Samantha Galluzzi, Moira Marizzoni, Elena Gatti, Natale Salvatore Bonfiglio, Annamaria Cattaneo, Francesco Epifano, Giovanni B Frisoni, Salvatore Genovese, Andrea Geviti, Lorenzo Marchetti, Giovanni Sgrò, Claudio Singh Solorzano, Michela Pievani, Serena Fiorito
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引用次数: 0
Abstract
Background: Developing interventions for older adults with subjective cognitive decline (SCD) has the potential to prevent dementia in this at-risk group. Preclinical models indicate that Citrus-derived phytochemicals could benefit cognition and inflammatory processes, but results from clinical trials are still preliminary. The aim of this study is to determine the effects of long-term supplementation with Citrus peel extract on cognitive performance and inflammation in individuals with SCD.
Methods: Eighty participants were randomly assigned to active treatment (400 mg of Citrus peel extract containing 3.0 mg of naringenin and 0.1 mg of auraptene) or placebo at 1:1 ratio for 36 weeks. The primary endpoint was the change in the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) total score across the 36-week trial period. Other cognitive outcomes included tests and scales evaluating verbal memory, attention, executive and visuospatial functions, and memory concerns. The secondary endpoint was the change of interleukin-8 (IL-8) levels over the 36-week trial period in a subsample of 60 consecutive participants. An Intention-to-treat approach with generalized linear mixed models was used for data analysis.
Results: The RBANS total score showed significant improvement in both Citrus peel extract and placebo groups at 36 weeks (p for time < .001, d = 0.36, p time x treatment = .910). Significant time effects were also found in cognitive domains of short- and long-term verbal memory (p < .001) and scales of subjective memory (p < .01), with no significant time x treatment interaction. The largest effect sizes were observed in verbal memory in the placebo group (d = 0.69 in short-term, and d = 0.78 in long-term verbal memory). Increased IL-8 levels were found at 36-week follow-up in both Citrus peel extract and placebo groups (p for time = .010, d = 0.21, p time x treatment = .772). Adverse events were balanced between groups.
Conclusions: In this randomized clinical trial, long-term Citrus peel extract supplementation did not show cognitive benefits over placebo in participants with SCD, possibly due to high placebo response. These findings might have specific implications for designing future nutraceutical trials in individuals experiencing SCD.
Trial registration: The trial has been registered at the United States National Library of Medicine at the National Institutes of Health Registry of Clinical Trials under the code NCT04744922 on February 9th, 2021 ( https://www.
期刊介绍:
Nutrition Journal publishes surveillance, epidemiologic, and intervention research that sheds light on i) influences (e.g., familial, environmental) on eating patterns; ii) associations between eating patterns and health, and iii) strategies to improve eating patterns among populations. The journal also welcomes manuscripts reporting on the psychometric properties (e.g., validity, reliability) and feasibility of methods (e.g., for assessing dietary intake) for human nutrition research. In addition, study protocols for controlled trials and cohort studies, with an emphasis on methods for assessing dietary exposures and outcomes as well as intervention components, will be considered.
Manuscripts that consider eating patterns holistically, as opposed to solely reductionist approaches that focus on specific dietary components in isolation, are encouraged. Also encouraged are papers that take a holistic or systems perspective in attempting to understand possible compensatory and differential effects of nutrition interventions. The journal does not consider animal studies.
In addition to the influence of eating patterns for human health, we also invite research providing insights into the environmental sustainability of dietary practices. Again, a holistic perspective is encouraged, for example, through the consideration of how eating patterns might maximize both human and planetary health.