The Power of a Blue Diet
By Kindy R. Peaslee, RD
Today’s Dietitian
Vol. 8 No. 7 P. 32

Blueberries may be tiny, but research suggests their health benefits are mighty.

What fruit is blue in color, a good-for-you super food, and known affectionately as “Madame” in the Veggie Tales children’s video series? Madame Blueberry definitely has bragging rights as the tiny berry that has more antioxidants than any other fruit or vegetable. Ongoing research is increasingly showing that blueberries contain powerful disease-fighters that may improve short-term memory, intelligence, night vision, and coordination. And if that’s not enough, they may also have the ability to prevent diseases such as cancer, strengthen blood capillaries, ease arthritis pain, and even slow the aging process.

In their new book SuperFoods HealthStyle, author Steven G. Pratt, MD, and coauthor Kathy Matthews discuss the powerful benefits of blueberries, calling them the “absolute powerhouses in the world of health-promoting foods.” Pratt and Matthews first identified blueberries as one of 14 “SuperFoods” in their best-selling book SuperFoods Rx. Pratt has long been an advocate of the fruit: “Blueberries are such powerful health promoters that if you ate only blueberries, along with wild Alaskan salmon and spinach, you would be ahead of the game,” he says.

History and Cultivation
Historically, blueberries were considered a commodity to early Native Americans. A type of blueberry tea was brewed and used medicinally as a cough medicine and diarrhea remedy. North American Indians used blueberries to season pemmican, a mixture of dried meat and fat. During the Civil War, many soldiers were forced to live on a type of sweet blueberry beverage to conserve food supplies.

Blueberries were not cultivated until the beginning of the 20th century, becoming commercially available in 1916. Cultivation of blueberries was spearheaded by a botanist at the USDA who pioneered research into blueberry production. His work was preceded by Elizabeth White, whose family established the first commercial blueberry fields.

Blueberry shrubs are less than 1 foot tall and produce a tiny cluster of fruits the size of small peas. Some giant varieties of blueberry shrubs can grow to a height of 7 feet and produce fruits the size of marbles. Blueberries belong to the heath family, whose other members include the cranberry, bilberry, azalea, mountain laurel, and rhododendron. Blueberries are native to North America, where they grow in the woods and mountainous regions of the United States and Canada. They are rarely found growing in Europe and have only recently been introduced in Australia.

There are roughly 30 varieties of blueberry plants, including the highbush variety found throughout the Eastern seaboard from Maine to Florida and the lowbush variety throughout the Northeast United States and Eastern Canada. The lowbush blueberry is often sweeter and tastier than the highbush blueberry. Blueberries are naturally covered with a thin, dull, waxy coating called the bloom and tiny seeds are found inside the berry’s sweet flesh. Cultivated blueberries are typically mildly sweet while those that grow wild have a more tart and tangy flavor.

Since blueberries contain several acids, including oxalic, malic, and citric acid, your clients may question you about the interaction between blueberries and their oxalate content. Individuals with already existing and untreated kidney or gallbladder problems may want to avoid eating large amounts of blueberries. Oxalates may interfere with calcium absorption, so individuals may want to avoid eating blueberries with calcium-rich foods, or if taking calcium supplements, may want to eat them two to three hours before or after taking their supplements.

Health Benefits of Blueberries
Antioxidant Powerhouse
One reason people are eating blueberries is because science and research is backing up the disease prevention claims of not only the phytochemicals they contain but also the antioxidant activity. Blueberries are ranked No. 1 in antioxidant activity compared with other fruits and vegetables, thanks to the vitamin C and vitamin A content in the fruit.

Packed with antioxidant phytonutrients called anthocyanins, blueberries neutralize free radical damage to cells and tissues, which is linked to cancer, heart disease, Alzheimer’s disease, and a range of other age-related conditions. Anthocyanins, the blue-red pigments found in blueberries, have been shown to enhance the effects of vitamin C, improve capillary function, and stabilize the collagen in body tissue.

