Washington D.C. — How can we better understand how what we eat affects our brain health? And how does our diet affect brain function as we age?
Scientists that study cognition often use different approaches, tests and even ways of thinking about the area. But a new paper answers a call from the 2020 Dietary Guidelines Advisory Committee report to address “inconsistent validity and reliability of cognitive test methods.” These limitations constrain the ability to make firm conclusions about diet and cognition over the life course.
Optimizing nutrition can maintain and possibly even enhance 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 into our old age.
Cognition includes attention, learning, memory and executive functions such as planning and reasoning. While there are many tests of these cognitive skills, there is no consensus on which to apply, and many different ways they can be implemented in studies.
Because of the importance of learning more about nutritional interventions that might affect cognition, IAFNS convened experts to discuss cognitive task selection in nutrition research. The group was charged with suggesting research pathways that could inform dietary guidance for cognitive health. The experts screened existing reviews to understand more about what cognitive tasks were being measured and if the tests used were reliable and valid.
The expert group agreed that validated tests do exist that can be used to examine the effects of nutrition on cognition. There was less agreement on whether, for example, verbal memory or working memory is more sensitive to what we eat. In addition, some of the review literature urged full batteries of cognitive tests while others warned that people in the studies may get frustrated with too many testing tasks, eroding their accuracy.
Reducing the differences and number of cognitive tests so that scientists can combine measures could result in more confident decisions about diet and thinking over the life course, according to the authors. That and other strategies are outlined in the paper, “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 reporting guidelines and cognitive test parameters would also be valuable additions, the authors say.
Some of the experts represented government agencies in different countries that described how they handle requests to place “health claims” about cognition on food products, enriching the discussion about the types of evidence that are 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 questions relating to nutrition and cognition across the lifespan, this could go a long way towards enabling firm recommendations from the dietary guidelines committees.”
The paper is available here.
The Institute for the Advancement of Food and Nutrition Sciences (IAFNS) is a 501(c)(3) science-focused nonprofit uniquely positioned to mobilize government, industry and academia to drive, fund and lead actionable research. This work was supported by IAFNS Cognitive Health Committee. For more information, visit iafns.org.
