The Latest on Preventive Nutrition

Countless studies show that you can't just pop a dietary supplement pill to stay healthy.

"To optimize your health, more research studies are pointing to the benefits of nutrients within foods," says Felicia Busch, R.D., a spokeswoman for the American Dietetic Association.

Granted, what you eat is only one part of the good-health equation. Exercising, drinking in moderation, not smoking, managing stress, and getting plenty of sleep also can make a big health difference. Still, because you eat so often—typically at least three times a day—"your diet counts for a lot," Busch says.

She offers the following suggestions for disease-proofing your diet.

Get fruity

Fresh, frozen, and canned fruits are packed with fiber, phytochemicals, and antioxidant nutrients such as vitamin C and beta carotene that may help protect you from major chronic diseases, such as heart disease, cancer, and macular degeneration. Fresh and frozen are preferable over canned. Canning may reduce the content of some vitamins, and the syrup the fruits are canned in is high in sugar.

Moreover, most fruit has little fat and fewer calories than most traditional desserts. Still, "most people don't eat enough fruit," Busch says. "Yet it's so convenient."

To add more fruit to your diet, Busch recommends sneaking it into the foods you already eat. Top off your breakfast cereal or yogurt with fruit and add it to homemade breads, cakes, cookies, salads, and sauces.  Avoid fruit-flavored yogurts and puddings, as they are high in sugar and calories and low in fruit.

To make your diet interesting and more disease protective, "go beyond the basics like apples, oranges, and bananas," Busch says. Experiment with more exotic options, such as kiwi, papayas, mangos, raspberries, blueberries, melons, cranberries, strawberries, and fresh pineapple.

"Tropical fruits and berries are especially potent sources of antioxidants," Busch says. Aim for 2 cups of fruit per day.

Drink some veggies

You should get 2-1/2 cups of vegetables a day, according to the USDA's Dietary Guidelines for Americans.

"Most Americans fall short for both fruits and vegetables," Busch says. "And that's not good, because vegetables contain antioxidants, fiber, and other vitamins and minerals that provide health benefits against a host of diseases—from cancer to high blood pressure."

To consume more veggies: "Drink vegetable juice," Busch says. "It's a quick trick to increase the numbers, and most vegetable juices are blends, so they provide more exposure to vegetables you might not otherwise eat."

Plus, variety makes the most of the types of disease-fighting nutrients you consume.

Added bonus: Many vegetable juices are calcium-fortified to help prevent bone-weakening osteoporosis.

Go a little nuts

"Nuts are chock-full of a lot of beneficial nutrients, like fiber, omega-3 fatty acids [alpha- linolenic acid or ALA], and unsaturated fatty acids zinc and B vitamins," Busch says.

Multiple studies have shown that adding a reasonable amount of nuts, particularly walnuts and almonds, to the diet decreases total cholesterol and LDL ("bad") cholesterol. Separate studies have shown that nuts significantly reduce the risk for fatal heart attack. Nuts contain a relatively high amount of vitamin E; studies show that foods rich in vitamin E may help neutralize free radicals created during energy production in the cells.

"When you add nuts to your diet, cut back on fat somewhere else," Busch says, "perhaps by using less oil when you cook or switching from 2 percent milk to skim milk."

Go fishing more often

"The average American eats fish about one time a week," Busch says. "But scientists say to aim for two or three times a week." Fish, especially cold-water fish such as salmon, mackerel and herring, are rich sources of omega-3 fatty acids, a heart-healthy fat that helps lower total cholesterol and LDL ("bad") cholesterol.

"Eating more fish may also reduce your cancer risk," Busch says, "and even lower blood pressure."

Because of the high mercury content of some fish, if you are pregnant or breast-feeding, follow guidelines from the FDA on limiting your intake of fish.