Dopamine is the neurotransmitter that helps you focus, keeps you alert and fuels your sex drive. It controls your motor skills and can prompt you to stand up for yourself in an adversarial situation. But your body needs tyrosine, an amino acid, to produce it. Tyrosine deficiencies are uncommon, because it's readily available in food.
The Dopamine Process
When you eat protein foods, your body breaks that protein down into amino acids. It then uses the amino acids to form hormones, enzymes and neurotransmitters. Your brain is responsible for forming the neurotransmitters, but amino acids can't always easily get to your brain for this to be accomplished. Your other cells compete for them and can snatch them from your bloodstream for their own use long before they reach their destination. When your diet is high in protein, however, the more amino acids it will provide, and more of them are likely to get to your brain to convert to dopamine.
Tyrosine Foods
Foods highest in protein will produce more tyrosine, but other foods provide it, as well. Soy, turkey, chicken, milk, fish and cheese are all good sources of this amino acid. Grated parmesan has 2,328 mg of tyrosine per 100 g. Provolone cheese has 1,520 mg per the same serving. Gruyere has 1,776 mg. Tyrosine is also present in fermented foods, such as yogurt, and in certain fruits and vegetables, including lima beans, bananas and avocados. Peanuts, almonds, sesame seeds and pumpkin seeds also are good sources.
Interactions
A healthy dose of tyrosine may not be sufficient to elevate your dopamine levels, depending on what you combine your protein foods with. Only one amino acid can pass your blood-brain barrier at a time; they must use the same channel to get there, and they can't do it simultaneously. Carbohydrates are rich in another amino acid, tryptophan, which your brain uses to produce serotonin. Serotonin is a neurotransmitter that has the opposite effect of dopamine. When carbohydrates hit your bloodstream as glucose, this triggers a release of insulin, and insulin clears your blood of all other amino acids except tryptophan. This means that the tryptophan can proceed to your brain unimpeded. The tyrosine you consumed through protein won't be able to get there. For the best effect from tyrosine foods, eat protein alone, without carbohydrates. Avoid caffeine and alcohol as well, which can both affect your brain's ability to process the tyrosine into dopamine.
Tips
More research is necessary to determine how much tyrosine is too much tyrosine. No side effects have been linked with doses of up to 1,000 mg a day, which is slightly more than what you would consume in 3.5 oz. of gruyere cheese. But eating more than this on a daily basis might result in insomnia and edginess.
