The National Institute of Dental and Craniofacial Research, or NIDCR, names cold sores as one of the most common disorders of the mouth that Americans face. Cold sores are caused by the herpes simplex virus. Once infected, a person carries the virus for the rest of her life. However, infected people don't always exhibit cold sores. Outbreaks usually occur in response to triggers such as stress, fever, illness and mouth injuries. Some people believe that eating specific foods such as tomatoes can trigger outbreaks, however, there is no evidence to support this.
Definition
Tomatoes, also known as Solanum lysopersicum, are a flavorful member of the nightshade family that also includes potatoes, eggplants, peppers and the deadly plant belladonna. Although tomatoes actually are seed-bearing fruit, the popular view of tomatoes as vegetables traces its origin to an 1893 ruling by the U.S. Supreme Court that classified tomatoes as a vegetable for tariff purposes. People consume tomatoes in many forms, including whole tomatoes, sauce, juice and paste.
Chemical Properties
Scientists define the chemical properties of food and other substances in terms of acidity and alkalinity. Most foods are acidic or neutral. Oklahoma State University food scientist William McGlynn further subdivides foods into high-acid and low-acid foods on the basis of pH. Tomatoes, with a pH ranging from 3.5 to 4.9, fall firmly into the high-acid group. Processed tomatoes, in particular, contain more acid than their fresh counterparts. Highly acidic foods can corrode the delicate tissues in and around the mouth, triggering cold sore discomfort and possibly delaying healing.
Physical Properties
Scientists define the physical properties of food and other substances in terms of state, including gas, solid and liquid. Tomatoes in liquid or semi-liquid form such as juice, paste and sauce cause more tissue corrosion than solid, fresh tomatoes. This is because liquid and semi-liquid tomatoes bathe tissues in their acid. Solid tomatoes are bound by skin and membranes, limiting their contact with the lips and mouth. For people with cold sores, this means that tomato juice, paste and sauce or worse than consuming whole, fresh tomatoes.
Nutritional Properties
Scientist define the nutritional properties of foods in terms of macronutrients--substances like proteins and carbohydrates that are measured in grams--and micronutrients--substances like vitamins, minerals and phytochemicals that are measured in milligrams and micrograms. Tomatoes are rich in vitamins, including vitamin C, and phytochemicals, like lycopene that help fight cold sores by supporting the health of the immune system. In the 2007 edition of his book, "Integrative Medicine," University of Wisconsin professor David Rakel recommends that people with cold sores consume at least seven or eight servings of fruits and vegetables per day, including tomatoes.
Options
As of November 2010, the National Library of Medicine lists no studies that show that tomatoes--or any other food--influence the frequency or severity of cold sore outbreaks. Theoretically, the chemical and physical properties of tomatoes could contribute to the formation of new cold sores and complicate the healing of existing cold sores, while the nutritional properties of tomatoes favor cold sore prevention and resolution. People who believe that tomatoes are a factor in their cold sore outbreaks should try eating fresh, whole tomatoes or applying over-the-counter lip balms and mouth ointments to provide a protective barrier between acids and mouth tissues.
Considerations
Tomatoes, along with other fruits and vegetables, are an important part of a healthy diet. Patients who are thinking about eliminating them should discuss this decision with a health care provider. No dietary strategy replaces conventional medical treatment for cold sores. People who experience severe, frequent or prolonged--longer than two weeks--cold sore outbreaks should see a doctor.
References
- National Institute of Dental and Craniofacial Research: Fever Blisters and Canker Sores
- Smithsonian.com: A Passion for Tomatoes
- Food and Drug Administration: Approximate pH of Food and Food Products
- "Integrative Medicine"; David Rakel, M.D.; 2007
- Oklahoma State University: The Importance of Food pH in Commercial Canning Operations
