Transcript: The Wrong Way to Boost Serotonin
Recent studies like this suggest that dietary patterns characterized by high intakes of vegetables, fruit, mushrooms and soy products are associated with fewer depressive symptoms.
The year before, it was this study, “The association between dietary patterns and mental health in early adolescence,” showing “[i]mproved behavioural scores…significantly associated with higher intakes of leafy green vegetables and fresh fruit.
Could any of this be because of the psychoactive substances found in plant foods?
The neurotransmitter serotonin, often referred to as the “happiness hormone,” is found in plant foods. But, serotonin doesn’t cross the blood-brain barrier. So, it shouldn’t affect our mood, no matter how much we eat.
The precursor to serotonin, however, what your body makes serotonin out of, is an amino acid called tryptophan. And, there’s a transport protein in the brain that plucks tryptophan out of the bloodstream, and so, what you eat can end up affecting your mood.
Back in the 70s, they did tryptophan depletion experiments, where you give people specially concocted tryptophan-deficient diets. And, indeed, their mood suffers. They get irritable, annoyed, angry, depressed, right? Their body just can’t make enough serotonin.
Likewise, you can give people tryptophan pills to improve their mood. And, indeed, it became a popular dietary supplement—until people started dying from something called eosinophilia myalgia syndrome, an incurable, debilitating, and sometimes fatal flu-like neurological condition, caused by the ingestion of tryptophan supplements.
May have been due to some unknown impurity, but, better safe than sorry. Instead of supplements, there are dietary strategies one can use to improve mood—which we’ll talk about next.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Kerry Skinner.
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