June 25, 2022
Frontiers in Nutrition
TAKE-HOME MESSAGE
- Berries are increasingly recognized as an important source of polyphenols, which are thought to be protective against cognitive decline with aging. This 12-week randomised trial evaluated the effect of daily cranberry consumption in the form of freeze-dried cranberry powder on cognition and brain function in adults aged 50 to 80 years. Daily cranberry supplementation was associated with an improvement in visual episodic memory (P = .028) and significantly reduced LDL cholesterol levels (P = .048). However, no improvement in other cognitive functional domains or increase in the level of brain-derived neurotrophic factor, a biomarker of neuronal signaling and growth, was noted.
- This study suggests that cranberry supplementation may improve episodic memory performance and neural functioning and decrease LDL cholesterol levels. Additional studies with longer periods of supplementation and supplementation in the context of specific neurological diseases are warranted.
BACKGROUND
Ageing is highly associated with cognitive decline and modifiable risk factors such as diet are believed to protect against this process. Specific dietary components and in particular, (poly)phenol-rich fruits such as berries have been increasingly recognised for their protection against age-related neurodegeneration. However, the impact of cranberries on cognitive function and neural functioning in older adults remains unclear.
DESIGN
A 12-week parallel randomised placebo-controlled trial of freeze-dried cranberry powder was conducted in 60 older adults aged between 50 and 80 years. Cognitive assessment, including memory and executive function, neuroimaging and blood sample collection were conducted before and after the intervention to assess the impact of daily cranberry consumption on cognition, brain function and biomarkers of neuronal signalling.
RESULTS
Cranberry supplementation for 12 weeks was associated with improvements in visual episodic memory in aged participants when compared to placebo. Mechanisms of action may include increased regional perfusion in the right entorhinal cortex, the accumbens area and the caudate in the cranberry group. Significant decrease in low-density lipoprotein (LDL) cholesterol during the course of the intervention was also observed. No significant differences were, however, detected for BDNF levels between groups.
CONCLUSIONS
The results of this study indicate that daily cranberry supplementation (equivalent to 1 small cup of cranberries) over a 12-week period improves episodic memory performance and neural functioning, providing a basis for future investigations to determine efficacy in the context of neurological disease. This trial was registered at clinicaltrials.gov as NCT03679533 and at ISRCTN as ISRCTN76069316.