Phytochemicals: beyond vitamins

Phytochemicals are non-nutritive chemicals in plant foods that protect plants from microbial invasions and infections. Phytochemicals are key micronutrients that are needed for the body’s immune system they are not vitamins or minerals but they are all found in natural foods.In the simplest sense they are any plant chemicals where the prefix phyto derives from the Greek word for plant. To nutritionist,phytochemicals are plant compounds that are not already classified as vitamins or minerals.Phytochemicals give the plant colour, aroma and flavour,but when we eat them, they work with other nutrients to fend off disease and more. Some phytochemicals stimulate the immune system; others slow the growth of cancer cells.

Several thousand have been identified, and certainly many more await discovery. What makes this area of nutrition research so exciting is that not only does the list keep growing, but researchers are also continually learning more about how important these compounds are to human health.Phytochemicals are not essential to humans i.e., not required by the body to sustain life, but they are essential to plants such as fruits and vegetables. They are part of a plant’s self-protection program, helping shield young buds and sprouts from predators, pollution, the elements and more. When we eat fruits and vegetables, they pass along many of these protective benefits to us.

There are many phytochemicals and each works differently, many phytochemicals are antioxidants e.g. Lycopene, quercetin and betacarotene are some of the better-known antioxidantphytochemicals. Organized into such basic groupings as carotenoids, flavonoids, isoflavones, and allylic sulfides, they are found in fruits, vegetables, nuts, legumes, and grains.Some other possible actions of phytochemicals include: Indoles, which are found in cabbages, stimulate enzymes that make the estrogen less effective and could reduce the risk for breast cancer. Other phytochemicals, which interfere with enzymes, are protease inhibitors (soy and beans), terpenes (citrus fruits and cherries).Isoflavones, found in soy, imitate human estrogens and help to reduce menopausal symptoms and osteoporosis.Saponins found in beans interfere with the replication of cell DNA, thereby preventing the multiplication of cancer cells. Capsaicin, found in hot peppers, protects DNA from carcinogens. Some phytochemicals bind physically to cell walls thereby preventing the adhesion of pathogens to human cell walls. Proanthocyanidins are responsible for the anti-adhesion properties of cranberry. Consumption of cranberries will reduce the risk of urinary tract infections and will improve dental health.The phytochemical allicin from garlic has anti-bacterial properties.

As yet, there are no official dietary requirements forphytochemicals. Scientists are steadily addressing this void, and as they isolate, identify and studyphytochemicals, they hope to gather sufficient data to make dietary recommendations. For now eating lots of plant
foods rich in phytochemicals may help to prevent at least one in every five cases of cancer, as well asother serious ailments such as heart disease.


Over the course of research and study of phytochemicals Scientists have identified the three major classes of plant chemicals as terpenoids, phenolic metabolites, and alkaloids and other nitrogen-containing plant constituents

The terpenoidsinclude: monoterpenoids, iridoids, sesquiterpenoids,sesquiterpene lactones, diterpenoids, triterpenoid saponins, steroid saponins, cardenolides and bufadienolides, phytosterols, cucurbitacins, nortriterpenoids,other triterpenoids and carotenoids.

The phenolic metabolites include anthocyanins, anthochlors, benzofurans, chromones, coumarins (minor flavonoids)flavonones and flavonols, isoflavonoids.Lignans, phenols and phenolic acids, phenolic ketones, phenylpropanoids, quinonoid, stilbenoids, tannins andxanthones

The alkaloids include: amaryllidaceae, betalain, diterpenoid, indole, isoquinoline, lycopodium, monoterpene, sesquiterpene, peptide, pyrrolidine and piperidine, pyrrolizidine, quinoline, quinolizidine, steroidal, and tropane compounds.

Other nitrogen-containing constituents include: nonprotein amino acids, amines, cyanogenic glycosides, glucosinolates, and purines and pyrimidines.

The largest group of phytochemicals comprises the phenolic chemicals. Plant polyphenols are secondary metabolites that are widely distributed in plants.Some of the well-known phytochemicals are lycopene in tomatoes, isoflavones in soy and flavonoids in fruits.



