Canker sores, a condition doctors call “aphthous ulcers,” are something of a medical mystery. What causes them? In most cases, nobody knows. Prevention and cures are equally elusive. One reader suggested a truly unorthodox remedy: a smallpox shot. Since smallpox was eradicated in 1980, this recommendation is now obsolete.
Smallpox Shot Worked Like Magic:
Q. I would like to share my challenges with canker sores. As a child, I was constantly in pain from these painful lesions. They would get as big as dimes on the insides of my cheeks and hurt so much I would cry just trying to talk.
Nothing the doctors came up with did the job. In my early 20s, I joined the Navy and the sores disappeared! After I left the Navy, they soon reappeared.
I read that a smallpox shot could prevent them. We were vaccinated in the Navy, and that is why they disappeared.
When I was able to get smallpox shots every two or three years, it worked like magic. When the vaccine was no longer available, I suffered with sores again.
Arginine and Lysine:
Then the University of Indiana did a study. They found that foods high in the amino acid arginine would cause canker sores. Some foods to avoid were chocolate, nuts and chickpeas. Another amino acid, L-lysine, acts as an antidote. If I accidentally eat something I shouldn’t, I pop some lysine tablets. I haven’t had a painful canker sore in decades.
Vaccinating Against Canker Sores:
A. You surprised us when you mentioned the smallpox shot. On searching the medical literature, we found references to some research in the mid-1950s. At that time, scientists experimented with smallpox vaccine to manage recurrent canker sores and fever blisters (Postgraduate Medicine, Jan. 1954). There were hints that this immune-boosting therapy worked, especially against recurrent herpes infections (cold sores).
You are not the first person to praise L-lysine against canker sores or cold sores. Keep in mind, though, that these two types of mouth sores are different. Cold sores are caused by the herpes virus. Canker sores are not.
Many readers find that L-lysine works well against cold sores. Others have found that this supplement eases canker sores, but mainstream medicine remains skeptical that it helps either problem (Integrative Medicine, June, 2017).