Consuming whole cranberry powder can limit changes in human gut microbiota from an animal-based diet, according to research published online Sept. 8 in The Journal of Nutritional Biochemistry. Led by researchers at Tufts University, an international team conducted a randomized, double-blind, crossover study of 11 healthy adults aged 25 to 54 with normal digestive function. They ate an animal-based control diet, plus 30 grams per day of a placebo powder, and then an animal-based treatment diet, which included 30 grams per day of freeze-dried whole cranberry powder.
Researchers found the cranberry-augmented diet showed fewer potentially negative microbiota changes. It also appeared to limit secondary gut bile acids that have been associated with colon and GI cancer. Overall, the treatment diet suggested cranberries may help support a healthy gut microbiome, researchers said.
"Among the 20 most commonly consumed fruits in the American diet, we chose to investigate cranberries and the gut microbiome as they are among the fruits with a high total phenol content," Oliver Chen, the study's author, said in a release. "An imbalance can increase the risk for several chronic diseases, including atherosclerosis, hypertension, kidney disease and Type 2 diabetes. Identifying foods — like cranberries — that can help shape and support a healthier gut microbiome could have a remarkable impact on public health."
Cranberries have shown other health benefits, such as limiting urinary tract infections in women, improving vascular function and cholesterol profiles in an animal study, delivering powerful antioxidants, reducing bacteria which can cause dental cavities and potentially reducing the incidence of ulcers and cancer.
While this new study's findings would likely be of interest to many consumers looking to adopt dietary changes to enhance their health, it's hard to tell how trustworthy the research is when there were only 11 participants. It might be more convincing if there were additional studies involving a much larger group.
As gut health has increasingly become a trend people care about, prebiotics have gained interest as a way to introduce food to promote the "good" bacteria already present in the digestive system. Probiotics, which are live bacteria added to the digestive system in the form of yogurt or kefir, as well as other foods and supplements, are also touted as helping to maintain a healthy gut, but their effectiveness has been questioned.
Because cranberries generally wear a health halo due to all the other studies that have been done, it's likely the industry will benefit from the outcome of this latest research. The Cranberry Institute helped to fund the Tufts University study. Executive Director Terry Humfeld said his organization, on behalf of cranberry growers and handlers, finds it exciting and rewarding to see new research about the potential benefits of cranberry consumption. The institute also tracks cranberry-related research on its website.
It's possible that, as more research stacks up pointing to the beneficial aspects of eating cranberries, the market will respond by featuring the ingredient at times other than Thanksgiving. Most of the harvest occurs in September and October, and the fresh fruit is usually available between September and December, according to the Cranberry Institute. Cranberries that aren't packaged to be sold fresh are available year-round in juice, sauce and dried products, so it's possible for manufacturers to advertise their benefits anytime.
Cranberries have one more marketing advantage compared to other fruits. They are native to North America and have been commercially farmed here since 1816.