Phytochemicals For Health

PHYTOCHEMICALS:
The most recent issue of "Nutrition and Weight Control For Longevity" 2006, from John Hopkins Medicine in Baltimore, Maryland, makes one thing perfectly clear:

The vast number of compounds in fruits, vegetables, grains and legumes makes it nearly impossible for supplements to substitute for a healthy diet. Read that one once more. It’s an important finding that I have had to emphasize in my blog site over this past year. Now, we know the rest of the story. A handful of pills cannot duplicate the complex nutritional benefits of nature.

Since first I heard of this special ingredient in fruits, vegetables and other plant foods, I was curious about its role in eating healthy. Fruits, vegetables, and other plant foods are packed with ingredients in addition to vitamins, minerals and fiber. From anthocyanins (the red pigment in strawberries and cherries) to allylic sulfides (which are responsible for the pungent flavor of garlic and onions), these compounds, which are also known as phytochemicals, may be responsible for some of the disease-preventing effects of fruits and vegetables.

Phytochemicals have no traditional nutritive value—that is, they are not vitamins or minerals—but they may have positive effects on the body over the long term. Possible beneficial effects include inhibiting tumor formation, preventing blood clots, blocking the cancer-promoting effect of certain hormones, and lowering cholesterol levels.

Studies of supplements have failed to show that a high intake of isolated minerals reduces the risk of disease. These observations raise the possibility that other substances in plant foods, namely phytochemicals, may be important in disease prevention, either on their own or in combination with antioxidants. For example, many studies have found that people who eat a diet rich in fruits and vegetables have half the risk of most types of cancer as people who eat a diet low in fruits and vegetables. By contrast, supplements of beta-carotene (present in green and yellow fruits and vegetables) do not protect against cancer in many studies. The researchers conclude that phytochemicals and other bioactive substances present in fruits and vegetables work together to protect against cancer and other diseases.

Phytochemicals are found in a wide variety of plant foods, and indeed many different phytochemicals are often present in a single food—for example, more than 170 have been identified in oranges. This vast number of compounds in fruits, vegetables, grains, and legumes makes it nearly impossible for supplements to substitute for a healthy diet. While the beneficial phytochemicals have yet to be proven, the following show some promise for disease prevention.

Allylic sulfides. Found in onions and garlic, these substances may enhance immune function, help the body excrete cancer-causing compounds, and interfere with the development of tumors.

Flavonoids. These compounds function as antioxidants. They may extend the life of vitamin C, inhibit the tumor development, prevent the oxidation of LDL cholesterol, and control inflammation. Flavonoids are found in a host of fruits and vegetables as well as in red wine, red and purple grape juice and green and black tea.