Scientists say that having a common cold impairs you as much as drinking alcohol or working through the night. Professor Andrew Smith at Cardiff University has been researching the effects of colds for 25 years and says; “activities like driving or operating dangerous machinery may be impaired when you have a cold”.
A study last year of almost 200 people compared those who caught colds, about a third of them, with those who didn’t. Those with colds reported less alertness, more negative moods and sluggish thinking, as you might expect. Tests showed that they also had slower reaction times, were slower at learning new information, and at completing verbal reasoning tests.
The research suggests that cold viruses interfere with neurotransmitters which could affect the transmission of noradrenaline (associated with reaction times), choline (linked to the encoding of new information), and dopamine (which affects working memory speed).
Other studies have shown cognitive impairment in people infected with a cold virus even if they showed no symptoms and that people with colds performed less well at simulated driving being slower to adapt to road conditions and to avoid collisions.
In 2008 Lloyds TSB Insurance estimated that more than 125,000 road accidents in Great Britain were caused by people driving when they had a cold or flu.
Why do some people get more colds than others? Well stress can undermine your immune system and make you more susceptible whilst being a parent and having a positive outlook can help protect you against them.
It seems older parents (over age 25) are less likely to catch a cold when exposed to the virus than people without children – but not because they were exposed to cold viruses their children picked up. The study at the Laboratory for the Study of Stress, Immunity and Disease at Carnegie Mellon University also showed that older parents were less susceptible to colds even if they weren’t married or if their children had let home.
The researchers think this resistance is due to older parents having a more positive outlook with a sense of purpose in their lives and positive emotional experiences compared to younger parents being less well prepared emotionally and economically. Having a positive mental outlook appears to prevent you developing a cold even when exposed to the virus or having fewer symptoms if you do catch one (about a third of people exposed to virus).
On the other side of the coin the researchers found that anyone suffering stress for a month or more is more likely to get sick. People suffering long-term inter-personal stressors such as a bad marriage or conflict at work were 2.5 times more likely to get a cold and people who were unemployed were 5 times more likely to.
The symptoms of a cold are not produced by the virus but are a result of the body’s immune system’s response to it which includes the release of cytokines, messenger proteins which stimulate the immune response. When people are chronically stressed they produce too much cortisol and prolonged exposure to the heightened hormone levels makes the immune cells insensitive to cortisol triggering the release of more cytokines that make the cold symptoms worse.
The research reported didn’t differentiate between men and women, which is a pity as the arguments about man flu will continue. Perhaps men are just more sensitive or women might see themselves more as parents?
Based on an article by Brenda L Smith “Colds and Cognition” in Monitor on Psychology February 2013