A Systematic Review of Omega-3 Consumption and Neuroprotective Cognitive Outcomes

Can the gut microbiome inform the effects of omega-3 fatty acid supplementation trials on cognition?

PURPOSE OF REVIEW

Most omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation clinical trials report inconsistent or null findings on measures of cognition or Alzheimer's disease (AD) with a relatively large variability in the response to n-3 PUFA supplementation. The purpose of this review is to identify whether the gut microbiome together with the metabolome can provide critical insights to understand this heterogeneity in the response to n-3 PUFA supplementation.

RECENT FINDINGS

A Western diet with high saturated fat and omega-6 fatty acid content, obesity, and lack of exercise puts strain on the gut microbiome resulting in imbalance, dysbiosis, reduced bacterial diversity, and increased abundance of the pro-inflammatory taxa. A plant-based diet has beneficial effects on the gut microbiota even when deficient in n-3 PUFAs. Human and animal studies show that increased intake of the n-3 PUFAs correlates with increased beneficial intestinal bacteria when compared to a Western diet.

SUMMARY

The composition of the gut microbiota can help define the effects of n-3 PUFA supplementation on the brain and lead to more personalized nutritional interventions.

Vegan Diets for Children: A Narrative Review of Position Papers Published by Relevant Associations

The scientific discourse on vegan diets for children and adolescents primarily involves referencing position statement papers from different scientific and professional organizations, including paediatric associations. Over the past two decades, specialized associations have issued official statements and published position papers about adopting well-designed vegan diets during crucial life stages, including pregnancy and lactation, infancy, and childhood. A subset of these associations firmly supports the notion that a well-designed vegan diet can indeed be healthy and support normal growth and development during particularly delicate life stages, emphasizing careful planning, vitamin B12 supplementation, and regular supervised medical and dietetics oversight. In contrast, specific paediatric associations caution against vegan diets for children and adolescents, citing potential harm and the lack of adequate substantiation. These criticisms in position papers frequently point to lower-quality studies and/or outdated studies. Additionally, concerns extend to comparing vegan and omnivorous diets, considering public health issues such as obesity and early stages of cardiovascular disease as well as the risk of prediabetes and type 2 diabetes. Notably, some scepticism stems from studies where children's adherence to a well-designed vegan diet is incomplete. Scientific rigor suggests performing a comparable assessment of omnivorous and vegan diets. This narrative review highlights the need for a comprehensive, up-to-date literature review to inform balanced perspectives on vegan diets for children and adolescents. Researchers and decision-makers should aim to actively improve the design and consistent implementation of both diet types.