Serotonin Series - Serotonin and Diet

Serotonin is synthesised from the amino-acid tryptophan. A diet particularly low in tryptophan, therefore, is likely to inhibit our body’s ability to create sufficient tryptophan. However, it is unfortunately more complicated than just eating a high-tryptophan diet. This is because, eating a high protein diet; high in amino acids therefore, actually inhibits serotonin production. This is because amino-acids compete to cross the blood-brain barrier and tryptophan often becomes crowded out. There are two ways, however, to increase tryptophan absorption into the brain.

Firstly, the consumption of foods with a particularly high ratio of tryptophan to other amino-acids. Seeds have a particularly optimum ratio, so consuming sunflower seeds, pumpkin seeds, tahini, butternut squash seeds, sesame seeds etc, is a great way to boost tryptophan, without boosting other amino acids. Turkey is often touted as a particularly good tryptophan food, however, due to its amino-acid content, its consumption is actually correlated with a reduction in serotonin levels.

Secondly, a diet high in carbohydrates is associated with an increase in serotonin levels. This is most likely because carbohydrate consumption increases insulin, which results in more nutrients being stored in the muscles. Therefore, more amino-acids are transported to muscles, meaning tryptophan isn’t crowded out when it comes to the blood-brain barrier.

There are some interesting studies that demonstrate such dietary impacts on serotonin. One such study demonstrated that a diet high in butternut squash seeds and low in animal protein, increased serotonin levels and reduced the impact of social anxiety and increased general mood. This demonstrates the power diet has over our mental health. Some researchers argued that this may by the reason why, when someone becomes depressed, their craving for high carbohydrate foods increases – their body is attempting to make more insulin to ultimately increase serotonin levels. However, mental health isn’t only about serotonin, but about a whole range of neurotransmitters, hormones, physical health and much more. So eating a ton of chips isn’t going to improve mental health.

So what diet is best for ensuring good serotonin levels, as well as maintaining positive mental health? A predominantly whole foods, carbohydrate rich diet. Focusing on fruit, vegetables, nuts, seeds, beans and wholegrains. Such a diet provides a huge amount of anti-oxidants, which fight of free radicals, a constant supply of carbohydrates to ensure our insulin levels are high enough to transport all the positive nutrients to the right places, as well as healthy fats, fibre for microbiome health and good sources of protein (such as black beans) which are also hugely beneficial for our microbiome. To consume such a diet 80% of your week, will have a huge impact of your mental health and, combined with regular exercise, will ensure a constant supply of serotonin, looking after your cognitive health, avoiding a multitude of diseases and reducing your likelihood of depression and anxiety.