Do you ever wonder what makes you happy – or why sometimes you are in a good mood for no apparent reason?
Your brain chemistry can contribute to these feelings, particularly the neurotransmitters in your brain.
The function of neurotransmitters is to relay messages between neurons (nerve cells) and a common one is Serotonin. Serotonin is mostly synthesised in the gastrointestinal tract where it helps to regulate bowel movements, however, the remainder is synthesized in the brain where it has many functions including regulating mood, appetite, sleep and cognitive functions such as memory and learning.
Serotonin is most commonly known as the neurotransmitter associated with feelings of contentment and happiness, and has been long associated with mental health.
Selective-serotonin reuptake inhibitors (SSRI’s) are a class of antidepressants which increase the levels of serotonin in your brain as it is thought that low levels are associated with poor mental health.
A simple solution would be to provide the right nourishment so that you can naturally produce more serotonin to keep feeling happy and content – but infortunately, our brain is a bit more complicated and it’s not as simple as it sounds …
The Making of Serotonin
For serotonin to affect your mood, it needs to be in your brain. This involves making it across the very selective blood-brain barrier which serotonin as a molecule cannot cross. However, the bits and pieces that serotonin is made from can, and once they are in the brain, serotonin can be formed.
The main precursor molecule for serotonin is tryptophan, so the first challenge is getting tryptophan into your brain.
Tryptophan is an amino acid which means that it comes from protein rich foods such as eggs, cheese, pork, turkey and soybeans. When these kinds of foods are eaten and digested, the protein is broken down into individual amino acids including tryptophan. The issue is that tryptophan is one of the least abundant amino acids in foods, so even though we have more tryptophan in our system, we also have more of the other amino acids which tryptophan has to compete with to get through the blood brain barrier.
So in theory, eating foods high in tryptophan should increase serotonin, but in practice, it doesn’t work that way.
Ways to Increase Serotonin
This is where carbohydrates come in. When you eat foods containing carbohydrates, your body produces insulin. Insulin is a hormone produced by our pancreas and its main role is to move glucose from our blood into our cells to be used as energy.
It also causes cells to uptake circulating amino acids which is how it helps with our tryptophan/serotonin problem. By causing the cells to absorb amino acids, it reduces circulating levels of 6 or more amino acids that would compete with tryptophan for transport into the brain.
As a result, tryptophan is left as the dominant amino acid in your blood, so is more likely to make it into your brain.
You may have heard that you should eat certain foods because they are high in serotonin – for example, bananas, walnuts, kiwi fruit and pineapple. As I mentioned above, serotonin cannot cross the blood-brain barrier so eating foods rich in serotonin won’t have any effect on your mood.
Carbohydrates + Protein = Serotonin
Eating foods high in tryptophan is not enough to increase serotonin in your brain.
The best way to increase serotonin and improve your mood is to have some carbohydrates at the same time as your protein/tryptophan foods. This allows tryptophan to enter the brain to be synthesised into serotonin. Here are a few practical ways you can do this:
- Try for whole grain carbohydrates like brown rice, barley, quinoa or whole grain bread;
- Have protein that is high in tryptophan, so you have plenty available for your brain eg milk, yoghurt, cheese, egg, fish, poultry, chickpeas, almonds and red meat;
- Enhance the absorption of tryptophan into your brain, by eating protein and carbohydrates together.
Author: Ashleigh Hamilton, BHlthSc (Nutr & Diet), MSc (Diet), APD.
Accredited Practicing Dietitian and Nutritionist, Ashleigh Hamilton, is passionate about a whole of body approach to health which encompasses both physical and mental aspects. She works with people to make lifestyle changes that will benefit their health for the future, using a range of counselling techniques including aspects of cognitive behavioural therapy, mindfulness and person-centred therapy.
To make an appointment with Brisbane Dietitian and Nutritionist, Ashleigh Hamilton, try Online Booking – Mt Gravatt or call Vision Psychology (Mt Gravatt) on (07) 3088 5422.
- Daniel, Peter M., et al. “The effect of insulin upon the influx of tryptophan into the brain of the rabbit.” The Journal of physiology 312 (1981): 551.
- Afaghi, Ahmad, Helen O’Connor, and Chin Moi Chow. “High-glycemic-index carbohydrate meals shorten sleep onset.” The American journal of clinical nutrition 85.2 (2007): 426-430.
- Young, Simon N. “How to increase serotonin in the human brain without drugs.” Journal of psychiatry & neuroscience: JPN 32.6 (2007): 394.