Q: I read briefly in a magazine about the beneficial effects of phytochemicals. What exactly are these chemicals? In which foods can we find them and how do they help our body?

PM, Calcutta

Phytochemicals are a large group of beneficial chemicals of plant origin (phyto means plant) that are found in vegetables, fruits and a few grains. These chemicals have been found to play a vital role in strengthening our immune system and in regulating the hormones and enzymes in our body, thereby protecting us from diseases like cancer, hypertension and heart disease, arthritis and joint pains, macular degeneration of the eye and cataracts and perhaps diabetes and osteoporosis. In many cases these drug-like chemicals even reverse the disease conditions.

Here?s a glimpse at what phytochemicals can do in our lives:

The phytochemical ?carotenoids? are a group of some 500 different compounds found widely in everyday coloured fruits and vegetables. Two of these carotenoids ?lutein? and ?zeaxanthine? have a special relevance for the eyes. These yellow-coloured pigments found in green leafy vegetables, corn and kale can get specifically deposited in the macula of the eye and half absorb the high-energy blue portion of the spectrum of light, thereby protecting the sensitive retina from damage. This greatly reduces the risk of developing age-related macular degeneration of the eyes. These pigments prevent cataract of the eye.

Lutein and other carotenoids like lycopene, indoles and beta-carotene along with chlorophyll ? all found in dark green, leafy vegetables, cruciferous vegetables (cabbage, cauliflower, turnips, radish, horseradish), tomatoes, watermelon, germinated wheatgrains and seaweed (cooking does not destroy them) have a direct effect on our immune system. By increasing the number of lymphocytic ?helper T-cells? and ?killer T-cells? and enhancing their effectiveness, these compounds reinforce our body?s defence against bacterial and viral infections and against cancer cells. These carotenoids are not only helpful in preventing a wide variety of cancers but also in destroying tumour cells and slowing the growth and spread of tumours.

Other phytochemicals: Isothlocyanides found in cruciferous vegetables can suppress colon cancer. Bioflavonoids isolated from decaffeinated green tea have been found to have properties similar to the beta-blocker drug propanolal (Inderal) in lowering the blood pressure. Black and green tea contain chemicals that probably lower blood sugar. Phytoestrogens present in soya and in smaller amounts in citrus fruits, licorice, pulses and aniseed can bind the xeno-estrogens, thus decreasing the risk of breast cancer. They also help menopausal symptoms. Ellagic acid found in grapes, apples, strawberries and raspberries enhance the enzyme system that help neutralise carcinogens.