7 Ways to Build Immunity Before Flu Season Hits

Nov 7

ESTIMATED READ TIME:  4-5 MINS

Your immune system isn't something you can strengthen overnight. By the time you're surrounded by coughing coworkers, sick kids, and holiday travelers, much of the work that determines how resilient you are has already been happening for weeks or months.

That's why fall is the best time to intentionally prepare for what's ahead, including by building adequate nutrient stores, a diverse gut microbiome, healthy metabolic function, plenty of lean muscle, and a routine with daily habits that support a strong immune system.

Here are seven things I would focus on now before flu season arrives.

1. Take Advantage of the Midday Sun

I'll keep this one simple because I've written extensively about vitamin D before: get outside while strong sunshine is still available.

During the fall, aim for 20–30 minutes of sun exposure four or five times each week. Ideally, head outdoors as close to noon as possible, without sunscreen, as long as you don't allow your skin to burn.

Your skin uses UVB radiation to produce vitamin D, and vitamin D is needed for both innate and adaptive immune function, meaning it helps you respond quickly to invading germs, helps manage inflammation, and supports more targeted immune defenses that develop against specific pathogens.

Think of early fall as your opportunity to take advantage of the sun while you still can and build up vitamin D for the colder, darker months.

Studies have found that having higher vitamin D intake (including from supplementation) is helpful for reducing the incidence and severity of influenza.

Depending on your skin tone and where you live, your ability to produce vitamin D from sunlight can drop considerably during the winter, which is where supplements can be helpful.

2. Pay Attention to Your Zinc-Copper Balance

When you think about immune minerals, zinc might come to mind, considering it's involved in the development and function of numerous immune cells, and inadequate zinc intake can impair normal immune responses.

However, zinc and copper work in balance, and taking high doses of zinc for long periods can interfere with copper absorption. That's why I don't recommend loading up on zinc without considering your overall mineral intake.

During this time of year, I typically aim for about 20 milligrams of zinc along with 2 milligrams of copper each day from a combination of food and supplements (when appropriate).

You get both from a quality multivitamin, or you can take them separately. But aiming for the right ratio is important either way.

Liver is also one of the richest food sources of copper, which is one reason organ meats have traditionally been such valuable foods. If you don't eat liver, a high-quality liver supplement is another option.

3. Consider a Fall Fast

Here's something I like to do before the holidays rather than only after them: fast.

Fasting might be popular in January, after the holidays are done and people feel wiped from weeks of overeating, drinking, traveling, and celebrating. But I prefer getting ahead of it and fasting earlier in the season.

A short fast sometime in mid-fall can be a useful metabolic reset before Thanksgiving and Christmas arrive. For example, you might decide to do a 24-hour fast from dinner one evening to dinner the next day, or to establish a habit of doing intermittent fasting more regularly.

While fasting, insulin levels fall, and your body changes how it obtains and uses energy. Fasting also activates cellular processes such as autophagy, which helps cells break down and recycle damaged or unnecessary components.

Some research shows that fasting affects immune-cell activity and regeneration. While this doesn't mean it necessarily "boosts immunity" or prevents the flu, there are good reasons to believe that fasting can support overall metabolic and cellular health, as long as it's used wisely.

A fast doesn't need to be extreme to be useful. Begin with 14—16 hours of fasting several days per week, or a 24- to 48-hour fast.

4. Give Your Microbiome Extra Attention

If you want to support your immune system, you can't ignore your gut. 70—80% of immune activity takes place in and around our gastrointestinal tract, where immune cells are constantly interacting with microbes, food components, and compounds produced by your microbiome.

During fall, I like to increase my intake of probiotics from two directions: supplements and fermented foods. For you, that might mean taking an SBO probiotic supplement while also eating more kefir, yogurt, sauerkraut, kimchi, and other traditionally fermented vegetables (which are natural sources of probiotics).

For most people, I recommend spore-forming probiotics such as Bacillus subtilis. These organisms form hardy spores that help them survive challenging environmental conditions, including passage through the gastrointestinal tract, where they may help support immune function.

The other half of the equation is feeding your microbiome. Eat a wide variety of vegetables, fruits, herbs, spices, and other fiber- and polyphenol-rich plants alongside your fermented foods to help "fuel" the beneficial microbes living in your gut.

5. Turn Your Spice Cabinet Into an Immune-Support Tool

One of the easiest upgrades you can make this fall? Use more herbs and spices.

Food should taste good, and fortunately, flavor can also be one of the easiest ways to increase the diversity of beneficial compounds in your diet.

Garlic, ginger, clove, turmeric, oregano, rosemary, thyme, cinnamon, sage, and other herbs and spices contain an enormous variety of naturally occurring polyphenols and other protective antioxidants and compounds.

One trial even found that adding a relatively large dose of mixed spices to a high-fat, high-carbohydrate meal improved post-meal inflammatory markers compared with eating the same meal without the spices.

Instead of thinking about these foods as tiny garnishes, use them generously. Add garlic, oregano, and thyme to meat and vegetables. Put cinnamon and cloves into fall recipes. Cook with fresh ginger and turmeric. Add rosemary to roasted potatoes. Drink herbal teas.

6. Replenish Your Electrolytes

Vitamin C, vitamin D, and zinc get most of the attention during flu season, but to truly keep your defenses up, you require a broader spectrum of minerals.

Three that deserve more attention are sodium, potassium, and magnesium. These electrolytes are involved in fluid balance, nerve transmission, muscle contraction, energy production, and countless cellular processes.

You'll find plenty of sodium in processed foods, but I much prefer seasoning real food with a quality mineral salt.

On top of this, intentionally eat foods that supply you with potassium and magnesium, which many people lack.

Potassium-rich foods include potatoes, avocado, squash, beans, yogurt, bananas, and leafy greens. Magnesium is abundant in foods such as pumpkin seeds, almonds, cacao, leafy greens, avocado, and legumes.

Getting enough electrolytes is even more important if you're exercising frequently, sweating heavily, using a sauna, or otherwise losing more fluids and electrolytes, such as if you're sick.

7. Build Muscle Before the Holidays

You don’t want to wait until January to start an exercise routine or to get in shape. I would argue that the weeks before Thanksgiving are amongst the best times of the year to double down on exercise.

You want to enter the holiday season with more lean muscle, better insulin sensitivity, greater work capacity, and a healthy metabolism, not spend October and November slowly becoming more sedentary.

Muscle is metabolically active tissue. Building and maintaining it can improve glucose disposal and metabolic health, while regular physical activity can help reduce excess body fat and increase energy expenditure and thermogenesis.

That doesn't mean exhausting yourself every day or spending hours in the gym. You can try to:

Walk frequently
Lift weights or perform resistance training several times per week
Carry heavy things
Sprint, if appropriate for you
Take the stairs more often
Work outside around the house
Keep your body moving throughout the day however you can

If you do this, when Thanksgiving, Christmas, travel, and parties arrive, you're starting from a position of strength rather than trying to undo months of inactivity.

Final Thoughts: Don't Wait Until You're Sick to Build Immune Defenses

The common theme among all seven of these strategies is preparation.

You don't build muscle the day you get the flu. You don't create a diverse microbiome overnight. You don't correct a nutrient deficiency with one meal. And you can't store up months of healthy habits by taking a handful of supplements when you wake up with a sore throat.

Your everyday habits lay the foundation of a strong immune system that can handle flu season well. So use the weeks ahead wisely: