Summary: Scientists have asked for consensus on which cognitive tests to use to assess the impact of nutrition on brain function They recommend reducing the number of tests and standardizing reporting guidelines, which could allow researchers to pool data and take safer decisions about how diet affects cognition throughout life.
How can we better understand how what we eat affects our brain health? And how does our diet affect brain function as we get older?
Scientists studying cognition often use different approaches, tests, and even ways of thinking about the area.
But a new paper responds to a call from the 2020 Dietary Guidelines Advisory Committee report to address “the inconsistent validity and reliability of cognitive testing methods.” These limitations limit the ability to draw firm conclusions about diet and cognition across the lifespan.
Optimizing nutrition can maintain and perhaps even improve cognitive functions known to be affected by aging, such as memory and processing speed. Evidence has shown that nutrition is associated with changes in cognition from before we are born to our old age.
Cognition includes attention, learning, memory, and executive functions such as planning and reasoning. While there are many tests of these cognitive abilities, there is no consensus on which one to apply, and many different ways can be implemented in studies.
Because of the importance of learning more about nutritional interventions that might influence cognition, IAFNS convened experts to discuss the selection of cognitive tasks in nutrition research.
The group was tasked with suggesting research avenues that could provide dietary insights into cognitive health. Experts sifted through existing reviews to understand more about which cognitive tasks were being measured and whether the tests used were reliable and valid.
The Panel agreed that there are validated tests that can be used to examine the effects of nutrition on cognition. There was less agreement that, for example, verbal memory or working memory are more sensitive to what we eat.
Additionally, some of the review literature called for comprehensive batteries of cognitive tests, while others warned that people in the studies may become frustrated with too much test activity, eroding their accuracy.
Reducing the differences and the number of cognitive tests so scientists can combine the measures could lead to more confident decisions about diet and thinking later in life, according to the authors.
This and other strategies are outlined in the document “Advancing Dietary Guidance for Cognitive Health: Focus on Solutions to Harmonization of Test Selection, Implementation and Evaluation,” which appears in the journal Advances in nutrition. Standard guidelines for reporting and metrics of cognitive tests would also be valuable additions, say the authors.
Some of the experts represented government agencies from several countries who described how they handle requests to include cognition “health claims” on food products, enriching the discussion on the types of evidence accepted in different regulatory regimes.
According to the paper, if the suggested: ‘methods and practices were implemented universally by researchers in the field, and large datasets could subsequently be pooled to examine issues related to nutrition and cognition across the life course, this could go a long way to enable companies to make recommendations from dietary guideline committees.”
About this news about diet and cognition research
Author: Steve Gib
Contact: Steve Gibb – IAFNS
Image: Image is public domain
Original research: Access closed.
“Advancing Diet Guidance for Cognitive Health: Focusing on Solutions for Harmonizing Test Selection, Implementation, and Evaluation” by Romijn AR et al. Advances in nutrition
Advancement of Dietary Guide for Cognitive Health: Focus on solutions to harmonize test selection, implementation and evaluation
This perspective article is the product of an expert workshop convened by the Institute for the Advancement of Food and Nutrition Sciences (IAFNS), a non-profit organization that brings together scientists from government, academia and industry to catalyze the science related to food and nutrition for public benefit.
An expert panel was convened in March 2022 to discuss current issues related to cognitive task selection in nutrition research, with a focus on solutions to inform dietary guidance for cognitive health, to fill a gap identified in the Advisory Committee report on the 2020 US Dietary Guidelines, especially the “considerable variation in the testing methods used, [and] inconsistent validity and reliability of cognitive testing methods.
To address this issue, we first undertook a general review of the relevant reviews already undertaken; these indicate agreement on some of the issues affecting heterogeneity in task selection and on many of the fundamental principles underlying the selection of cognitive outcome measures.
However, resolving disagreements is critical to ensure a meaningful impact on the issue of heterogeneity in job selection; these issues hamper the evaluation of existing data to inform dietary guidance.
This literature summary is then followed up from the perspective of the expert panel in the form of a discussion of potential solutions to these challenges, with the aim of building on the work of previous reviews in the area and promoting dietary guidance for cognitive health .