Serotonin and its brother neurotransmitters have been the talk of, well, everywhere at least since the appearance of Prozac, during the 1990s. But the more that is learned about this tiny molecule, the more amazing it seems. It is apparently omnipresent in nature, and it rides a fascinating feedback loop between our brains and our guts that has implications.

We’ve all felt that amazingly relaxed feeling after eating a big bowl of pasta, taking a long walk outdoors, cuddling with a mate, parent, child or pet, or just thinking about any of those things. There! There’s that feeling just now! Right, you know what I mean. Just thinking about any of those things can produce a release of serotonin in the body. That calm, serene feeling that lets us know all is well.

That’s serotonin! The happy hormone! My favourite neurotransmitter A neurotransmitter is a chemical that relays messages between the nerves in the body causing a physiological action. Serotonin is also known as 5HT (5 Hydroxytryptanine) – for the science geeks it is a monoamine neurotransmitter. It is one of the four main neurochemicals (the body produces thirty): serotonin, epinephrine, dopamine and endorphins. It is found almost everywhere in nature, controlling different aspects of physiology, including appetite, sexual desire and function, mood, sleep, memory, temperature and social behaviour in everything from worms to humans. Its action is sometimes compared to a volume control, either amplifying or reducing the intensity of messages sent between the synapses of the nerve endings throughout our system. It is found in the brain, the gut and blood platelets.

The Skinny on How It Works :

An electrical impulse initiates the process and generates the release of serotonin (or any of the neurotransmitters) from the end (axon) of a nerve cell to the synapse (the small space between the nerves). Next, the serotonin is recognised by a receptor site on the dendritic area of the next cell, which then grabs it. In simple terms, this relays a signal for whatever physiological action is desired and that signal is passed from one cell to another, resulting eventually in the signalled action. The serotonin spends a short time in the synapse and then is re-absorbed back into the axon of the original nerve cell with the help of serotonin transport molecules. The cells are ready to start the process again. It might help to understand the process if you visualise a chain of people: the first person wants an apple. He reaches out his hand, touches the next person and whispers, ‘I want to pick an apple.’ He then brings his hand back to his body. The person he touched repeats this action, touching and whispering to the person next to her. This is repeated down the line of people until the last person – the one next to the apple tree – picks an apple.

And that’s just the beginning.

Serotonin regulates signal intensity and affects how efficiently our nerves communicate with each other. There are over 40 million brain cells and most of them are influenced by serotonin. But wait, there’s more. Over 95 percent of the serotonin in our body is made and stored in the enteric nervous system – ‘The GUT Brain’. The nervous system in your gut is made from the same embryonic tissue as your cerebral brain and produces and utilises the same neurotransmitters. It has over 100 million nerves (more than the spinal cord). It is in constant communication with the brain via the vagus nerve (nine signals are sent from the gut to the brain for every one the brain sends to the gut). It can also act independently of the brain, taking its own measurement, making its own decisions and learning its own lessons. You have those ‘gut feelings’ when you know something is right or wrong or is going to be good or bad. Well that’s your ‘gut brain’ and its buddies, the neurotransmitters, talking to you. Just think how we abuse our gut – eating unhealthy foods and irritants, and allowing stress to give us ulcers! You have felt serotonin working in your gut in response to one of those irritants. There is either too much or too little serotonin produced, which leads you to make too many or too few trips to the loo.

Sounds simple, right? Maybe not. This process controls and affects so much of our lives and there are many reasons it may not work correctly. Too little serotonin produced, too few receptor sites, too many receptor sites, too few transport molecules, too many transport molecules, our genetics, diet, exercise, our gender, sex lives, weather, sunlight, thought patterns, and stress – all affect the system. There is evidence that women have more serotonin receptors and fewer of the proteins that transport serotonin back into the cells. This initially sounds great. But in reality, research shows that the receptor sites open up when hormone levels are low so they are certain to bind to every last drop of serotonin. In the same manner, the transport proteins are reduced to allow serotonin to stay in the synapse longer (this is how many anti-depressants work – by keeping the serotonin in between the cells longer, by preventing breakdown, or by blocking the signals to the transporter proteins that bring the molecule back to the cell).

