I have wanted to write this post for a long time.
What would be nice would be an easy list of foods that you often see such as “eat turkey and bananas as they contain tryptophan”. Unfortunately, these list are oversimplified and do not contain adequate information to be useful.
The reason it has taken me so long to write this is because the concept of how foods can help to boost your mood is a complex one, way more complex than I can do justice to, with plenty more research to come in that area, but there is plenty of information that is worth sharing.
Here is my brief summary:
Foods containing Tryptophan
L-tryptophan is a dietary amino acid and is the precursor to serotonin, one of the important neurotransmitters considered to play a role in mood. Many antidepressants work by increasing levels of serotonin in the brain. So, the idea of eating foods high in L-tryptophan is a good concept. L-tryptophan is moved across the blood brain barrier into the neurons by the large neural amino transporter (LNAA) which also moves other amino acids. L-tryptophan must compete with these other amino acids for transportation into the brain and therefore the higher the concentration of L-tryptophan in the blood, the greater the chance of it making it into the brain.
Foods high in tryptophan include meats, poultry, seafood, dairy products, nuts and seeds, legumes, many fruits and vegetables, some grains. Supplementation with L-tryptophan has not been shown to be effective for treating depression in controlled studies.
We need oxygen, iron and vitamin B6 to convert L-tryptophan into serotonin
A lack of vitamin B6 not only inhibits serotonin production in the brain and body but can also lead to other neurological symptoms. It is much better to get this (and all) vitamin from food sources rather than supplements. Foods rich in B6 include sunflower seeds, pistachios, tuna, salmon, halibut, turkey, chicken, beef, bananas, spinach and sweet potato. Many of these foods are also good sources of iron and L-tryptophan.
Foods containing Tyrosine
Tyrosine is another amino acid and is the precursor to the neurotransmitters dopamine and norepinephrine which are also involved in mood regulation. While tyrosine can be made by the body from the amino acid phenylalanine so i s considered non-essential (doesn’t need to be obtained through food), under prolonged stress your body might not be able to manufacture enough tyrosine. You can however, get it from your diet by consuming high protein foods such as meat, fish, poultry, cheese, yoghurt and legumes.
Vitamin C participates in the conversions of tryptophan to serotonin and tyrosine to norepinephrine which as stated above, are both important neurotransmitters involved in mood. In addition, during periods of stress our bodies use of Vitamin C increases so we need to ensure that we consume adequate amounts. The best sources of Vitamin C are fruit and vegetables.
Recent research has suggested that zinc deficiency may play a major role in depression. Serum zinc levels have been shown to be low in people suffering from depression and zinc supplementation has been shown to have antidepressant effects. This research paper gives an excellent description. Zinc also plays an important part in inflammation, immune function and skin health. Major sources of zinc are meat, poultry and oysters. Some people have a condition called pyroluria which stops them from properly absorbing zinc. This condition is quite under diagnosed and is useful to keep in mind if experiencing problems with mood, immunity and inflammation.
Magnesium is another micronutrient that has been linked to depression. It plays a significant role in brain biochemistry and deficiencies in magnesium have been linked to depression, insomnia, behavioural disturbances, irritability and headaches. Magnesium can be obtained from many foods including green leafy vegetables, nuts and seeds, fish and avocados. Magnesium has been used as a treatment for depression in homeopathic medicine for many decades.
Vitamin D deficiency is associated with depression (and inflammation). The best source of vitamin D is the sun so try to get 15 to 20 minutes of sun exposure (without sunscreen) each day or as often as possible. (I know this is not a food but is very important which is why I have included it).
More recently there has been an interest in the role of inflammation in depression and the idea that depression might be a result of chronic immune activation and consequential inflammation (Here is a good article). It is believed that cytokines (messenger molecules) cross the blood brain barrier via leaky regions and once inside the brain may metabolically alter neurotransmitters including serotonin, dopamine and noradrenaline, all of which have been implicated in depression. It has been suggested that the cytokines reduce the availability of L-tryptophan and also reduce the release of dopamine which then impacts on the brain’s ability to produce these neurotransmitters.
Foods that are linked to inflammation are wheat (and other sources of gluten) and sugar. Omega-6 fatty acids are also problematic for inflammation. Foods high in omega-6 fatty acids are vegetable and seed oils such as canola, corn and sunflower oil, margarine and hydrogenated or partially hydrogenated oil. Processed foods are generally high in omega-6 fatty acids.
There is a strong link between our gut and our brain known as the gut-brain axis and the gut is considered to be our ‘second brain’. 90% of serotonin is actually found in the gut. Research has suggested that depression may be a manifestation of inflammation in the gut. Depression is often seen alongside inflammatory and autoimmune disorders and some people believe that inflammation may be the major risk factor in depression. Clinical studies have found that using probiotics, omega-3 fatty acids, vitamin D and vitamin B to treat inflammation may also improve symptoms of depression.
Foods that improve gut health include fermented foods, probiotics and probiotic foods (kefir, kombucha, real yoghurt) and bone broths. All of which are easy to include in your daily diet and can be made at home.
As you can see, nutritional causes and treatments of depression are complicated and new research continues to provide more information.
So, what is my take on foods and your mood? –
Basically, good overall physical health, a well nourished brain and body and good gut health will go a long way towards maintaining a balanced mood as well as helping your body and brain to recover from mental health problems. Therapy and/or medications will work more effectively if your body and brain are functioning optimally. Eating real, unprocessed foods and reducing (or eliminating completely) your intake of sugar and gluten (or all grains if that works for you) will have a positive effect on overall health, help to prevent further inflammation and increase nutrient absorption. Including fermented foods, probiotics, bone broths and omega-3 fatty acids help to reduce inflammation and improve gut health. Ensuring you get adequate doses of sunshine and plenty of foods that are rich in zinc, B6, Vitamin C and tryptophan give further assistance to the production of important neurotransmitters. Including plenty of healthy fats means that your body and brain will function well which in turn has a positive effect on your mood.
Eating real food is far superior to taking supplements. In real food nutrients are found together and in our bodies nutrients work together and often need other nutrients to do their jobs. Supplements simply can’t provide these important combinations and expose us to the risk of toxicity if not taken correctly. Of course, there are some cases where supplementation is required but always do this under the supervision of a health care practitioner – never self prescribe. Adjusting your diet to ensure adequate nutrition should always be the first step.
For some excellent information on healing your gut, nutrition for autoimmune disorders and chronic health problems (including mental health) and on how gluten is linked to neurological issues I recommend the books Gut and Psychology Syndrome by Dr Natascha Campbell-McBride, The Wahls Protocol by Dr Terry Wahls, Primal Body, Primal Mind by Nora Gedgaudas and Grain Brain by Dr Perlmutter.
There are many recipes on the internet for bone broths and various fermented and probiotic foods/drinks – have a look around and give some a try. If you have any favourite recipes please share them here!