Written by Carmela Pengelly. Carmela is a dietary therapist and nutritional therapist, trained in the UK.
She now lives in Perth, Western Australia, where she practises as a nutritionist, specialising in SIBO (small intestinal bacterial overgrowth), methylation issues, and vegan/vegetarian diets. She also offers consultations outside of Australia, via Skype.
The UK is becoming a nation of depressed, overweight people. Lack of serotonin is one of the major contributors, with nearly 1 in 10 people relying on antidepressants to raise their levels of this so-called ‘happy hormone’. What exactly is causing this significant issue at a societal level and what changes in your lifestyle and diet can you make to address it? Let’s take a closer look.
What Does Serotonin Do?
Serotonin is most well-known for its mood-boosting properties. It creates feelings of well-being, helps you feel relaxed and in control.
But it also has other important functions in the body:
Even though serotonin is most often associated with mood, only 10% is made in the brain and the remaining 90% is made in the gut.
Its role here is to control muscle contractions (peristalsis) that move matter through the digestive system.
Serotonin governs impulse control. Cravings for alcohol and food, particularly sugary foods are often due to low levels of this neurotransmitter.
Is Low Serotonin Making You Fat?
If you’re overweight and have trouble curbing your appetite, lack of serotonin may be the problem. You’ve got the double whammy of comfort eating because you feel low combined with your physiological need for carbs driven by your brain chemistry.
Chocolate contains tryptophan, which is the raw ingredient of serotonin. If you’re a chocoholic, it might be your unconscious desire to increase serotonin.
A typical symptom of PMS (pre-menstrual syndrome) is hard-to-control cravings for sugary comfort foods.
Being weak willed is not the reason - it’s more to do with the fact that serotonin levels drop at around the time of your period.
If you know you’re prone to pre-menstrual snacking, you may be able to circumnavigate this by including foods in your diet that will promote serotonin production.
See the table below for serotonin-boosting foods.
Melatonin, the hormone that regulates sleep, is made from serotonin. This is one of the reasons why low mood and insomnia often go hand-in-hand.
Serotonin plays a complex role in the cardiovascular system, which is not yet fully understood. High levels of serotonin are found in the blood of people with hypertension, yet, researchers are discovering that serotonin can actually lower blood pressure.
Serotonin modifies bone turnover. This is a problematic side effect of antidepressants as they double your risk of osteoporosis.
On the plus side, scientists are optimistic that effective drugs can be developed to treat osteoporosis, by lowering gut serotonin.
Serotonin works in tandem with hormones to regulate sexual function. In general, too much serotonin decreases libido while low serotonin tends to cause over-arousal.
Our brain is our communication centre where nerve cells (neurons) ‘talk’ to each other via chemical messengers called neurotransmitters. They can receive, process and transmit these signals at the speed of about 200 mph.
Examples of neurotransmitters include dopamine, adrenaline and serotonin. Serotonin and adrenaline are considered both neurotransmitters and hormones.
The brain and gut make serotonin from tryptophan, an essential amino acid we get from food.
The other important factor with serotonin is that low mood is not just about how much neurotransmitter you are making. It also depends on how long it hangs around in the brain before it is transported back to the cell for reuse. This is called reuptake.
Anxiety and depression
Drugs That Raise Serotonin
The most commonly used antidepressants today are SSRIs (selective serotonin reuptake inhibitors), which prevent the reuptake of serotonin back in to the cell.
These are among the top 20 drugs most commonly prescribed in the UK.
Interestingly, researchers are discovering that SSRIs may not improve depression because they increase serotonin – neurotransmitter levels generally drop back down to pre-treatment levels after about six weeks.
Instead, SSRIs may be having an anti-inflammatory effect and promote the generation of new brain cells.
5 Natural Ways to Increase Serotonin
- Eat High Tryptophan Foods
It is possible to find foods that contain serotonin itself – for example, bananas and other tropical fruits.
However, most experts believe that serotonin from foods cannot cross over the blood brain barrier, a semi-permeable membrane that prevents the passage of certain molecules.
So, the value of eating high-serotonin foods is questionable.
Eating foods that contain tryptophan, the precursor to serotonin, has been proven to raise levels of this neurotransmitter in the brain and improve mood.
BEST FOOD SOURCES OF TRYPTOPHAN
LOW PROTEIN SOURCES*
HIGH PROTEIN SOURCES
Source: USDA Food Composition Databases; Based on normal serving size.
- Try Natural Solutions
There is a big selection of supplements on the market that are effective at raising serotonin naturally.
Avoid taking more than one of these at any one time, or at the same time as conventional antidepressants, without medical supervision or advice from a health care practitioner.
5HTP (5-hydroxytryptophan) is a natural supplement sourced from the Griffonia plant.
It is the precursor to serotonin. Normally, the brain would have to convert tryptophan to 5HTP and then 5HTP to serotonin. Taking 5HTP means you can skip a step in making serotonin. 70% of 5HTP in the brain will be converted to serotonin, whereas only around 3% of tryptophan is converted to serotonin.
Compared with tryptophan, it is also much better absorbed in the gut and more easily crosses the blood brain barrier.
As well as depression, some studies have shown 5HTP to be effective in helping the symptoms of:
Learn more about Nu U Nutrition 5HTP supplements from natural griffonia extract.
