Summary: Researchers urge agreement on which cognitive tests should be used to evaluate how nutrition affects brain function. They recommend narrowing and standardizing test selection and reporting, enabling data pooling across studies and strengthening conclusions about diet and cognition across the lifespan.
Source: IAFNS
How does diet influence brain health, and how can we more reliably measure its effects over a lifetime?
Scientists who study cognition currently rely on a wide range of tests, procedures, and conceptual approaches. This diversity has made it difficult to draw consistent conclusions about the relationship between nutrition and cognitive function.
A new perspective paper responds to a recommendation from the 2020 Dietary Guidelines Advisory Committee to address the “inconsistent validity and reliability of cognitive test methods.” These inconsistencies limit the ability to assess how diet affects thinking, memory, attention, and other cognitive processes from prenatal development through older age.
Nutrition plays an important role in brain health: good dietary patterns can help preserve and sometimes improve cognitive abilities such as memory and processing speed. Evidence links nutrition to cognitive changes at many stages of life, including before birth, in childhood, adulthood, and later years.
Cognition covers a range of mental skills—attention, learning, memory, and executive functions such as planning and reasoning. While many validated tests exist to measure these skills, there is no consensus on which tests are best for nutrition studies, nor on how they should be implemented. This variation increases heterogeneity across studies and complicates interpretation and synthesis of results.
To address these gaps, the Institute for the Advancement of Food and Nutrition Sciences (IAFNS) convened an expert group to examine cognitive task selection in nutrition research and propose practical solutions. The group’s goal was to recommend methods that could support clearer, evidence-based dietary guidance for cognitive health.
Experts reviewed existing systematic reviews and meta-analyses to catalog the cognitive tasks currently in use and to evaluate their reliability and validity. They found that while many validated measures are available, disagreement remains about which specific cognitive domains—such as verbal memory versus working memory—are most sensitive to dietary influences.
Researchers and reviewers differed on the optimal scope of testing: some advocated for comprehensive test batteries to capture multiple cognitive domains, while others cautioned against lengthy assessments that can frustrate participants and reduce data quality. Balancing breadth and participant burden is therefore a key practical concern.
The experts concluded that harmonizing and reducing the number of cognitive tests, and standardizing their implementation and reporting, would allow researchers to combine datasets and conduct more powerful pooled analyses. Greater comparability across studies would improve confidence in recommendations about dietary strategies to support cognitive health throughout life.
The paper, titled “Advancing Dietary Guidance for Cognitive Health: Focus on Solutions to Harmonization of Test Selection, Implementation and Evaluation,” outlines specific strategies for test selection, consistent implementation, and standardized reporting. The authors emphasize the value of adopting common test parameters and reporting guidelines to make results more interpretable and usable for policy-making.
Participants in the expert group included representatives from government agencies and other sectors who described how different regulatory systems evaluate claims about cognition on food products. These perspectives helped clarify what types of evidence are considered acceptable by different authorities and underscored the need for consistent, high-quality measures.
According to the paper, if researchers widely adopt the recommended methods and practices, and if large datasets can be pooled, this approach could greatly strengthen the evidence base for dietary guidance related to brain health. Standardized methods would make it more feasible for dietary guidelines committees to offer firm, evidence-based recommendations on nutrition for cognitive health.
About this diet and cognition research news
Author: Steve Gibb
Source: IAFNS
Contact: Steve Gibb – IAFNS
Image: The image is in the public domain
Original Research: Closed access. “Advancing Dietary Guidance For Cognitive Health—Focus On Solutions To Harmonize Test Selection, Implementation And Evaluation” by Romijn AR et al. Advances in Nutrition
Abstract
Advancing Dietary Guidance For Cognitive Health—Focus On Solutions To Harmonize Test Selection, Implementation And Evaluation
This perspective summarizes the outcomes of a March 2022 expert workshop convened by the Institute for the Advancement of Food and Nutrition Sciences (IAFNS). The workshop brought together scientists from government, academia, and industry to identify actionable solutions to the considerable variation in cognitive testing methods described in the 2020 United States Dietary Guidelines Advisory Committee report.
The expert group conducted an umbrella review of prior reviews to identify shared concerns and established principles for selecting cognitive outcome measures. While the literature agreed on several foundational issues, key disagreements about task selection and implementation persist. Resolving these disagreements is essential to reduce heterogeneity across studies and to make existing data more useful for informing dietary guidance on cognitive health.
Following the literature summary, the paper presents the expert group’s recommendations for harmonizing test selection, standardizing implementation practices, and improving reporting standards. These steps aim to advance the quality of nutrition-cognition research and to support stronger, more consistent dietary guidance for brain health over the lifespan.