Squeezing Health Benefits From Juices

Many blame calorie-ridden beverages as the cause, or at least a major contributor, to the burgeoning obesity problem in America. And truth be told, some beverages contain little nutrition beyond sugar and calories. On the other hand, pure fruit and vegetable juices can offer nutrients and other beneficial components without significantly upping the caloric content.

Beyond nutrients 

The value of fruits and vegetables is a basic tenet of nutritional wisdom. Until recently, nutrient content alone qualified fruits and vegetables as dietary requirements. But the increasing body of data on phytochemicals points to other beneficial components in traditional and exotic fruits and vegetables. This opens up new marketing opportunities for juices. “Recent research has shown a variety of health benefits relating to the consumption of fruit and fruit juices that we were unaware of 10 years ago,” says Lorenzo Nicastro, senior vice president of research and development, Naked Juice Company, Azusa, CA. “These health benefits can range, depending on the fruit, from heart health to antioxidant benefits to assisting with healthy aging and memory.”

Ongoing investigations into benefits occur on many fronts. Epidemiological and general consumption studies look for associations of overall intake of fruits, vegetables and their juices with specific diseases and health parameters in various populations.

Other research focuses on specific fruits and vegetables. Some studies strive to identify compounds that may provide protection as an antioxidant, through action on the immune system or some other physiological function. However, often, specific compounds fail to produce the intended effect when feed to people in isolation. Currently, leading scientists in this field think various phytonutrients in specific fruits and vegetables act synergistically to provide benefit.

Traditional pluses 

All this research means many mainstream, traditional juice favorites can tout phytonutrient benefits along with their nutritional pedigree. Many juices claim their antioxidant content as the protective factor that prevents cellular damage associated with many chronic illnesses and usually name specific types of compounds such as flavonoids, proanthocyanidins, anthocyanins and carotenoids. Almost all the commodity marketing boards and growers associations sponsor health-related research and include summaries on their websites.

Citrus, among the most popular U.S. juices, provides several nutrients—vitamin C, potassium, dietary fiber, thiamin and folate. Additionally, it contains more than 60 antioxidant phytonutrients, mostly flavonoids and carotenoids. This combination of nutrients and phytonutrients makes it a natural functional food with several potential health benefits, including risk reduction for heart disease, stroke, hypertension, intestinal disorders such as diverticular disease and constipation, eye diseases such as cataracts and macular degeneration, and cancer.

Apple research now provides some science behind the old adage, “An apple a day keeps the doctor away.” Usually considered a nutritional lightweight compared to citrus fruit, flavonoidrich apple juice and other apple products provide antioxidant effects that can help protect cells from damage by free radicals implicated in the development of heart disease and age-related cancers. Several animal studies indicate that apples and apple juice improve cognitive function and memory and may reduce the risk of breast cancer. The mild and pleasing taste of apple juice appeals to people of all ages, making it an easy juice to include solo or as part of juice blends.

Another all-time favorite, grape juice—and the adult version, red wine—also have high antioxidant levels. While studies on red wine credit the antifungal chemical resveratrol as the protective agent for cardiovascular disease, brain and mental health, and colorectal cancer, re-search on grape juice attributes synergy among the high levels of polyphenol antioxidants as the probable reason for improved cognitive and motor skills in aging mice and improved blood pressure in mildly hypertensive men.

The muscadine grape, native to Southeastern United States, differs in composition from the morecommon wine grape, Vitis vinifer. It contains high levels of phenolic compounds, including anthocyanins, ellagic acid, flavonols and catechins. Animal studies illustrated its anti-inflammatory properties, and a study in diabetics demonstrated a lowering of blood glucose levels with muscadine juice or wine consumption. Other laboratory studies showed an inhibition of enzymes involved in the spread of cancer. “The muscadine grape holds promise as a powerful nutraceutical product,” says Chris Paulk, president, Muscadine Products Corporation, Wray, GA.

Tart-cherry juice also exhibits high antioxidant content and antiinflammatory properties that may help ward off cardiovascular disease and ease the pains of arthritis. “People buy and consume cherry juice based on anecdotal information,” says Phil Korson, president, Cherry Marketing Institute, Lansing, MI. “We have funded a series of studies at the University of Michigan. Last year, toxicity studies were completed, and the results will be published this winter. Now we are in the early stages of clinical trials designed to show the benefits of consuming cherry juice.”