St John’s Wort
St John’s Wort works in a very similar way to SSRIsby inhibiting reuptake of serotonin into the brain cell. Strong evidence shows it to be as effective as conventional antidepressantsfor people with mild to moderate depression.
SAMe (s-adenosyl methionine) plays an important role in methylation, a biochemical process needed for the manufacture of neurotransmitters. We make SAMe from the amino acid methionine but it is also available as a standalone supplement and it can be an effective (if expensive) way to boost serotonin.
In a minority of cases, some people with certain genetic variations can feel worse if they take SAMe. Stop taking straightaway if you think this is happening to you.
Saffron is derived from the crocus plant and is a traditional Persian remedy used to help depression. Studies show it can significantly improve symptoms in people with severe depression by increasing serotonin levels.
The ‘happiness bark’ comes from the mimosa tree. It is traditionally used by Chinese herbalists, who also call it ‘nature’s Prozac’. It can be found under the name, huan hua or he huan pi, depending on which part of the plant is used.
- Get Some Sunshine
There is evidence to suggest that exposure to sunlight or very bright light can increase your serotonin levels.
This is why sufferers of seasonal affective disorder (SAD), otherwise known as the winter blues, benefit from light therapy.
- Get Your Exercise
Exercise, particularly aerobic activity, raises serotoninand improves mood, by increasing availability of tryptophan to the brain.
- Put On A Happy Face
Amazingly, just thinking happy thoughts can improve serotonin levels. In a study on the effect of emotions on neurotransmitters, participants were asked to think of happy past experiences, while another group had to think of bad memories.
The first group had elevated levels of serotonin while the latter group suffered lowered levels.
Why Your Serotonin Might Be Low
Lack Of Co-Factors
Co-factors are nutrients which are needed for certain chemical reactions to take place in the body. To convert tryptophan to 5HTP and then 5HTP to serotonin we need:
- Vitamin C
If you’re feeling low and your diet is lacking in wholefoods, consider taking daily supplements that contain these nutrients and try to include as many natural, unprocessed foods into your diet as you can.
Lack of Folate
We need folate to make neurotransmitters through methylation reactions in the body. Lack of folate will impair these biochemical processes and negatively impact serotonin levels.
Folate is found in green leafy vegetables, legumes, avocadoes and tropical fruits.
We also get folate from folic acid, a synthetic version of this nutrient is found in fortified foods and some supplements. However, a significant proportion of the population have gene mutations which make it difficult to convert folic acid to folate.
To avoid this, choose supplements that offer the active form of folate, called MTHF (methyltetrahydrofolate).
If you’re concerned about your folate levels, have your doctor test for homocysteine, which is a good indicator of folate status.
In a small proportion of people, folate supplementation can make you feel worse. If this happens to you, stop taking it straightaway, and stick to getting folate from your diet.
Another sign that you might need more folate is if you tried SSRIs they didn’t help. Simply supplementing with folate in these cases can often make a big difference in helping symptoms.
Too Much Protein
Protein foods are our main sources of tryptophan.
Paradoxically, too much protein will inhibit tryptophan uptake in the brain. Amino acids need a carrier to transport them across the blood brain barrier. Other amino acids in protein foods will compete to be carried into the brain ahead of tryptophan.
The key is to have enough protein but not too much in your diet. This should be up to 1 g of protein for every kg of your body weight.
You can also eat more lower protein foods that still contain tryptophan in your diet (see table of tryptophan-rich foods).
Not Enough Carbohydrates
We’ve mentioned above that tryptophan has a hard time competing with certain other amino acids for uptake by the brain.
Carbohydrates cause you to release the hormone, insulin. Insulin will drive competing amino acids into muscle, leaving tryptophan with less competition at the blood brain barrier.
If you think that your serotonin is low, you could try lowering your protein intake and having carbohydrate-rich foods at a separate time to protein foods. In her book, Potatoes Not Prozac, Kathleen DesMaisons recommends eating a baked potato before you go to bed - certainly worth a try.
In depression, several very common genetic mutations (polymorphisms) can either reduce the amount of serotonin being made or shorten the amount of time serotonin persists in the brain.
Common polymorphisms include MTHFR (methylenetetrahydrofolate reductase), in which you have less of the enzyme needed to metabolise folate, and MOA-A (monoamine oxidase), which causes you to break down serotonin too quickly in the brain.
There are several genetic tests available now which can identify these variations.
Our old enemy stress causes elevated levels of the hormone, cortisol, which will inhibit serotonin production.
Cholesterol-lowering drugs, which are the most commonly prescribed drugs in the UK, cause a drop in serotonin. Among its many functions, cholesterol is important for healthy nerve cell membranes so.
A survey of statin users showed that nearly a third experienced depression which they attributed to the medication.
Not Enough Water
Dehydration reduces blood flow to the brain – your blood literally becomes thicker. This reduced blood flow slows delivery of tryptophan to the brain.
Addressing Serotonin Deficiency in Your Life
If you feel down, depressed, or generally low on energy, talk to your doctor and learn if you might be suffering from a serotonin deficiency – the kind that can be addressed through diet and lifestyle changes. Nutrition is a key balancing factor in how you feel on a daily basis. Supplementation may help to fill any remaining gaps.