In addition, variations in sex hormones also affect serotonin production, release and re-absorption. Oestrogen specifically stimulates serotonin receptors in the brain. When the levels of hormones change, the brain’s sensitivity to serotonin also changes, causing an increased need for serotonin to accomplish the same effect. This effect is also cumulative. Over time it may chip away at the ability of the brain and the adrenal gland to regulate mood, sexuality and response to stress. This can cause depression, especially in women. If you add in familial genetics – some people have increased levels of serotonin or receptors inherently – the saga becomes more complex. Men, it appears, make 52% more serotonin then women. They do not have fluctuations in levels of sex hormone until middle age, when amounts decrease steadily. (Yes, PMS is a real syndrome! Women are wired to be grumpy at that time!) The old saw that the way into a man’s emotions is through his stomach may be quite literally true. Both are modulated by serotonin! As I said, serotonin has been my favourite neurotransmitter and for years I’ve been trying to manipulate it. How do you keep the happy hormone happy? There are ways to do it.

Diet:

We know that food affects our bodies physically. We can see it on our waistlines and in lab reports. How often do you reach for chocolate or breads or pasta when you’re feeling down? Diet also affects our mental state. Those cravings are the body trying to increase its serotonin level. Diet affects our serotonin production and serotonin levels affect our diet choices. Serotonin is naturally found in many foods. It is also is produced in the body from tryptophan, which is an amino acid, one of the building blocks of complex proteins.

Some foods that contain high levels of serotonin:
Walnut
Plantain
Pineapple
Banana
Kiwi
Plum
Tomato
Date
Papaya

These foods can boost serotonin in the gut, but because serotonin cannot pass the blood-brain barrier you must also consume foods that contain tryptophan, the precursor to serotonin.

The following foods contain high levels of tryptophan:
Turkey
Banana
Milk
Yogurt
Dairy Products
Eggs
Meat
Nuts
Beans
Chick peas
Fish
Cheese (especially Swiss and Cheddar)
Carbohydrate-based foods – pasta, bread, rice, sweets, crackers

The confusing point is that although proteins contain more tryptophan than some other food groups, when you eat high protein foods your level of serotonin may not elevate quickly. There is a biological competition between proteins for entry to the brain. You may not make as much serotonin as you might think. On the other hand, when you eat carbohydrates like pasta, bread or crackers, you secrete insulin, which causes a decrease in the competitive protein metabolism and allows increased tryptophan to enter the brain and increase serotonin.

When you are tired, upset, moody, sad or stressed, consume some crackers and cheese or a bowl of pasta to increase your serotonin levels. This will promote feelings of security, safety, confidence and happiness. Eating foods that increase your serotonin levels also decrease anger, aggression, and depression. If you eat two serotonin-containing foods at the same time you may actually do more harm than good – you’ll get the high but you also will get a drop later which may make you feel worse Vitamin B is also very important, especially thiamine and folic acid. Both have been shown to improve moods, decrease depression and stabilise personality swings upon supplementation. Researchers believe that folate is correlated to serotonin via the SAMe (US dietary supplement.ed) precursor. When SAMe is low, serotonin is low.

Dieting is serotonin’s worst enemy! Calorie restriction decreases serotonin levels in both men and women – so, yes, diets do make you grumpy! Low serotonin levels make you constantly hungry, so it’s a vicious circle.

Exercise :

Exercise also been shown to increase serotonin levels. Both moderate aerobic exercise and yoga will increase the serotonin levels in the body. Too much exercise or feeling forced to exercise may have the opposite effect. Choosing to exercise creates serotonin; forcing exercise does not. This might be correlated to an ancient fight or flight response – running to hunt and get food vs. running away from being the food. Usually, when you don’t feel like getting up and moving it’s then when you need it the most. Exercise also helps regenerate neurons in the brain, creating feelings of well-being, energy and youth.

