The role of phytonutrients in prevention of diseases

WE have considered components of plant food such as minerals and vitamins in the past. These are mostly essential to the body; they are life-saving to the body, but are not produced by the body. They have to be sourced from food that we eat, water we drink and from supplements.

Also referred to as phytochemicals, the phytonutrients are plant chemicals which protect the plants against insects, bacteria, fungi and Ultra Violet (UV) radiation. The phytonutrients give colour, peculiar smell and taste to the different parts of the plants such as the fruits (dried or fresh), the leaves, the stem, tubers, flowers etc. With these, the plants are able to destroy or keep attackers at bay.

These phytonutrients, apart from such benefits to the plants, have been shown scientifically to benefit human beings, health-wise. In their activities in the body they function either as antioxi- dants, anti-inflammatory agents or immune system boosters. They also act as detoxifiers of foreign substances, especially in the liver where they also support a healthy liver.

Sources of phytonutrients

Generally speaking, phytonutrients can be sourced from veggies, fruits, whole grains, nuts, seeds, beans (legumes), herbs and spices. Phytonutrient-rich sources can also be identified by the colour, which is conferred on them by the pigments which contain the phytonutrients. For example, the green colour of leaves come from the chlorophyll that is predominantly found in them. The orange/yellow colour of carrots, papaya (paw paw), water melon and winter squash come from beta-carotene. Blue/purple foods such as blue berries, black berries, red cabbage are so because of the flavonoids in them. There are also the pink/red colour of fruits and veggies such as tomatoes, water melon and guava which are coloured by lycopene.

There are some other foods that may not be identified by these striking colours, they appear almost white but have peculiar smell and taste. Commonly, these are the sulfur-containing phytonutrients found in garlic and onions.

In terms of classification, phytonutrients can be grouped according to what type of chemicals they contain which in most cases can be determined by their colour. Others may be grouped according to their peculiar smell or taste. It is therefore common to have such groups as carotenoids, flavonoids, glucosinolates, sulforazones, phenols, ellargic acid, resveratrol, phytoestrogen, tea etc. In discussing phytonutrients, it is important to note that they are not related to any other groupings in the plant and animal kingdoms. They are a group of their own. Health benefits of phytonutrients

There are possibly up to 100,000 phytonutrients found in plants and there are different ones in different plants. The advice that human beings should have 5-9 servings of vegetables and fruits daily is so that we should have different varieties of the phytonutrients. This is so important because the phytonutrients work in synergy, allowing for optimal cellular function. Phytonutrients are mainly preventive against diseases in their role in the body. However, they may also improve the health status of individuals in certain of the chronic degenerative diseases and some actually have played curative roles.

Carotenoids

These are found in the yellow, orange and red vegetables and fruits.

Common carotenoids are alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein and zeaxanthin.

Alpha and beta-carotene and beta-cryptoxanthin are all converted in the body to vitamin A. Vitamin A is a member of the vitamin antioxidant defence system. Together with others in this group, they neutralize the harmful free radicals that destroy cells and tissues in the body. By this action, they prevent diseases such as cancer. These carotenoids also boost the immune system and improve the health of the eyes.

Lycopene prevents heart disease and prostate cancer. Indeed lycopene supports the health of the prostate gland and also prevents benign prostate hypertrophy (BPH). Tomato juice, a rich source of lycopene, taken by men of 50 years and above is said to be a sure preventive against BPH and prostate cancer.

Lutein and zeaxanthin are carotenoids that are highly concentrated in kale, collard greens and carrots. They alter the course of the three major diseases that afflict the eyes with blindness. These are glaucoma, cataract and age-dependent macular degeneration.

To summarize, the carotenoids, together prevent such conditions as heart disease, glaucoma, cataract, macular degeneration and they prevent and reduce the risk of such conditions as cancer of the prostate gland and BPH.