Consuming brain foods is your best way to boost focus, memory, concentration and other cognitive functions. Foods which nourish the brain have a high amount of antioxidants, good fats, vitamins, and minerals, and they could be a great option to have just before you take a test!
Foods for Focus and Memory
The best brain foods include blueberries, avocados, salmon, broccoli, pumpkin seeds, dark chocolate, extra virgin olive oil, and walnuts, among others.
With high levels of monounsaturated fats and vitamin K, these fruits can help reduce blood clots and thus improve cognitive health. 
There are nitrates and antioxidants in beets that can help prevent plaque deposition in the brain.
Like many other green leafy vegetables, romaine lettuce is associated with better brain function and blood flow.
The luteolin content in celery can help reduce inflammation in the microcapillaries in the brain. 
Cruciferous vegetables like broccoli are ideal for keeping your memory intact, thanks to its vitamin K and choline content.
Packed with flavonols and other antioxidants, dark chocolate is known to protect brain health.
Choline is an important nutrient for brain development and repair, and egg yolks are rich in this nutrient.
Omega-3 fatty acids, which are found in high concentrations in salmon, are known to reduce inflammation and help with protecting the brain from oxidative stress. 
One of the most antioxidant-rich spices in any kitchen, turmeric’s active ingredient, curcumin, is known to boost memory and focus.
Fatty, cold-water fish like mackerel are often high in omega-3 fatty acids, which can help reduce plaque deposition and prevent the development of neurodegenerative disease.
EPA and DHA are two omega-3 fatty acids found in sardines that can help protect the brain. 
Lycopene is a powerful antioxidant in tomatoes that prevent oxidative stress in the neural pathways.
High in anthocyanins, research has found that black currant can protect against chronic inflammation.
There are magnesium and omega-3 fatty acids in these seeds, both of which can reduce inflammation.
Omega-6 and omega-3 fatty acids in these seeds will boost memory and concentration.
Vitamin K is found in high quantities in spinach and is known to help boost brain function. 
The medium-chain fatty acids in coconut oil are metabolized into ketones, which are high-efficiency fuel for the brain.
Good amounts of lutein and zeaxanthin make carrots an ideal brain-boosting food that can eliminate inflammation.
Popular herbs like rosemary and sage contain rosmarinic acid, which has been linked to improved cognition and focus. 
Other Top Brain Foods
Other foods which can improve brain functioning include green leafy vegetables like kale, swiss chard, and romaine lettuce. Different types of fish like trout, tuna, pilchard, and kippers are also good brain foods.