Superfruits: Back to Basics

You do not have to travel to faraway places to get your antioxidants.

By Diane Toops, News & Trends Editor

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Turn on the television, open your newspaper, pick up your favorite consumer magazine, check the web -- chances are there will be an article touting the health benefits of superfruits, fruit containing exceptional nutrients and antioxidants, often with a unique taste.

Nutritionists and moms know that all fruits -- fresh, frozen, canned or freeze-dried -- are good for you. But in 2005, marketers in the food & beverage industry coined the term superfruit to describe those fruits that were particularly high in nutrients, especially antioxidants.

Unfortunately, the term usually was used to describe exotic fruits, many of them new to American consumers. That’s grossly unfair, as some traditional American crops deliver just as much in the way of antioxidants and other nutrients as fruits that travel halfway around the globe.

In these tough economic times, consumers are going back to basics and food options closer to home. As they do, surely they will appreciate the less heralded American-grown superfoods: blueberries, strawberries, cherries, blackberries, cranberries, grapes, plums, and raisins, which offer as many nutrients and antioxidants in their plump, compact shapes as their foreign cousins. And they offer product formulators the same opportunity to deliver potent antioxidants in new products.

Fight the free radicals
Antioxidants, important disease-fighting compounds, are believed to help prevent and repair the stress that comes from oxidation, a natural process that occurs during normal cell function. A small percentage of cells becomes damaged during oxidation and turns into free radicals, which can start a harmful chain reaction. Pollution, sunlight, smoking and alcohol also contribute to oxidation, and unchecked free radical activity has been linked to cancer, heart disease, Alzheimer's disease and Parkinson’s disease.

Antioxidants are nutrients (vitamins and minerals) and enzymes that combat free radicals. Berries – blueberries, blackberries, cranberries, raspberries, and strawberries -- contain the most antioxidant bang for the buck, according to a major study assessing antioxidant levels in 100 foods, published in the Journal of Agricultural and Food Chemistry. In fact, just one cup of most berries provides all the disease-fighting antioxidants you need in a single day.

Developed by USDA, Oxygen Radical Absorbance Capacity (ORAC) is the rating scale that measures antioxidant content in foods. USDA recommends eating foods that contain at least 3,000 ORAC units a day. While berries as a class are stars of the list, the actual leaders are spices: Ground cloves are No.1 with an ORAC value of 314,446, followed by sumac bran, ground cinnamon, sorghum bran and dried oregano. Exotic superfruit acai berry is No. 6 with a score of 161,400.

Among the classic American berries, wild blueberries are the overall ORAC winner: One cup has 13,427 antioxidant units, vitamins A and C, plus flavonoids (a type of antioxidant) querticin and anthocyanidin. That’s more than four times the USDA’s recommendation in just one cup. Cultivated blueberries have 6,552 in two-thirds of a cup and are equally vitamin-rich.

Cranberries are also antioxidant powerhouses (9,584), followed by black plums (6,259), blackberries (5,347), raspberries (4,882), strawberries (3,577) and cherries (3,365).
Dried versions of fruits contain good doses of antioxidants, as well. Half a cup packs quite a punch: prunes/dried plums (6,552), dates (3,895), figs (3,383), and raisins (3,037).

How does one get the most antioxidants from fruit? Even with a high antioxidant content, the body does not absorb all of it. The concept is bioavailability, explains Ronald Prior, a chemist and nutritionist with the USDA’s Arkansas Children’s Nutrition Center in Little Rock, Ark.

“Bioavailability has to do with absorption or metabolism in the gut,” Prior explains. “What’s absorbed will be impacted by the mechanical structure of different antioxidants in food -- if they’re tied up with fiber or if they have sugar molecules attached.” He told WebMD that by mildly steaming blueberries, the antioxidant level was enhanced, making more antioxidants available to the body. 

Sainsbury's Blueberries
Stephen Pratt, author of Fourteen Foods That Will Change Your Life-Superfoods RX, calls blueberries “brainberries.”

