To understand how foods can make you happy, it's important to understand how the brain regulates mood. The brain uses neurotransmitters as communication signals to communicate with the rest of your body and to issue its commands. "Beat, heart!" the brain says when it sends octopamine to receptors located in the nerve fibers that make up the cardiac muscle tissue [source: Johnson, et al].
The same goes for keeping our moods stable. Two types of neurotransmitters are responsible for our moods: inhibitory and excitatory. Excitatory neurotransmitters like norepinephrine stimulate our bodies and minds. We get worn out after being amped up for too long, though, and so this type of neurotransmitter can actually lead to unhappiness. Inhibitory neurotransmitters like serotonin exert a calming influence on our minds, in part by counteracting the effects of excitatory neurotransmitters. Ultimately, the best moods are found when there is a balance between these two types.
These mood-affecting chemicals aren't made out of thin air, however. They're created by compounds found in food, and some foods are better at helping neurotransmitter production than others. We'll call these happy foods.
Typically, serotonin is the neurotransmitter most linked to happiness, since you need it to regulate sleep and pain. It's also a powerhouse at counteracting excitatory neurotransmitters [source: Neurogistics].
Foods that aid serotonin production include spinach, turkey and bananas. Spinach contains high concentrations of folate, a B-vitamin used in the serotonin creation process. Bananas and turkey pack lots of tryptophan, an amino acid that's converted into serotonin in the brain. Tryptophan manages to go directly to the brain by crossing the protective cellular barrier between the bloodstream and the brain. This makes tryptophan a rarity, since serotonin can't cross this blood-brain barrier [source: Hyde and Gengenbach].
Another major neurotransmitter that helps regulate and stabilize mood is gamma aminobutyric acid (GABA), commonly referred to as "nature's Valium" because of its tranquilizing effects on the body. GABA is produced during the Krebs cycle, a physiological process by which nutrients are converted to energy for cellular use. Foods don't contain GABA, but some contain the neurotransmitter's building block, an amino acid called l-glutamine. Pork, beef and sesame and sunflower seeds all have high concentrations of glutamine [source: Neurogenesis]. Since l-glutamine can also transcend the blood-brain barrier and aids GABA production during the Krebs cycle, these foods can have an indirect but useful impact on your happiness.
While some foods have been proven to contain compounds that impact mood, others make us feel good just by eating them. Read about comfort foods on the next page.