Several recent animal studies report that berry extracts alone or in combination may help decrease some of the problems of aging. “There is something good about all berries,” says Thomas Payne, food technology consultant, U.S. Highbush Blueberry Council, San Francisco. “They seem to be complementary across the board. In other countries, blueberry juice is marketed as an antioxidant and anthocyanin, which is thought to be good for eyesight.” The anthocyanin might be the bioactive agent, and some human studies at the Human Nutrition Research Center on Aging, Tufts University, Boston, are backing up animal studies.

Women prone to urinary-tract infections recognized the value of cranberry juice as a treatment and prevention tool long before scientists discovered the mechanism.

Research shows that its proanthocyanidins prevent bacteria from adhering to urinary tract cells, limiting their ability to cause infections. Preliminary research indicates that this antiadhesion activity may help inhibit the bacteria that cause stomach ulcers and gum disease. Additionally, cranberries are high in flavonoids and polyphenols, antioxidants associated with many health benefits. Even though the naturally low sugar content of cranberries necessitates sweetener addition and/ or blending with other juices to appeal to most consumers, research shows urinary-tract health benefit with about 10 oz. of 27% juice cocktail.

Maximizing benefits 

Processing and handling can affect nutrients and phytonutrients, especially those sensitive to heat. Korson points out that cherry-juice anthocyanin is heat-sensitive, so it is best to not expose it to high heat, which will reduce its content. On the other hand, concentrates have higher anthocyanin content and are frequently used by consumers, diluted or combined with other food. He adds that most people recommend only 2 tablespoons of concentrated juice a day.

In the wild, high-bush blueberries are not homogeneous in flavor, which causes problems for manufacturers. Now beverage companies are selecting specific cultivars and are also using concentrates and blends. “Until recently, blueberries were not used extensively in juice,” Payne says. “But people believe that the juice has antioxidants, and there is a high demand for it now. Blueberry juice is good when blended, and several products use the concentrate. We are seeing a lot of blending with pomegranate juice now.”

Handling and processing methods can influence the final composition of juices. “We have quality controls that begin with handling and storing product from the time it reaches our facility,” says Anthony Popielarz, director of innovation and research, Vegetable Juices, Inc., Bedford Park, IL. “We are trying to stay natural. We believe that our proprietary process that is gentler than traditional methods results in better retention of nutrients.”

Marketing strategy can also determine ingredient selection. “Those who don’t want to say ‘concentrate’ on the label use single-strength juice. Others prefer to start with a concentrate or juice and add a purée to add fiber or change the body or opacity. This approach gives more flexibility to the characteristics and nutritional profile of the finished product,” Popielarz says. “Sometimes, blending a vegetable with fruit gives a flavor profile that appeals to a wider audience, including kids. Lately, we have been working with our cucumber juice as well as other vegetables mixed with grape juice to showcase unique, good-tasting flavor combinations.”

The best way to capitalize on the health benefits that a fruit offers is to pair a “feature fruit” with complementary fruits that have similar health benefits, notes Nicastro. “For example, consumers are looking for food and beverages that help maintain healthy-looking skin,” he says, noting that a recent product featured golden kiwifruit to appeal to such consumers. “Golden kiwi has naturally occurring lutein, which assists with cellular renewal and skin health. Other fruits and boosts were selected to complement the golden kiwi’s natural health benefits and flavor profile.”

Exotic examples 

In recent years, the market for exotic fruits has grown. According to Wayne Geilman, Ph.D., senior scientist, Pure Fruit Technologies, American Fork, UT, many exotic fruits are high in phytochemicals. The company offers products with mangosteen, goji berry, gac fruit and sea buckthorn berries. “Our juices are mixed with other familiar juices and purées, like apple,” he says. “They are sold as dietary supplements and require only a small quantity on a daily basis.” He adds that when choosing a base fruit juice, the company looks for one that has a good history, scientific documentation of health benefit, and availability. Processing will affect many vitamins, but many polyphenols appear to be heat-stable. “We don’t use chemical preservatives and rely on pH and heat treatment to preserve our products,” he states.