Blueberries (brainberries?)

Bright, bold, beautiful blueberries combine the best nature has to offer: nutrients and luscious flavor. With 80 calories per cup, blueberries are an excellent source of vitamin C. In fact, a serving contains about 14mg or almost 25 percent of the DV. Blueberries are a good source of dietary fiber, an excellent source of manganese and polyphenols -- specifically anthocyanins that give blueberries their blue hue and help neutralize free radicals. 

Since animal studies suggest blueberries help protect the brain from oxidative stress and may reduce the effects of age-related conditions, Stephen Pratt, author of Fourteen Foods That Will Change Your Life-Superfoods RX, calls blueberries “brainberries.”

A recent study on rats at the University of Michigan Cardiovascular Center suggests that eating blueberries can help get rid of belly fat. “Some measurements were changed by blueberry even if the rats were on a high-fat diet,” says E. Mitchell Seymour, lead researcher. “We found by looking at fat muscle tissue that blueberry intake affected genes related to fat-burning and storage. Looking at muscle tissue, we saw altered genes related to glucose uptake.”

As new research is introduced on the goodness of blueberries, their popularity continues to grow. Formats to meet a variety of formulation needs include: fresh, frozen, dehydrated, freeze-dried, preserved, canned, concentrate, juice and powder.

When EnWave Corp. (www.enwave.net), Vancouver, British Columbia, developed a novel food dehydration technology using microwave energy, it chose blueberries as its first application, in large part because of their nutrient values. Since they remove or at least reduce the amount of water in the berry, all the drying technologies concentrate the anthocyanins and other antioxidants. “Our NutraREV process can produce dried fruits with a wide variety of moisture contents and puffing,” says Jennifer Thompson, vice president of corporate development. And it does so more efficiently than freeze-drying.

“Blueberries are used in hundreds of products, and the industry has experienced explosive growth in the export markets, where new products continue to proliferate,” says Tom Payne, industry specialist for the U.S. Highbush Blueberry Council, Folsum, Calif. Some of these product ideas are finding their way back to the U.S. and are stimfulating new product development in North America. And because they add value and are in consumer demand, blueberries are showing up in many specialty food products.
 
Radiant red raspberries

Red raspberries rank in the top 10 antioxidant-rich fruits and vegetables, and they provide important anti-inflammatories, including anthocyanins (the pigments in red, purple and blue fruits), which may help reduce cardiovascular disease, diabetes, cancer, macular degeneration and improve memory.

With only 70 calories, one serving (1 cup) provides 50 percent of a day’s requirement for vitamin C, fiber (32 percent), folate (6 percent), magnesium (6 percent), potassium (5 percent) and calcium, niacin, B6, phosphorus (4 percent each) and zinc.

“Long before the public became aware of the value of high-antioxidant foods, red raspberries were a favorite ingredient in functional foods and beverages such as yogurts, ice creams, juices, teas and other beverages,” says Andrew Carter, in quality control, at Gardena, Calif.-based NP Nutra, which specializes in the manufacture of red raspberry powder extracts such as Red Raspberry 20% Ellagic Acid and Red Raspberry Leaf P.E. 10:1.

“Red raspberries tend to score around 5,000 ORAC units per 100g, which make them one of the highest North American berries, and the high contents of ellagic acid, vitamin C, vitamin A, anthocyanins and cyanidins contribute to the excellent antioxidant activity of red raspberries,” he says, adding, “Since red raspberries taste great and are also high in fatty acids, fiber, iron, manganese, pectin, selenium and vitamin E, their uses as a functional ingredient are virtually unlimited.”

One of the most exciting developments is that red raspberries, especially the seeds, may become important in the booming cosmeceuticals market (skin care products with health benefits), according to the Washington Red Raspberry Commission, Lynden, Wash. The oil in raspberry seeds is rich in vitamin E and omega-3 fatty acids and has a natural SPF (sun protection factor) of 25 to 50.