The antioxidant package gets even better when wild blueberries enter the scene. Wild blueberries have been found to have the highest antioxidant activity per serving compared with cranberries, strawberries, plums, raspberries, and even cultivated blueberries.1 According to Ronald Prior, PhD, lead researcher at the USDA Arkansas Children’s Nutrition Center and Agricultural Research Service, “Wild blueberries are stars in terms of their antioxidant capacity.” Since wild blueberries have even more antioxidants than commercial varieties, it makes sense to purchase frozen wild blueberries, which are available year-round.

Improve Learning and Memory
Some of the most exciting news about blueberries is their effect on brain health. Some researchers are calling them “brain berries,” showing that a blueberry diet slowed and in some cases reversed deficits in brain function. Blueberries were more effective than other foods such as strawberries or spinach in countering the effects of aging and may reduce the effects of Alzheimer’s disease or dementia.

Spanish researchers at the University of Barcelona found that after eight weeks of feeding lab rats various blueberries, they saw a reversal of age-related learning abilities and memory improvements in the animals. Another study, published in the April 2005 issue of Nutritional Neuroscience, reported the benefit of blueberries’ phytonutrient compounds such as anthocyanin and polyphenols on brain tissue regions important for learning and memory.

Protect the Brain From Stroke Damage
Eating plenty of blueberries may also significantly lessen brain damage from strokes and other neurological disorders, suggests a study published in the May 2005 issue of Experimental Neurology. Neuroscientists at the University of South Florida College of Medicine, James A. Haley VA Medical Center, and the National Institute on Drug Abuse found that rats fed diets enriched with blueberries, spinach, or spirulina (a type of algae) suffered the loss of much fewer brain cells and recovered significantly more of their ability to move following a stroke.

Animal trials conducted by Marva Sweeney-Nixon and her team at the University of Prince Edward Island, Canada, indicate that consumption of wild blueberries provides protection against brain damage from a stroke.2

Antiaging Benefit
We are seeing the baby boomer generation getting older and wanting more answers on growing older gracefully. The blueberry has been shown to have a positive effect on the aging process.

James Joseph, PhD, and his team at the USDA Human Nutrition Research Center on Aging in Boston report that a diet of blueberries may improve motor skills and reverse the short-term memory loss that comes with aging and age-related diseases such as Alzheimer’s disease. USDA animal trials showed improved memory skills after a two-month diet of blueberry extract. Although other fruits and vegetables were studied, only blueberries were effective in improving motor skills.3 Use these reports to challenge your baby boomer clients to consume at least 1 cup of blueberries per day as an antiaging “dietitian-inspired” remedy.

Protection Against Colon Cancer
In addition to anthocyanins, blueberries contain another antioxidant compound called ellagic acid, which blocks metabolic pathways that can lead to cancer. In addition to containing ellagic acid, blueberries are high in the soluble fiber pectin, which has been shown to lower cholesterol and prevent bile acid from being transformed into a potentially cancer-causing form. A study published in the September 2005 issue of the Journal of Agricultural and Food Chemistry shows that blueberry intake can inhibit colon cancer cell growth.

Healthier Elimination
Blueberries can help relieve both diarrhea and constipation. In addition to soluble and insoluble fiber, blueberries also contain tannins, which act as astringents in the digestive system to reduce inflammation.

Blueberries also promote urinary tract health. They contain the same compounds found in cranberries that help prevent or eliminate urinary tract infections. At the Rutgers University Blueberry and Cranberry Research Center, Amy Howell, PhD, showed that blueberries, like cranberries, contain compounds that prevent the bacteria responsible for urinary tract infections from attaching to the bladder wall.4

Heart Health
With their antioxidant activity, blueberries may reduce the buildup of low-density lipoprotein cholesterol, which contributes to cardiovascular disease and stroke, according to scientists at the University of California, Davis.5

New research by Dorothy J. Klimis-Zacas, PhD, and her team at the University of Maine, Orono, concludes that a diet of wild blueberries may reduce risk from cardiovascular disease due to the antioxidant activity of the anthocyanins.6 Pterostilbene, another powerful antioxidant compound found in blueberries, which is already known to fight cancer, may also help lower cholesterol.

Vision Health
Move over carrots. The blueberry is also a “visionary fruit” that clears up eye inflammation and can be used to treat tired, weak, or infected eyes. The anthocyanin content in blueberries may improve night vision and prevent tired eyes.

