What Do Vegetables and Fruits Do to the Body?

You may have heard your mother say, “Eat your vegetables!” or “Have some fruit!” when you were growing up. Studies show that most Americans eat too few fruits and vegetables, according to Kathleen Mahan and Sylvia Escott-Stump in “Krause's Food, Nutrition & Diet Therapy.” Vegetables and fruits provide needed nutrients with few calories. When you eat more fruits and vegetables you are likely to eat fewer high-fat and high-starch foods and reduce your risk for certain chronic diseases.

A woman is shopping for fruits and vegetables in the supermarket. (Image: Tay Jnr/Digital Vision/Getty Images)

Guidelines

Guidelines for a nutrient-dense healthful food plan are included in the USDA MyPyramid food guide. The recommended daily amount of fruits and vegetables varies depending on your age, sex and level of physical activity and is within the range of 1 ½ to 2 cups of fruit and 2 ½ to 3 cups of vegetables for adults.

Vitamins and Minerals

Fruits and vegetables are generally low in fat, sodium and calories and none have cholesterol, according to the USDA MyPyramid food guide. Fruits and vegetables are sources of potassium, fiber and vitamin C. Fruits contain folate and vegetables contain vitamin A and vitamin C.

Potassium helps maintain blood pressure and fiber helps reduce cholesterol. Folate helps build red blood cells and prevent birth defects. Vitamin A promotes healthy eyes and skin. Vitamin E protects essential fatty acids from free radical damage. Vitamin C helps wounds heal, promotes the health of teeth and gums and assists in the absorption of iron.

Fiber

The fiber in fruits and vegetables can help you control your weight, lower blood cholesterol and helps prevent colon cancer, diabetes, appendicitis and diverticulosis -- pouches of infection that develop in weakened areas of the intestinal wall. Most fruits and vegetables -- for instance 1 cup of raw carrots or 1 medium apple -- contain about 2 g of fiber per serving.

Phytonutrients

The protective effect of fruits and vegetables depends, in part, on nonnutrient compounds called phytochemicals that help protect you from chronic disease. Phytochemicals deliver taste, aroma and color. Some act as antioxidants that protect your body from tissue damage. Examples of phytonutrients in fruits and vegetables include the carotenoids in carrots, broccoli and spinach that act as antioxidants and possibly reduce the risks of cancer, according to MayoClinic.com. The capsaicin in peppers reduces the risk of fatal clots in heart and artery disease. Phenolic acids in apples, blueberries and cherries may influence the production of enzymes that make carcinogens water soluble so they can be excreted, according to Eleanor Whitney and Sharon Rolfes in “Understanding Nutrition.”

Considerations

Persons with diabetes may benefit from limiting fruits like watermelon that have a high glycemic index. this means they produce a rapid rise and sudden fall in blood glucose levels, which can harm diabetics and people with hypoglycemia. High insulin production also causes higher triglycerides. Bananas, pineapples and orange juice have a moderate effect. Peaches, apples and oranges produce a less pronounced effect on blood sugar, according to Eleanor Whitney and Sharon Rolfes in “Understanding Nutrition.” The fructose sugar content of fruit, juices and sweetened beverages may promote abdominal fat storage, according to Liwei Chen and colleagues in the May, 2009 issue of the “American Journal of Clinical Nutrition.” If you have diabetes or high triglycerides talk to your dietitian about the amount, frequency and types of fruits you should eat.