Health benefits of fruit and vegetables are from additive and synergistic combinations of phytochemicals.

Liu RH.

Department of Food Science and the Institute of Comparative and Environmental Toxicology, Cornell University, Ithaca, NY 14853, USA.

American Journal of Clinical Nutrition. 78(3 Suppl):517S-520S, 2003 Sep.

Abstract
Cardiovascular disease and cancer are ranked as the first and second leading causes of death in the United States and in most industrialized countries. Regular consumption of fruit and vegetables is associated with reduced risks of cancer, cardiovascular disease, stroke, Alzheimer disease, cataracts, and some of the functional declines associated with aging. Prevention is a more effective strategy than is treatment of chronic diseases. Functional foods that contain significant amounts of bioactive components may provide desirable health benefits beyond basic nutrition and play important roles in the prevention of chronic diseases. The key question is whether a purified phytochemical has the same health benefit as does the whole food or mixture of foods in which the phytochemical is present. Our group found, for example, that the vitamin C in apples with skin accounts for only 0.4% of the total antioxidant activity, suggesting that most of the antioxidant activity of fruit and vegetables may come from phenolics and flavonoids in apples. We propose that the additive and synergistic effects of phytochemicals in fruit and vegetables are responsible for their potent antioxidant and anticancer activities, and that the benefit of a diet rich in fruit and vegetables is attributed to the complex mixture of phytochemicals present in whole foods.

More Americans are eating "5 a day" but intakes of dark green and cruciferous vegetables remain low.

Johnston CS. Taylor CA. Hampl JS.

Department of Nutrition, Arizona State University East, Mesa 85212, USA. carol.johnston@asu.edu

Journal of Nutrition. 130(12):3063-7, 2000 Dec.

Abstract
Epidemiological investigations repeatedly show that the regular consumption of dark green and cruciferous vegetables, tomatoes and citrus fruits in particular is related to reduced cancer risk. We used the 1994-1996 Continuing Survey of Food Intakes by Individuals to examine the types of fruits and vegetables consumed by Americans. The analytic sample population, which consisted of 4806 men and women (25-75 y old) who completed two nonconsecutive 24-h recalls, consumed 3.6 +/- 2.3 servings of vegetables and 1.6 +/- 2.0 servings of fruit daily. Iceberg lettuce, tomatoes, French fried potatoes, bananas and orange juice were the most commonly consumed fruits and vegetables, accounting for nearly 30% of all fruits and vegetables consumed. The most popular items, lettuce and tomatoes, were consumed by 39-42% of the sample population during the reporting period. Fewer respondents (16-24%) consumed French fried potatoes, bananas or orange juice. Only 3% of the sample consumed broccoli during the reporting period. White potato consumption averaged 1.1 servings daily, with French fried potatoes representing 0.4 serving. Tomato product consumption averaged 0.5 serving daily, dark green vegetable consumption averaged 0.2 serving daily and citrus, berries or melon consumption amounted to nearly 0.8 serving daily. These data indicate that Americans are consuming more fruits and vegetables but that dark green and cruciferous vegetable intake is low.