How to Support Your Immune System During Cold and Flu Season

Sinking temperatures and shorter days may call for more time cooped up inside, which means cold and flu season is upon us.    

Wondering if there’s a way to avoid getting sick this fall and winter without sacrificing your social life? 

Here’s how you can bolster your immune system and increase your odds of avoiding airborn infections. 

What causes cold and flu?

The common cold and the flu are upper respiratory illnesses with similar symptoms, yet the flu may be more severe and abrupt. 

Roughly 200 viruses can trigger a cold, including rhinoviruses and seasonal coronaviruses (not the same as COVID-19). Meanwhile, the flu is mainly caused by influenza A and B viruses. Both, however, are caught by inhaling airborne droplets from someone with the virus, or by handling recently infected objects and touching your mouth, eyes, or nose. 

While it’s possible to catch these infections any time of year, colder and drier weather means three things.  First, it raises your exposure to viruses because we’ll spend more time indoors with other people. Cold, dry air also dries out the mucus lining your throat and sinuses, weakening your immune system’s natural defences. And to top it off, less sunlight creates a more hospitable environment for viruses.

No wonder fall and winter are prime cold and flu season!

How does my immune system fight cold and flu?

Think of your immune system as your body’s loyal army, assembled to monitor, remember, and eliminate the enemies threatening your safety.

Once a virus enters your cells, it multiplies and infects the surrounding cells. Your immune system prepares to fight, releasing chemical messengers (cytokines) to alert your body of  disease before it’s overrun. 

Cytokines trigger inflammation, which may cause swelling, pain, and fluid accumulation. What you may perceive as annoying cold or flu symptoms is actually the result of your body battling these invaders. A fever means your immune system is working! However, prolonged and excessive inflammation can damage and overwhelm the immune system, so a balanced inflammatory response is everything.

Next, your immune system rallies the troops to attack the virus: white blood cells (including B-cells and T-cells) and other immune cells. B-cells create antibodies that bind to the virus and mark it as an intruder, and T-cells destroy the marked cells.

Some white blood cells and antibodies may stay in your body after you recover to keep a memory of the virus. If you’re exposed to the same virus again, your immune system will recognize it and quickly kill it. 

Yet, viruses are constantly evolving, so you may still be at risk of new strains in the future. That’s why you may get repeated colds in winter

Naturally, supporting your immune system can optimize your defences and protect your health and lifestyle, and it starts with hormone balance.

How does hormone balance affect my immune system?

Hormones are chemical superstars coordinating vital processes like metabolism, reproduction, and immune function.

If your immune system is an army, then hormones are executive messengers, coordinating every system throughout your body to ensure everything goes to plan.

Hormone balance fluctuates with the rhythms of life, but aging, stress, diet changes, and other variables may result in too much or too little of a hormone. These hormone imbalances can disrupt your immune system, increasing your chances of getting a virus or compromising your ability to fight it.

Pituitary hormones play a regulatory role in your immune activity. They stimulate other glands to secrete effector hormones, which act directly on cells, tissues, and organs involved in your immune response.

Here’s how an imbalance of your effector hormones can affect your immune system:

• Estrogen – Enhances your inflammatory response, boosting your white blood cell function and increasing antibody production. Excess estrogen may trigger an autoimmune response, where your immune system mistakenly targets and attacks your own cells.
• Testosterone – Has a suppressive effect. Elevated testosterone may restrain your immune system’s activation and decrease your white cells’ reaction. Low testosterone may result in higher levels of cytokines in your body (pro-inflammatory messengers), which can lead to a life-threatening inflammatory response (known as a “cytokine storm”).
• Progesterone – Inhibits your immune system’s inflammatory response and focuses on tissue repair. When progesterone is too low, you may also risk developing autoimmunity (misidentifying and killing healthy cells).
• Thyroid – Fundamental in the metabolism and production of blood cells. An excess or deficiency of thyroid hormones can reduce white cell production, impairing your capacity to fight diseases. A thyroid deficit can also slow down your immune reaction, giving viruses more time to replicate and spread (more on the thyroid).
• Cortisol – Balanced bursts of the “stress hormone” can optimize your immunity by limiting inflammation. Yet, high levels can diminish your capacity to respond to cortisol’s anti-inflammatory signals, resulting in increased inflammation.

Research has found interesting seasonal patterns in these effector hormones that overlap with cold and flu season (Oct-Feb). Although pituitary hormones seem to peak in summertime, most of their effector hormones tend to peak in winter.

Another study agrees with cortisol spikes in winter, adding that reduced daylight and other changes may also aggravate the immune stress response and contribute to inflammation during colder months. 

These trends may play a part in hormone imbalances and in the seasonality of infections.

Given their pivotal role in your immune system and yearly fluctuations, keeping your hormones balanced is essential for your well-being this season.

Simple habits to support your  immune system and hormone balance this winter

Eat immunity-friendly foods

Your gut houses about 70% of the immune system, so keeping it in good shape can help you take care of infections. Following a diet full of whole foods, lean proteins, whole grains, fruits, and veggies, is a great place to begin.

What specific foods support the immune system? 

• Fruits and vegetables high in vitamin C and flavonoids (anti-inflammatory and antioxidant compounds): citrus fruits, berries, kale, broccoli, spinach, tomatoes, red peppers
• Tea and cocoa (high in flavonoids)
• Prebiotics (feed “good” bacteria): garlic, bananas, onions, asparagus
• Probiotics (contain “good” bacteria): yogurt with live and active cultures, kombucha, kefir, kimchi, and other fermented foods
• Protein: eggs, fish, chicken, lean meat, beans, broccoli, chickpeas and lentils, peas, seaweed, and spinach
• Other anti-inflammatory foods: ginger, turmeric, pineapple, papaya, dark chocolate, and more

Thai Chicken Soup

Blanche veggies like broccoli, bean sprouts, and baby bok choi for a meal in a cup!

Move your body

You don’t need to be a “gym rat” to see the gifts of movement. Regular moderate-vigorous exercise stimulates the circulation of immune cells and enhances your immune vigilance. 

Sprinkle a few hours of physical activity throughout the week. And even better: head outside! Bundle up and go for a walk, run, or a fun snow activity—anything that allows you to move while enjoying the fresh air is best. Remember, viruses thrive indoors.

But don’t overdo it!

Be careful with overexerting yourself. Too much physical, mental, or environmental stress can deplete your body, increasing inflammation and weakening your immune system. 

If you are feeling tired or overwhelmed, slow down. Ensure you pause to rest and unwind during the day. And get enough quality sleep at night to help your system recover.

Balance your hormones and be healthy this season!

Balancing your hormones may not only result in enhanced immunity this cold and flu season, but it can support your health and quality of life all year, every year, forever round.

These steps are a fantastic starting point, but for a deeper understanding of yourself and how to feel your best, book a naturopathic assessment today.