Many people start their days with a cup of coffee, and it turns out this ritual could actually benefit your cognitive functions in the short term. Adding herbs like parsley and thyme to your diet may help boost your brainpower. This is due to a flavonoid, apigenin, found in these herbs. Essential oils are an excellent way to treat mental fatigue and to boost your mental capacity. Here’s a look at some of the herbs and spices found to benefit the brain.