Among the several triggers for cold sores – the most common culprits being UV radiation, stress, and a diet full of arginine-rich foods – there is another that sometimes gets overlooked, an invisible trigger that is unfortunately incredibly difficult to avoid: pollution.
Air pollution can re-activate the cold sore virus, meaning that is even more imperative that the UK and other countries meet the World Health Organisation's targets on reducing the density of ultra-fine pollution particles in the air.
This revelation comes in the wake of various studies published this year linking pollution particles to a range of health conditions and illnesses, including heart disease, cancers, lung disease, and impaired foetal and brain development.
Like asbestos particles, ultra-fine pollution particles are so small that they are able to permeate deep into the lungs, but unlike asbestos particles they are also more easily able to reach other organs in the body, including the brain and heart.
Those who thought health-related pollution problems were largely confined to developing countries ought to think again; European air pollution standards allow for air pollution levels that are 2.5 times higher than those proscribed by WHO guidelines, and the problem is particularly bad in the major cities of Europe, including London.
“Particles are a major and invisible danger to our health, especially in London and our big cities,” Professor Annette Peters, director of the Institute of Epidemiology at the Helmholtz Zentrum, Munich, recently told The Guardian.
“We initially had evidence of the effect on the lungs and heart, but now we also have evidence that it alters the metabolism as well as impacting the brain.”
Professor Peters went on to say that there was an increasing, and conclusive, body of evidence that ultra-fine air pollution particles went beyond the lungs and had a range of broader health implications. She said that a number of her colleagues had recently been able to demonstrate that the "ultra-fine particles are able to reactivate the herpes virus which lies dormant among carriers".
Furthermore, the research, which was published in the Lancet, identified ambient air pollution as one of the top ten global risk factors for attributable death worldwide.
One problem with ultra-fine air pollution is the fact that, unless you are a scientist, it is intangible. This means that it is able to travel thousands of miles without anyone’s knowledge. “In most times you don’t see or smell it, the pollution, so it’s clear, if you look to India or the Far East, the pollution is very visible. Here, we have blue skies but that doesn’t mean we have truly clean air.”
It seems that if they are to become less reliant on cold sore cream, cold sore sufferers need the same thing as everyone else: cleaner air to improve their health.