A study published in Molecular Nutrition & Food Research (2022) by Cheng et al. systematically reviewed 80 randomized controlled trials (RCTs) involving 5,519 participants, assessing the effects of dietary flavonoids on cognitive function across the entire age spectrum.

Can Dietary Flavonoids Improve Cognitive Function? A Meta-Analysis of Human Studies

Interesting News . April 25, 2025

A study published in Molecular Nutrition & Food Research (2022) by Cheng et al. systematically reviewed 80 randomized controlled trials (RCTs) involving 5,519 participants, assessing the effects of dietary flavonoids on cognitive function across the entire age spectrum.[1]

Key Findings

Dietary flavonoids positively influenced cognitive performance, with pooled results showing g = 0.148, p < 0.001.

Cognitive benefits were most saliently pronounced for:

Cocoa flavonoids (g = 0.224, p = 0.036)
Ginkgo biloba (g = 0.187, p ≤ 0.001)
Berries (e.g., blueberries, strawberries) (g = 0.149, p = 0.009)

At least a 6-week duration of supplementation was required for cognitive improvements to manifest.
Older adults and people with cognitive impairments were found to be the most responsive.
These effects were most clear in areas of long-term memory, processing speed, and mood enhancement.

Cognitive Health Support from Flavonoids

Consider looking for flavonoid-containing foods or supplements from the following sources:
Cocoa flavonoids—found in dark chocolate and cacao, have been linked with memory and attention.
Ginkgo biloba—a very popularly used supplement that claims to improve circulation and cognitive performance.
Berry flavonoids (Anthocyanins & Flavanols)—found in blueberries, strawberries, and blackberries, and studied for their benefits on memory and processing speed.

Citrus flavonoids (Hesperidin, Naringin, Quercetin)—found in oranges, lemons, and grapefruit, considered to provide brain-boosting effects, though largely unexplored.
Pine bark extract (Proanthocyanidins)—claimed to assist blood flow and cognition but does require some further study.
Tea flavonoids (Catechins & Theaflavins)—present in Green and Black teas, help sustain alertness and calm away stress.

Level of Evidence: Strength of the Evidence?

Based on:

80 randomized controlled trials (RCTs) → Level 1B (high-quality individual studies)
RCT meta-analysis → Level 1A (strongest level of evidence)

The meta-analysis of RCTs provides the highest level of evidence, and thus we placed high credibility in this study; however, citrus, pine bark, and tea are some sources of flavonoids grossly understudied, and this means that more studies are needed.[2]

Final Verdict: Does Science Stand by it?

Indeed, flavonoids can improve cognitive functions, especially in older people and those with cognitive impairments. The most consistent improvement seems to involve cocoa, ginkgo biloba, and berries in terms of memory, processing speed, and mood control. More research will be needed to decide upon the dosages and possible long-term effects.

What Next?

Future research could be concentrated on:

Designing appropriate dose-response trials for optimal daily intake of flavonoids.
More substantial, longer-term trials indicating how flavonoids can prevent some cases of cognitive decline with aging.
Standardization of the cognitive assessment protocols to allow comparison of the flavonoid effects across different brain cognitive domains.
Further examination of little-explored or forgotten flavonoid types, such as citrus, pine bark and tea, but many more for cognitive health benefits.

At present, eating large amounts of dark chocolate, berries, and tea which are rich in flavonoids is a safe way of effectively and cost-effectively improving cognitive health. Even though there are no short terms, it is very good for mind processing speed and memory.