Geilman says, when formulating new juice blends, look for defined benefits, palatability and cost. Generally, the fruit juices and pulp can maximize phytochemical content. “Most Americans think vitamin C, sugar and fiber is all that you get in juices, so we spend a lot of time educating the public about the other benefits of these juices,” he says. “Right now, I am big on sea buckthorn berries, which have been in use in Asia and Northern Europe for thousands of years and appear to have several health benefits, involving the cardiovascular and immune systems,” he states. “Juices are a way to get a fruit serving, and it is possible to make it taste good.”

Polynesians have used noni, a novel fruit from the tropics, as a food and for health benefits for years, according to Brett West, director of research, Tahitian Noni International, Provo, UT. Until 1996, noni juice was not available here. “We started doing research on the health benefits from the beginning. Noni is high in antioxidants and has some novel compounds—lignans and flavonoids—never discovered before. When compared to grape and blueberry juices, noni juice provided significant benefit. So far, it appears that noni juice supports the immune system, improves energy and well-being, and is a good, healthy fruit juice,” he says. “Noni fruit is low in sugar and has an interesting taste, which for many is an acquired one. Usually, you drink only small quantities at a time, about 1 oz., as a supplement. We control the whole process from tree to bottle, and we use the whole fruit minus the seeds.” Currently, the company’s supply of juice is used to satisfy the demands of consumers and is not available to other manufacturers.

Only a few years ago, pomegranate juice was virtually unknown in the retail market. Now it commands shelf space as a stand-alone juice and as a key component of health-oriented juices. Widespread publicity about its high antioxidant content and a growing body of solid research on its potential health benefits fueled its popularity and helped move this once-exotic fruit into the mainstream.

Only time will tell if other exotic fruits will follow the same path, but if they do, the face of the healthy-juice market may become as diverse as the American population. 

Angela M. Miraglio, M.S., R.D., is a Fellow of the American Dietetic Association from Des Plaines, IL. Her firm, AMM Food & Nutrition Consulting, provides communications and technical support to the food and beverage industry. She can be reached at [email protected].

Conventional Wisdom

When sugar-sweetened and diluted with water, the nutritional cost-benefit ratio of juices becomes controversial. A Sept. 2006 report on “Fruit-Flavored Juice Drinks” from Mintel International, Chicago, cites obesity concerns as a major factor in the decline of U.S. fruit-flavored fruit-juice-drink sales.

However, recent studies on the effect of juice and juice-drink consumption on the weight of children shed some light on this controversy. In the Oct. 2006 issue of Pediatrics (118:1010- 1018), investigators reported that an analysis of National Health and Nutrition Examination Survey (NHANES) data showed increased consumption of beverages, including fruit juices and drinks, was associated with increased calories but not body-mass index (BMI) in preschool-age children. At the April 2006 Experimental Biology meeting held in San Francisco, researchers presented NHANES data on the impact of 100% juice consumption on the weight of children 2 to 18 years old with some surprising results. Not only were there no differences in body weight, BMI, waist size or risk for being overweight between consumers and nonconsumers of 100% juice, juice consumers aged 12 to 18 had lower BMI and risk for being overweight. Additionally, the analysis revealed that juice consumers’ diets contained more total fruits, fiber and key nutrients, such as vitamin C, potassium, magnesium and folate, and less total fat, saturated fat and sodium.

The Dietary Guidelines Advisory Committee analyzed the impact of removing fruit juice from recommended food patterns, based on NHANES 1999 to 2000 consumption data. Examining intake patterns for four groups of fruits and juices from these data revealed that about one-third of fruit intake comes from juices, with the majority being citrus. When they removed the juice component and substituted comparable fruits, calorie intake decreased, as did several nutrients, specifically vitamin C, folate, thiamin, magnesium and potassium, but they were still adequate for recommended intake levels. Overall, the committee concluded that fruit juices provide higher amounts of several vitamins and minerals than whole fruit and, in fact, may be helpful in meeting potassium intake recommendations. The MyPyramid recommendations, based on the 2005 Dietary Guidelines for Americans, include juices as equal substitutes for other forms of fruits and vegetables.