Neurotransmitter

 Acetylcholine 

Ach is a parasympathetic neurotransmitter. It facilitates digestion and breathing. It is responsible of memory processes and of mental disorders. Acetylcholine is not a component of foods; instead, it is built from choline. Choline is in lecithin and phosphatidyl choline, which is mostly contained in yolk, peanuts, wheat germ, meat, fish, cheese and vegetables such as cruciferous (16). Eggs are a significant source of choline, mainly because their yolks contain lecithin. Raw egg yolks contain 682 mg of choline per 100 g of food, which is more than the total daily recommended amount. Cooked whole eggs have much less choline, depending on the method of preparation. Fried eggs have 272 mg, while hard-boiled eggs have 225 mg per 100 g of food (17).

Adrenaline 

Adrenaline is synthesized from phenylalanine and is a sympathetic neurotransmitter. It contributes to gastrointestinal relax and dilation of the bronchi, increases heart rate, diverts blood flow to muscles, liver and brain and increases blood glucose. It is mostly contained in walnuts, almonds, meat and cheese.

An egg contains over 500 mg phenylalanine. 

Most nuts are high in protein, which a significant amount is derived from phenylalanine. Five walnuts contains 540 mg, 10 almonds contains 980 mg, and 30 roasted peanuts contains 1400 mg. Peanut butter contains over 3500 mg/100 g. Beans, chickpeas and lentils contain the most phenylalanine, roughly 100 mg/100 g. Soy products, including soy protein isolate, soybean flour and tofu, are also good sources (18). 

Serotonin 

Serotonin is synthesized from tryptophan. Human body is not able to produce tryptophan so it has to be assumed with nutrients (19). Serotonin is a inhibitory neurotransmitter, it acts on sleep patterns, sexual behavior, sensation of appetite and pain perception. It also stimulates intestinal peristalsis. Many symptoms are associated to low serotonin levels such as pain, depression, personality disorders, insomnia, hunger, hypertension, premature ejaculation, poor memory, migraine.

Among the foods with the highest content of tryptophan there are cocoa (about 50 mg/100g), bananas (about 14 mg/100g), green vegetables (about 50mg/100g), almonds (394 mg/100g), whole grains (120 mg/100g), meat (about 400mg/100g), legumes (about 200 mg/100 g), yeast (more than 500 mg/100 g) and fish (about 300 mg/100 g) (20). 

The composition of a meal, for example, protein or carbohydrate content, influences these behaviours8 . These effects have usually been attributed to altered serotonin function, because protein and carbohydrate have been found to affect brain serotonin in rats

Endorphins 

It also have an antidepressant effect. Physical activity and smile stimulate the production and release of endorphins. They are also important for those who quit smoking as they replace the nicotine and during childbirth (22). There are many sources of endorphins but their production can be increased; generally sweet and sugar stimulate their production, among them, the chocolate is at the first place but also the chili and spicy foods promote the release of endorphins (20, 23).

Rising food intelligence

 Eggs, milk, liver, beef and turkey contain choline, essential for the construction of neurotransmitters (26, 27). Prunes contain high levels of antioxidants that neutralize free radicals responsible of the reducing memory and mental deterioration. Oats are able to increase the flow of blood to the brain with improvement of mental activities (28).