In the world of super foods, berries are nutritional winners, and the chokeberry tops the list for its rich pigments that contain scores of beneficial phytochemicals.
When Bolling arrived at UConn in 2010 after completing a postdoctoral fellowship at the Tufts University Jean Mayer USDA Human Nutrition Research Center on Aging, he was fascinated by Mark Brand’s chokeberry research. Brand is a professor in the Department of Plant Science and Landscape Architecture.
Brand had been researching the genetics of the wild type of chokeberry, Aronia melanocarpa, which is native to New England and North America. Aronia was already a useful landscape crop: hardy in cold climates and bearing attractive dark berries in shades of red, purple and black. Bolling’s interest was piqued when the aronia berries proved to be rich in polyphenols.
Initially, Brand began studying aronia as a native landscape shrub to replace the invasive Japanese barberry and winged euonymus. He says, “No one else in the United States was working on aronia and it had great potential as an ornamental due to its cultural adaptability, white spring flowers, summer and fall fruit and good fall colors. Soon, I became aware of aronia’s potential as a nutraceutical fruit crop and reworked my research priorities to include plant improvement for both ornamental and nutraceutical purposes.”
“We’re very interested in aronia, as each berry in this group has its own polyphenol profile,” says Bolling. “We’re looking at the genetically wild type to identify potentially interesting genotypes that Dr. Brand could use to increase phytochemical content in a way that benefits health.”
Brand began his aronia tissue culture research in the early 1990s. One of his undergraduate students was Bill Cullina, a well-known horticultural author and executive director of the Coastal Maine Botanical Gardens. Brand says, “I like to think that Bill’s involvement with aronia helped to cultivate his interest in native plants, for which he is now a well-respected authority.”
From a taste perspective, chokeberry is tart and may not garner wide consumer appeal. Bolling is collaborating with Valerie Duffy, professor in the Department of Allied Health Sciences, to identify ways to make aronia juice more palatable. She says, “The high levels of antioxidant nutrients in aronia juice are terrific for health but challenging for taste and liking. The juice has sourness, bitterness and some astringency, which is a drying feeling, but a wonderful fruity flavor. Some individuals like the juice as it is. For most people, we’ll have to figure out how to enhance the natural sweetness and fruitiness to make an enjoyable beverage. To get the nutrient benefit, people have to like and drink the berry juice.”
In one study, Bolling is studying the potential of aronia berry to ease symptoms of inflammatory bowel disease (IBD). “We have some very interesting preliminary data in mice models,” Bolling says. “It looks very promising. We already know that children who consume the highest amount of fruit are at the lowest risk for developing IBD later on. We’re trying to understand the role of this in the initiation and progression of the disease.”
While these studies could eventually lead to dietary recommendations for IBD sufferers, Bolling points out that more research needs to be completed before dietary guidelines are publicized. “Diet is very appealing to people because it’s something that can be changed quickly. There’s a trend to sensationalize these things, but our studies have been done in animals and need to be conducted in human populations.”
Several other studies on aronia berry are in progress, including one funded by the Connecticut Department of Public Health, that examines the benefit of an aronia berry dietary supplementation with former smokers. Another study is using a mouse model to look at the cardiovascular health benefits of aronia berry.
In a project funded through the Almond Board of California , Bolling is studying the phytochemicals in almonds. He has discovered two new classes of polyphenols in almonds. The first, in the category of stilbenes, a compound similar to the resveratrol found in wine, was present in low levels but was a surprise discovery nonetheless. “We did not know that almonds have this capability to synthesize these types of compounds,” Bolling says.
The second find is an ellagitannin, which is a similar type of compound found in pomegranates. This compound was identified at 15 mg per 100 grams of almonds, a fairly significant content.
“Polyphenols are a broad class of compounds that are chemically diverse. We are working to understand the metabolic fate of these compounds and how they are metabolized in the body. People have unique capacities to metabolize these polyphenols. From a dietary standpoint, we need to learn how these processes affect their ability to promote health.”
In a new study funded by the Dairy Research Institute, Bolling will conduct a human study on low-fat yogurt consumption and the potential reduction of a type of chronic inflammation associated with obesity.
“Foods have an untapped potential for affecting health,” Bolling says. “It’s a challenge to study, but that’s what makes it so interesting and promising at the same time.”
Participants are needed for nutritional research studies. Visit the Department of Nutritional Sciences research studies page for more information.