by R. Drum

Created on: July 20, 2009

Phytochemicals are compounds that occur naturally in plants and that may benefit human health. Phytochemicals are the ever-tantalizing but not-yet-unraveled mystery in nutrition science. There is an ever-increasing body of scientific research demonstrating that a diet rich in vegetables and fruits has a multitude of health benefits, including decreasing the risk of heart disease and stroke, lowering blood pressure, protecting from some types of cancer, guarding against cataracts and macular degeneration, and improving learning and memory. But nutrition science still doesn't have enough reliable evidence to decide whether consuming a specific phytochemical will produce a desired health benefit. Without such evidence, the

FDA won't allow nutritional supplement makers to advertise, for example, that consuming the phytochemical lycopene (abundant in tomatoes and tomato sauce) decreases the risk of heart disease or prostate cancer.

The two most-studied sub-categories of phytochemicals are flavonoids and carotenoids. Flavonoids are the red, blue, and purple pigments in plants. Quercetin is a phytochemical flavonoid present in tea, wine, apples, cranberries. Rutin is another phytochemical flavonoid found in citrus fruits and sometimes added to vitamin C supplements. Beta-carotenoids are phytochemicals that can be converted to vitamin A in the body, and are present in carrots, pumpkins, and oranges. Lycopene is another phytochemical carotenoid plentiful in tomatoes, grapefruit, watermelon and apricots.

The health benefits of these phytochemicals have some scientific backing. For example, a 15-year study showed that Danish men who ate the the highest amount of beta carotene-rich foods had a 20% lower risk of developing heart disease. (Source: Journal of Nutrition 2008;138:344-350). Another well-publicized study showed the phytochemical flavonoids in blueberries, in particular anthocyanins and flavanols, can enhance learning and memory by stimulating existing brain cell connections and by promoting regeneration of the pathways between brain cells. Tea, whether green, black or oolong contains high levels of the phytochemical polyphenols (e.g., catechin, gallaogatechin, epicatechin) which have strong antioxidant activity, contributing to tea's beneficial effects against high cholesterol, diabetes and obesity.

While nutritional science hasn't solved the puzzle of phytochemicals, it's still wise to follow your Mother's sage advice and eat all your vegetables and fruits every day. For optimal health, you should be consuming at least 4 cups of fruits and vegetables every day. Potatoes, while very popular and widely-available, grow underground and don't provide the phytochemicals your body needs. Strive to eat a wide variety of different kinds and colors of fruits and vegetables, to give yourself plenty of phytochemicals. Dark leafy greens, cooked tomatoes, and anything that's a rich yellow, blue, orange, purple or red color will be a good source of phytochemicals. Get into the habit of having some fruits and vegetables with every meal, and every day. For starters, fill half your plate with vegetables and fruit at each meal. Eat more dark green salads or fruit salads. Fruits and vegetables can be healthful and low-calorie snacks as well.

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