Pairing foods that are high in tryptophan, including cheese, pineapples, turkey and salmon, with carbohydrates can increase serotonin levels, according to Healthline. Other foods that are high in tryptophan include eggs and their yolks and soy products, which are excellent sources of protein. Nuts and seeds are good sources fiber, vitamins and antioxidants, and a serving of nuts per day lowers the risk of heart disease, respiratory problems and cancer.
Other foods that aid in serotonin production are those that contain vitamin B complex, including bananas, wheat germ, mushrooms, watermelon and shellfish, according to SFGate. Magnesium helps activate vitamin B and is found in spinach, avocado, apples, raisins and potatoes with their skins. Green tea contains caffeine and the amino acid L-theanine, which may also increase levels of serotonin in the brain.
When tryptophan is consumed, it is transported to the brain along with other amino acids where it has the ability to promote serotonin production, according to PubMed Central. However, it has to compete for transportation to cross the blood-brain barrier. Generally tryptophan is the least abundant of the competing amino acids, reducing the impact it has on the brain.
Consuming carbohydrates such as oats, whole-grain bread and rice initiates insulin production, which helps tryptophan's chances of getting across the blood-brain barrier, explains Healthline. Insulin works to usher the essential amino acids into vital organs, making tryptophan more dominant in the remaining amino acid pool and providing better access to the brain.