What if Nutrition Recommendations Were Designed With Brain Health in Mind?

Cognitive decline has become a more prominent health concern in the US and globally, in part due to increased life expectancy. Efforts to mitigate this decline through research, product development, and education have garnered increasing attention. Cognitive decline and reducing its risk is a complicated phenomenon, involving genetics, physical activity and capability, social and intellectual interactions, and even creative pursuits —among other factors. Diet is generally agreed upon as one modifiable risk factor – but the specific elements of diet that can support optimized brain health, including what and when across the life course, remain elusive with mixed research findings.

Over the last decade, several large and influential studies have tried to determine whether specific diets, nutrients, or food components can meaningfully support cognitive health, prevent dementia, or slow brain aging. Collectively, these studies also highlight why the evidence base remains insufficiently harmonized to support precise nutrition recommendations for brain health.

What do some of the more significant pieces of research tell us about diet and cognition? Results from the relatively large COSMOS trial¹ resulted in improved global cognition with multi-vitamin provision for 2 years compared to placebo, in adults 60 years of age and older. In another large trial assigning the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet or a control diet to adults ages 65 or older, both with caloric restriction, for 3 years there was no difference in global cognition across the two groups (both improved).² In this study, the weight loss that occurred across all groups may have been a confounder as weight is associated with cognition, and the age window may have been too late to enable brain plasticity.

The FINGER (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability) trial included participants ages 60-77 engaged in a program combining nutritional guidance, exercise, cognitive training, social activities, and vascular risk management for a two-year period.³ Overall cognitive performance was improved in the intervention group compared to controls, but there is no way to know if the effect was the result of any one of the interventions over another. PREDIMED was another large intervention study in which subjects were assigned to a Mediterranean diet or a control diet. In a subgroup analysis, global cognitive performance was improved after 6.5 years of adherence to the Mediterranean diet, whether it was supplemented with extra-virgin olive oil or with mixed nuts. Subjects in this study were on average 75 years of age at the beginning.⁴

Apart from these larger trials, there are also studies of specific foods and nutrients or bioactives, with some showing effects, and some not. The variation in results may be due to the specific populations studied, age ranges, durations of intervention, individual responses to nutrients, or other factors.

In this milieu of mixed evidence, we know that specific nutrients have fundamental roles in brain structure and function, and many of these roles are mentioned in the Dietary Reference Intake (DRI) reports. The DRI reports set recommended intakes of nutrients for the United States and Canada. For example, folate is critical for neural tube development which is a nervous system outcome.⁵ Iodine recommendations consider support of neurodevelopment in early life.⁶ Vitamin B12 isrequired for myelin synthesis and maintenance.⁵ Iron is critical for neurotransmitter synthesis.⁶ However, only choline, which has an Adequate Intake level (somewhat less ‘stringent’ than a ‘requirement’) has neurodevelopmental considerations as core to its rationale.⁵

The brain is in fact, the most metabolically active organ, precisely controlling physiological functions. As proposed by D. Benton in 2012, defining optimal nutrition from the point of brain health may be a critical consideration.⁷ It is possible that optimal nutrient or bioactive intakes for brain health fall outside of currently established DRIs or other recommended intake levels (e.g., for non-essential bioactive food components). In addition, much of the available research focuses on individuals ages 65 and over, and newer evidence suggests that the optimal window for effective intervention may occur earlier in life.

The Cognitive Health Committee of the Institute for the Advancement of Food and Nutrition Sciences (IAFNS, www.iafns.org) explores how dietary patterns, foods, nutrients and bioactive food components support optimization and maintenance of cognitive performance and mood- and emotion-related outcomes. As a step toward understanding whether there is an optimal nutrient or bioactive component intake to support brain health, this committee initiated a project to review the evidence, with the goal to identify the most promising compounds if one were to target a DRI for this specific outcome. As part of this work, led by Northwestern University, researchers will be documenting how ‘brain health’ is defined and measured in the scientific literature.

This project is the first step in moving toward improved guidance for intake of nutrients or bioactive food components to support brain health across the lifespan. Outcomes of this work will: 1) establish the landscape of compounds that have been substantially investigated with respect to cognitive or brain health at various life stages; 2) allow stakeholders to understand how cognitive performance or brain health has been conceptualized and measured; and 3) facilitate identification of target compound(s) for additional work on quantification of recommended intakes. Findings will provide direction to researchers and healthcare practitioners that wish to understand the state of the science and how to advance toward more definitive public health guidance for the maintenance and optimization of brain health across the lifespan.

References

1. Vyas CM, Manson JE, Sesso HD, et al. Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS. Am J Clin Nutr. 2024;119(3):692-701. doi: 10.1016/j.ajcnut.2023.12.011.
2. Barnes LL, Dhana K, Liu X, et al. Trial of the MIND Diet for Prevention of Cognitive Decline in Older Persons. N Engl J Med. 2023.17;389(7):602-611. doi: 10.1056/NEJMoa2302368.
3. Kivipelto M, Solomon A, Ahtiluoto S, et al. The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER): Study design and progress. Alzheimer's & Dementia. 2013;9: 657-665. doi:10.1016/j.jalz.2012.09.012
4. Martínez-Lapiscina EH, Clavero P, Toledo E, et al. Mediterranean diet improves cognition: the PREDIMED-NAVARRA randomised trial. Journal of Neurology, Neurosurgery & Psychiatry. 2013;84:1318-1325. doi: 10.1136/jnnp-2012-304792
5. Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes and its Panel on Folate, Other B Vitamins, and Choline. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. National Academies Press (US); 1998. doi:10.17226/6015
6. Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academies Press (US); 2001. doi:10.17226/10026
7. Benton D. To establish the parameters of optimal nutrition do we need to consider psychological in addition to physiological parameters?. Mol. Nutr. Food Res. 2013;57: 6-19. doi: 10.1002/mnfr.201200477

Marie Latulippe, MS, MBA, RD, is Senior Director of Science Programs at IAFNS where she works with several Nutrition Committees, manages the Board Program Committee and the Scientific Leadership Council. Marie has held a variety of positions within science-based organizations, in the US and in Europe. Additionally, she served as Study Director at the National Academies of Sciences Food and Nutrition Board.

The Institute for the Advancement of Food and Nutrition Sciences (IAFNS) is committed to leading positive change across the food and beverage ecosystem. This research is supported by IAFNS Cognitive Health Committee. IAFNS is a 501(c)(3) science-focused nonprofit uniquely positioned to mobilize government, industry and academia to drive, fund and lead actionable research. iafns.org