As if the above list of blueberry benefits isn’t impressive enough, more research is on the horizon exploring further benefits. Last year at the eighth annual Wild Blueberry Health Research Summit, researchers discussed new research on the role of wild blueberries in the long-term health of children, with a focus on childhood obesity and the effect of a wild blueberry diet on longevity and stress resistance.

How to Select, Prepare, and Store
When buying, choose blueberries that are firm, free of mold, and uniformly blue. Fresh berries are very fragile and should be washed briefly and carefully and then gently patted dry. Wash berries just prior to use so as not to prematurely remove the protective bloom that resides on the skin’s surface. If you know the source of either wild or organic berries, try not to wash them at all. Blueberries cultivated in the United States are available from May through October while imported berries may be found at other times of the year.

Ripe blueberries should be stored in a covered container in the refrigerator where they will keep for approximately one week, although they will be freshest if consumed within a few days. Always check berries before storing and remove any damaged berries to prevent the spread of mold. Berries may spoil if kept out at room temperature for more than one day.

Blueberries can be canned or frozen, though freezing may alter the flavor and texture. When purchasing frozen berries, shake the bag gently to ensure that the berries move freely and are not clumped together, which may suggest that they have been thawed and refrozen. Berries should last up to one year in the freezer. You may notice that berries used in baked products can take on a green color. This is a natural reaction of their anthocyanin pigments and does not make the food item unsafe to eat.7

Blueberries are delicious mixed in fruit salads or cereals or used as a topping for crepes and waffles. They can also be served with whipped cream and added to all kinds of desserts, including pies, cakes, muffins, ice cream, yogurt, and sorbets. They make delicious jams, jellies, and juices. They can even be dried. North American Indians used to cook blueberries to make a concentrated paste that they then dried in the sun, thus ensuring a supply of the fruit during the off-season.

Blueberry Market
As it gains popularity, the blueberry is no longer just an ingredient for blueberry pie. The market has gained momentum as consumers are eating more blueberries for healthier diets and bodies. Production has increased more than 14% in recent years. Mark Villata, executive director of the US Highbush Blueberry Council, says, “The interest in the healthfulness of blueberries by consumers continues, as shown by the recent increases in per capita consumption, which totals an estimated 20 ounces per person in 2006—up from 16.8 ounces per person five years ago.”

Blueberries are gaining momentum in the restaurant industry, as noted in an article in the Nation’s Restaurant News reporting on a Beverly Hills restaurant, Solar Harvest, which tailors its menus to lifestyle and dietary choices. Included on the lunch menu is a blueberry beef or bison burger that contains pureed blueberries and spices. The Food Network features blueberry recipes regularly, and www.Emerils.com recently provided an article titled “Blueberry Season Berry, Berry Good” and recipes for Blueberry Drop Cookies and Blueberry Pudding.

The recent media reports on blueberries may challenge and inspire your patients and clients to taste and cook with the tiny summertime fruit. Consider that a serving of blueberries (1/2 cup) counts as one fruit serving, is only 80 calories, and makes an easy, nutrient-packed snack perfect to eat during a summertime hike or even at the pool. Blueberries are rich in vitamins and minerals such as C and E, beta carotene, folic acid, iron, fiber, and potassium. Plus, they are naturally free of fat, cholesterol, and sodium. July is the prime season for blueberry picking—think local, as in farmers’ markets and blueberry bushes in the wild. Getting family or friends together for blueberry picking can be a fun, healthy outdoor activity.

Other “power of blue” ideas: for breakfast, add 1/2 cup of blueberries to cereal; for lunch, add them to yogurt or a salad; or for a snack, eat them with milk or soy milk. Add frozen blueberries to a breakfast shake. Fresh or dried blueberries add color to cold breakfast cereals. For a deliciously elegant dessert, layer yogurt and blueberries in wine glasses and top with crystallized ginger. Make a blueberry fruit pizza for children to enjoy. Blueberry pie, cobbler, and muffins are classic favorites that can be enjoyed throughout the year.

