Nuts and Seeds

• Generally, levels of the amino acid L-arginine are high in foods that contain a lot of protein. This makes nuts and seeds a good source of the amino acid, and therefore makes them a food that increases nitric oxide levels in the body. Foods such as peanuts, almonds, walnuts, hazelnuts, Brazil nuts, pistachios, pecans and cashews are amongs the best gram-for-gram sources of arginine. As well as this, sunflower seeds and flax seeds are also good sources of the amino acid.
  
  

Beans

• Various types of beans are high in protein, and therefore also high in L-arginine. This includes kidney beans, soy beans and French beans. Lentils are also a good source of L-arginine. Unfortunately, however, these must be eaten raw to gain the full benefit of the amino acid content. Exercise caution when eating raw red kidney beans because they contain a toxin when uncooked. Eating as little as four raw kidney beans has been known to produce undesirable effects.
  
  

Animal Products

• Many different animal products are high in levels of L-arginine. This includes milk and eggs, as well as meat products such as pork, chicken, turkey and beef. Egg yolk actually contains more L-arginine than the white. Seafood is also a good source of the amino acid, with foods such as tuna, salmon, mackerel and prawns containing relatively high amounts. Fish is in many ways a better option than meat because of the lower fat content. Saturated fats have a negative effect on the endothelium activity required to turn L-arginine into nitric oxide.
  
  

Areas for Caution

• Increasing levels of L-arginine is generally a good idea because of the benefits it provides for your arteries and heart, but it is also known to affect the body's ability to fight viral infection. This is because L-arginine makes lysine less effective at fighting viruses. As a result, people suffering from a virus are advised to lower their L-arginine intake. Pregnant or lactating women should also be cautious of their intake.