Ginseng Clinical Evidence

Journal of Psychopharmacology. 
Reay J, Kennedy D and Scholey A. Effects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained ‘mentally demanding’ tasks. 2006 Nov;20(6):771-81. 

Topic: 
Can Panax ginseng lower glucose levels and improve cognitive performance?

Background:

Previous studies have shown that single doses of ginseng can lower blood glucose levels and improve cognitive performance. This study sought to replicate these findings.

Study Type:

Human intervention trial

Study Design:

Double-blind, placebo-controlled, balanced-crossover. Subjects took a cognitive test at baseline and then took either ginseng capsules or placebo. Thirty minutes later, they consumed a drink containing either glucose or placebo. An hour after the baseline cognitive test, they took a battery of additional cognitive tests. Blood glucose levels were measured several times during the experiment.

Subjects:

27 healthy young adults

Dosage:

200 mg, single dose

Results:

Both glucose and Panax ginseng improved performance on the mental arithmetic tasks and reduced feelings of fatigue induced by the tests.

Conclusion:

Panax ginseng caused a reduction in blood glucose levels 1 hour following consumption when ingested without glucose. These results confirm that Panax ginseng may possess glucoregulatory properties and can enhance cognitive performance.”

Ginseng Mechanism of Action

Panax ginseng improves aerobic endurance by increasing free fatty acid levels in the blood and by maintaining blood glucose levels. Free fatty acids (FFA) serve as fuel for muscle contractions and general metabolism and they yield ATP, which is necessary for cells to produce energy. 

Ginseng is thought to enhance endurance by changing the way the body metabolizes fuel, allowing cells to use FFA instead of glucose. It also raises the oxygen capacity of the heart and improves the coronary reserve, or the heart’s potential to work beyond a baseline level.