and other fruits and vegetables.

3. Prebiotics

Prebiotics are compounds in food that suppress the growth or activity of useful microorganisms like bacteria and fungi. Prebiotics can alter the composition of organisms in the gut microbiome. The most common example is in the gastrointestinal tract. Prebiotics are dietary ingredients that beneficially affect the host by selectively altering the composition or metabolism of the gut microbes.

Food Source: whole grains, bananas, greens, onions, garlic, soybeans.

4. Polyunsaturated Fatty Acid (PUFA)

PUFA are fatty acids that contain more than one double bond in their structure. PUFA rich oils instead of saturated fats and other unhealthy fats can reduce the risk of heart disease. PUFA contains Omega 3 fatty acids which contains strong anti-inflammatory properties which lower risk of heart disease, Alzheimer’s disease, improves vision and boost brain health. 

Food Source: Walnuts, soya bean oil, flax seeds, sunflower seeds, Salmon fish, mackerel, tuna, poultry and eggs.

5. Antioxidant Vitamins

Antioxidants include the vitamins A, C and E, and the minerals copper, beta-carotene, zinc and selenium. These may help to protect cell damage caused by free radicals. Plant based products are very best to get sufficient antioxidants. Naturally occurring antioxidants also include flavonoids, tannins, phenols and lignin’s. 

Food Source: All berries like strawberry, blackberry, raspberry, Blueberries etc., pecans, sweet potatoes, cabbage, beetroot, kale, spices and other vegetables.

6. Polyphenols:

Polyphenols are micronutrients that confer on fruits and vegetables mostly but it is absent in animal foods. These contains antioxidants, catechins, hydroxy acids and leucoanthocyanins. These are present in the tissues of woody plants such as apples, almonds, peaches, and grapes. Presence of polyphenols effect the quality of fruit. So that polyphenols may improve digestive problems, weight management, diabetes, and cardiovascular diseases.

Food Source: Seasonings like cloves, ginger, garlic, rosemary saffron etc., berries, cocoa powder, all fruits and vegetables, nuts, soy products, green tea,


The natural foods that are medicinally valued are known as nutraceuticals. These are abundantly food in basic 5 food groups like fruits, vegetables, spices, nuts, cereals, milk products. By taking nutraceuticals regularly in required amounts may help to maintain good health by improving digestive health, by preventing many diseases. Generally, most of the nutraceuticals are found in plant based foods. So, it is very best to consume more and more plant based food items.