Serotonin is a substance that contributes to our well-being and a lack of it seems to be associated to depressive states. We can obtain it from the food we ingest, but can eating better really make us happier?



Serotonin is undoubtedly one of the most popular neurotransmitters in our body. This is, above all else, because it is related to medication to treat depression. It was back in the 1980s when it was discovered that people with depression had lower levels of serotonin. The solution came in the form of selective serotonin reuptake inhibitors (SSRIs) which are responsible for increasing the amount of this substance available, by blocking the “reabsorption” of this neurotransmitter. Over the past 30-plus years their prescription by psychiatrists and physicians has become increasingly common. For some, too common. According to Oscar Picazo, a chemistry graduate and dietitian-nutritionist at Fundación MAPFRE: “Recent studies (such as the one at Copenhagen University Hospital) cast doubt on their efficacy, and reveal that their side effects may have been underestimated. The cost-benefit ratio is not clear, and there are signs that they have been overprescribed.” On the other hand, the same substance is now being taken into account for treating digestive problems.

“Although it may seem surprising, most of the body’s serotonin is actually found in the intestine, not in the brain. Moreover, it has been observed that, with disorders such as diarrhea or celiac disease, serotonin levels are increased, while, in the case of constipation, they are reduced. This has led to an interest in the role of serotonin in irritable bowel syndrome, given that the pharmacological treatment may help regulate the intestinal motility, thus alleviating the symptoms,” Picazo remarks. It should be noted that the verb he employs is regulate and not increase. The Fundación Mapfre expert explains the reason for this too: “In biology, more is not always better. There are generally certain ranges of physiological values within which the body functions optimally. Above or below these values, there may be imbalances. In addition, it should be borne in mind that processes within the body are normally interrelated. If we increase something a lot, we are probably causing an imbalance in other parts of the system,” he states.

It seems clear that an adequate amount of serotonin can help keep us in a good mood while, at the same time, facilitating our digestion

What does seem clear is that an adequate amount of serotonin can help keep us in a good mood while, at the same time, facilitating our digestion. But medicines are not necessary to achieve this balance; it can all be done through what we eat. “The body is capable of producing serotonin from an essential amino acid present in food proteins – tryptophan,” Picazo points out. You might think that, if we were to eat more foods high in tryptophan, thus could make us happier. Among these foods are some seeds, such as sesame, sunflower or pumpkin seeds, almonds and other nuts, cheese, meats and fish, pulses and eggs. It is said that some foods such as bananas contain serotonin, but they are really very small amounts. In addition, vitamin B6 plays its part in the synthesis of melatonin and serotonin. And carbohydrates help to make tryptophan more available, compared to other amino acids, by improving the formation of these neurotransmitters.

Despite all this, there appears to be no evidence that, if more tryptophan is consumed, serotonin levels will increase. “It is true that a tryptophan-deficient diet could adversely affect serotonin levels. But a high intake is not necessarily better, since the transport of tryptophan across the blood-brain barrier is limited and regulated.

The solution, in Oscar Picazo’s view, does not solely depend on a good diet. “It seems that focusing on aspects such as our quality of life, social support, resilience and, of course, healthy lifestyle habits (diet, exercise, rest, avoiding smoking and alcohol) is, in the long term, most likely to be the best recipe for happiness.”