Phytochemical(s) Plant Source Possible benefits
(beta‐carotene, lycopene, lutein,
Red, orange and green fruits and
vegetables including broccoli, carrots,
cooked tomatoes, leafy greens, sweet
potatoes, winter squash, apricots,
cantaloupe, oranges and watermelon.
May inhibit cancer cell growth, work as antioxidants and improve immune response
(anthocyanins, quercetin)
Apples, citrus fruits, onions, soybeans and
soy products (tofu, soy milk, edamame,
etc.), coffee and tea
May inhibit inflammation and tumour growth; may aid immunity and boost production of detoxifying enzymes in the body
Indoles and Glucosinolates
Cruciferous vegetables (broccoli,
cabbage, collard greens, kale, cauliflower
and Brussels sprouts)
May induce detoxification of carcinogens, limit production of cancer‐related hormones, block carcinogens and prevent tumor growth
(phytic acid)
Bran from corn, oats, rice rye and wheat,
nuts, soybeans and soy products (tofu,
soy milk, edamame, etc.)
May retard cell growth and work as antioxidant
(daidzein, genistein)
Soybeans and soy products (tofu, soy
milk, edamame, etc.)
May inhibit tumor growth, limit production of cancer‐related hormones and generally work as antioxidant
Isothiocyanates Cruciferous vegetables (broccoli,
cabbage, collard greens, kale, cauliflower
and Brussels sprouts)
May induce detoxification of carcinogens, block tumor growth and  work as antioxidants
(ellagic acid, resveratrol)
Green tea, grapes, wine, berries, citrus
fruits, apples, whole grains and peanuts
May prevent cancer formation, prevent

inflammation and work as antioxidants

(perillyl alcohol, limonene, carnosol)
Cherries, citrus fruit peel, rosemary May protect cells from becoming cancerous, slow cancer cell growth, strengthen immune function, limit production of cancer‐related hormones, fight viruses, work as antioxidant


Some of the most important phytochemicals are plant pigments, such as carotenes, chlorophyll, and flavonoids. Although these phytochemicals work in harmony with antioxidants such as vitamin C, vitamin E, and selenium, they also offer considerably greater protection against cancer than these simple nutrients do. A considerable amount of research indicates that accessory nutrients and phytochemicals are critical in the battle against the development of many chronic degenerative diseases, such as heart disease and cancer. Although some of these valuable food components are available as dietary supplements, in many cases accessory nutrients and phytochemicals are even more bioavailable in foods. This fact once again shows the tremendous healing power of a whole-food diet.


The Problem with the current medical and pharmaceutical industry is that most nutrition products only focus on vitamins and neglect the power of secondary phytochemicals. Unfortunately this due to lack of the previous study on these essential nutrients, though this is changing. A ‘big bang’ is currently impacting the food, health and pharmaceutical industries, among others. This ‘big bang’ derives from an explosion in research and publications providing scientific evidence to
support hypotheses that phytochemicals in foods and in isolated form provide health benefits to the consumer. No longer is ‘an apple a day keeps the doctor away’ a cliche ´ quoted solely by persuasive mothers

Phytochemicals, that have the potential of being incorporated into foods or food supplements as nutraceuticals The term nutraceutical was coined by DeFelice, director of the Foundation for Innovation in Medicine. A nutraceutical is any non-toxic food extract supplement that has scientifically proven health benefits for both disease treatment and prevention. With the mission to help people heal we offer pure monomer flavonoid Phytochemicals. For example, we have a product containing 5 different flavones found in different plants

Baicalein- skullcap
Apigenin- Chamomile
Luteolin- Sophora Japonica
Chrysin- passionflower


Cora J Dillard and J Bruce German(2000), ReviewPhytochemicals: nutraceuticals and human health, journal of science of food and agriculture

DeFeliceSL(1995), The nutraceutical revolution: its impact on food industry R&D. Trends Food SciTechnol 6:59–61.

Haslam E(1998), Practical Polyphenolics: From Structure to Molecular Recognition and Physiological Action, Cambridge UniversityPress, Cambridge, UK

Karrie Heneman, Sheri Zidenberg-Cherr, NUTRITION AND HEALTH INFO SHEET PHYTOCHEMICALS, University of California (publication 8313)

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