Lysine is an essential amino acid, or protein precursor, that concentrates in the muscles and liver of humans and animals, according to University of Vermont Professor Dwight E. Matthews, Ph.D. in the "Proteins and Amino Acids" chapter of the 2005 edition of "Modern Nutrition in Health and Disease. Matthews says that scientists use the term "essential," to refer to amino acids that the body must obtain from food, because they can't synthesized in the body. Lysine may help protect against chicken pox.
Function
In the 2007 edition of "Integrative Medicine," University of Wisconsin Professor David Rakel, M.D. explains that lysine opposes the effects of another essential amino acid, arginine, in promoting the replication of the herpes simplex types 1 and 2. The varicella-zoster virus that causes chicken pox is closely related to herpes simplex---so closely, in fact, that another name for it is human herpesvirus 3, according to Baylor College of Medicine Professor Wayne X. Shandera, M.D. in the "Herpes Viruses" chapter of the 2010 edition of "Current Diagnosis and Medical Treatment."
Dietary Requirements
Matthews says that the nutritional requirement for lysine decreases with age. Infants need the most---about 40 mg per pound of body weight per day, consistent with the rapid growth seen at this age. Children between 1 and 3 need about 26 mg per pound of body weight per day, children between 4 and 13 need about 20 mg per pound of body weight per day and teens and adults need about 16 mg per pound of body weight per day. Lysine deficiencies are rare, Matthews says, and usually encountered among vegans who don't eat legumes.
Supplemental Doses
If you're considering adding a lysine supplement to your diet or your child's, the University of Maryland Medical Center recommends adding a maximum dose of 10 mg per pound of body weight, per day for children between 2 and 12. For adults and children 13 and older, the University of Maryland Medical Center recommends adding a maximum dose of 5 mg per pound of body weight, per day. Ideally, you should discuss this decision with your physician before you start.
Sources
According to the University of Maryland Medical Center, food sources of lysine include red meat, pork, poultry, cheese and other dairy products, eggs and legumes such as lentils and beans. You can purchase purified lysine supplements in the form of tablets, powders, creams or liquids at many online or bricks-and-mortar grocery and health food stores. You should take care to choose products labeled "l-lysine," since Matthews says that the "d" form of lysine has a different conformation that your body cannot use.
Effectiveness
As of September 2010, the National Library of Medicine does not list any studies evaluating the use of lysine supplements in people with chicken pox. Rakel says that studies on the effectiveness of supplemental lysine at preventing or treating herpes simplex outbreaks have produced mixed results, with some showing modest benefits and others showing no benefits at all. However, while there's no evidence that extra lysine helps you fight chicken pox, there is some evidence that not enough lysine makes chicken pox worse. An April 1998 study in the "Journal of Inherited Metabolic Disease" led by Finnish pediatrician Mari Lukkarinen, M.D. found that children who required low lysine diets due to an inherited metabolic disorder developed severe, near-fatal cases of chicken pox.
Considerations
For patients who wish to supplement the amount of lysine in their diets, Rakel recommends starting with additional portions of lysine-rich foods. If you have kidney or liver disease or you are pregnant or nursing, you should not take lysine or any other dietary supplements, except as directed by a physician. Lysine does not replace conventional medical treatments for chicken pox, or any other condition. As with any over-the-counter product, if you use lysine supplements, you should share this information with your health care providers.
References
- "Modern Nutrition in Health and Disease"; Maurice E. Shils, M.D. et al.; 2005
- "Integrative Medicine"; David Rakel, M.D.; 2007
- University of Maryland Medical Center: Lysine
- "Journal of Inherited Metabolic Disease"; Varicella and Varicella Immunity in Patients with Lysinuric Protein Intolerance; Mari Lukkarinen, M.D. et al.; Apr. 1998
