Can food make people happy?

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.

There's a big difference between foods that contain compounds that can physically affect your brain chemistry and foods that just make us feel good. Foods in the latter group are called comfort foods. While foods that produce physical happiness affect our physiology, comfort foods provide happiness on a psychological level. When you're down in the dumps, however, you probably won't care about the distinction, as long as you feel better.

Psychological studies have turned up evidence that the comfort foods we crave are actually artifacts from our pasts [source: Galisson]. We all have memories of happier times, and by eating foods that remind us of those times, we symbolically consume that past happiness. Comfort foods can also be linked to specific people in our lives: Eating a specific food that a loved one favored can produce happy thoughts by triggering fond memories or associations of that person [source: Wansink]. This makes comfort foods fairly unique to each individual. If your childhood birthday parties represented the pinnacle of happiness for you, you'd likely crave birthday cake or some variation of the dessert when you're blue.

Although comfort foods (or the events attached to them) vary from person to person, the foods we associate with comforting or happy emotions vary by gender. A 2005 Cornell University survey of 277 men and women found that females tend to seek comfort in sweet and sugary foods like ice cream, while males prefer savory comfort foods like steak and soup [source: Smith]. The study also found that men tend to use comfort foods as a reward, while women often feel guilty after indulging.

Interestingly enough, the females' guilt may signal an evolutionary leg up over males. Regular comfort eating as a response to stress -- especially chronic stress -- is considered an unhealthy behavior akin to smoking cigarettes. Why? Because comfort foods are often low on nutrition. One 2007 study found that when given both grapes and hot buttered, salty popcorn to eat while watching a sad movie, the participants ate far more popcorn [source: Lang].

Read the next page to learn about how some foods may help you fight against depression, and how eating less can also make you happy.

The science of happiness has turned up evidence that food can make you happy. However, a lack of certain foods -- or at least some of their essential ingredients -- can actually make you sad. A fatty acid called docosahexaenoic acid (DHA) is the most abundant fat found in the brain. This is good, since it's an essential building block for brain structure. It's also easy to get; two major sources of DHA are fish and shellfish. A study by the National Institutes of Health (NIH) uncovered a link between DHA deficiency and an increase in the prevalence of depression in the United States.

Though no direct causal link has been discovered, other studies support the correlative link the NIH found. One study turned up the fact that North American and European countries that don't eat a lot of fish have 10 times the prevalence of depression in their populations than does Taiwan, where fish is a staple of the popular diet [source: The Franklin Institute]. Although this doesn't prove causation, it's a pretty good reason to eat more fish and other foods containing DHA.

Oddly, while some foods have been shown to improve mood in the human brain, restricting food intake can have an even more pronounced effect on happiness. A hormone called ghrelin within the stomach heads over to the brain and tells it that it's time to eat. When ghrelin is produced, you feel hungry. After you ingest food, ghrelin production stops and your brain ceases to receive hunger signals.

When you don't eat, however, ghrelin production continues and the hormone builds up in the brain. While the increased ghrelin will prolong your hunger, researchers have found that the hormone also acts as a natural antidepressant. A 2008 University of Texas study found that rodents injected with ghrelin showed decreased symptoms of stress and anxiety [source: Lutter, et al]. Interestingly, rodents that were placed on a calorie-restricted diet (40 percent of normal caloric intake) showed the same results.

Whether it's psychological or physiological, it's clear that foods have a powerful effect on our moods. It would appear that eating only nutrient-packed foods that affect brain chemistry might be the best way to achieve happiness, but the occasional indulgence should make you just as happy. Perhaps a healthy balance of nutritious foods and comfort foods can help maintain the balance in a person's mood best of all.