Influenza got you drowsy?
The common cold making you feel stupid?
There’s a good reason for that: your body is doing that on purpose!
Whether ill-stricken with the influenza or the common cold, there’s a lot going on in our bodies when we’re hit with these viruses. We’re sneezing, coughing, throats are sore, we’re disgusting; but what goes on in our nervous system as this internal fight is going down? Keep reading to find out.
The Common Cold
When feeling ill, we’re not on our best mental game as U.K. researchers found. They tested 189 men and women when they were healthy on reaction time, verbal-reasoning skills, memory and mood. Of the 189 participants, 48 participants developed a cold and were retested within 24 to 96 hours of being symptomatic rating their sore throat and sneezing symptoms on a 5-point scale. Their sleep duration was accessed as well. While the healthy remaining 141 participants without symptoms were retested 12 weeks later [source].
A significant difference was found between healthy participants versus sick ones on the tests, including the ones for: mood, including alertness and well-being, reaction time, memory, information processing and speed [source]. Accuracy on the memory-recall tests remain unaffected. The healthy subjects were able to improve their tests indicating that learning may be impaired during a cold as it interrupts our abilities to store new memories and information.
Why the impairment?
The moment we come down with a virus, our body detects the invading bug leading our immune system to release several specific cytokines. These small proteins are immune system messengers: they alert the Central Nervous System that we’re sick and need a counter-attack. At the same time, they also play mind games with us since our mood is the first thing to change; both men and women get pissy and short-tempered [source].
While fighting a cold, there is a flood of chemicals that screw with our mental performance, specifically reaction time and alertness. While our ability to formulate verbal information coherently suffers, there are changes happening in our frontal lobes which creates problems with psychomotor functions, things like: coordination, strength, speed, and balance – you know, important things.
The level of cognitive impairment we experience during the common cold mimics the effects of alcohol consumption, working at night, or working prolonged hours. Cold viruses interfere with neurotransmitters causing that wonderful mental sluggishness. It was proposed that the common cold virus perhaps affects the transmission of the following neurotransmitters in specific:
1) noradrenaline (reaction time)
2) choline (encoding new information)
3) dopamine (working memory speed)
Writing that report will not be your only challenge, think twice before getting behind the wheel. Those under weather due to the common cold are also more likely to bump into curbs and tailgate others while driving since their ability to detect collisions decrease versus those who are healthy.
Similar to the common cold, influenza will produce the same cognitive impairments. In a Journal of Neuroscience article, scientists found that influenza infected mice exhibited increased inflammation in the hippocampus, an area important for cognitive function, and cognitive deficits.
Here’s where it gets interesting…
In contrast to the common cold, Washington State University Spokane scientists found a brain protein that boosts healing power while asleep and speeds recovery when infected with the influenza virus [source].
This brain protein, AcPb, is essential for Influenza recovery but it also involves, Interleukin-1, an immune system signaling chemical. The latter chemical is an inflammatory molecule that is responsible for those freezing, aching, feverish symptoms we love so dearly and makes us hate life.
While influenza is a lung disease, it somehow manages to reach the brain causing an inflammatory reaction that involves Interleukin-1 and AcPb thus inducing the increased sleep response that helps the body overcome. Sleep is necessary for a healthy immune system and is critical to our body’s response to bacterial and viral infections.
Without this protein animals developed more severe symptoms of the infection and died at higher rates than regular or control mice. Mice who lacked AcPb slept less after becoming infected and developed symptoms of chills, sluggishness, loss of normal circadian rhythms, and died in higher numbers than mice who slept longer amounts.
This discovery could lead to an alternative influenza treatment by using intranasal sprays to stimulate the production of brain protein AcPb and help regulate sleep similarly like in the bodies of healthy animals.
Other Contributing Factors:
Interestingly enough, amongst all that stress that comes with parenting there comes a benefit for caring for those those precious walking petri dishes called children: parents have an extra resistance to colds. Stephen Cohen PhD., found that parents aged 25 and older were less likely to develop colds after exposure to viruses than people without children [source].
While you may think it is due to greater exposure to germs not so, actually scientists theorize that parenthood produces feelings of purpose in life and positive emotional experiences that help boost the immune system. Older parents were found to be less susceptible to colds regardless if they were married or still had children living at home with them or not.
Unfortunately, this benefit didn’t apply to parents ages 18-24. It was theorized that younger parents may not receive same protective benefit against colds because they are less prepared psychologically and economically to be parents and thus, this increases feelings of being overwhelmed.
Another contributing factor is: stress. Stress increases the likelihood of infection for people who suffer prolonged long-time stress, more than a month, of interpersonal stressors, such as work conflicts or bad marriages; and were found to be 2 ½ times more likely to get a cold. Those who are unemployed or underemployed were 5 times more likely! [source]
Stressed groups are found to engage in unhealthy activities like smoking and skipping exercises but that wasn’t found to be the main culprit. When chronically stressed our body produces too much cortisol, a stress hormone that helps regulate level of cytokines. The increase in hormone levels causes our immune cells to become insensitive to cortisol, triggering the release of more cytokines that exacerbate oncoming cold symptoms. Thus, making you feel more shitty.
Relax though, once those symptoms lift so do cognitive abilities however, reaction time remains slow ONE WEEK after the illness passes. To circumvent this shortcoming drink caffeine which helps with alertness, even when you’re unwell. As if I needed more of a justification to take in caffeine, now I can abuse this advantage when ill. Although, who wants to be alert when feeling disgusting and grotesque? Pass the Nyquil and let’s increase those AcPb puppies so I can sleep through whatever is going on internally.
This topic was inspired by an inquiry submitted by Tamara from Tamera Camera Blog, if you have anything you’re curious about or have a topic you’d like me to research, shoot me an email or tweet me!
How is your week going? Has the influenza or cold bug got to you this season?
Sources: header image