Tryptophan is essential for mental and intestinal well-being.
Two experts explain its role in the body and the foods that are its richest sources.
We know that to ensure good mental and intestinal balance, the composition of our daily meals is important.
However, we are less aware that tryptophan deserves full attention in our diet.
And with good reason: it is a key molecule, in particular, in the production of serotonin, known as the “happiness hormone,” and melatonin, the “sleep hormone.” It is also known as an essential amino acid.
More precisely, “a molecule that the body needs, but which it cannot produce on its own, so it must be obtained from food,” defines Emily Steinbach, neuroscientist, PhD student in nutrition at Inserm and founder of Feed your brain; an Instagram account and company that popularizes scientific knowledge about the impact of our lifestyle on our brain.
The main ingredient in the recipe for a good mood
So, tryptophan’s main role is to be a precursor for the synthesis of serotonin, the neurotransmitter responsible for mood. “If you compare the synthesis of serotonin to a recipe,” explains Emily Steinbach, “tryptophan is the main ingredient.” Thanks to this molecule, which is partly directed to the brain, but also to the intestines, serotonin can, for example, carry out its functions of regulating emotions and controlling appetite
.
It makes sense that a tryptophan deficiency would have consequences for mood. “The alteration of serotonin synthesis can lead to various symptoms, such as irritability, aggression, sadness, cravings for sweeter or fattier foods, an insatiable appetite, or an inability to step back and find peace,” explains the neuroscientist. This deficiency is certainly not the only enemy of a good mood. High levels of stress and deficiencies in certain vitamins also affect it.
The second role of tryptophan concerns sleep regulation. “In the evening, serotonin can be converted into melatonin, a hormone involved in sleep and, above all, in the regulation of circadian rhythm, the rhythms of sleep and wakefulness,” the specialist explains.
A “key function” in the gut
Tryptophan also influences intestinal transit, explains Harry Sokol, professor of gastroenterology at Saint-Antoine Hospital and head of a research group at Inserm and Inra. 80% of the “happiness hormone” is produced in the gut, describes the author of the comic “The extraordinary powers of the gut” (1): “Serotonin plays a role in diarrhea, constipation, immunity, diabetes and obesity,” he explains.
In addition, tryptophan is used by the intestinal microbiota: “Intestinal bacteria use it to stimulate immunity and maintain the intestinal barrier,” says the researcher. “This is a key function.” According to the doctor, the molecules produced by the microbiota from tryptophan then act throughout the body. “They are found, for example, in breast milk, where they play a role in the maturation of the intestine of a breastfed newborn,” explains Harry Sokol.