After taking two 500 mg capsules of pure ground black seed powder each evening for 9 weeks, 20 healthy men in their 50s tested markedly better on measures of memory, attention, and cognition than 20 placebo-popping counterparts. Black cumin’s antioxidant, anti-inflammatory, and neuron-protecting properties are likely responsible for the brain-boosting results, says study author Muhammad Shahdaat Bin Sayeed, a lecturer in the department of pharmacy at the University of Asia Pacific in Bangladesh.  Black seeds are also rich in essential oils, which have been linked to brain-stimulating benefits, and may put the brakes on the breakdown of the neurotransmitter acetylcholine, which medical herbalist Kevin Spelman, PhD, says is a well-established pharmaceutical method for improving memory.  “When neurotransmitters responsible for memory retention degrade, normal memory is compromised,” says study author Muhammad Shahdaat Bin Sayeed, a lecturer in the Department of Pharmacy at the University of Asia Pacific in Bangladesh. “This compound can stop that.”  Heart, liver, and kidney function was unaffected by black seed supplementation in the brief study, joining other clinical trials that have declared black cumin safe for humans.  The dark seed hasn’t yet hit the market in capsule form, but Bin Sayeed says in the Middle East, a few drops of black seed oil are typically paired with honey or boiled mint to blunt the bitter flavor. Unsavory taste aside, if more research churns out similar results, swallowing black cumin could prove to be a truly appetizing brain food.  More from Prevention:  10 Tricks To Reboot Your Brain  9 Reasons You Can’t Concentrate  Ask Dr. Taz: Can I Improve My Memory?