Most mornings, Jim Joseph tosses a handful of blueberries into a soy-protein smoothie as part of his breakfast. Then he commutes to his laboratory at Tufts University in Boston and breaks out more blueberries. This time, he feeds the berries to rats as part of ongoing experiments about the nutrients in fruits and vegetables.
What Joseph and other researchers are finding has surprised even themselves. Mostly known for filling pies or dotting muffins, the petite blueberry is gaining a reputation as one of nature’s nutritional heavyweights.
Joseph conducted an experiment showing blueberries can effectively protect against age-related memory loss and diminished motor skills in lab rats, a feat unmatched by even spinach in his experiments.
“What struck me was the ability to change motor behavior (for the better),” said Joseph, chief of the neuroscience lab at the U.S. Department of Agriculture Human Nutrition Research Center at Tufts. “There is virtually nothing out there that can change motor behavior in aging.”
His Tufts colleague, Ronald Prior, rated 60 fruits and vegetables for potency of antioxidants, which keep cells normal and fight cancer, heart disease and other degenerative conditions. Blueberries topped the list.
What’s going on here?
The Tufts research appears to be part of a grander color scheme for getting your daily nutrientsand showing us that we might be missing the point about getting our five servings of fruits and vegetables.
Five servings of pigment might be more like it: Get your blues, reds, purples, oranges and yellows along with your greens.
“The substances that give pigments to fruits and vegetables were discovered and named long ago,” said Phyllis Bowen, associate professor of human nutrition and dietetics at the University of Illinois-Chicago. “But it’s been a revelation to all of us in the last few years that the pigments can be so beneficial to your health and well-being. The research is building.”
From berries to beets
For instance, strawberries, prunes, black currants and boysenberries also rated high on the Tufts test for antioxidant strength. A similar analysis by German researchers revealed high marks for beets, too often an afterthought at the salad bar. One caveat: Bowen said water-soluble antioxidants in berries and other produce are believed to show up more readily than fat-soluble antioxidants during such analyses.
A Michigan State University study showed that sour cherries provide 10 times the anti-inflammatory relief of aspirin and don’t irritate the stomach. Other university researchers have documented the protective value of pale yellow and orange produce for macular degeneration, a debilitating vision condition that can lead to blindness. What’s more, carrots, long associated by folklore (and now science) with improved eyesight, have also been linked to reduced cholesterol and risk of stroke.
The reported health benefits of green tea and red wine (and purple grapes) have gotten much publicity. Same for the tomatoes in your favorite marinara sauce or ketchup. Score more points for Pigment Power.
Any colorful fruit or vegetable (skin or interior, provided you eat it all) contains phytochemicals. These antioxidant substances fight against cancer, heart disease and other illnesses by neutralizing “free radicals,” which if left unchallenged can destroy or “oxidize” healthy cells. Many of these natural antioxidants also have anti-inflammatory properties, and some naturally reduce blood cholesterol.
Each of nature’s food hues has its own bundle of pigment-related phytonutrients, which are broadly sorted into such categories as polyphenols, flavonoids and carotenoids. The categories do overlap. Polyphenols are plentiful in the deeper-colored plant foods such as blueberries, strawberries, grapes, green tea and, happily, chocolate. Flavonoids can also be found in the newfound champion blueberries, along with cranberries, currants, teas and olives.
Carotenoids are responsible for the oranges and yellows in such foods as cantaloupe, mangos, carrots, sweet potatoes and pink grapefruit. Another class of carotenoids are in red foods, such as tomatoes and watermelon. The most famous carotenoid, beta carotene, which helps the body make vitamin A, is just one carotene among hundreds.
Other individual pigment substances have been singled out, such as lycopene in tomatoes or lutein in peas, carrots and squashes. Most everyone knows that chlorophyll is the pigment in green vegetables and leaves. One term you will be hearing more in coming months is anthocyanin, which is a natural dye and nutrient that gives blue and purple color to blueberries, plums and cherries. Joseph, of Tufts, is applying for a grant to identify which of four polyphenol families in blueberries, including anthocyanins, are most responsible for the anti-aging effects. The study will take two to three years.
Eat, don’t pop
No matter what individual researchers might discover, there is consensus that consumption of whole foods, not supplements, is the most effective method for getting maximum antioxidant benefits. Joseph admits to taking a bilberry (wild blueberry) extract because the plant has powerful antioxidants (one benefit is for vision) but is not widely grown in the U.S. But otherwise he recommends farmers markets over supplement stores.
“What people need to remember is the multiple action of the chemicals in plant foods,” Joseph said. “It’s not just about antioxidants or anti-inflammatory properties. Eating the fruits or vegetables or grains guarantees you will get the health benefits. We just don’t know enough about supplements to recommend them as a reasonable substitute.”
The emerging nutritional palette might seem like just another gimmick to get produce onto Americans’ plates, but many nutritionists are excited about providing clients with sound scientific reasons why eating your mangos, kiwis or red peppers can keep you well.
“Nobody is going to deny the idea of eating something sweeter like berries or roasted peppers is more appealing than a serving of sauteed spinach,” said Leslie Bonci, a nutritionist at the University of Pittsburgh and spokeswoman for the American Dietetic Association.
