Cranberries May Support Memory and Brain Health, Study Finds

A cup of cranberries a day may support memory and brain health while also lowering "bad" cholesterol, according to a new study published in Frontiers in Nutrition.

Cranberries contain flavonoids, a type of anti-inflammatory phytonutrient found in fruits, vegetables, grains, wine, and tea. Research suggests that flavonoids may protect against cognitive decline and the development of Alzheimer's disease and dementia.

"Although cranberries are rich in anthocyanins and proanthocyanidins, two classes of flavonoids, these have been understudied for their cognitive benefit. We therefore tried to address this knowledge gap by running the trial," said David Vauzour, PhD, a senior research fellow at the University of East Anglia in the United Kingdom, and a co-author of the study.

The study participants, aged between 50 and 80, showed significant improvements in visual episodic memory and circulation of nutrients in the brain from consuming cranberry extract.

This is the first longitudinal study to find promising results on cranberries and brain health. An older study in 2005 found that cranberry juice offered no significant benefit to cognitive health. Both studies had a relatively small sample size of cognitively-healthy older adults, and they were both partially funded by The Cranberry Institute.

Vauzour said that the discrepancies between the two studies could be attributed to the duration of the trials and the type of cranberry product used.

The new study was conducted over the course of 12 weeks and tested a powder made from freeze-dried cranberries, while the 2005 study only lasted six weeks and used cranberry juice.

Should You Start Taking Cranberry Supplement?

The study participants were given a daily allotment of freeze-dried cranberry powder—made from whole cranberries—equivalent to one cup of fresh cranberries.

Whitney Linsenmeyer, PhD, RD, LD, an assistant professor in nutrition and dietetics at Saint Louis University, told Verywell in an email that it might be unsustainable to incorporate cranberry powder into one's long-term diet. And many cranberry byproducts tend to contain high amounts of sugar to make them more palatable, she added.

Angel Planells, MS, RDN, a Seattle-based registered dietitian, said that people might miss out on the fiber and hydration from whole cranberries if they opt for cranberry powder instead.

Supplements can help certain individuals meet their nutritional needs, Planells said, but it's important to remember that they aren't regulated by the Food and Drug Administration to the same extent as medications. He suggested looking for third-party verification from USP to confirm a supplement's safety.

Since cranberry is rich in oxalate, it could increase the chance of developing kidney stones and it may interact with medications like aspirin or warfarin.

How Was the Study Conducted?

More than six million Americans currently live with Alzheimer's, the most common form of dementia. There is no known cure so the current focus is on treatment and prevention. Many researchers believe that certain dietary and lifestyle factors could influence the development of dementia.

While this new study was dubbed "long-term," it only lasted 12 weeks. It only included 60 participants and some were unable to complete the baseline and follow-up MRI scans due to pandemic restrictions. However, Vauzour said his team was still able to obtain cognitive data and biological samples with the help of remote testing and mail service.

The study does add to the growing body of research that cranberries and other flavonoid-rich fruits can support cognitive health. However, experts say it is important to remember that this study was funded by The Cranberry Institute, which works to promote the success of cranberry growers.

"Readers should be highly skeptical about research funded by the food industry. Industry-funded research is more likely to report findings that support that industry," Linsenmeyer said.

It is not uncommon for the food industry to fund nutrition research. A 2018 review of the original studies published in the top nutrition journals found that over 13% received food industry funding.