Has the COVID-19 Lockdown Affected Our Immune Systems?

The COVID-19 pandemic required most people to spend more time in their homes as personal interactions were limited to avoid the spread of the disease. While these efforts were crucial in helping curb the transmission of the virus, they may have come with a few non-life-threatening side effects—including a lack of vitamin D, reduced exercise, and increased stress. Due to the prolonged minimal exposure to other people and outside elements, many are also wondering, “Did the COVID-19 lockdown affect my immune system?” 

Let’s investigate. Here are some of the potential side effects of our more isolated, indoors-focused lifestyles.

A Lack of Vitamin D

Our bodies evolved on a planet with a 24-hour cycle of light and dark. By staying inside more during daylight hours, we see less overall exposure to the sun. As a response to the sun’s ultraviolet lights, our bodies create Vitamin D, which is used to help strengthen bones, teeth, and immune cells. Vitamin D, in particular, enables the macrophages in our lungs, which act as an important defense against respiratory infections. Vitamin D also increases the activity of other immune cells, which orchestrate longer-term responses to other diseases. Those who find themselves exposed to less sunlight have less Vitamin D and are at a greater risk of respiratory infections and the flu.

Reduced Exercise and Physical Activity

While there are few conclusive studies that show exercise improves immune system function, there is belief that working out can reduce stress; this reduction in stress may help the immune system work better. Sadly, people have primarily exercised less often during the pandemic and taken part in less physical activity due to staying home more. Increased stress can weaken immune system function; a lack of exercise can keep stress and cortisol levels high, making it more difficult for the body to fend off any virus or bacteria it comes into contact with.

Not Enough Sunlight

The same can be said for sleep. By staying inside more, people have had less exposure to the sun, which could disrupt their circadian rhythm. This rhythm relies on bright light hitting a set of light-sensitive cells in the back of the eye. Without enough exposure to sunlight, these cells cannot provide accurate information to the suprachiasmatic nucleus, which functions as the body’s master clock.

Staying inside more may also mean more exposure to computer screens and blue light. This type of light can keep the brain active, making it more difficult to fall asleep and increasing the stress response of the body.

Psychological Challenges

The overall stress of the pandemic may have impacted the immune system for many. Spending more time inside and operating with a fear of being in contact with other people could raise a person’s stress hormones and response. Feelings of loneliness can also lead to additional stress, which also weakens the immune system. This is one of the major unforeseen challenges we face as a result of the pandemic; regular personal connection—even through phone calls, text messages, and video calls—can greatly improve a person’s mental well-being and impact their immune system’s overall effectiveness.

The Myth About Microbes

As the human body develops, it learns to defend itself against different viruses and bacteria. This is especially true when we are younger, as our immune system teaches itself to fight these different intruders. Some parents believe in the “hygiene hypothesis” where they want to expose their children to viruses and bacteria—allowing them, for instance, to play on dirty floors or other traditionally unclean areas—to build up the immune system. Doctors have yet to conclusively prove this theory. There is an idea that more time spent in quarantine and at home could lessen exposure to the bacteria and viruses that build immune system functionality. That idea, however, is not yet confirmed.

Medical professionals largely believe that any illnesses developed during quarantine likely came from the reasons mentioned earlier: a lack of Vitamin D, reduced physical activity, and an increase in mental stress.

The pandemic has been incredibly difficult on many people. Time spent isolated inside has only added to the difficulty. As restrictions lighten, take time to go outside, exercise, and connect with others to improve mental health. Doing these activities will boost immune system and quickly help create a new baseline of health following the COVID-19 pandemic.

Not convinced? Here are 5 ways your diet can impact your health! 


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