Verbal Fluency Research Analysis

Summary of Verbal Fluency

Scientific Information on Verbal Fluency

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect verbal fluency

Grade	Level of Evidence [show legend]
	Robust research conducted with repeated double-blind clinical trials
	Multiple studies where at least two are double-blind and placebo controlled
	Single double-blind study or multiple cohort studies
	Uncontrolled or observational studies only

Outcome	Magnitude of effect ? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.	Consistency of research results ? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.	Notes
Oxiracetam	Minor	Very High See 2 studies	Appears to favor improvements in verbal fluency in persons with cognitive dementia, despite benefiting most parameters measured
D-Serine	-	- See study	In a category fluency test, 2.1g D-serine taken two hours earlier appears to improve fluency. The increase was larger than seen with placebo, but comparing the two groups did not yield a significant benefit with D-serine over placebo statistically
Ginkgo biloba	-	Very High See 2 studies	No significant influence of supplemental ginkgo on verbal fluency even in persons with cognitive injuries.
Polygala tenuifolia	-	- See study	No significant improvements in verbal fluency noted in elderly adults with memory complaints supplementing this herb.
Vitamin E

All comparative evidence is now gathered in our A-to-Z Supplement Reference.

The evidence for each separate supplement is still freely available here.