Monday, December 22, 2014

Cranberries--America's "Superfruit"

While news headlines may lead to you believe we need to travel to far-off, exotic locations to unearth nature’s “superfoods,” the reality is we can find “superfoods” right in our back yards.  Gogi, noni or acai berries are popular among health trendsetters; marketers of said foods promise a life-altering experience after consumption of those foods and often the price tag would lead you to believe that yes, this outrageously priced food must be a food cure-all! 

While I cannot vouch for the validity of such promises, I can vouch for the benefits of all-natural, versatile and affordable cranberries.  Cranberries are actually one of two native fruits of North America, the other being blueberries.  Native Americans used cranberries for their medicinal purposes and also to make an energy bar-like product called pemmicana.  While Native Americans called cranberries sassamanesh, Dutch Settlers eventually called them crane berries because the flower resembles the head and bill of a crane.1   Nowadays, we call them cranberries and I was surprised to learn that cranberries far outrank blueberries and cherries in yield, production and consumption. 2 So while we may think of cherries and blueberries as patriotic fruits, cranberries really are all-American.

Besides widespread consumption and popularity, cranberries have numerous convincing health benefits backed by research.  It’s worth noting that a pound of cranberries rings in at about $2.50 per pound while those other, exotic “superfruits” cost around $27 per pound.  So after checking out just a few of cranberries’ health benefits, below, consider keeping a bag of affordable cranberries around year-round, not just throughout the holiday season. 

Urinary tract infections: Antibacterial resistance is an increasing issue and health professionals are looking for other options in treating and preventing infections.  Cranberries have been shown to reduce the incidence of recurrent urinary tract infections (UTIs) in women and children.  Cranberry consumption prevents bacteria from adhering to cell walls in the urinary tract; if bacteria cannot adhere they won’t grow and cause infection.  Studies have tested 100% juice, juice cocktails as well as capsulated cranberry extracts and found positive results in all.  It appears that drinking a glass of cranberry juice twice a day may have the best benefits.

Cardiovascular:  Cranberries contain a unique set of proanthocyanidins (PAC), including the rare type-A PAC.   With the exception of lingonberries, no other fruit contains type-A PACs at the high level of cranberries.  It is these PACs that give cranberries their associated health benefits. 3 Cranberry consumption leads to an improvement in several cardiovascular disease risk factors, such as cholesterol, inflammation, arterial stiffness and endothelial function. 

Cholesterol—Both animal and human studies show that consumption of cranberry juice anthocyanins lowers LDL cholesterol by interfering with LDL uptake.  Additionally, cranberry anthocyanins inhibit cholesterol ester transfer protein which increases HDL concentrations. 
Inflammation—Because cardiovascular disease is an inflammatory disease, risk is often expressed in terms of levels of C-reactive protein (CRP) and other inflammatory biomarkers.  In vitro and in vivo studies have shown that cranberry juice consumption leads to decreases in CRP and vascular cell adhesion molecules in patients with hypercholesterolemia, thus lowering risk.
Arterial Stiffness—Arterial stiffness measures predict cardiovascular events and are often used as a measure of the pathogenesis of hypertension and heart failure.  Luckily for CVD patients, arterial stiffness responds to dietary interventions - and a study by Dohadwala et al. showed that drinking about two cups of a 54% cranberry juice beverage led to a decrease in aortic stiffness.  Additionally, Jennings et. al. found that higher intakes of anthocyanins and flavones are inversely associated with arterial stiffness. 4
Endothelial dysfunction—A healthy vascular endothelium produces many factors that maintain vasomotor tone, thrombosis, inflammation and capillary growth.  One of those, nitric oxide, plays an important role in CVD risk as it influences blood vessel dilation, platelet aggregation and anti-inflammatory markers.  Studies have shown that cranberry bioactives increase the bioavailability of NO by increasing concentrations of enzymes that promote NO production; as such, studies have shown increased endothelial dilation and improved function after consumption of cranberry juice consumption (about 2 cups).   

In addition to a reduction in specific CVD risk markers, observational studies have also shown a decreased risk of CVD with increased anthocyanin intake from cranberries.  Considering most Americans are not eating enough fruit, according to the dietary guidelines, cranberries and cranberry products would make an excellent addition to any diet while also reducing risk of disease.  While cranberry products are often sweetened, it is worth noting that cranberry juice contains less sugar (11.7g/100mL) than 100% grape, apple and orange juices (16.5, 11.1 and 10.5 g/100mL).  Additionally, dried or fresh cranberries are also prepared with added sugar but the best use of added sugar is to improve the palatability of nutrient-dense food.  Looking at the research, it is obvious that cranberries definitely are a nutrient-dense food with positive health benefits.

Kym Wroble earned her Bachelor of Science degree in nutrition and dietetics and minored in food science at Dominican University, River Forest, Illinois. She completed the clinical component of her dietetic internship with Iowa State University at Great River Medical Center in Burlington, Iowa. Her previous experience working as a nutrition educator at Scott County WIC provided her with additional focused training in several areas including pregnancy, postpartum wellness, breastfeeding and infant and child nutrition. In June of 2009, Kym completed the CDR Certificate of Training in Adult Weight Management.  Kym is a member of the Academy of Nutrition and Dietetics (formerly the American Dietetic Association) and the Iowa Dietetic Association.  Additionally, she is also a member of several dietetic practice groups, including the Dietitians in Business and Communications, Food and Culinary Professionals dietetic practice group and the Sports, Cardiovascular and Wellness Nutrition dietetic practice group. She has a particular interest in culinary nutrition and enjoys cooking, baking, recipe modification, and learning about food and wine. She played varsity volleyball at Dominican University and continues to enjoy an active lifestyle jogging, biking and weight training.

1.        Cranberry History,” Ocean Spray, Ocean Spray Cranberries, Inc., Web. 26 November 2014.
2.        “Trends and Insights of the Blueberry, Cranberry, and Tart Cherry Industries,” Cherry Industry Administrative Board., CIAB., Web. 26 November 2014.
3.        Blumberg, Jeffrey B., et. al, “Cranberries and Their Bioactive Constituents in Human Health,” Amer. Jour. for Clin. Nutr., 4:2013, 618-632. Web. 25 November 2014.

4.        Jennings, Amy, et. al, “Higher anthocyanin intake is associated with lower arterial stiffness and central blood pressure in women,” Amer. Jour. for Clin. Nutr., 112.042036v1, Web. 26 November 2014.