Foods high in simple carbohydrates, such as pastas, potatoes, bread, pastries, pretzels, and popcorn, increase insulin levels and allow more tryptophan (the natural amino acid building block for serotonin) to enter the brain, where it is converted to serotonin. The calming effect of serotonin can often be felt in thirty minutes or less by eating these foods.
This may be one of the reasons simple carbohydrates are so addictive. They can be used to make you feel happy, but also cause high blood sugar levels that over time are associated with brain atrophy and dementia. Good complex carbohydrates, such as sweet potatoes, apples, blueberries, carrots, and garbanzo beans, are a healthier way to boost serotonin.
Brain serotonin levels can also be raised by eating foods rich in L-tryptophan, such as chicken, turkey, salmon, beef, nut butter, eggs, and green peas.