Additionally, the more muscles you have the more serotonin you produce. The muscles use up many of the competing amino acids and allow a greater level of tryptophan to reach the brain. So people who have a regular exercise regimen have higher levels of serotonin to start with.

Daylight/Sleep:

Historically, we humans spent much of our time outside in the sun during the day and in the dark at night. UV light absorbed through the skin creates vitamin D, which in turn plays a part in serotonin production. Research has demonstrated this so convincingly that major companies are trying to incorporate direct sunlight into their offices to help increase production and decrease stress.

Serotonin is also involved in sleep. In the presence of calcium, serotonin is a precursor for melatonin. Light decreases melatonin production and interrupts the sleep patterns. This prevents us from reaching the deeper levels of sleep where healing and complete rest take place. It is during our sleep that we cut away the things that are not important to us, the things we don’t spend much time thinking about or are not attached to, and the time that the neurons of our brain cells begin to regenerate. Lack of sleep desensitises the serotonin pathway. If we don’t sleep we are anxious, cranky, panicky, tired and become sick. Most of us are bombarded by light at night whereas a century ago that was not a problem for most.

Once again this is a two-way street.

Serotonin helps us to sleep, and sleep helps produce serotonin. That’s why our grandmothers used to tell us to have warm milk at night with some cookies or biscuits. Milk has high levels of tryptophan to help you sleep.

Happy Thoughts :

Researchers have found that even just thinking happy thoughts can initiate serotonin production and thinking sad thoughts can decrease serotonin levels. The more happy thoughts you think the less room for sad thoughts! This is also a two-way street. You can actually see changes in the brain that correlate to serotonin production when you are having pleasurable memories and painful memories were negatively associated with serotonin levels.

Unhappiness is contagious. Moody or chronically unhappy people often find themselves without social support – lovers, friends and family – which also contributes to a decrease in serotonin levels. Dominant personalities tend to have higher levels of serotonin (confidence). Also, people who have been victims of childhood physical, emotional, or sexual abuse and crime may have lower serotonin levels.

Massage:

Once again we see the benefits of touch. Massage and pleasurable human contact increase serotonin levels. Serotonin levels jumped 34% in babies of depressed mothers when they were given fifteen-minute massages. In mothers that were depressed, levels increased 30% after bi-weekly massages. Either way, massage improves your mood. Have one – see the results! Yoga and Meditation : Through yoga and meditation, you can change your body’s normal responses to create a better parasympathetic response: more calm and more joy. Massaging the inner organs through flowing movements creates health. It helps the body release stored memories and physical injuries, as well as accruing all the other benefits that come from exercise. It helps to release the fascia, strengthen the muscles and build body confidence -all of which will increase serotonin levels. Meditating and calm, slow, regular, rhythmic breathing send messages to the body that all is well. Dr. Michael Gershon, in his book on neurogastroenterology, The Second Brain: A Groundbreaking New Understanding of Nervous Disorders of the Stomach and Intestine, states that the gut monitors pressure so when you’re sending soothing signals to it via this calm, rhythmic breathing, you’re telling it: everything’s OK! And your gut brain learns from that and relaxes.

In summary, it takes a few minor steps to keep your happy hormone high:

• Eat healthy snacks that contain carbohydrates like crackers, whole grains, cheese and nuts
• Think happy thoughts
• Rest – eight hours of sleep in a dark room
• Exercise
• Spend quality time with friends, family and pets
• Do yoga – especially restorative – and meditation
• Deep rhythmic breathing
• Follow your gut feeling!

When you are feeling down or tired, listen to your gut! Experiment with different foods and lifestyle options and see if you can change your brain! Find well-being every day or you could just eat biscotti. Either the serotonin or the treat will make you feel better.