Q: Can certain foods exacerbate cold sores?
A: Cold sores, or fever blisters, are caused by the herpes simplex virus. While the virus cannot be cured, cold sores can be treated. Along with avoiding triggers, such as excessive sun exposure, stress and colds, there is some evidence that nutrition plays a role in cold sore prevention.
Studies have shown that topical zinc oxide cream shortens the duration of a herpes outbreak, while oral zinc tablets are associated with reduced frequency and duration of flare-ups. In addition, lemon balm may speed up the healing process, but has no impact on prevention.
Lysine and arginine are amino acids – building blocks of proteins – that have been implicated in cold sore management. Lysine has been shown to inhibit normal replication of the virus, thereby lessening outbreak duration, while arginine seems to promote growth of the virus. Thirty years ago, a multi-centered study gave patients 1,200mg daily oral lysine doses, which appeared to accelerate recovery from infection and suppress recurrence of outbreaks (Griffith et al., 1978). It is difficult, however, to make a recommendation for daily lysine supplementation, because more recent studies have supplied participants with anywhere from 500 to 3,000mg lysine per day and long-term research is inconclusive.
In short, there does seem to be some consensus that diets high in lysine and low in arginine are beneficial for those who suffer from cold sores. See below for a list of potentially beneficial foods and a list of foods to avoid. If you find that limiting certain foods makes no impact on your cold sore symptoms, add those items back into your diet! Very restrictive diets may not supply adequate amounts of certain necessary nutrients.
Beneficial: Foods high in lysine & low in arginine
Dairy (e.g. milk, cheese, yogurt)
Meat, chicken, fish
Mango, apricots, pears, apples, figs
Tomato, tomato juice, tomato paste
Foods to avoid: High in arginine & low in lysine
Grape juice, orange juice
Puffed wheat, corn, rice and oats
Lastly, in the midst of an outbreak, it may be best to avoid acidic foods, such as soda, citrus fruits, tomatoes, vinegar and alcohol, which may exacerbate the blisters.
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