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The Best Natural Immunity Boosters for Cold & Flu Season


Cold and flu season are coming. So are the holidays. Colder weather and seasonal gatherings will put people - and germs - in closer quarters just as they do every fall and winter. Here's how to boost your immune system, reduce stress, and increase energy naturally so you can fight off this cold and flu season.

According to the Center for Disease Control (CDC), about 5-20% of the US population contracts the flu each year during flu season, which runs from October to May. This is IN ADDITION TO the 2-3 colds per year that the average adult experiences. (1)

With the season of sniffles coming, we're going to focus on some natural "biohacks" to help you optimize your immune system so you can slip the snot and sore throat as much as possible.

Optimizing Your Immune System


Long known for it's ability to fend off vampires, werewolves and other creatures of the night, garlic is one of the oldest medicinal foods on the Earth. In the book, 150 Healthiest Foods On Earth, several top nutrition experts list Garlic among their Top 10 Favorite Foods!


Garlic has major antioxidant properties that protect against aging, and can attenuate our response to stress. It lowers cholesterol and blood pressure, detoxes heavy metals, and neutralizes bacteria, viruses, and fungi. It was even used in World War 2 as Russian penicillin. (2)

The pro tip from health and fitness expert Joe Carabase: take 1TBSP minced garlic 1-2 times daily during times of intense stress or when feeling cold or flu-like symptoms. (Just make sure your minced garlic doesn't contain added sugars or inflammatory oils - read the ingredients!)


Renowned herbalist Crosby Tailor raved about Chaga and Reishi for their immunity boosting properties when he was on the Optimal Performance Podcast HERE. (In fact, we may (or may not) be working behind the scenes to bring you a mushroom-based immunity product. They're that powerful!)

Cordyceps has been shown to boost ATP production, providing more energy at the cellular level. In a time when our body is in overdrive fighting pathogens and other invaders, the extra energy boost is very beneficial to keep from feeling so run down.

Chaga is loaded with beta-d-glucans which act as Biological Response Modifiers (BRM). This is due to the fact that beta-d-glucans can bolster a suppressed immune system or slow down one that is overactive. Chaga has also been shown in studies to initiate cancer fighting responses and help offset some of the negative side-effects of chemotherapy. (3)

Reishi contains bio-active compounds that fight aging, increase lifespan in lab rats, reduce allergies, asthma and more. As it relates to cold and flu season, Reishi reduces oxidation, protects cellular and mitochondrial DNA, and increases expression of a key longevity gene. It also reduce the release of histamine, making it a natural anti-histamine. (4) All things we want on our side when fighting bacteria, fungi, and viruses.


That's just the beginning of the mushroom family's benefits. Shitake, oyster, white, maitake, chanterelle, and porcini all have major health benefits as well. Try adding as many as possible into your salads, stir-fries, roasted vegetable dishes or enjoy mushroom teas to give your immune system a boost.

Vitamin C + Zinc

Possibly the most well-known immune system booster, Vitamin C is the first thing many people reach for during cold and flu season. It's an antioxidant, meaning it combats oxidative stress, it speeds recovery, and it promotes cellular health and protection. (5) Vitamin C is also responsible for increased blood levels of the body's master endogenous antioxidant - glutathione.

Zinc is a powerful mineral itself. Involved in cell division and replication, zinc speeds up injury repair, and ensures proper growth patterns and sensory development. Even mild levels of zinc deficiency can lead to reduced killer cell and macrophage activity, and is associated with increased levels of infections and disease.

When combined, these two pack an amazing 1-2 punch in the fight against cold and flu season (that's why we stacked them). In fact, when reviewing 15 independent studies with a total of 1,360 participants, researchers found that “zinc administered within 24 hours of onset of symptoms reduces the duration and severity of the common cold in healthy people.” and “When supplemented for at least 5 months, it reduces cold incidence”. [6]

Vitamin C + Zinc

Product formulator and Natural Stacks co-founder Roy Krebs told me personally that he kept Zinc low in this formulation because he loves to take Vitamin C and wanted to keep that possibility in tact without getting too much zinc.

