According to a new US study conducted to analyze the effects of caffeine only two cups of black or green coffee a day can have a beneficial effect on visual memory. The study has been published in the famous scientific journal Nature, reports AFP.
Researchers at Johns Hopkins University in Baltimore found that the active ingredient in coffee - caffeine - improves long-term memory for at least one day after it is consumed. Until now it was known that caffeine has cognitive-enhancing effects and stimulates the brain but no study analyzed how caffeine can strengthen the memories making them resilient to the passage of time.
Authors of the study, coordinated by Professor Michael Yassa, asked the 73 volunteers, who are not regular consumers of products that contain caffeine, to watch different images of a series of objects.
Then, half of them received a dose of 200 milligrams of caffeine equivalent of two cups of coffee, five minutes after the task was completed while others received a placebo.
The next day, researchers asked two groups involved in the double-blind trial to view another series of images. Some were the same as the ones in the previous day, others were new and others were similar but with some differences.
There wasn't a meaningful disparity between the study groups on how well they could separate the new images from the old ones, but volunteers who received caffeine were more easily able to distinguish differences in similar pictures.
If the images are more similar, the subjects must perform a more difficult task, the scientist say the brain must apply 'pattern separation'. It seems that this process appears to be stimulated by caffeine, says Professor Yassa, who recalls that "this substance (caffeine) is associated with longevity, health and may have protective effects against cognitive decline caused by various diseases such as Alzheimer's disease."
A study by the National Cancer Institute (NCI), published in May 2012, states that people between 50 and 71 years old who consume an average of three cups of coffee a day, regular or decaf, have a lower risk of death from cardiovascular and respiratory diseases, strokes, diabetes and infections.