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Tryptophan

Overview​

Tryptophan is an essential amino acid that serves as the precursor for serotonin and melatonin, neurotransmitters that play crucial roles in mood regulation, emotional control, and sleep. Tryptophan's entry into the brain occurs via the LAT1 transporter, where it competes with other large neutral amino acids (LNAAs) like tyrosine and phenylalanine. Carbohydrate-rich, low-protein meals can raise the plasma tryptophan:LNAA ratio because insulin pushes competing LNAAs out to muscles, making more tryptophan available for brain uptake. Tryptophan can also feed NAD+ synthesis via the kynurenine pathway, supporting cellular energy metabolism.

Recipes​

9 recipes containing this substance

Chocolate Quinoa Crisp Clusters

A delicious cereal-to-snack hybrid with satisfying crunch, steady energy, and a low glycemic profile. Perfect for breakfast or anytime snacking.

Ginger Yogurt and Blueberries

An Anti-inflammatory polyphenol-rich breakfast bowl with high fibre. Start the day with anti-inflammatory gingerols and omega 3 nuts, blueberry polyphenols, a fibre from steel rolled oats. Great to set up dopamine for focus and attention.

Mitochondrial Power Bowl

A nitrate-rich, polyphenol-dense bowl supporting mitochondrial function, ATP generation, and metabolic resilience

Salmon Bowl-pistachio-cacao-nibs

A functional ECS-supportive bowl combining salmon, avocado, pistachios, cacao nibs, and early harvest olive oil to help preserve anandamide tone, improve membrane lipid composition, and support gut–brain signaling.

Turkey Wing Stew

A collagen-rich, glycine-heavy slow-cooked stew made from affordable turkey wings — supporting gut, joint, sleep, and brain health.

Turmeric Lentil Dahl

Anti-inflammatory curcumin-rich lentil dish supporting gut health, NF-κB inhibition, and SCFA production

Turmeric Milk

A warming drink combining turmeric (curcumin) with milk/fat for enhanced curcumin absorption

Foods​

29 foods containing this substance

Almonds

Vitamin E, plant protein, and healthy fats

Bananas

B6 source and tryptophan-containing fruit

Beef

High creatine, CoQ10, heme iron, and complete protein

Black Beans

Legume with polyphenols and protein; optimal soaking conditions detailed

Cashews

Plant protein and zinc source

Chicken

Complete protein with niacin, zinc, and tryptophan

Chickpeas

Legume providing protein, fiber, folate, magnesium, and B6

Clams

High taurine and B12 content

Eggs

Complete protein with choline, B vitamins, and phospholipids

Kefir

Fermented milk with diverse probiotics and GABA potential

Lamb

Creatine, heme iron, and complete protein

Lentils

Legume rich in protein, fiber, folate, iron, and prebiotics

Milk

Complete protein, nicotinamide riboside, and calcium

Oats

Beta-glucans, tryptophan, and B vitamins for gut and neurotransmitter support

Peanuts

Niacin, resveratrol, and plant protein for NAD+ and mitochondrial support

Pork

Thiamine, creatine, zinc, and complete protein

Pumpkin Seeds

High zinc, tryptophan, and magnesium for neurotransmitter support

Quinoa

Pseudograin with complete protein, magnesium, and GABA potential in sourdough

Salmon

Oily fish rich in EPA/DHA, protein, and B vitamins

Scallops

High taurine and creatine content with complete protein

Soy

Complete plant protein with isoflavones (genistein) and choline

Tempeh

Fermented soy providing probiotics and enhanced nutrient bioavailability

Tofu

Soy-based protein source with isoflavones and choline

Turkey

High tryptophan and niacin for serotonin synthesis and NAD+ production

Walnuts

ALA omega-3, polyphenols, and ellagitannins for urolithin A production

Yogurt

Fermented dairy providing probiotics and complete protein

Biological Mechanisms and Implications​

Biological TargetTherapeutic AreasMechanism of Action
Neurochemical BalancePrecursor for serotonin and melatonin; brain entry competes at LAT1 with other large neutral amino acids (LNAAs); carbohydrate-rich, low-protein meals raise the plasma tryptophan:LNAA ratio because insulin pushes competing LNAAs out to muscles; can feed NAD+ synthesis via the kynurenine pathway

References​

  • Tryptophan is a precursor for serotonin and melatonin and can feed NAD+ synthesis via the kynurenine pathway; brain entry competes at LAT1 with other LNAAs
  • Serotonin: Mood regulation, emotional control, impulse moderation; cofactors include tryptophan, B6, magnesium; carb co-ingestion aids LAT1 transport
  • Tryptophan has been linked to reduced anxiety, improved mood, and lower depressive symptoms, but shows very limited benefit for ADHD symptoms Aquili 2020 Dinu et al. 2023
  • Carbohydrate-rich, low-protein meals raise the plasma tryptophan:LNAA ratio because insulin pushes competing LNAAs out to muscles, lowering competing LNAAs in plasma Wurtman et al. 2003
  • Compared to the high protein breakfast, the high carbohydrate low protein breakfast raised the tryptophan:LNAA ratio by a median ~54% (range ~36–88%)
  • Carbohydrate type matters: sucrose produced a larger rise in tryptophan:LNAA (+34%) than starch (+20%), consistent with higher-GI carbohydrates more strongly enhancing brain tryptophan bioavailability Lyons and Truswell 1988
  • Tryptophan + complex carbohydrates aid serotonin conversion to melatonin; examples include pumpkin seeds + oats
  • Nutritional strategies that support sleep include evening meals rich in tryptophan and complex carbohydrates to promote melatonin synthesis, along with micronutrients such as magnesium and zinc Peuhkuri et al. 2012 Rondanelli et al. 2018
  • Small intestinal bacterial overgrowth (SIBO) impairs absorption of vitamin B12, iron, and tryptophan, depriving the brain of essential neurotransmitter precursors
  • Enhancing dietary protein, prebiotics, and microbiome diversity promotes microbial metabolism and absorption of key amino acids, increasing tryptophan availability for central serotonin and dopamine synthesis Sinha et al. 2024 O'Mahony et al. 2015