There’s not much information about concussion and diet in the medical literature. There is some on nutrition and general brain health and well-being in the elderly. Some of the more researched supplements on diet include fish oils, turmeric, green tea extract and resveratrol. Any supplements taken should be in addition to a well-balanced diet high in fruits and vegetables and low in saturated fat and processed foods.
One thing to consider is that a concussed person may not feel as hungry or thirsty as before. Make sure to encourage eating throughout the day to keep blood sugar up and to try and drink six 8 oz. glasses of fluid (water, juice, Gatorade®) throughout the day. The brain is sensitive to low blood sugar and dehydration and these conditions can mimic or worsen concussion symptoms like headache, dizziness, fogginess, stomachache and irritability.