Does Cold Weather Weaken Your Immune System?

Does Cold Weather Really Weaken Your Immune System

Your mother may have told you that you’ll catch your death of cold, but it was only recently that scientists were able to prove that cold weather does indeed make people sick. Yale University scientists found that lower temperatures weaken the nose’s first line of immune defenses.

The researchers discovered that cooler temperatures result in a “sluggish immune response” and leave people more susceptible to infection. The immune cells’ response was weaker under cold conditions, which enabled the rhinovirus to invade and multiply.

Later research by the Yale team found that in colder temperatures, immune cells were less likely to commit intentional suicide, or apoptosis, to prevent the spread of viruses to other cells. Under warmer conditions, cells sacrifice themselves via apoptosis to protect the body; however, colder temperatures slow the infected cell’s ability to carry out this protective function. As we breathe in cold air, the temperature inside the nose drops, leaving immune cells at a disadvantage when defending against invading viruses and other pathogens—highlighting the importance of immune-support strategies, such as del immune v, designed to help strengthen the body’s natural immune response year-round.

Cold Weather and Immune Health: Getting to the Bottom of an Old Wives’ Tale

The idea that cold weather can make you sick—or weaken your immune system—has long been considered an old wives’ tale, yet for centuries it has been clear that colds, viruses, and other illnesses increase during the winter months. In fact, “flu season” in the United States can begin as early as October and last as late as May, a time frame that closely aligns with cooler temperatures across much of the country. According to the Centers for Disease Control (CDC), flu season is defined as the period when flu viruses circulate at higher levels. During this time, maintaining a strong first line of defense immune system, including physical and biological barriers such as the nose, mucus, and immune cells, is especially important for preventing infection.

While it would be easy to link cold weather with illness and place blame squarely on winter for a nasty bout of the flu, it’s not actually cold air that makes you sick. Germs are what make you sick; it just so happens that “cold air may contribute to conditions that lead to illness,” Healthline explains. There are a few things going on behind the scenes that contribute to this phenomenon.

Lack of Vitamin D Suppresses the Immune System During Cold Weather

During cold weather, people tend to stay inside more often. This means that people are not being exposed to as much sunlight, and a lack of vitamin D leads to a weakened immune system. Scientists know that vitamin D is critical to immune defense activation. When we get sufficient levels of vitamin D, our immune system’s killer cells, or T-cells, can react to invaders and protect us from serious infections.

In fact, T-cells first seek out vitamin D in order to activate; when a T-cell activates, it becomes a ruthless immune cell that seeks out and destroys every trace of a foreign pathogen. Researchers at the University of Copenhagen discovered that if T-cells cannot find enough vitamin D, they fail to activate and leave us vulnerable to infections and diseases.

Facts about the Nose and the Immune System

The effects of cold temperatures on your nose also play a role in the increased incidence of colds and illness during the winter months. You may not have considered your nose as part of your immune system, but it serves a vital protective function. Your nose is one of the first lines of defense against sickness because it is lined with cilia, or tiny hairs. The mucus inside the nose prevents dryness while working with the cilia to trap dust, bacteria, and other potential invaders—an example of what is innate immunity, the body’s built-in defense system that provides immediate protection against pathogens before the adaptive immune system responds.

Nasal mucus is made of water, proteins, antibodies, and salt and becomes yellow or green when the body fights an infection. Our noses run when the body produces more mucus to flush invaders out; the immune system turns your nose to a faucet in order to keep you healthy. But, the immune response of your nose is suppressed by cold weather.

How to Boost the Immune System During Cold Weather

One of the best things people can do to keep their immune systems strong in cold weather is to wrap a scarf around their noses and moths. Keeping a higher temperature inside the nose enables the immune cells inside the nose to carry out apoptosis and protect the body from viruses. It’s also a good idea to eat well during the winter and include plenty of fruits, vegetables, whole grains, and lean proteins in your diet. Make it a point to get fresh produce from the market even when you can’t grow your own garden because of the cold temperatures.

You can also boost your immune system in winter by taking probiotics. The good bacteria found in probiotics strengthen the immune system and help defend against infection. In fact, a study found that people who took probiotics experienced approximately 40% fewer colds and gastrointestinal infections. Products containing Lactobacillus gasseri, Bifidobacterium bifidum, and Bifidobacterium longum are especially effective at supporting the functions of the immune system, including protecting the body against colds, infections, and other common illnesses.

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