Out of the bog 

Cranberries slices
Cranberries are an excellent source of vitamin C, a good source of fiber, which reduces levels of LDL  cholesterol levels, is fairly high in vitamin A and has antioxidant phytonutrients that promote heart health.

Although most of us associate cranberries with Thanksgiving and Christmas celebrations, cranberries lend their potent antioxidants to all kinds of year-round foods. One serving (1 cup) is an excellent source of vitamin C (sailors ate them to fend off scurvy), a good source of fiber, which reduces levels of LDL (bad) cholesterol levels, is fairly high in vitamin A and has antioxidant phytonutrients that promote heart health.

“The cranberry’s complex mixtures of polyphenols, such as quercetin, and unique tannins suggest that it is capable of delivering a wide range of health benefits and a variety of different functional activities,” says Christina Khoo, research sciences manager at Ocean Spray Cranberries Inc., Lakeville-Middleboro, Mass. “Much of the research up until a few years ago focused on the cranberry’s role in preventing urinary tract infections, but emerging research suggests the fruit also has health potential throughout the body, including cardiovascular, cellular, oral and gastrointestinal health.

“These whole body benefits are made possible by the fruit’s complex make-up,” Khoo continues. “Unique A-linked compounds called proanthocyanidins prevent bacteria from adhering to cell walls and removing the potential to cause infection, while the high antioxidant content helps fight free-radicals that can damage cells throughout the body. Cranberries also have a rich combination of other nutrients, such as fiber and vitamin C, giving them these multidimensional health benefits.”

Blackberries always chic

Blackberries are a top fruit source of fiber, an excellent source of vitamin C and are jam-packed with antioxidant phytonutrients that help promote heart health. Harvard and University of North Carolina researchers found that for each 10g of fruit fiber eaten per day (blackberries provide 7g), you may reduce the risk of coronary heart disease death by 30 percent.

Prescribed to cure scurvy in the past, blackberries are an excellent source of vitamin C, which helps protect against infections, cancers and aging. At 75 calories, one cup (144g) is an excellent source of vitamin E, which is beneficial for the heart and circulatory problems. A good source of potassium, manganese and folate, blackberries also contain the soluble fiber pectin, which helps to eliminate cholesterol and protects against environmental toxins.

The high tannin content and resultant antiseptic properties makes them good for tightening tissues as well as treating minor bleeding. They have been found to be beneficial for those suffering from diarrhea, intestinal inflammation and hemorrhoids. Blackberries have been used to treat mild infections, like sore throats and mouth irritations.

Seductive strawberries

Strawberries, the most popular berry fruit in the world, contain unique antioxidant phytonutrients that promote heart health. Anthocyanins, which give berries their red and blue hues, also act as potent antioxidants. Specific antioxidants present in strawberries include quercetin, kaempferol, chlorogenic acid, p-coumaric acid, ellagic acid and vitamin C.

Bioavailability has to do with absorption or metabolism in the gut. What’s absorbed will be impacted by the mechanical structure of different antioxidants in food -- if they’re tied up with fiber or if they have sugar molecules attached.

– Ronald Prior, USDA Arkansas Children’s Nutrition Center

At a mere 50 calories, one serving of strawberries (about eight, or 1 cup) is an excellent source of vitamin C, more vitamin C than an orange. Strawberries also contain fiber (2.9g), potassium and folate.

Research suggests the high antioxidant activity of strawberries may help reduce levels of oxidized LDL cholesterol, a risk factor for cardiovascular disease, and flavonoids may also provide cardio protection by inhibiting platelet aggregation and thromboxane synthesis, according to the California Strawberry Commission, Watsonville, Calif. In addition, anthocyanins in strawberries may help protect the neuronal cells from inflammation that is linked to declines in cognitive function.

In addition to traditional nutrients, strawberries are also rich in phenolic compounds such as flavonoids and elagic acid, which are the focus of intense study due to their antioxidant, anticancer and antimutagenic properties. They help control three of the risk factors associated with heart disease: high cholesterol, high blood pressure and high homocysteine levels.

