Nutritional Powerhouses: Plant Foods
By Joel Fuhrman, M.D

Natural plant foods, though usually carbohydrate-rich, also contain protein and fats. On average, 25 percent of the calories in vegetables are from protein. Romaine lettuce, for example, is rich in both protein and essential fatty acids, giving us those healthy fats our bodies require.

Many large-scale epidemiological studies have shown conclusively that certain plant foods play a role in protecting the body against diseases that affect - and kill - at least 500,000 Americans each year. 

There is no longer any question about the importance of fruits and vegetables in our diet. The greater the quantity and assortment of fruits and vegetables consumed, the lower the incidence of heart attack, stoke, and cancer. There is still some controversy about which foods cause which cancers and whether certain types of fat are the culprits with certain cancers, but there's one thing we know for sure: raw vegetables and fresh fruits have powerful anti-cancer agents. Studies have repeatedly shown the correlation between consumption of these foods and a lower incidence of various cancers, including those of the breast, colon, rectum, lung, stomach, prostate, and pancreas. This means that your risk of cancer decreases with an increased intake of fruits and vegetables, and the earlier in life you start eating large amounts of these foods, the more protection you get.
Humans are genetically adapted to expect a high intake of natural and unprocessed plant-derived substances. Cancer is a disease of maladaptation. It results primarily from a body's lacking critical substances found in different types of vegetation, many of which are still undiscovered, that are metabolically necessary for normal protective function. Natural foods unadulterated by man are highly complex - so complex that the exact structure and the majority of compounds they contain are not precisely known. A tomato, for example, contains more than ten thousand different phytochemicals.

It may never be possible to extract the precise symphony of nutrients found in vegetation and place it in a pill. Isolated nutrients extracted from food may never offer the same level of disease-protective effects of whole natural foods, as nature 'designed' them. Fruits and vegetables contain a variety of nutrients, which work in subtle synergies, and many of these nutrients, cannot be isolated or extracted. Phytochemicals from a variety of plant foods work together to become much more potent at detoxifying carcinogens and protecting against cancer than when taken individually as isolated compounds.

According to Joel Fuhrman, M.D. author of "Eat to Live," pp. 52 - 53