What is phytochemicals?

Phytochemicals, also called phytonutrients, are naturally occurring plant chemicals that can have protective qualities for human health.

Phytochemicals are compounds found in plants that give a stimulating colour and flavour to fruits and vegetables and are vital for optimal health and disease prevention.

These phytonutrients alone or in combination with others are believed to impart beneficial effects and play a pivotal role in metabolic abnormalities such as dyslipidaemia, insulin resistance, hypertension, glucose intolerance, systemic inflammation, and oxidative stress.

Phytochemical consumption is associated with a decrease in risk of several types of chronic diseases due to in part to their antioxidant and free radical scavenging effects.

Recent research has also highlighted their potential role in improving Nutrition and Health endothelial function and increased vascular blood flow.

Why are phytochemicals important?

The health benefits of phytochemical-rich foods or concentrated nutritional supplements are often being highlighted in the medical and popular media, and hence they are an increasing topic of conversation between medical practitioners and their patients, especially those with cancer who have a particular interest in over-the-counter self-help strategies.

There is increasingly convincing evidence to show that plant phytochemicals, particularly polyphenols, have significant benefits for humans, such as reducing our risk of cancer and helping people living with and beyond treatments.

Three major groups of Phytonutrients

There are three major groups of phytochemicals:

  1. Polyphenols – subcategorised as the flavonoids, phenolic acids and other non-flavonoid polyphenols.
  2. Terpenoids – subcategorised as the carotenoids and non-carotenoid terpenoids.
  3. Thiols – includes the glucosinolates, allylic sulfides and non-sulfur containing indoles


Polyphenols (flavonoids, lignans, stilbenes, etc., see Table 1) are the most diverse group of phytochemicals and exhibit wide range of protective roles such as hypolipidemic, antioxidative, antiproliferative, and anti-inflammatory effects to reduce the onset of disease progression .

Table 1

How do phytochemicals work?

There are many phytochemicals and each works differently. These are some possible actions:

  • Antioxidant – Most phytochemicals have antioxidant activity and protect our cells against oxidative damage and reduce the risk of developing certain types of cancer. Phytochemicals with antioxidant activity: allyl sulfides (onions, leeks, garlic), carotenoids (fruits, carrots), flavonoids (fruits, vegetables), polyphenols (tea, grapes).
  • Hormonal action – Isoflavones, found in soy, imitate human estrogens and help to reduce menopausal symptoms and osteoporosis.
    Stimulation of enzymes – 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).
  • Interference with DNA replication – 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.
  • Anti-bacterial effect – The phytochemical allicin from garlic has anti-bacterial properties.
  • Physical action – 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.

Tips to increase your intake of phyto-chemicals

To maintain health, it is important to take at least 5 servings of fruit and vegetables. Studies have shown that the intake of fruits and vegetables increases antioxidant capacity and improve immunity.

These easy (and almost free) tips can help you to increase your daily intake of phytochemicals from herbs, fruits and vegetables:

Tip 1: Eat at least 5 portions of fruits and vegetables.

The World Health Organisation recommends that we eat daily at least 5 portions of fruits and vegetables. This 5 PLUS a day strategy is adopted by many countries. The 5 PLUS a day message is the most successful health promotion idea because research has shown that eating at least five portions of fruits and vegetables each day could reduce cancer rates by 20 percent.

Tip 2: Drink herbal teas

Reduce your intake of coffee and soft drinks and increase the intake of herbal tea, including ordinary tea. Today there is a large selection of teas available: camomile, linden, sage, green teas, etc.

Tip 3: Eat dried fruits as snack

You should substitute your candy and snacks with dried fruits such as prunes, apricots, dades and raisins.

Tip 4: Add herbs and spices to your meals

Spices and herbs do not only add flavour to your meals but many are loaded with phyto chemicals. Try to add following herbs and spices: parsley, sage, thyme, oregano, basil, etc.

combo pack2

Known Phytonutrients in Chaya include: Alkaloids, Anthocyanins, Anthracene, Anthraquinones, Cardiac glycosides, Coumarone, Flavonoids, Hexadecanoic acid, Lignans, Octadecenoic acid, Oxalate, Phenolics, Phlobatannins, Phytate, Propanetriol, Saponins, Triterpenes, Xanthenes.

The results showed that the leaves of Chaya contain useful chemical compounds that are both medicinal and nutritional which can be utilized for chemotherapeutical purposes and nutritional supplements.