Abstract
Objectives:
The aim of this research was to conduct the first known clinical trial of the short-term (i.e., 6 weeks) efficacy of cranberry juice on the neuropsychologic functioning of cognitively intact older adults.
Participants:
Fifty (50) community-dwelling, cognitively intact volunteers, ≥60 years old, who reported no history of dementia or significant neurocognitive impairments, participated in this study.
Design:
A 6-week, double-blind, placebo-controlled, randomized, parallel-group, clinical trial was utilized. Participants were randomly assigned to receive either 32 ounces/day of a beverage containing 27% cranberry juice per volume (n = 25) or placebo (n = 25) for 6 weeks, and administered a series of neuropsychologic tests at both pretreatment baseline and again after 6 weeks of either cranberry juice or placebo treatment to assess treatment-related changes.
Outcome measures:
Efficacy measures consisted of participants' raw scores on the following standardized neuropsychologic tests: Selective Reminding Test, Wechsler Memory Scale-III Faces I and Faces II subtests, Trail Making Test (Parts A and B), Stroop Color and Word Test, and the Wechsler Adult Intelligence Scale- III Digit Symbol-Coding subtest. A subjective Follow-up Self-report Questionnaire was also administered to participants at the conclusion of the end-of-treatment phase assessments.
Results:
Two-factor, mixed analyses of variance (ANOVA) revealed no significant group (cranberry juice and placebo) by trial (pretreatment baseline and end-of-treatment assessments) interactions across all of the neuropsychologic tests and measures utilized in this study when a Bonferroni corrected alpha level was used to correct for multiple comparisons (i.e., .05/17 group by trial comparisons = .003). Pearson Chi-Square analyses of the groups' self-reported changes over the 6-week treatment phase in their abilities to remember, thinking processes, moods, energy levels, and overall health on the Follow-up Self-report Questionnaire revealed no significant relationships. However, a nonsignificant trend (X2(1) = 2.373, p = 0.123) was noted for participants' self-reported overall abilities to remember from pretreatment baseline to the end-of-treatment assessment. Specifically, more than twice as many participants in the cranberry group (n = 9, 37.5%) rated their overall abilities to remember by treatment end as "improved" as compared to placebo controls (n = 4, 17.4%).
Conclusions:
Taken together, no significant interactions were found between the cranberry and placebo groups and their pretreatment baseline and end-of-treatment phase (after 6 weeks) standardized neuropsychologic assessments. A nonsignificant trend was noted, however, on a subjective, self-report questionnaire where twice as many participants in the cranberry group rated their overall abilities to remember by treatment end as"improved" compared to placebo controls.
Get full access to this article
View all access options for this article.