MORE THAN PRETTY COLORS
Lower cholesterol
Reduce the risk of heart disease and cancer
Protect eye tissue
All great chefs know that the eyes eat first. That’s why they put so much effort into presentation, livening up the plate with vivid vegetables.
For a long time, in fact, nature’s colorful bounty—an emerald bed of lettuce, shiny scarlet tomato wedges, or bright orange slivers of carrot—was used mainly as a bit of colorful warmth to fill up the empty spaces between the meat and potatoes.
Now we know that there’s a better reason to serve vegetables. The pigments that give fruits and vegetables their cheery hues, called carotenoids, are more than pretty colors. They could save your life.
Researchers have found that people who eat the most carotenoid-rich yellow, orange, and red vegetables—such as pumpkins, sweet potatoes, watermelons, and sweet red bell peppers—have significantly lower risks of dying from heart disease and cancer. The same is true of the dark green leafy vegetables, such as spinach and kale. (The chlorophyll they contain masks the lighter carotenoid hues.)
How can a simple food coloring be so good for you? The reason, as is often true with nutrition, comes down to chemistry. Our bodies are constantly under attack by free radicals—oxygen molecules that have lost an electron and zip through the body trying to steal replacement electrons from healthy cells. In time, this process causes internal damage to tissues throughout the body, possibly causing heart disease, cancer, and many other serious conditions. The carotenoids in vegetables neutralize free radicals by offering up their own electrons. This effectively stops the destructive process, helping prevent your cells from being damaged.
Researchers have pinpointed more than 600 carotenoids, but only 50 to 60 of them are found in common foods. The key carotenoids identified so far are alpha-carotene, beta-carotene, gamma-carotene, beta-cryptoxanthin, lutein, lycopene, and zeaxanthin, and scientists continue to investigate others.
People have been fighting the cholesterol war since doctors first uttered the words “hardening of the arteries.” Along with avoiding high-fat foods, you can make progress in winning this war by eating carotenoid-rich fruits and vegetables—such as sweet potatoes, spinach, and cantaloupe—every day.
Carotenoids contribute to heart health by helping prevent the dangerous low-density lipoprotein (LDL) cholesterol from oxidizing—the process that causes it to stick to artery walls. Studies show that people with high levels of carotenoids have significantly lower risks for heart disease than those who don’t.
Researchers at Johns Hopkins University in Baltimore found that smokers who already had one heart attack were less likely to have a second if they had high blood levels of four important carotenoids—beta-carotene, lutein, lycopene, and zeaxanthin.
“Enjoy a variety of fruits and vegetables,” says Allan Maga-ziner, DO, director of the Maga-ziner Center for Wellness and Anti-Aging Medicine in Cherry Hill, New Jersey. “There are hundreds of carotenoids, and different foods offer different ones. So eat many different fruits and vegetables. And choose deeply pigmented fruits and vegetables over lightly colored ones because they have more carotenoids. For example, spinach contains more carotenoids than iceberg lettuce.”
The same process by which carotenoids protect against heart disease also seems to protect against cancer. Researchers believe that these compounds, by neutralizing free radicals, can prevent damage to DNA, the genetic material that controls how cells behave.
For example, in one study, researchers at the National Cancer Institute found that people with the highest intakes of carotenoids were as much as six times less likely to develop skin cancer than those with the lowest intakes. Researchers think that betacarotene plants itself in the skin, where its pigments help deflect sunlight.
“There are several other studies now yielding the same results,” says Harinder Garewal, MD, PhD, professor of medicine at the University of Arizona College of Medicine in Tucson. “These findings are important because they suggest that you can do something to reverse the onset of cancer.”
Another carotenoid that seems to be a crusader against cancer is lycopene—the pigment that gives tomatoes their rosy glow and that is also found in watermelons, guavas, and pink grapefruit. Researchers from the Harvard School of Public Health found that people who ate 10 or more servings per week of tomato-based foods had a 45 percent decrease in their risk for prostate cancer. Those who only ate four to seven servings a week—less than one a day—still came out ahead, with a 20 percent reduction in risk. It wasn’t only whole tomatoes that provided the benefits either. Pizza, tomato juice, and other tomato-based foods also were protective.
Although evidence clearly shows that people who get the most carotenoids in their diets tend to get less cancer, the case for taking supplements of carotenoids isn’t quite so clear.
For example, when researchers tested the effectiveness of beta-carotene supplements, they found that this compound wasn’t effective in preventing cancer. In fact, some studies have shown that taking beta-carotene supplements may accelerate the disease.
“There is very clear evidence that we know less than we thought we did,” says Walter Willett, MD, DrPH, professor of epidemiology and nutrition, and chairman of the department of nutrition at the Harvard School of Public Health. It’s possible that beta-carotene supplements cause problems because high doses interfere with the body’s absorption of other protective carotenoids.
For now, the best strategy for preventing cancer is to get carotenoids from foods rather than supplements. “Our hope is that with more research, we’ll be able to pinpoint which compounds are most beneficial and which fruits and vegetables people should emphasize in their diets,” says Dr. Willett.
All rich yellow, orange, and red vegetables contain generous amounts of carotenoids. So do the deep green leafy vegetables, like spinach and kale. To get the greatest amounts of these healing compounds into your diet, here are some of the best food sources.
Cantaloupe
Carrots
Dark leafy greens
Kale
Oranges
Peaches
Pumpkin
Spinach
Sweet potatoes
Tomatoes
As his name suggests, Popeye has his share of vision problems. But according to research on his favorite leafy elixir, he won’t likely have problems with macular degeneration—the leading cause of severe vision loss in older adults.
People who eat spinach, collard greens, and other dark green leafy vegetables five or six times a week have about a 43 percent lower risk for macular degeneration than those who eat such foods less than once a month, according to a large study in Massachusetts.
The carotenoids that seem to be responsible, lutein and zeaxanthin, are believed to block the effects of free radicals in the outer retina, preventing them from damaging healthy eye tissue.
With a sharp knife, pierce the squash in 3 or 4 places. Microwave on high, turning once, for 2 to 3 minutes, or just until the squash starts to soften under the skin. To test, press with your thumb. Carefully cut the squash into quarters. Scoop out and discard the seeds. Cut off and discard the peel. Cut the squash into 1-inch chunks. Rinse the kale and strip the leaves from the coarse stems. Coarsely chop the leaves.
In a large saucepan, heat the oil over medium heat, Add the garlic and cook for 20 seconds, or until fragrant. Add the squash, tomatoes and their juice, and water.
Cover, and reduce the heat to medium-low. Cook until the squash is tender but not mushy, 25 to 30 minutes . Test for doneness by inserting the tip of a sharp knife into a piece of squash. Add more water if necessary to keep the squash from sticking. With the back of a large spoon, break the tomatoes into smaller pieces. Add the kale, basil, and sage. Cook until the kale softens, 3 to 4 minutes longer.
Makes 4 servings
Cook’s Note: Serve over hot cooked brown rice or quinoa.
Calories: 134
Total fat: 4.1 g
Saturated fat: 0.6 g
Cholesterol: 0 mg
Sodium: 207 mg
Dietary fiber: 6.2 g