The brain controls the function of many organs, the movement of limbs, and the release of certain hormones. It also acts as the control center for thoughts and memory. The brain’s cognitive abilities—learning, recalling memories, focusing, and solving problems—can decline with age. However, certain lifestyle factors, like what you eat, can support brain health and cognition. Research shows that foods rich in omega-3 fatty acids, antioxidants, and vitamins and minerals, are especially supportive of optimal brain health.
Here are five healthy foods help you focus and retain optimal cognitive health
Aim to eat fatty fish in a meal or two a week
Fatty fish, such as salmon, cod, and tuna, are key for brain health and staying focused. One study of 76 healthy adults found that higher weekly fish consumption was linked to healthy brain structure and improved cognitive scores on assessments.  The brain-boosting benefits of fatty fish are related to their high concentration of omega-3-fatty acids, namely docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). The body uses these healthy fats to build brain and nerve cell walls, which help maintain communication between these cells.  Brain cells that communicate efficiently also help fight inflammation and protect brain cells. Given the integral role omega-3 fatty acids play in brain health, it is not surprising research has linked higher intake of these fats with slower age-related mental decline [3-4].
The Dietary Guidelines for Americans recommends that adults consume eight ounces of fish (like those listed previously) a week for a rich-natural source of these healthy fats.
Drinking coffee daily may improve focus and attention
Coffee offers more than just a quick energy boost. Research suggests the caffeine found in coffee can improve focus and cognitive performance by increasing the brain’s capacity for processing information.
In a 2014 study published in the Journal of Nutrition, participants with higher caffeine intake scored better on tests of mental function and attention.  Caffeine may improve focus by blocking receptors for a chemical called adenosine, which normally prevents the release of excitatory brain chemicals. Without adenosine, these excitatory neurotransmitters continue to flow and enhance mental performance. However, caffeine is not the only reason a daily cup of coffee can provide a cognitive boost. Coffee is also an excellent source of phytonutrients—beneficial plant compounds—that have antioxidant capabilities and help keep inflammation at bay. 
For most people, three cups of coffee (eight ounces each) is safe and may offer health benefits. If you’re looking for that boost of focus, regular coffee may serve you better because of the caffeine fix. But, both regular and decaf coffee contain phytonutrients.
Eating blueberries may help you retain information
Blueberries make the top focus food list due to their high concentration of flavonoids. These compounds not only give blueberries their vibrant blue color, but also they have powerful antioxidant and anti-inflammatory properties that protect brain health. 
In one randomized double-blind placebo-controlled trial, researchers assigned a group of participants to either consume blueberries or a blueberry placebo for ninety days. At the end of the study, the blueberry group scored significantly higher than the placebo group on several cognitive tests.  These findings are supported by other studies that have noted links between blueberry intake and improved cognitive performance. 
One serving of blueberries is equivalent to one cup of the fruit fresh or frozen. For cognitive support, aim to eat one to two servings of blueberries a day.
Incorporating leafy greens into your diet may slow cognitive decline
Leafy greens like lettuce, kale, spinach, broccoli, and collard greens are loaded with nutrients that promote a healthy brain and daily focus. For example, leafy greens are an excellent source of vitamin K, and the intake of vitamin K is linked to improved cognition.  They also contain folate, a B vitamin essential for neurotransmitter production. 
In a cohort study of 960 older adults, researchers found that those with the highest intake of leafy green vegetables had significantly slower cognitive decline than those with the lowest leafy green intake.  Other research has shown that leafy green consumption (in addition to other fruits and vegetables) is associated with better cognitive performance.  Incorporating this nutrient-dense food group into meals may promote steady focus.
One serving of leafy greens equals two cups of uncooked greens or one cup of cooked greens.
Sipping grape juice may improve memory
Several studies have revealed grape juice has the potential to improve memory and cognition, easing efforts to process information and stay focused. [14-16] Grape juice is a particularly high concentration of polyphenols, a group of compounds that have been shown to fight inflammation and disease, and researchers suspect the variety of polyphenols present in grape juice is likely what makes it a great choice for brain health. 
In a small randomized, placebo-controlled, double-blind study of older adults with memory decline, supplementation with grape juice for 12 weeks led to a significant improvement in learning . But the cognitive benefits of grape juice are not only reserved for older adults. Another study in healthy middle-aged women found that daily consumption of 12 ounces of grape juice was associated with a significant improvement in spatial memory and executive function. 
Research has shown benefits from daily grape juice intake ranging from 8 to 12 ounces (that’s about 1 to 1 ½ cups. If you decide to incorporate grape juice into your diet, opt for 100% juice options.
- What you eat plays a key role in brain health.
- Food supplies nutrients and compounds that are used to build brain tissues, facilitate communication between brain cells, and protect the brain from oxidative damage and inflammation.
- By promoting and protecting brain health, foods like fatty fish, coffee, leafy greens, blueberries, and grape juice can thereby impact cognition, memory, focus, and concentration.