Activated Charcoal

When a substance has been used by every ancient culture like charcoal has been (The Chinese, Ayurvedic medicine, and the physically cultured Romans loved it), there must be some truth to it's effectiveness in order to keep it in good favor for thousands of years. Charcoal works via adsorption - meaning it "binds to" and helps us excrete things rather than absorb them into our bodies. Activated charcoal:

  • removes toxins
  • eases digestive issues
  • counteracts "poisons" like alcohol, mold, chemicals on non-organic food, etc
  • moves unwanted bacteria and pathogens through our system faster (7)

Charcoal is great to stack WITH these other immune boosters as it helps us remove the waste and toxins that our immune system is fighting. The faster we get it OUT of our body, the faster we feel optimal again.


Glutathione is our body's master antioxidant. It is present in every single cell of our body and functions to keep our cells & nervous running optimally, (8)

Unfortunately things like travel, stress, our environment and fatigue deplete this resource - increasing our chances of falling victim to an opportunistic cold or flu virus. Staying loaded up on Vitamin C and Glutathione is a great idea for longevity - but also a key during cold and flu season to stay on your feet and away from the tissues.

Glutathione is poorly absorbed, so it's not often recommended as a supplement (although Bulletproof has a liposomal delivery system that enhances absorption). The best way to boost glutathione is by eating a lot of sulphur-containing vegetables, things like broccoli, cabbage, kale, garlic, onions and Brussel sprouts. (There's garlic again - maybe we should just keep eating it by the spoonful!) These foods, along with avocados and walnuts, promote glutathione production as they contain

Rhodiola Rosea

One of the world's most powerful adaptogens, Rhodiola can lower cortisol, reduce stress and fatigue, fight free radicals, improve glucose and fat metabolism, and it even increases antimicrobial gene expression - so we're better able to fight off germs. (9)

Rhodiola can be taken as a stand-alone herb or in a stack like our Serotonin Brain Food that boosts the feel-good, fear, anxiety, and stress modulating neurotransmitter serotonin.

Vitamin C + Zinc (1)

Creating Your Immune Boosting Stack

Now that we've talked about these immune boosting superfoods and supplements, let's look at how to incorporate them into your day.

When you travel more than usual, are exposed to the elements, stress levels significantly increase, or you start to feel a sore throat or cold coming on, here's how to incorporate these natural remedies into your day.

  • Morning: 3 x Serotonin Brain Food, 2 x Vitamin C + Zinc, and your other morning pills/supplements + 1TBSP minced garlic. If using glutathione and or charcoal, take here as well.
  • Morning Coffee: Try drinking mushroom coffee or tea or add chaga, reishi, and cordyceps to your favorite coffee.
  • Lunch: Take another 2 x Vitamin C + Zinc with your salad. Load that salad up with mushrooms (shitake, oyster, and white), dress with 1 TBSP raw apple cider vinegar and down another 1 TBSP minced garlic. Be sure to brush your teeth!
  • Mid-afternoon: Take second dose of 3 x Serotonin Brain Food, glutathione and charcoal if using.
  • Evening: 1 more TBSP minced garlic, more mushrooms with your meal or in a tea/powdered drink mix, and 2 x Vitamin C + zinc

If you do get a cold or the flu, these natural remedies will not "cure" you - but they will help speed up the recovery process. Instead of being down and out for a day or two, you're just slightly under 100% for 24-36 hours. And with a little luck these trick will help you avoid being under the weather at all.



  1. Center For Disease Control.
  2. Bowden, J. The 150 Healthiest Foods On Earth. 2007. p. 186, 246, 282-284.
  3. Youn MJ, Kim JK, Park SY, et al. Chaga mushroom (Inonotus obliquus) induces G0/G1 arrest and apoptosis in human hepatoma HepG2 cells. World J Gastroenterol. Jan 28 2008;14(4):511-517.
  4. Steiner, E. Life Extension Magazine Online. 2013.
  5. Maggini, S. A Combination of High Dose Vitamin C + Zinc for the Common Cold.
  6. Singh, M. Zinc For The Common Cold.
  7. Asprey, D. Coconut Charcoal: The Best Activated Charcoal Detox.
  8. Whitaker, J. Reap The Benefits Of Glutathione.
  9. Zhu, C. The protective effects of Rhodiola crenulata extracts on Drosophila melanogaster gut immunity induced by bacteria and SDS toxicity.


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