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Tyrosine

Tyrosine structure

Overview​

Tyrosine is a nonessential amino acid that serves as the precursor for the catecholamine neurotransmitters dopamine and norepinephrine, which are essential for attention, motivation, and executive function. Tyrosine's brain transport via LAT1 competes with other large neutral amino acids, and moderate carbohydrate intake can reduce this competition. The conversion of tyrosine to dopamine requires tyrosine hydroxylase, which depends on iron as an essential cofactor, along with B6, folate, omega-3s, and BH₄ (tetrahydrobiopterin) to support rate-limiting steps in catecholamine synthesis.

Recipes​

5 recipes containing this substance

Creamed Corn on Roasted Sweet Potato

Roasted sweet potato with creamed corn and a mixed lipid phase to enhance carotenoid absorption; served with broccoli for fibre and glucosinolates.

Ginger Yogurt and Blueberries

A polyphenol-rich breakfast bowl with high fibre, combining ginger, omega-3 nuts, blueberry polyphenols, and probiotic yogurt.

Mitochondrial Power Bowl

A nitrate-rich, polyphenol-dense bowl combining leafy greens, beets, berries, nuts, and early harvest olive oil

Foods​

6 foods containing this substance

Cheddar Cheese

Hard cow’s-milk cheese rich in protein, calcium, and vitamin B12

Pumpkin Seeds

High zinc, tryptophan, and magnesium for neurotransmitter support

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

Biological Mechanisms and Implications​

Biological TargetTherapeutic AreasMechanism of Action
Neurotransmitter RegulationCatecholamine precursor (dopamine, norepinephrine); brain transport via LAT1 competes with other LNAAs; iron is an essential cofactor for tyrosine hydroxylase, the rate-limiting enzyme in conversion of tyrosine to dopamine; cofactors include iron, B6, folate, omega-3s, and BH₄ (tetrahydrobiopterin) to support rate-limiting steps in catecholamine synthesis

References​

  • Tyrosine is a catecholamine precursor (dopamine, norepinephrine); brain transport via LAT1 competes with other LNAAs; iron/B6/folate/BH4 are cofactors
  • Dopamine: Attention, motivation, executive function; DMN-to-task switching; cofactors include tyrosine, phenylalanine, iron, B6, folate, omega-3s
  • Iron is an essential cofactor for tyrosine hydroxylase, the rate-limiting enzyme in the conversion of tyrosine to dopamine Beard et al. 2003 Erikson et al. 2000
  • Moderate carbohydrate intake reduces competition at the LAT1 transporter; both pathways rely on cofactors (iron, B6, folate, omega-3s, and BH₄) to support rate-limiting steps in catecholamine synthesis Fanet et al. 2021
  • These nutrients, along with omega-3 fatty acids, support LAT1 transport, membrane fluidity, and neurotransmitter production
  • Compared to the high carbohydrate breakfast, the high protein breakfast raised the tyrosine:LNAA ratio by a median ~28% (range ~10–64%)
  • Norepinephrine: Attention, arousal, executive modulation; cofactors include tyrosine, phenylalanine, vitamin C, copper
  • Tyrosine may enhance working memory performance in healthy older adults, potentially through modulating functional connectivity in brain regions associated with cognitive control Hensel et al. 2019
  • Meta-analysis of L-tyrosine suggests quick tolerance after limited efficacy of only 2 weeks, suggesting that extra tyrosine will not fix a dopamine dysregulation problem alone F W Reimherr and M Ward 1987
  • Enhancing dietary protein, prebiotics, and microbiome diversity promotes microbial metabolism and absorption of key amino acids, increasing tyrosine availability for central serotonin and dopamine synthesis Sinha et al. 2024 O'Mahony et al. 2015