Today’s consumers do seem to have a more heightened awareness of the nutritional value and versatility of blueberries and berries in general. Amanda Archibald, RD, founder of Field to Plate (www.fieldtoplate.com), a food and nutrition education company that believes in promoting pleasurable eating experiences, reflects that the goal we all have as RDs continues to be to get great-tasting fruits and vegetables into the mouths of consumers. Archibald emphasizes, “If blueberries are recognized as a nutritionally value-packed food, then we move one step closer to achieving that goal.”

— Kindy R. Peaslee, RD, is the founder of Kindy Creek Promotions, an upstate New York-based marketing firm specializing in the promotion of natural and organic food and beverage products. She can be reached at kindy@kindycreek.com. Visit her recipe Web site for parents: www.healthy-kid-recipes.com.

References
1. Wu X, Beecher GR, Holden JM, et al. Lipophilic and hydrophilic antioxidant capacities of common foods in the United States. J Agric Food Chem. 2004;52(12):4026-4037.

2. Sweeney MI, Kalt W, MacKinnon SL, et al. Feeding rats diets enriched in lowbush blueberries for six weeks decreases ischemia-induced brain damage. Nutr Neurosci. 2002;5(6):427-431.

3. Joseph JA, Denisova NA, Arendash G, et al. Blueberry supplementation enhances signaling and prevents behavioral deficits in Alzheimer disease model. Nutr Neurosci. 2003;6(3):153-162.

4. Schmidt BM, Howell AB, McEniry B, et al. Effective separation of potent antiproliferation and antiadhesion components from wild blueberry (Vaccinium angustifolium Ait.) fruits. J Agric Food Chem. 2004;52(21):6433-6442.

5. Rimando AM, Kalt W, Magee JB, et al. Resveratrol, pterostilbene and piceatannol in vaccinium berries. J Agric Food Chem. 2004;52(15):4713-4719.

6. Norton C, Kalea AZ, Harris PD, et al. Wild blueberry-rich diets affect the contractile machinery of the vascular smooth muscle in the Sprague-Dawley rat. J Med Food. 2005;8(1):8-13.

7. The Visual Food Encyclopedia. Les Éditions Québec/Amérique. Montreal, Quebec: 1996.

Blueberry Nutritional Information
(Numbers based on 100-gram serving)
Water: 85%
Protein: 0.7 grams
Fat: 0.4 grams
Carbohydrates: 14 grams
Fiber: 2.3 grams
Calories: 56

— Source: The Visual Food Encyclopedia

Wild Blueberry Smoothie
Serves 2

Ingredients:
6 ounces wild blueberries (fresh or frozen)
6 ounces yogurt (vanilla or blueberry)
1 T honey (if plain yogurt is used)
1/2 cup ice (3 ice cubes)

Directions:
Blend well at high speed; serve immediately.

Wild Blueberry Bran Muffins
Makes 36 muffins

Ingredients:
11 ounces (3 cups) bran cereal
21/2 cups low-fat buttermilk
12 ounces (11/2 cups) nonfat plain yogurt
12 ounces (3 cups) all-purpose flour
21/2 T baking powder
1 tsp baking soda
1/2 tsp salt
3 ounces (3/4 cup) wheat germ
6 ounces (3/4 cup) egg substitute
3/4 cup unsulfured molasses
3/4 cup maple syrup
4 ounces (1/2 cup) brown sugar
1/3 cup canola oil
18 ounces (3 cups) wild blueberries

Directions:
In large bowl, combine bran, buttermilk, and yogurt. Let stand 15 minutes. Reserve.

In separate bowl, combine flour, baking powder, baking soda, and salt. Stir in wheat germ. Reserve.

In another bowl, blend egg substitute, molasses, syrup, brown sugar, and oil; stir into bran mixture and mix well. Add to flour-wheat germ mixture and mix just to moisten.

Fold in wild blueberries. Scoop 1/4 cup batter into each greased 1/3-cup muffin tin (36 total) and bake in 400° F conventional oven or 375° F convection oven 20 to 25 minutes or until firm to the touch. Serve warm.

— Source: www.wildblueberries.com

Web Site Resources
• Michigan Blueberry Growers Association, www.blueberries.com

• US Highbush Blueberry Council, www.blueberry.org

• Wild Blueberry Association of North America, www.wildblueberry.com

• The World’s Healthiest Foods, www.whfoods.com