Do you have days when you are feeling extra sluggish and slow in concentration? Some studies found that there are actually certain foods that are shown to help improve brain function, encourage focus and clarity, and protect against age-related cognitive decline. Studies further show that what we eat actually have a correlation with our cognitive functions. 
Here are some foods that help improve your brain functions:

1. Dark chocolate
According to studies, the caffeine content of dark chocolates is regarded to play a role in maintaining sharpness of brain functions. Chocolate is also rich in flavonoids, a kind of antioxidant that helps to improve blood flow and thus brain health by regulating cholesterol and lowering blood pressure.

2. Berries
A recent study that sampled a large group of middle-aged women published in the Annals of Neurology discovered that a diet that consists of blueberries, strawberries and others were connected to a slower decline in memory and focus. 

3. Spinach
A study at Harvard Medical School found that women who reported eating the most leafy green vegetables had a lower rate of cognitive decline compared to those who ate the least. Spinach is rich in the antioxidant lutein, which is also thought to help protect against cognitive decline, according to researchers from Tufts University.

4. Walnuts
Walnuts are full of heart-healthy and anti-inflammatory nutrients. They are the only good nut source of alpha linolenic acid (ALA). That means they help promote blood flow, which in turn allows for efficient delivery of oxygen to the brain.

5. Sardines
Fatty fish like sardines and salmon have omega-3 fatty acids that are well-know brain boosters. These have been connected to an improved focus and memory and a lower risk of dementia.