As if seeing the world more positively, reduced risk of cancer and increased longevity weren’t enough, coffee lovers now have another reason to revel in their morning cup. A new study concludes that caffeine may help enhance memory.

They found that 200 milligrams was enough to do the trick. And if you’re not a consumer of coffee, you can reap the boost by getting your caffeine from tea, soda or chocolate as well.

For the study, Michael Yassa and his team at Johns Hopkins University recruited 160 participants who studied a series of images. After five minutes they consumed either a 200-milligram caffeine tablet, a cup of coffee containing 200 milligrams of caffeine, or a placebo.

The following day the study group was asked to identify the images they had seen the previous day; some images were the same, but some has slight differences.

The participants who had consumed the caffeine were better able to identify which images were the same and which were different from the earlier images.

"We've always known that caffeine has cognitive-enhancing effects, but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans," said Yassa. "We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours."

Similar experiments with 100 milligrams of caffeine showed no boost, and 300 milligrams had the same effect as did 200 milligrams, but came with some reported side effects such as headache and jitters.

For 200 milligrams, a strong cup of brewed coffee should do the trick. An espresso generally has around 80 milligrams of caffeine, so a coffee drink with a double shot would just about do it.

And while coffee lovers can rejoice, the new research isn’t a green light to overindulge. Yassa cautions that high doses of caffeine can have negative effects, such as anxiety, increased heart rate, increased blood pressure and headaches.

The study was published in the journal Nature Neuroscience.

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