METHODOLOGY/PRINCIPAL FINDINGS: Using a double-blind, placebo controlled, crossover design, participants (N = 24) received two doses of Panax Ginseng (500, 1000 mg) or Ginkgo Biloba (120, 240 mg) (N = 24), and underwent a series of cognitive tests while systolic, diastolic, and heart rate readings were taken. Ginkgo Biloba improved aspects of executive functioning (Stroop and Berg tasks) in females but not in males. Ginseng had no effect on cognition. Ginkgo biloba in females reversed the initial (i.e. placebo) increase in cardiovascular reactivity (systolic and diastolic readings increased compared to baseline) to cognitive tasks. This effect (reversal) was most notable after those tasks (Stroop and Iowa) that elicited the greatest cardiovascular reactivity during placebo. In males, although ginkgo also decreased cardiovascular readings, it did so from an initial (placebo) blunted response (i.e. decrease or no change from baseline) to cognitive tasks. Ginseng, on the contrary, increased cardiovascular readings compared to placebo.

CONCLUSIONS/SIGNIFICANCE: These results suggest that cardiovascular reactivity may be a mechanism by which ginkgo but not ginseng, in females is associated with certain forms of cognitive improvement.

METHODS: A randomized, double-blind, placebo-controlled trial among 35 healthy middle-aged women was performed, and subjects were randomized to receive either 250 mg PM or placebo of 100 mg maltodextrin each were taken twice daily for 6 weeks. Subjects were assessed for neuropsychological test, psychosocial status, and anthropometric at baseline, week 3, and week 6. Biomarkers were also determined at baseline and week 6.

RESULTS: The supplementation of PM showed significant intervention effect on Digit Span test (P<0.05) social functioning domain of 36-Item Short Form Health Survey (P<0.05) among subjects with mood disturbance. While, among subjects with good mood, PM supplementation improved Wechsler Abbreviated Scale of Intelligence (WASI) for IQ verbal (P=0.016) and Full Scale IQ of WASI (P=0.004). There were no adverse effects reported for the supplementation as indicated using biomarkers, including liver function and clinical symptoms.

METHODOLOGY: Sixty-four healthy volunteers received either a single dose (200 mg) of modafinil (n = 32) or placebo (n = 32) in a randomized, double-blind, placebo-controlled, parallel group study in which the principal outcome measures were response latencies on the response initiation and response inhibition sections of the HSCT.

PRINCIPAL FINDINGS: Participants dosed with modafinil had significantly longer mean response latencies on the HSCT for both the response initiation and response inhibition compared to participants dosed with placebo. However, participants in both groups made a similar number of errors on each of these measures, indicating that modafinil did not enhance the accuracy of performance of the task relative to placebo.

CONCLUSIONS: This study demonstrated that administration of single 200 mg doses of modafinil to healthy individuals increased the latency of responses in the performance of the HSCT, a task that is highly sensitive to prefrontal executive function, without enhancing accuracy of performance. This finding may provide important clues to defining the limitations of modafinil as a putative cognitive enhancer.

OBJECTIVES: This study investigated the effects of fish oil supplementation on cognitive function in elderly person with MCI.

METHODS: This was a 12-month, randomised, double-blind, placebo-controlled study using fish oil supplementation with concentrated docosahexaenoic acid (DHA). Thirty six low-socioeconomic-status elderly subjects with MCI were randomly assigned to receive either concentrated DHA fish oil (n = 18) or placebo (n = 18) capsules. The changes of memory, psychomotor speed, executive function and attention, and visual-constructive skills were assessed using cognitive tests. Secondary outcomes were safety and tolerability of the DHA concentrate.