Can diet ensure our happiness?

A new study suggests that boosting serotonin through diet may be an important complementary “weapon” in the battle against depression.

Serotonin, also known as the “happiness hormone,” plays a critical role in regulating mood, sleep, and overall mental health. Its deficiency has been associated with symptoms of depression, anxiety, and fatigue. According to Mental Health America, in the US, about 21 million people suffer from depression, with many experiencing low serotonin levels.

Although antidepressants (SSRIs) are a widespread and effective treatment, new research shows that lifestyle - especially diet - can also affect serotonin levels.

Serotonin production starts in the gut

Nutritionist Melanie Murphy Richter explains that most serotonin (about 90%) is produced in the gut and not in the brain. “The gut-brain connection, through the vagus nerve and microbiome, clearly shows that what we eat directly affects our mood,” she says.

A well-nourished microbiome helps with the smooth production of serotonin. Fibre is key as it promotes gut function and boosts ‘good’ bacteria such as Lactobacillus and Bifidobacterium. Such bacteria contribute to the production of serotonin precursors. Foods such as yogurt, kefir, kimchi, and other probiotic or polyphenol-rich options (e.g., berries, artichokes) can help significantly.

The role of tryptophan and carbohydrates

To produce serotonin, the body needs the amino acid compound tryptophan, which is found in foods such as tofu and pumpkin seeds. However, tryptophan competes with other amino acids to cross the blood-brain barrier. This is where carbohydrates come into play. According to Richter, eating complex carbohydrates, such as quinoa, lentils, and sweet potatoes, causes the release of insulin, which “diverts” the other amino acids in the muscles and lets tryptophan pass into the brain. The most appropriate diet to support serotonin is the Mediterranean or a “plant-based” diet, which is rich in fiber, good fats, and colorful whole foods. This approach supports both the microbiome and neurotransmitter production.

“It's not just about increasing serotonin, but about creating a balanced internal environment that supports mood and well-being,” Richter says. She notes that for many people, nutritional interventions can complement medication or psychotherapy, always with expert advice. While there is no “magic food” that cures depression, science agrees that a balanced, fiber-rich, probiotic-rich diet can boost gut function and - by extension - mental health.

What foods boost serotonin?

It's important to understand that while certain foods contain tryptophan, the precursor to serotonin, simply eating these foods doesn't guarantee a direct and immediate increase in brain serotonin. The process is complex, but incorporating the following foods into your diet will certainly help.

Foods containing Tryptophan

• Salmon: Salmon is a good source of tryptophan and omega-3 fatty acids, which are beneficial for brain health.

• Eggs: Eggs contain tryptophan and other essential nutrients.

• Cheese: Various cheeses, such as cheddar, mozzarella, and parmesan cheese are a good source of tryptophan.

• Turkey: Turkey is well-known for its tryptophan content.

• Nuts and Seeds: Almonds, walnuts, and pumpkin seeds are examples of tryptophan-containing options.

• Tofu: A good source of tryptophan for those who are vegetarian or vegan.