Beneficial Effects of Vegetables and Fruits

Beneficial Effects of Vegetables and Fruits

Beneficial Effects of Vegetables and Fruits

Greater consumption of vegetable has been associated in the majority of epidemiological with a lower risk or lung, oral esophageal, stomach and colon cancer. Evidence is less strong for cancers considered hormonal, such as breast and prostate. Diet can be an important factor even in cancers caused, in large part, by other factors. For instance, many studies have found a lower risk of lung cancer among those who eat or vegetables and fruits in their diet. Although the major factor that causes lung cancer is tobacco smoking, diet also modifies risk, both in smokers and in lifelong nonsmokers.

Evidence that vegetable and fruit consumption reduces cancer risk has led to attempts to isolate specific nutrients and to administer these in pharmacological does to high-risk populations. Most of these attempts have been unsuccessful in preventing cancer or its precursor lesions, and in some cases, have had adverse effects. Notable example are the three random sized trails of beta-carotense for the prevention of lung cancer, initiated because of many observational epidemiological studies indicating lower risk of lung cancer in person eating foods high in beta-carotene. Two of the clinical trials showed that smokers taking high-dose beta-carotene supplements developed lung cancer at higher rates than those taking a placebo, while a third study showed no effect. These findings support the idea that beta-carotene may be only a proxy for other single nutrients or combinations of nutrients found in whole foods, and that taking a single nutrient in large amounts may be harmful.

It is presently unclear which components of vegetables and fruits are most protective against caner. Vegetables and fruits are complex foods, each containing more than 100 potentially beneficial vitamins, minerals, fiber, and other substances that may help to prevent cancer b=vegetables and fruits also contain specific phytochemicals, such as carotenoids, flavonoids, terpenses, sterols, indoles, and phenols that show benefit against certain cancers in experimental studies. There is ongoing research, for example, on the potential benefits of green and dark yellow vegetables, plants related to the cabbage family, soy products, legumes, allium (onion and garlic), and tomato products. Until more in known about specific food components, the best advice is to eat five or more servings of a variety of vegetables and fruits in their various forms: fresh, frozen canned, dried, and juiced.

Despites recommendations from numerous health agencies to eat at least five serving of vegetables and fruits each day, intake of these foods remains low among adults and children.