Cold sores are tiny, painful blisters caused by the herpes simplex virus that develop on and around the lips and mouth. In the June 9, 2008 edition of "Archives of Internal Medicine," dermatologist Christina Cernik describes how cold sore blisters typically rupture spontaneously after three or four days, leaving behind a raw, red, weeping open sore that takes another six to 10 days to heal. Foods like yogurt affect cold sores directly through physical contact during eating and indirectly through nutrients that affect the immune system.
Definition
On his "Yogurt Making Illustrated" web page, University of Cincinnati professor of biology and chemistry, David B. Fankhauser, Ph.D., says that yogurt was introduced by the Mongols, as the end result of milk fermented by various species of bacteria, including Lactobacillus bulgaricus, Lactobacillus acidophilus and Streptococcus thermophilus. These bacteria digest lactose, the sugar naturally present in milk, to lactic acid. It is the acid, Fankhauser says, that creates yogurt's semi-solid texture and confers its sour taste.
Chemical Properties
Scientists describe the chemical properties of substances in terms of acidity or alkalinity. Most foods are acidic or neutral. Among foods, yogurt is a high-acid food, according to University of Oklahoma food scientist William McGlynn, because it falls below the 4.6 pH that McGlynn calls the "dividing line" between high-acid and low-acid foods. For people who consume a lot of yogurt, this acid could trigger cold sore outbreaks or make existing outbreaks worse. However, there are no studies to prove this and cold sore triggers vary from person to person.
Physical Properties
Scientists describe the physical properties of substances in terms of state: solid, liquid or gas. The proteins in yogurt exist in a semi-solid state, enabling them to stick to tissues on the lips and inside the mouth. A December 2007 study published in the "Journal of Agricultural and Food Chemistry" found that proteins in dairy products, including yogurt, inhibited the spread of the herpes simplex virus when they came into direct contact with infected cells. This suggests that consuming yogurt may actually help treat cold sores.
Nutritional Properties
Yogurt contains nutrients including vitamins, minerals and protein. Because bacteria consume some of the sugar that is naturally present in milk, unsweetened yogurt actually contains less sugar than milk. On Askdrsears.com, pediatrician Barry Sears claims that yogurt enhances the immune system by boosting levels of a hormone called interferon and increasing the number of infection-fighting white blood cells that circulate in the bloodstream. A healthy immune system, in turn, may lead to fewer and less severe cold sore outbreaks.
Considerations
As of November 2010, the National Library of Medicine lists no studies on yogurt consumption in people with cold sores. People who believe that eating yogurt relates to cold sore outbreaks should try keeping a food diary. A food diary is a daily log of the types and quantities of food a person eats. If outbreaks occur 12 to 36 hours after eating yogurt, the patient should avoid it. Otherwise, Dr. Sears describes yogurt as a "top health food."
References
- "Archives of Internal Medicine"; "The Treatment of Herpes Simplex Infections; Christina Cernik, M.D., et al.; June 9, 2008
- "Journal of Agricultural and Food Chemistry"; Antiviral Activity of Esterified Alpha-Lactalbumin and Beta-Lactoglobulin Against Herpes Simplex Virus Type 1; Mahmoud Sitohy, Ph.D. et al.; December 2007
- Oklahoma State University: Food and Agricultural Products Center: The Importance of Food pH in Commercial Canning Operations
- AskDrSears.com: Family Nutrition: Yogurt
- University of Cincinatti: Yogurt Making Illustrated
