"I'm strong to the finish 'cause I eats my spinach," said Popeye the Sailor Man. Eating spinach may not give you bulging forearms or the wisdom of an old sea captain, but the leafy green vegetable can lift your mood and may even improve your temperament.
Serotonin is a brain chemical that serves as a powerful mood regulator. According to Dartmouth Undergraduate Journal of Science, serotonin regulates sleep, impulse control and appetite, and is linked to mood elevation. 
This important neurotransmitter is derived from tryptophan, an amino acid derived through food. Although this is the same chemical that makes us feel sleepy after a Thanksgiving dinner, turkey isn't the only source. Tryptophan is also found in -- you guessed it -- spinach! It is also found in other forms of poultry, as well as cheese, yogurt, nuts, pineapple, bananas, eggs and fish. 
Researchers have proven that people who eat fish are less likely to be depressed. New studies indicate that it's the Omega-3 acids in fish that are responsible for improvements in mood , and they may be more effective than antidepressants. Harvard school of Public Health reports that food contains two types of Omega-3 fatty acids, commonly known as ALA and EPA. Fish is the source of EPA, but spinach produces worthwhile amounts. 
Spinach is a good source of Vitamin B9, also known as folate. According to Weill Cornell Medical College, further research is needed to determine the strength of the link between mood and folate.  Although the jury is still out, it definitely can't hurt to load up on the leafy vegetable, which is proven to provide plenty of health-promoting substances, including beta-carotene and fiber.
Experts at North Carolina State University Extension report that potassium is a "de-stressing" food. While bananas get the most credit, spinach is an excellent source of this healthy mineral. In fact, when it comes to the amount of potassium per calorie, spinach outperforms the popular yellow fruit. 
Selection and Preparation of Spinach
- Look for fresh, deep green spinach with no yellowing or wilting.
- Store the leaves in your crisper and wash them immediately before cooking.
- Washing the leaves ahead of time decreases the life and quality of the spinach.
- Lightly steamed or boiled
Scientific American notes that while most vegetables are best served fresh, spinach is the exception to this rule and retains more nutrients when the leaves are lightly steamed or boiled.