By Andrea Jacobs, Certified Naturopath

In our 5-part “Common Colds and Influenza Series” we will be discussing topics concerning these infectious winter diseases: how they develop, how they spread, how you can protect yourself against them, which natural remedies exist and much more. This week we are starting with our first contribution:


The term “common” cold already contains its meaning.  Colds, feverish infections and influenza-like infections mainly occur during the “cold” season. The same applies to influenza, a far more severe infection.  The word influenza originated in the mid-18th century from the Italian phrase, “Influenza di Freddo”, simply translated, “influence of the cold”.

In 2005, Scientists in New York discovered that the virus is more stable in cold dry air which predominates during the winter season. The influenza virus is far more likely to be transmitted on the way to the bus stop than in a warm room ‘, said Peter Palese, an influenza researcher at the Mount Sinai School of Medicine, New York.

In the past there were many hypotheses on how common colds and influenza viruses are transmitted. One theory said that viruses are transmitted more easily in winter because people and especially children, stay indoors in crowded conditions which means the infections have short transmission paths.

Another theory proposed an ailing immune system because people lose vitamins due to winter’s short daylight hours.  “We know that many children get infected in schools, but this still does not explain why there are hardly any outbreaks of influenza before October”, said Dr. Jonathan McCullers, influenza specialist at the St. Jude Children’s Research Hospital, Memphis.

Designing the correct study protocol to investigate the transmission of influenza viruses is complex.  Ethically, you cannot expose healthy people to the virus. Experiments with animals pose further problems regarding differences in lung architecture. Furthermore, mice can contract influenza but they cannot transmit it. Ferrets are aggressive and are expensive, so they are not suitable either.

The breakthrough came when humidity and temperature variations were tested with guinea pigs whose lungs resemble ours. When the guinea pigs were exposed to various levels of humidity and temperatures. it was discovered that the virus was most efficiently transmitted at low humidity (20%). At a humidity level of 80% the virus was not transmitted at all.

The virus was transmitted most frequently at 5 degrees Celsius while transmission at 20 degrees Celsius was not observed. At a temperature of 5 degrees, the guinea pigs also shed the virus for two days longer than at room temperature.

Influenza viruses can be transmitted via droplets through the air. The influenza viruses survive longer and can travel further in the air at 5 degrees Celsius and when the humidity is lower. Hence, they are much easily transmitted during winter.

It is advisable to ensure humidity over 35% and rooms heated over 20°C.  Inexpensive meters can measure the humidity in a room. When necessary, special humidifiers or damp towels on the heating can reduce the risk of virus infections.

Vaccination is another strategy for protection against influenza. Regular exercise, warm clothing, fresh fruit and vegetables are all recommended.

Traditional remedies like elderberry, which is available in practical capsules, lozenges and syrups can also ensure an additional mobilization of the body’s defences.