Tryptophan is an amino acid found in foods that contain protein.
Amino acids are the building blocks of protein, but they also have other roles in the body.
One of these roles is to produce molecules that help the body transmit signals.
Tryptophan, specifically, can be converted into a molecule called 5-HTP (5-hydroxytryptophan). This is used to make serotonin and melatonin.
So to boost your serotonin levels, you need tryptophan.
Find out exactly which plant-based foods you can get your tryptophan from, and what benefits increased tryptophan and serotonin can have on the body.
Tryptophan and Serotonin
To understand tryptophan, its role in mood and the plant-based foods we can obtain it from, we first need to understand serotonin.
Serotonin is of significant important because it affects a number of organs, including the brain and intestines.
Known as the ‘happy hormone/molecule', serotonin plays a crucial role in regulating mood and also in promoting feelings of wellbeing and positivity.
Serotonin also works to support healthy brain function, which includes promoting mental cognition and emotional stability.
Other body processes also greatly benefit from the presence of serotonin, such as social behavior, sex drive, a solid sleep schedule, and learning and memory.
What Happens When You're Serotonin Deficient?
Because serotonin has such an effect on the body and the brain, a lack of serotonin in the body can lead to some unpleasant symptoms.
- digestive disorders (including constipation).
- an increased sensitivity to pain.
- changes in eating patterns (including binge eating bouts and an increased desire for carbohydrates).
- separation anxiety or dependency.
- disrupted sleep schedule.
- issues with self-esteem.
- headaches and migraines.
- general bad moods.
Women with a lack in serotonin have a general propensity to experience depressed moods and increased anxiety. Men are more prone to impulse control disorders, including ADHD. Low serotonin also makes men more susceptible to alcoholism and potentially other addictive diseases.
Studies show that a decrease in serotonin can also greatly impact a person’s length of life and lead to increased rates of many diseases, including:
- heart disease.
- irritable bowel syndrome (IBS).
- Serotonin Production: Intestine Vs. the Brain
- Interestingly, 90%+ of serotonin is produced in the digestive tract.
Peripheral serotonin is created in the intestines by the enterochromaffin cells, and also by immune cells and certain gut neurons.
Serotonin produced in the brain is created by raphe neurons that directly supply the brain.
The serotonin is molecularly the same, but the molecules are produced by different types of cells and can elicit a variety of functions.
A common misconception is that eating serotonin-rich foods will improve the amount of serotonin molecule in the brain and improve mood.
Unfortunately it isn't that simple. Serotonin produced in the intestine can’t cross the blood barrier to the brain.
However, it can with the help of a precursor.
This precursor is then amino acid, tryptophan.
Humans have a transport protein in the brain that plucks tryptophan out of the bloodstream. So what you eat can end up affecting your mood.
How Carbs Increase Serotonin Synthesis
Eating carbohydrates triggers a release of insulin, which forces muscles to ‘eat’ non-tryptophan amino acids as their food or fuel.
This is actually beneficial to the brain – because it frees tryptophan up to be absorbed by the brain.
Interestingly, researchers found that women who suffer from PMS experience carb cravings. This may be a message from the brain to ingest more tryptophan in order to alleviate their symptoms.
The researchers note that:
Consumption of a carbohydrate-rich, protein-poor evening test meal during the premenstrual period improved depression, tension, anger, confusion, sadness, fatigue, alertness, and calmness scores significantly among patients with premenstrual syndrome.
The synthesis of serotonin in the brain also tied with mood and appetite – serotonin will also spike after carbohydrate intake, leading to a very understandable reason for carbohydrate cravings during PMS (Study).
The study followed 19 patients who suffered from severe premenstrual syndrome.
Mood was assessed by the Hamilton Depression Scale. Fatigue, sociability, appetite, and carbohydrate craving were also measured.
The researchers also measured nutrient intake in the patients, noting that carbohydrate intake increased significantly during the late luteal phase (24% from meals and 43% from snacks).
The researchers also found that carbohydrate-rich, protein-poor evening test meal during the luteal phase improved PMS symptoms like depression, tension, confusion, sadness, fatigue, anger, alertness, and calmness
They reasoned that synthesis of brain serotonin increases after carbohydrate intake.
This makes sense, as women with PMS might be trying to improve their moods through their meals.
Let's face it, we all feel good when we “carb up!”
Fruit for Treating Depression (Low Serotonin)
A recent article in the Journal of Neuropsychiatry and Clinical Neuroscience noted that fruit could be used as an effective treatment for depression, for which a low level of serotonin may be held accountable.
While most treatments for depression now hinge on SSRI drugs, such as Prozac, the side effects of such drugs are significant enough to want to choose an alternate method.
Researchers found that depression patients who supplement with fruits like plantains, pineapples, bananas, kiwis, plums, and tomatoes see reduced symptoms.
However, the best foods to eat to promote serotonin levels in the brain are those with a high protein to tryptophan ratio, as we'll find out below.
10 Tryptophan-Rich Vegan Foods
1. Butternut Squash Seeds
Because serotonin is best elevated with a source of tryptophan and protein, seeds are a great choice, specifically butternut squash seeds.
These seeds were used during a study of those suffering from social phobia. Significant improvement in anxiety was measured among those who consumed squash seed bars.
For a typical serving of 1 cup (or 129 g), you'll get 0.74 g of Tryptophan.
2. Sea Vegetables
Veggies like kelp, seaweed, and spirulina are all fantastic sources of tryptophan. These veggies contain about 3 percent of your daily tryptophan requirement.
You can get your soy through soybeans, tofu, and soymilk.
One cup of soy beans contain 535mg of Tryptophan. That's 191% of the RDA.
4. Oat Bran
Containing 315 mg (113% RDA) of tryptophan per cup, oat bran is cheap and easy to add to cereal, salads and other dishes. Wheat is also a good source of this amino acid.
Walnuts are an incredible source of polyunsaturated fats, omega-6 fatty acids, and can reduce bad cholesterol.
These healthy nuts also improve metabolism and can help control diabetes.
One serving of walnuts (about a handful) contains 318 mg of tryptophan. That's more than the RDA.
6. Leafy Greens
Known for their alkalizing properties, leafy greens are high in fiber, vitamin C and phytochemicals and they’re low in fat. Leafy greens help fight chronic disease.
Greens like spinach are high in tryptophan, at 80 mg per ounce.
Another cheap and accessible food source, potatoes are a great source of vitamin B6, potassium, vitamin C and dietary fiber.
Potatoes also contain 80 mg of tryptophan per ounce.
Closely related to broccoli, cauliflower is an excellent source of protein, fiber and also potassium. It is loaded with amino acids, including tryptophan, and contains about 25 mg per ounce.
Another healthy tryptophan food is mushrooms.
Mushrooms are rich in vitamin D, selenium, antioxidants, and B2 vitamins, and also contain 25 mg of tryptophan per ounce.
Even your side salad can boost your tryptophan.
Cucumbers are a great source of molybdenum, vitamin K, vitamin C, potassium, magnesium, and silica, and provide a moderate amount of tryptophan at 10 mg per 100 grams.
A serving of walnuts or pumpkin seeds, some soy milk, and veggies for dinner and you will easily hit your tryptophan requirement and boost your serotonin production.