Phytosterol

Phytosterols are widespread in plant foods, with the best sources in seeds such as corn, oats, rice, soy, wheat and nuts.

Phytosterols reduce the risk of heart disease by lowering blood cholesterol levels and contributing to the production of ‘good’ HDL cholesterol.

Terpines

Terpines are a group of hydrocarbons which are powerful anti-oxidants.

There are three sub-groups of terpines. Each sub-group also has additional benefits:

• carotenoids are brightly-coloured pigments with wide anti-cancer action, recognisable in foods according to their colour, for example:

  • yellow and orange fruits and vegetables such as tomatoes, apricots, mangoes, carrots, pumpkin and red sweet potatoes contain lutein, lycopene, xanthophylls and carotenes, which protect DNA from damage and appear to protect against cancer including breast, colorectal, lung, prostate and uterine

  • yellow and green fruits and vegetables such as oranges, spinach, and sweet corn provide zeaxanthin, beta-cryptoxanthin, and carotenes, which appear to lower the risk of uterine cancer, agerelated blindness and cataracts

  • red fruits and vegetables such as tomatoes, watermelon, rhubarb and berries include lycopene and beta-carotene, which are highly efficient free radical scavengers, protecting against heart disease and possibly helping to prevent prostate cancer

• limonoids which occur in the peel of citrus fruit, have been shown to reduce the severity and duration of bronchial infections, so lemon drinks can help when you have a cold; those from mandarins stimulate liver production of enzymes which rid the body of harmful substances, with specific effects against cancer and heart disease

• saponins found mainly in legumes (including peanuts), with soybeans as the richest source, help lower LDL cholesterol and increase HDL cholesterol, anti-oxidant actions credited with anticancer effects and stimulation of your body's immune systems.

Organosulphur compounds

The sulphur component gives these compounds a distinctive flavour and a pungent odour when cooking, most noticeable in cabbage and onions. gllucosiinollattes iindolles tthiiosullphonattes iisotthiiocyanattes

They all help to eliminate potentially cancer-causing substances from the body, and activate production of liver enzymes that protect against cancer. There are four sub-groups of organosulphur phytochemicals, some with additional properties:

• glucosinolates present in vegetables of the cabbage and mustard families, especially in broccoli

• indoles found especially in cabbage

• thiosulphonates richly supplied in onions, garlic, leeks, shallots and chives, lower cholesterol, reduce arterial plaque, and destroy harmful micro-organisms

• isothiocyanates occur in vegetables of the mustard family including horseradish, wasabi, mustard seeds and greens.

Phenols

Phenols are flavouring molecules found most abundantly in herbs such as dill, parsley, oregano and rosemary, and also in many plant pigments.

There are more than 2 000 phenolic phytochemicals, which all act as anti-oxidants, anti-fungals, anti-infectives and antiseptics.

Some groups of phenols have additional functions, for example:

• polyphenols have anti-oxidant, anti-inflammatory, anti-clotting, anti-tumour and anti-cancer effects, reduce the risk of heart disease and include three main groups:

  • anthocyanins, the red, blue and purple pigments of beetroot, apples, blueberries, eggplants, grape juice, raspberries and tea

  • bioflavinoids in citrus fruit and nuts

  • tannins and other compounds such as resveratrol in tea, wine, grapes and peanuts, shown in some studies to play a role in maintaining brain and nerve health

• isoflavones, (also known as phyto-oestrogens because of the chemical similarity to the human female hormone, but with weaker effects in your body), are present in legumes, most richly in soy and soy products, and in other seeds such as linseed, and protect against heart disease and some cancers, especially breast cancer, can relieve menstrual and menopausal symptoms and there is evidence they can reverse osteoporosis.