Why we get sicker in winter—and how to stay healthy

The moment the air turns cold, classrooms, offices and grocery stores alike are filled with winter’s familiar soundtrack—the steady chorus of sniffles, sneezes and coughs. That’s because, when temperatures drop each year, viral illnesses such as the flu, RSV and even the common cold spread more easily. But why is that?

While the brisk, dry air itself can weaken our immune response, there are other wintertime factors—many of which are interconnected—that put people at a higher risk for illness, according to Julia Dovgy, DO, a family medicine physician with Primary Care Feasterville and St. Mary Family Medicine Bensalem.

The negative effects of staying inside

Folks tend to spend more time indoors when it gets chilly, and understandably so. That lunchtime walk in 30-degree weather just doesn’t seem very enjoyable compared to a stroll in 70 degrees. However, skipping the opportunity to absorb just a few minutes of sunlight—even while bundled up like Randy from A Christmas Story—can have detrimental effects on the immune system.

“If you are always home, since you’re isolating, you are technically protecting your immune system. But at the same time, you also have reduced exposure to these viruses. They could actually boost your immune system,” says Dr. Dovgy. “It’s like a catch-22. You could either not go anywhere and keep your immune system safe, or you could go out and be exposed to small, mild viruses that may not show symptoms, boost your immune system and prevent you from getting sick as often.”

For example, when a child first enters daycare, they may be constantly sick those initial three or four months in the fall/winter because their body is being introduced to brand new germs. Even a simple adenovirus or rhinovirus (which causes the common cold) can feel more intense, explains Dr. Dovgy. However, after a year or so, these exposures strengthen the immune system, and they no longer contract viruses as easily.

A stagnant immune system isn’t the only negative effect of staying indoors this winter. A lack of exposure to sunlight can lower levels of vitamin D, which can make people more susceptible to the cold and flu. This can be negated by taking vitamin D supplements (at least 2,000 IU), with studies by the National Institute of Health showing that these could reduce risk of upper respiratory infection.

Vitamin D deficiency is also linked to increased feelings of stress and anxiety, both of which can impact the immune system.

“For people who are under stress, cortisol goes up when it doesn’t need to. This actually suppresses their immune system. Any kind of virus that’s hanging around, you’re more prone to getting it or having a higher response to it,” says Dr. Dovgy, who recommends meditation, yoga and diaphragmatic breathing to regulate the body.

The importance of overall wellness

In addition to stepping out of the house and getting a few minutes of sunlight daily, diet and exercise are important for immune health. Around the holidays, explains Dr. Dovgy, many people practice unhealthy dietary habits and significantly increase their carbohydrate intake.

“That worsens insulin resistance, predisposing you to chronic inflammation and suppressing your immune system,” says Dr. Dovgy.

While all the classic holiday treats can still be enjoyed, it’s important to balance them with foods that are high in protein, zinc, and vitamins A, C, D and E—all beneficial to boosting immunity. Specifically, lean proteins (fish), healthy fats (avocado and almonds) and citrus fruits are great for immune health, as well as heart health and diabetes.

Additionally, staying active reduces inflammation, stress and risk of upper respiratory infection. Though getting to the gym or going on a long walk might be difficult in winter weather, cardio and weight training can both be done from the comfort of home. Dr. Dovgy recommends a mini stepper, which can get the heart pumping while sitting at a desk or on the couch.

Preventative habits—including frequent handwashing, covering coughs and sneezes in the elbow, and getting routine vaccines (flu for everyone, RSV for children and older adults, pneumonia for 50+)—are also key in decreasing illness risk and slowing the spread of germs.

When sickness catches up

Even if these healthy habits are implemented, the cold and flu are—unfortunately—never 100 percent avoidable. Luckily, the body gives warning signs when the immune system is about to go into overdrive.

“Fatigue is the big one. You start feeling rundown and there’s just an overall bad feeling in the body,” says Dr. Dovgy. “That’s how you know that you might be more prone to getting sick soon or are starting to get sick.”

For anyone who does get sick this winter, it’s important to determine when an illness can be treated at home versus when medical intervention is required. Dr. Dovgy urges those with the following symptoms to see their provider immediately:

• A high fever that lasts more than seven days and doesn’t improve with antipyretics (Tylenol)
• Passing out
• Sore throat with no other upper respiratory symptoms (could mean strep)
• A cough that persists for more than four weeks
• Sinus pain that worsens after the first bout of a cold with low grade fever and mucus color changes
• Wheezing and no relief from a rescue inhaler for those with asthma and COPD
• Neck pain or sudden difficulty moving the neck with a high fever and vomiting in kids and young adults.

Visit Family Medicine for more information and to make an appointment.