Peanuts

Contrary to popular belief, peanuts aren't true nuts; they're actually members of the legume family, related to lentils, peas and other beans. Each peanut shell encases two to three kernels. In ancient Peru, Incas cultivated wild peanuts and offered them to the Sun God as part of their religious ceremonies.

Health benefits: Peanuts have health benefits for the body, mind and soul. They contain oleic acid, a heart-healthy source of unsaturated fat and folate, which is essential to the formation of our DNA. Maintaining adequate levels of folate may decrease the risk of birth defects by half for women who are pregnant or trying to become pregnant.

A study in the July 2004 issue of The American Journal of Clinical Nutrition followed women for 20 years and found that those who frequently consumed nuts, including peanuts and peanut butter, had a lower risk of cholecystectomy (surgical removal of the gallbladder). Peanuts also contain resveratrol, an antioxidant compound that is also found in red grapes and red wine.

Nutritional value: One ounce (22 nuts): 165 calories; 14 grams of fat.

Avoid if: You have allergies. Peanuts are one of the most common food allergens, according to Anaphylaxis Canada. The Food Allergy and Anaphylaxis Network (FAAN) recommends that children under the age of three not eat these nuts to reduce their risk of developing an allergy.  If you're concerned about your thyroid. Peanuts contain goitrogens, naturally occurring substances that can interfere with the thyroid.  If you're prone to cold sores. Peanuts contain arginine, high levels of which the herpes simplex virus needs to replicate.

How to add them to your diet: Enjoy peanuts in staples such as peanut butter (make your own by simply blending roasted peanuts until smooth) and peanut oil, which adds a savoury taste to stir-fries and salad dressings. Also try peanuts in soups and desserts. Roasting adds to their digestibility and protects against aflatoxin, a toxin to which peanuts are susceptible.