Phytochemicals

Phytochemicals are compounds found in plant-derived foods (phyto means plant) that are biologically active in the body. Essentially, they are disease-fighting mechanisms for plants. These natural plant-based chemicals have antioxidant activity and are involved in regulating bodily functions and metabolic processes that help to maintain optimum health.

A deficiency of phytochemicals from the diet has not been linked to specific diseases. However, an abundance of them may prevent the development of diseases, such as cancer and heart disease.

The existence of phytochemicals has been known for some time, but their link to health and nutrition has only been scientifically researched in detail during the last few years. There are tens of thousands of phytochemicals, and only some of these have been researched - new phytochemicals are being discovered almost daily. The majority of phytochemical research has been related to the prevention of cancer.

Each food has a unique variety of phytochemicals and these compounds are responsible for the characteristics of foods, such as taste, aroma and colour. For example, phytochemicals give garlic it's strong flavour and peppers their 'hot' sensation.

Variety is key

The actions of phytochemicals may be complementary or overlapping - which reinforces the fact that people should eat a variety of foods. Researchers have found that a variety of foods in our diet is essential because mixtures of these protective compounds are more effective than single compounds.

Scientific validation for the protective power of food is accumulating. The best way to ensure that your diet has a healthy amount of phytochemicals is to eat a wide variety of different vegetables and fruits, cooked in different ways. Eat at least five servings of fruits and vegetables a day.

Flavonoids

Flavonoids are a large group of phytochemicals found in whole grains, tea, red wine, vegetables, fruit, herbs and spices. They are powerful antioxidants that may help to protect against heart disease.

Soybeans

Soybeans are a rich source of protein and a variety of phytochemicals, including phytosterols. Soy protein and phytosterols lower serum cholesterol and protect against heart disease.

Scientists have discovered that people who traditionally eat a soyfood-rich diet have reduced incidence of cancers of the breast, colon and prostate. The soy components that have been identified as biochemically active are isoflavones. Besides having anticancer activities, soy isoflavones lower cholesterol and can behave like oestrogens. Soy isoflavone effects may also include heart protection, free radical scavenging and protection against kidney disease and osteoporosis.

Tomatoes

Lycopene is the pigment that gives tomatoes, guava, papaya, pink grapefruit and watermelon their red colouring. It acts as a powerful phytochemical with an antioxidant effect and it appears to be protective against certain cancers.

Garlic

For centuries, garlic has had a reputation as a healing plant. Recent studies show that populations that consume large quantities of garlic have a much lower incidence of cancer. Garlic contains various phytochemicals, most from the sulphur compound family of allylic sulfides. Scientists believe that garlic components, such as s-allyl cysteine and allicin (a derivative of allium), are responsible for the healing properties of garlic. Garlic may also reduce the risk for coronary heart disease.

Grapes

Researchers have been studying causes for the phenomenon called the French Paradox. The French consume a diet rich in high-fat foods, yet they have a low incidence of heart disease. Originally, wine appeared to be the obvious reason for protection. It is however now known that it is not the alcohol content of wine, but actually the juice and skin of red and purple grapes that may be responsible for the low heart disease incidence in the French.

Grapes contain phytochemicals called polyphenolic antioxidants that have been shown in animal studies to prevent cancer-related tumours. Researchers have isolated a biologically active flavonoid called resveratrol, that may play a crucial role in preventing heart disease and cancer, as well as promoting good health and well being.

Grape seeds

Grape seeds contain protective compounds called oligomeric proanthocyanidins that scavenge free radicals and promote growth and repair of connective tissue. They inhibit destructive enzymes and also reduce inflammation. Researchers have reported on the superior antioxidant effects of oligomeric proanthocyanidins, which are derived from grape seeds, tea or the bark of Bordeaux pine trees. Research has also demonstrated benefits such as the repair of connective tissue including skin, tendons, ligaments, blood vessels, and organ and body cavity linings.

Increasing your phytochemical intake

·    Serve chicken topped with blackberries and peach slices.

·    Combine green, red or yellow peppers, radishes, onions, broccoli stems, cabbage and carrots as a salad.

·    Add a cup of grated carrots, apples or baby marrows to muffin batter.

·    Add corn kernels or finely chopped peppers to bread batter.

·    Top a pizza with artichokes, asparagus and onions.

·    Serve sliced tomatoes with a little pesto.

·    Combine spinach and garlic with crumbled feta cheese as a side dish.

·    Dice a block of firm tofu, saute lightly, add to a sauce of your choice and add to pasta.

·    Add chopped garlic and ginger to your food.

·    Grate the peel of lemons and oranges into your dishes for a citrus flavour.