Tryptophan is an essential amino acid, meaning the body cannot synthesize it and must obtain it from dietary sources. It plays a crucial role in protein synthesis, neurotransmitter production, and NAD⁺ biosynthesis.
Explanation of Tryptophan’s Role in the Body
Tryptophan is involved in multiple biological functions, including:
- Precursor to Serotonin (Mood Regulation)
- Tryptophan → 5-HTP → Serotonin
- Serotonin is a neurotransmitter that regulates mood, sleep, and appetite.
- Low tryptophan levels are linked to depression, anxiety, and sleep disorders.
- Conversion to Melatonin (Sleep Hormone)
- Serotonin → Melatonin (Regulates Sleep-Wake Cycles)
- Tryptophan indirectly helps regulate circadian rhythm and deep sleep.
- NAD⁺ Biosynthesis (Energy Metabolism)
- Tryptophan can be converted into Nicotinamide Adenine Dinucleotide (NAD⁺) through the kynurenine pathway.
- Pathway: Tryptophan→Kynurenine→QuinolinicAcid→NAD+Tryptophan \rightarrow Kynurenine \rightarrow Quinolinic Acid \rightarrow NAD⁺Tryptophan→Kynurenine→QuinolinicAcid→NAD+
- This means tryptophan is an alternative source for NAD⁺ production, helping maintain energy levels and cellular function.
- Immune System & Cognitive Function
- Kynurenine (a metabolite of tryptophan) plays a role in immune regulation.
- Tryptophan metabolism affects brain function and inflammation.
Dietary Sources of Tryptophan
Since the body cannot produce tryptophan, it must come from food.
✅ High-Tryptophan Foods
- Animal Sources 🥩🍗
- Turkey 🦃 & Chicken (~350mg per 100g)
- Salmon 🐟 (~335mg per 100g)
- Eggs 🥚 (~170mg per large egg)
- Dairy (Milk, Cheese, Yogurt) 🧀🥛 (~100-200mg per serving)
- Plant Sources 🌱
- Pumpkin Seeds 🎃 (~576mg per 100g – highest plant source)
- Soybeans (Edamame, Tofu) (~590mg per 100g)
- Almonds 🌰 (~200mg per 100g)
- Oats & Whole Grains 🌾 (~180mg per 100g)
- Bananas 🍌 (~10mg per banana, but aids serotonin production)
Tryptophan & Its Connection to NAD⁺ Production
- About 1% of dietary tryptophan is converted into NAD⁺.
- The kynurenine pathway breaks down tryptophan into NAD⁺ precursors, contributing to energy metabolism.
- This makes tryptophan an important dietary alternative to direct NAD⁺ supplementation.
Pro Tip: If you want to naturally boost NAD⁺ and serotonin, eat tryptophan-rich foods along with healthy carbohydrates (like oats or bananas) to enhance absorption.