Andrews et al., in a study published in Nutrition Reviews (2023), systematically reviewed 20 meta-analyses and systematic reviews for 43 randomized controlled trials (RCTs) and 1 cohort study assessing 18 different nutritional interventions for mild cognitive impairment (MCI).

Can Dietary Patterns and Supplements Improve Cognitive Function in Mild Cognitive Impairment? A Systematic Review of Previous Reviews

Interesting News . Apr 17, 2025

Andrews et al., in a study published in Nutrition Reviews (2023), systematically reviewed 20 meta-analyses and systematic reviews for 43 randomized controlled trials (RCTs) and 1 cohort study assessing 18 different nutritional interventions for mild cognitive impairment (MCI).

Key Findings

B vitamins, omega-3 fatty acids, and probiotics showed the most consistent positive effects on cognitive function.
Souvenaid (medical food) and the Mediterranean diet were implicated in reduced cognitive decline or slower progression to Alzheimer’s disease (AD), but these associations were found in single trials and less than 500 participants.
Other possible cognitive enhancers included: Vitamin D, Low-carbohydrate diet, Medium-chain triglycerides (MCTs), Blueberries, grape juice, cocoa flavanols, and Brazil nuts. These showed promise in improving specific cognitive domains but require more research.
The small sample sizes and study quality limitations of most reviews weakened their conclusions.

What Nutrients Might be Beneficial for Cognitive Health in MCI?

For those contemplating dietary styles or supplements for MCI, there are certain key features to be considered:

B Vitamins (B6, B9/Folic Acid, B12) – Attenuates homocysteine levels that target the slowing of cognitive decline.
Omega-3 Fatty Acids (DHA & EPA) – May offer neuroprotection and memory facilitation.
Probiotics – Novel evidence seems to indicate the improvement of gut-brain signaling.
Vitamin D – Linked to cognitive functioning; however, results appear somewhat inconsistent.

MCTs may serve as an alternative source of energy for the brain, particularly in cases of MCI

Polyphenol-rich food (Blueberries, Grape Juice, Cocoa Flavanols, and Brazil Nuts) may protect against free radicals and neurottective activity though more studies are needed.
Mediterranean Diet Apparently slows cognitive decline and improves overall brain functioning.

Level of Evidence: How Strong Is the Science?

This study is based on:

20 systematic reviews and meta-analyses → Level 1A (strongest level of evidence)
43 RCTs and 1 cohort study → Level 1B (high-quality individual studies, but varied in methodology)

Although systematic reviews and meta-analyses are high-quality evidence, the studies within this review had small sample sizes and methodological limit which made the findings suggestive rather than definitive.

Final Verdict: Does Science Support It?

While B vitamins, omega-3s, probiotics, and the Mediterranean diet provide certain cognitive benefits, the review shows the evidence for other interventions to be indefinite. Certain types of food and nutrients could enhance specific cognitive functions but require more top-notch research to validate their long-term outcomes and dementia prevention effects.

What Comes Next?

Research Future Should Address:

Larger, well-controlled trials lasting longer to determine whether cognitive effects can be sustained.
Stronger insights into dietary effects, especially Mediterranean and Souvenaid, in establishing long-term efficacy.
More defined population characterization(s) to understand whom are the most benefited from these interventions (e.g. individuals with high homocysteine levels or genetic risk factors).
Nurturing synergies between nutrition, physical activity and dietary supplementation for one stop holistic cognition health approaches.
For now, they must be integrated into overall health rather than relying solely on diet patterns or supplements, though some appear promising.