Ginseng has significantly positive effects on working memory and mental performance
Researchers in Melbourne tested 32 healthy men and women aged from 18 to 40 – sat them down in separate rooms with headphones for the day and performed a large range of tests, the kind neurology books are filled with. They had to remember images, words, letters, numbers, shapes and faces. They were tested with number puzzles and problems involving shapes and sequences. They even tested how calm they were. Amazingly, all returned a week later for more punishment. This time, and again for the next three weeks, some of them were given capsules with an American ginseng extracts (100mg, 200mg or 400mg) and some received a capsules with no ginseng. This was changed around each week and they didn’t know which they received. This is about as good as trials get – randomised, double-blind, placebo-controlled and cross-over.
The results were clear – those who took American ginseng had significantly better working memory and mental performance, and were faster at making decisions than those who did not. Those who took ginseng were also significantly calmer and more relaxed. In most people even the lower dose of ginseng was effective. The researchers hypothesised that ginseng benefits were due to its effect on acetylcholine (see below) in the hippocampus and to a lesser extent the brain cortex.