Consuming high amounts of cranberries over several weeks may confer benefits to brain health and lower LDL cholesterol, according to a recent double-blind, randomized, placebo-controlled human clinical trial published in Frontiers in Nutrition. The study was supported by a grant from the Cranberry Institute, a nonprofit organization supporting the industry of cranberry growers.
 
Among 60 cognitively healthy adults between the ages of 50 and 80, consuming freeze-dried cranberries equivalent to one cup of fresh cranberries was linked to improved measures of brain perfusion (how much blood is taken up by certain areas of the brain), scores of visual episodic memory and neural functioning, and a significant decrease in LDL cholesterol which is known to contribute to atherosclerosis. The brain perfusion test specifically looked at improvements in circulation of oxygen and glucose to important neural areas that support memory consolidation and retrieval. Improvements in episodic memory scores coincided with improvements to brain perfusion, according to the authors.
 
The authors noted that this supports previous theories that cranberries can improve vascular health, and that this may in turn confer health benefits in people.
 
“The pathophysiological processes leading to neurodegeneration, like many other diseases, are proposed to involve the dysfunction of multiple systems in the body,” the authors conclude. “Neurodegeneration is hypothesized to be characterized by progressive changes in several interlinked cellular and molecular mechanisms, including chronic neuroinflammation, oxidative stress and metabolic imbalances, as well as the loss of vascular integrity and function, deposition of aggregated proteins, mechanisms that underlie not only pathological but also normal brain aging, resulting in loss of neural plasticity and neuronal death.
 
Brain-derived neurotrophic factor (BDNF) did not have any significant changes among the group supplementing their diets with cranberries. Cranberry intervention did not have any further impact on other neurocognitive domains, the authors noted, such as working memory and executive functioning. “The relatively small sample size of this intervention may have been a limiting factor particularly with regards to having sufficient power to detect significant differences in both cognition and brain perfusion […] furthermore, although it was not reported by any participants, other health conditions which may have influenced cognitive results such as sleep apnea were not systematically excluded in this study.”
 
“These findings are, however, certainly encouraging that sustained intake of cranberry over a 12-week period produced significant improvements in memory and neural function in older adults who were cognitively healthy,” the authors concluded.
 
“Demonstrating in humans that cranberry supplementation can improve cognitive performance and identifying some of the mechanisms responsible is an important step for this research field,” according to Dr. David Vauzour, senior research fellow in molecular nutrition at the Norwich Medical School, University of East Anglia. “It is essential that novel solutions are identified to help reduce age-related neurodegeneration and until now, cranberries were an unutilized natural resource.”
 
According to the authors, past studies have identified that higher dietary flavonoid intake is associated with slower rates of cognitive decline and dementia, and foods rich in anthocyanins and proanthocyanins such as berries have been linked to improvements in cognition. This study is one of the first to examine cranberries and their long-term impact on cognition and brain health in humans. They also noted that other nutrients present in cranberries, including fermentable fibers, can influence the metabolism of polyphenols.
 
“The findings of this study are highly encouraging, considering that a relatively short 12-week cranberry intervention was able to produce significant improvements in memory and neural function,” Vazour said. “This establishes an important foundation for future research in the area of cranberries and neurological health.”