In the pages that follow, we've used this research to prepare a shopping list of 10 foods that pack a nutritional punch. That clove of garlic in your refrigerator? That jar of nuts in your pantry? Used correctly, they may have the power to prevent all kinds of serious ailments, including heart disease, diabetes and even cancer. You may never look at a tomato the same way again. (Or, as it turns out, a potato.)
A word of warning: you can find many of these compounds in dietary supplements, but they might not do any good. "Food is very complex," says JoAnn Manson, chief of preventive medicine at Harvard's Brigham and Women's Hospital. "It may be the combination of antioxidants, phytochemicals and fiber that work together to confer health benefits."
Fortunately, nature has given us a handy rule of thumb. Many of the very chemicals that make foods good for us are the ones that give them color, turning blueberries blue, spinach green and carrots deep orange. For optimum health, scientists say, eat a rainbow of colors. Your plate should look like a box of Crayolas.
You can start by passing the ketchup. Several studies have linked the cooked tomatoes in ketchup, soups and sauces to a reduced risk of prostate cancer and other cancers of the digestive tract. Tomatoes contain lycopene, probably the most powerful antioxidant among the carotenoids, the compounds that turn fruits and veggies deep orange. It is so good at mopping up free radicals that Lycopene outperforms the best-known carotenoid of them all, beta-carotene. It is readily released from tomatoes by cooking and--good news for pizza lovers--it's most easily absorbed when a small amount of oil is added. Like your tomatoes raw? That's good too. They can be a valuable source of vitamin C.
With his corncob pipe and his overdeveloped forearms, Popeye is hardly today's poster child of fitness, but his legendary food preference still makes a lot of sense. Spinach is loaded with iron and folate, a B vitamin considered so important that it is now routinely added to flour. Folate not only prevents neural-tube defects in babies but also lowers blood levels of homocysteine, an amino acid that irritates blood vessels and is linked to heart disease. Just as impressive, spinach contains two phytochemicals, lutein and zeaxanthin, that seem to ward off macular degeneration, a leading cause of blindness. One cup of spinach contains just 41 calories and no fat, so you needn't worry about any unsightly bulges in your forearms or anywhere else. Don't like spinach? Try kale, Swiss chard or collard greens.
How is it that the French can eat a diet rich in cheese and buttery sauces and still suffer less heart disease than Americans? The answer to the famous French paradox, say nutritionists, is French wine. The skins of the grapes used to make red wine contain supercharged antioxidants known as polyphenols, including one called resveratrol, which boosts HDL cholesterol (the good kind). Polyphenols, according to the latest research, may also inhibit the production of endothelin 1, a peptide that contributes to hardening of the arteries. But be careful. Wine may be great for the heart, but it's been blamed for everything from cirrhosis of the liver to hemorrhagic stroke, fetal-alcohol syndrome and possibly breast cancer, so consumption should be limited to no more than several glasses a week.
They're loaded with fat and can be very salty, yet these filling little snack foods are nutritional powerhouses. That's because the types of fat found in nuts--monounsaturated and polyunsaturated--are the good fats. When eaten instead of junk food high in saturated fats (like potato chips and doughnuts), nuts lower blood levels of triglycerides and LDL (bad) cholesterol while raising HDL (good) cholesterol--a perfect formula for preventing heart disease. Many nuts, such as pecans and walnuts, also contain a phytochemical called ellagic acid. In preliminary laboratory studies, ellagic acid seemed to trigger a process known as apoptosis, in which cancer cells kill themselves. Nuts provide another benefit: they contain vitamin E, a potent antioxidant that may help ward off heart disease and cancer. The downside? At about 150 calories per ounce, they are a sure ticket to the fat farm. Eat them by the handful, not the bowlful.
Who cares if Dubya's dad hated it? The fact is, broccoli is one mean green. It boasts a fistful of phytochemicals, including sulforaphane and indole-3-carbinol, that may detoxify cancer-causing substances before they have a chance to cause harm. In women, indole-3-carbinol may turn the estrogen associated with breast cancer into a more benign form. A number of studies have linked regular consumption of cruciferous vegetables like broccoli to a reduced risk of breast, colon and stomach cancers. Broccoli is a rich source of beta-carotene, fiber and vitamin C (1 cup contains more C than an orange). The best way to unleash the nutrients is by cooking light and chewing hard. But if you simply can't stand broccoli, try your luck with Brussels sprouts, cabbage and bok choy.