The strategy appears to have worked already with widely publicized research about cooked tomatoes and lycopene, which found that carotenoids are more available to the body if cooked slightly. Men are getting the message that multiple weekly servings of tomato sauce or soups can reduce risk for prostate troubles. Bowen just completed the first phase of a clinical trial at UIC that reduced PSA (prostate-specific antigen) levels in men awaiting radical prostatectomy surgery by 18 percent in three weeks. The African-American subjectsa high-risk group for prostate cancerbenefited by eating three-quarters cup of tomato sauce with pasta each day.
“We are starting to see that oxidative stress is a huge factor in aging diseases,” Bowen said, referring to the damage caused by free radicals. “Eating antioxidants in plant foods can hold off the damage. The deeper the pigment, the better for you.”
That goes for grains and legumes, too, in which you might be choosing between brown or white rice. Darker is better for antioxidant and fiber content. While beans might seem dull as a flavor category, there is no lack of flavonoids in kidney beans, black beans and other darker beans.
Make a splash
Getting more pigments in your diet is a realistic goal, Bonci said. Though more passionate cooks might respond by constructing colorful salads or vegetarian entrees, she said some simple dashes and splashes of color can brush up your nutritional picture.
“I tell clients to add color to that drab oatmeal by throwing in a handful of blueberries or dried cranberries,” she said. “Try not to eat waffles or pancakes without adding some fruit instead of just syrup and butter. You can also buy baby carrots and add them into pasta sauces without even knowing they are in there.”
And don’t sweat it if you can’t find some of these items in the fresh produce section. Bonci said studies show frozen vegetables and fruits are just as nutritious as fresh. Joseph, for one, said some freezing methods (one is known as IQF or individually quick frozen) might even be more effective at locking in antioxidants.
“You can greatly improve your soups or prepared rice and noodle mixtures by adding a bag of frozen vegetables,” Bonci said. “While you want to eat produce fresh when it’s in season, there are many more options at the supermarket these days for frozen fruits and vegetables not packed in syrup or cream sauces. You can also find more dried fruits to add color to your meals during the cold-weather months.”
Even 100-percent fruit and vegetable juices don’t offer the entire nutrient range of the plants from which they derive, and might provide too many daily calories if you’re not careful.
“Humans have thrived on plant foods for centuries upon centuries,” Bowen said. “Refining foods usually means we are reducing the nutritional value.
“Putting more colors on your plate is a powerful way to get the most from fruits, vegetables, grains and legumes.”
COLOR PALETTE
Whole fruits and vegetables are bursting with nutrients, from vitamins to fiber. But some antioxidants are directly linked to the pigments in plant foods. Here’s a sampling.
FRUIT ACTIVE COMPOUNDS POTENTIAL BENEFIT
Bluberries Polyphenols Anti-aging properties
Sour cherries Anthocyanins Inflammation relief
Carrots Lutein Reduced stroke risk
Tomatoes Lycopene Reduced risk of prostate cancer
%%
MANGO CILANTRO SALSA
Preparation time: 15 minutes
Chilling time: 3 hours
Yield: 2 cups
This salsa is good with grilled tuna or pork. It’s adapted from “Latin American Cooking Across the U.S.A.,” by Himilce Novas and Rosemary Silva.
1 mango, peeled, diced
1/2 cup minced red onion
1/4 cup cilantro leaves, minced
4 teaspoons fresh lime juice
1/2 jalapeno or serrano chili, seeded, minced Ground red pepper
Mix mango, onion, cilantro, lime juice and chili in small bowl; add pinch of red pepper or to taste. Cover; chill in refrigerator for at least 3 hours.
Nutrition information per 1/4 cup:
Calories ………… 22 Fat ………. 0.1 g Saturated fat .. 0 g
% calories from fat .. 4 Cholesterol … 0 mg Sodium …….. 2 mg
Carbohydrates …… 6 g Protein …… 0.3 g Fiber …….. 0.7 g
COUSCOUS WITH VEGETABLES
Preparation time: 30 minutes
Cooking time: 45 minutes
Yield: 6 servings
This is hearty enough to be a main course. It was developed in the Tribune test kitchen.
1 box (10 ounces) couscous
2 tablespoons olive oil
1/2 onion, thinly sliced
1 tomato, seeded, diced
1/2 small butternut squash, peeled, diced
1 large carrot, peeled, diced
1 can (15 ounces) chickpeas, rinsed, drained
1/2 teaspoon each: turmeric, coriander
1/4 head cabbage, chopped
1/2 red bell pepper, diced
1/2 cup vegetable or chicken broth
1 1/2 teaspoons salt
1/2 teaspoon pepper
1/4 cup minced cilantro
1. Prepare couscous according to package directions.
2. Heat olive oil in large skillet over medium-high heat. Add onions; cook, stirring often, until caramelized, about 7 minutes. Add tomato, squash, carrot, chickpeas, turmeric and coriander; stir. Cook, about 8 minutes. Add cabbage, bell pepper, broth, salt and pepper. Simmer covered, until chickpeas and squash are tender, about 15 minutes.
3. Toss cilantro and couscous with vegetables. Serve warm or cold.
Nutrition information per serving:
Calories ……….. 345 Fat ………… 7 g Saturated fat .. 0.7 g
% calories from fat ..17 Cholesterol … 0 mg Sodium …….. 840 mg
Carbohydrates ….. 63 g Protein ……. 11 g Fiber ……….. 11 g %%