Cherry picking

More than nine out of 10 Americans want to know where their food comes from, nearly 80 percent say they’re purchasing locally produced products, and the majority is defining “local” as made in America. About 95 percent of cherries consumed in the U.S. are grown here, with most coming from Michigan, Wisconsin, Utah, Washington, Oregon, Pennsylvania and New York, according to the Cherry Marketing Institute, Lansing, Mich. Coupled with potential health benefits, this homegrown advantage makes cherries an ideal ingredient for food product development in beverages, snacks, and cereals.

There are some 7,000 cherries on an average cherry tree, which results in more than 100 lbs. per tree per season, and it takes 8 lbs. of cherries to make 1 lb. of dried cherries. Cherries are available in dried, frozen and juice forms.

Cherries contain beta carotene (vitamin A), vitamin C, potassium, magnesium, iron, foliate, fiber and phytonutrients quercetin, kaempferol, chlorogenic acid, p-coumaric acid, gallic acid, perillyl alcohol, and D-glucaric acid. Researchers at the University of Michigan found that eating just 1 1/2 servings of tart cherries can significantly boost antioxidant activity in the body. In the study, healthy adults who ate a cup and a half of frozen cherries had increased levels of antioxidants, specifically five different anthocyanins - the natural antioxidants that give cherries their red color.

“This study documents for the first time that the antioxidants in tart cherries do make it into the human bloodstream and are coupled with increased antioxidant activity that could have a positive impact,” says Sara Warber, co-director of University of Michigan Integrative Medicine and principal investigator of the study. “And while more research is needed, what’s really great is that a reasonable amount of cherries could potentially deliver benefits, like reducing risk factors for heart disease and inflammation.”

Previous animal studies have linked cherries and cherry compounds to important benefits, including helping to lower risk factors for heart disease and impacting inflammation. Cherry-enriched diets can lower blood cholesterol levels and reduce triglycerides. Other benefits of cherries found in animal studies include a 14 percent lower body weight and less “belly fat,” the type linked with increased heart disease risk and type-2 diabetes.

Tart cherries are one of the few known food sources of melatonin, a potent antioxidant that helps regulate our circadian rhythms and natural sleep patterns, and who isn’t sleep-deprived these days?

Also notable, a study from the University of South Carolina and Clemson University supports findings that suggest foods containing quercetin, a natural anti-histamine and anti-inflammatory compound, may be a natural way to help boost the immune system and help fight off infection during flu season.

Amazin’ raisins and plums 

Raisin and Couscous salad
Raisin and Couscous salad

Raisins (dried grapes) rank high among antioxidant foods, as well, containing 3,037 ORAC units in 3.5 oz. (about 2/3 cup).

Research has shown that oxidized LDL cholesterol is more likely to be deposited on the artery wall. That buildup has the potential of causing a blockage. Therefore, protecting the LDL from oxidation is an important strategy for heart health – and antioxidant-packed raisins can help. In an 18-week University of California–Davis study, one serving a day of raisins actually helped lower LDL cholesterol and its oxidation in people with high LDL levels.

Raisins also contain catechins, a family of readily absorbed antioxidants which research shows may promote colon health. These helpful compounds are found in apples, grapes and raisins and beverages, such as chocolate, tea and red wine.

Formerly known as prunes, dried plums are packed with vitamins, minerals, fiber and antioxidants, according to the California Dried Plum Board, Sacramento, Calif. At only 100 calories, a single serving (four to five) has 3g of fiber, B vitamins, potassium, magnesium, boron and antioxidant phenolics. In addition to helping maintain healthy blood sugar levels and healthy cholesterol, dried plums promote satiety and may help reduce skin wrinkles.

Perhaps more important, an animal study suggests eating dried plums slows the development of atherosclerosis, which leads to heart disease and stroke. And regarding the laxative effect, research suggests that generally healthy adults can eat 10 to 12 dried plums per day without significant changes in their bowel habits.

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