The goal of the COSMOS Web study is to determine whether a dietary intervention with
flavanol-containing cocoa extract has an effect on cognitive function in older adults (age
60+). The study will be conducted in a subset of 4000 participants from the COSMOS study
(NCT02422745). The investigators' recent work (Sloan et al., submitted) showed that cocoa
flavanol consumption over 12 weeks led to improvements in immediate recall on the ModRey
verbal memory task in healthy older adults.
In COSMOS Web, the investigators are testing the effect of a dietary intervention with
flavanol-containing cocoa extract on a range of aging-related cognitive measures, as assessed
through a novel online-administered test battery, in a cohort of older participants. Change
in ModRey (Modified Rey Auditory Verbal Learning Test) immediate recall performance over 1
year of cocoa extract consumption will be our primary outcome measure. Secondary endpoints
will include change in ModRey performance at 2- and 3-year follow-up, and change in
performance tests of a novel object recognition task, executive function/working memory, and
spatial memory at 1-, 2-, and 3- years follow-up. This study will explore whether baseline
measures of cognition and nutritional status can predict differential effects of the cocoa
extract supplementation. This study will also explore the effect of multivitamin intake on
the primary and secondary outcomes noted above and test whether multivitamin intake interacts
with flavanol intake from cocoa extract to enhance or mitigate effects on cognitive outcomes.
In a subset of participants evaluated in person, this study will examine the impact of cocoa
extract intake and explore the main and interacting effects of multivitamins on cognitive
changes and brain structure and function appreciated with magnetic resonance imaging over a
2-year period.
Leveraging the COSMOS study, which has randomized 21,442 older adult participants into cocoa
extract and placebo interventions, the study team at Brigham and Women's Hospital, who
administer the parent COSMOS trial, are recruiting ~4000 older adult volunteers to
participate in COSMOS Web (this study) an online cognitive testing battery developed by the
team at Columbia University. These 4000 participants will complete an initial online
cognitive assessment and additional assessments after one, two, and three years of follow-up.
In addition, approximately 200 COSMOS Web participants who live in the Boston area will
complete clinic-based study visits at the Clinical and Translational Science Center at
Brigham and Women's Hospital. During that visit, they will complete a neuropsychological test
battery, for comparison to their performance online. This study will examine the impact of
dietary interventions with cocoa extract and explore the main and interacting effects of
multivitamin intake on cognitive changes and brain structure and function appreciated with
magnetic resonance imaging over a 2-year period.
After the COSMOS trial began, an advanced method to analyze cocoa flavanols was accredited by
AOAC International as a First Action Official Method of Analysis
(https://doi.org/10.1093/jaoacint/qsaa132). This updated method relies on a reference
material (RM8403) recently standardized and made commercially available by the U.S. National
Institute of Standards and Technology. While the actual cocoa flavanol content of the COSMOS
intervention remained unchanged throughout the trial, the application of this new analytical
method led to expected changes in how the total cocoa flavanol content is now reported.
Applying AOAC 2020.05/RM8403 to the COSMOS intervention, the total cocoa flavanol content of
the COSMOS intervention is now 500 mg/day. Reporting of (-)-epicatechin content remained
unaffected. Going forward, we will therefore apply AOAC 2020.05/RM8403 and report that the
COSMOS intervention tested 500 mg/day of cocoa flavanols, including 80 mg of (-)-epicatechin.
