Coffee does increase blood flow to the brain.
The caffeine in coffee is a stimulant and works by blocking the adenosine receptors in your brain.
The blockage of the adenosine receptors in the brain due to the caffeine in coffee, leads to the release of neurotransmitters, which among other things dilate blood vessels in your brain.
Caffeine in coffee can increase cerebral blood flow by up to 30 percent and the increased blood flow can also improve alertness, cognitive function and reaction time.
Although the effect of caffeine on cerebral blood flow can also vary depending on the dose, your individual caffeine tolerance and the time of day.
And high doses of caffeine might actually decrease blood flow to the brain in some cases.
You can also increase the blood flow to the brain by exercising regularly, especially through moderate aerobic or interval training and also incorporate foods in your diet that are rich in Omega-3- fatty acids, like oily fish as well as nitrates such as beets into your diet.
Also staying hydrated and drinking enough water and managing high blood pressure and limiting your intake of unhealthy fats can also help improve blood flow and circulation to your brain.
Engaging in moderate intensity aerobic activities like brisk walking or swimming can improve your circulation and reduce your risk of arterial plaque.