Chronic Consumption of Cranberries (Vaccinium macrocarpon) for 12 Weeks Improves Episodic Memory and Regional Brain Perfusion in Healthy Older Adults: A Randomised, Placebo-Controlled, Parallel-Groups Feasibility Study

Abstract

BackgroundAgeing 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.DesignA 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.ResultsCranberry 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.ConclusionsThe 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.

The Effects of Cranberry Consumption on Glycemic and Lipid Profiles in Humans: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

“…Then, 2556 studies were excluded because of in vitro or animal studies and irrelevant outcomes. Finally, 40 full-text studies assessed the above criteria preliminary, and 16 of them were included for qualitative synthesis and meta-analysis [ 10 , 11 , 12 , 13 , 14 , 15 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. The flow chart for the literature search is shown in Figure 1 .…”

“…Table 1 lists the characteristics and main results of sixteen included studies published from 2006 to 2023 [ 10 , 11 , 12 , 13 , 14 , 15 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ] and nine published in the past five years [ 14 , 15 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. In total, 708 participants aged 18 to 80 were systematically reviewed in this analysis.…”

Role of fruit and vegetables in sustaining healthy cognitive function: evidence and issues

“…The lack of effects at 24 weeks is difficult to explain, particularly as systolic blood pressure was reduced at 12 and 24 weeks, but a tentative explanation is that this is reflective of a practice effect whereby improved strategy in performing the tasks has reduced task sensitivity. Twelve weeks' consumption of 4⋅9 g/d freeze-dried cranberry extract (equivalent to one cup of fresh cranberries) was also shown to improve episodic memory in 50-80-year-olds (53) . Reduced LDL-cholesterol was also shown with some evidence for sex differences in response, as well as increased perfusion in specific regions of the right brain.…”

“…These findings potentially suggest that those at risk, either due to poorer nutrition or poorer education, may be more susceptible to cognitive improvements following a fruit or vegetable intervention. A number of studies (53,55,56,60) indicate increased cerebral blood volume following fruit/legume intervention, as well as improved cardiometabolic markers, and in some cases a correlation between changes in cognition and cerebrovascular/metabolic markers. These findings may suggest that cognitive improvement is more likely in those who are at risk for cardiometabolic dysfunction.…”

Gastrointestinal Dysfunction in Neurological and Neurodegenerative Disorders

“…103,104 Another study assessing a diet characterized by increased consumption of cranberry, which is rich in polyphenols and associated with more healthy gut microbiota, documented enhanced visual episodic memory and decreased low-density lipoprotein cholesterol levels in 50-to 80-year-old people. 105 An example of work in progress is a study involving a low-fat vegan diet, aerobic and resistance exercise, stress management, and group support, which are expected to have beneficial effects on the gut microbiome, gut-brain axis, and cognition. 106 These human intervention studies are important to confirm the promising environmentally controlled preclinical studies involving exercise and diet supplements aimed at improving gut and brain function.…”