In ancient Greece, before scientific
understanding could explain the natural world, civilisations relied on the oral passing down of stories. These are now known as myths
and offer simple explanations for much more
complex concepts; illness and disease were
often central themes of these. Although modern medicine, with the help of technology, has now made our understanding of the human body and illness much more advanced, similar misconceptions still exist today, often rooted in traditions and generational beliefs even if scientific evidence of them remains tentative.

A lecture by Daniel M. Davis, Professor of Immunology at Imperial College London, challenged many of my assumptions on illness and disease. Growing up surrounded by a culture deeply rooted in traditions, being told “cover up or you’re going to get sick” was normal. However, the professor’s lecture helped me understand the complexity of immune health and that such beliefs have little to no scientific basis. This sparked my interest in how much of what we believe about our immune system is scientifically proven and how much is simply mythical.

Many cultures hold the belief that the cold weather makes you sick. This common misconception arises from the transmission of generational knowledge as well as the observational correlation between the cold and the incidence of illness, where causation has been assumed. While it is true that during
the winter the incidence of disease
increases, this is not due to the cold
temperatures as these illnesses are
caused by pathogenic organisms. Lower
humidity and poor ventilation in the winter is what allows viruses to remain airborne for longer, and so to survive longer outside the body. Additionally, indoor crowding also
increases the rate of transmission. It has also been found that cold air can slightly affect the respiratory tract by reducing the effectiveness of mucus and cilia, which act as a first-line defence trapping pathogens and sweeping them away from the lungs. This results in a temporary reduction in local immune response in these passages. However, it is important to note that these do not directly cause infection; infection will only arise due to viral infection, highlighting how the myths are based on correlation rather than causation.

Everyone has heard the phrase “it will boost your immune system” at least once in their life, even though such common phrasing has no actual scientific basis. Over-consumerism has resulted in the production of supplements and so called “immune-boosters”, which twist our belief of the immune system. What we are supposedly “boosting” is a regulated network of organs and cells working together, where there is no single measurable output through which improvement can be observed. In fact, the overactivation of our immune system could actually lead to autoimmune diseases such as Rheumatoid Arthritis (inflammation of the joints). Not only that, but the dysregulation in the production of immune signalling proteins can cause inflammation as the body starts to “fight itself”, resulting in allergies. The immune system requires balance, not enhancement, and that is where this misconception often goes wrong.

In his lecture, Professor Daniel M. Davis discussed the circulating myth of vitamin C preventing colds. This misconception was popularised by Linus Pauling in the 1970s, where his book published on this correlation starkly
influenced public belief. On the contrary,
meta-analyses that have been conducted since
then show that vitamin C supplementation does not
reduce the incidence of catching colds. However,
they have also concluded that the regular
supplementation of the vitamin has an 8%
decrease in the duration of a cold. It is important to
note that confounding variables could have caused
this decrease, which is increasingly seen in
extreme physical stress groups (such as athletes).

Although these ideas are passed down as common sense, they reflect correlational relationships and are rarely able to mirror the complexity and nuance of the immune system which requires careful consideration and scientific understanding to be able to uncover. What I once accepted as common sense I now see has little to no scientific grounding, highlighting how scientific evidence can sometimes contrast with public belief.