How to Thrive This Cold and Flu Season

Winter’s here, and with it come cozy nights by the fire, comfort food, holiday joy, and time with family. At least, that’s what greeting card companies want you to believe. For too many people, with all the good stuff comes cold and flu season.

Colds and flus used to really knock me out – I’d sometimes get sick every month of winter. Fortunately, I learned lots of tricks running the Silicon Valley Health Institute – the kinds of things you may not hear about at your doctor’s office (unless you’re going to a good functional medicine doctor!).

Here are a few hacks to help you keep your immune system working well, and if you do get a cold or flu, to help you knock it out as quickly and comfortably as possible. View infographic version of this article here.


Essential Oils

Essential oils are extracted from plants that have biological healing properties. Essential oils have been used for centuries and have documented effects besides just smelling nice. You usually either use them topically or put them in a diffuser. Sometimes you can take them orally, too. Here are a few good essential oils for kicking a cold or flu.

  • Eucalyptus oil contains eucalyptol, which relieves congestion, decreases coughing/bronchitis, and kills infectious bacteria in your respiratory tract [1,2,3]. Eucalyptus oil is generally safe to put on your skin if you’re an adult; to breathe more easily, you can rub a bit of it under each nostril – an especially useful trick if you’re stuffed up and have trouble falling asleep.
  • Cinnamon oil kills antibiotic-resistant bacteria and fungi [4]. It’s a good way to disinfect your house if you’re sick, and you can also take it in pill form. Three notes: First, be sure you get Cinnamomum verum (Ceylon cinnamon) oil and not a Cassia product. Cassia is high in coumarin, a compound that thins your blood and stresses your liver and kidneys [5]. Second, cinnamon oil is powerful stuff and can be toxic in high doses, so don’t take it for more than a week. Third, before you take cinnamon oil orally, test a bit of it on your skin to see if you’re sensitive or allergic to it. Some people have reactions to cinnamaldehyde, the compound that gives cinnamon its warm flavor and smell.
  • Oregano oil is an antiviral, antifungal, and antioxidant [6] and it contains carvacrol and thymol, both of which inhibit bacterial reproduction [7]. Oregano oil’s benefits have only been tested in vitro – that is, on bacteria in a glass dish. However, clinicians I work with have had profound success with it, especially for fungal and parasitic infections. These clinicians note that oregano oil can have an impact on the bacteria in your gut as well, so I recommend more probiotics when you’re on oregano oil. If you want to try it, swallow 4-6 drops of oregano oil diluted with coconut oil or Brain Octane. Don’t take oregano oil for more than a week.
  • Tea tree oil also kills resistant bacteria [8]. Again, it’s great for disinfecting your house if you have a cold, and you can breathe in tea tree oil vapor to relieve congestion. Just don’t swallow this oil.



Depending on who you listen to, supplements either do nothing, or they do something. I’ve had a lot of success with supplements, and these ones in  particular. The evidence is in that they do work for immune enhancement. Here are the superstar supplements for enhancing immunity, the ones with the most research.

  • Vitamin D3 – During winter, taking 1,000 IU of D3 for every 25lbs of body weight can greatly increase your ability to fight off infections [9]. I’d take vitamin D3 over a flu shot any day. You should balance your D3 with K2 and Vitamin A, as explained here.
  • Vitamin C, contrary to popular belief, won’t necessarily prevent you from getting sick. It can, however, help you get rid of your cold more quickly [10]. The problem is that vitamin C has an L-shaped response curve. That means that you have to take enough to almost cause “disaster pants” and then keep taking that amount for it to work. When you’re getting sick, your body will demand far more vitamin C than normal. For instance, if you can take no more than 5 grams per day normally, you may be able to take 25 or 50 grams per day when you’re getting sick. It won’t work to just take a little extra vitamin C! Bonus points for intravenous vitamin C, which does wonders for a cold.
  • Glutathione recharges antioxidants after your body uses them, so taking it with vitamin C gives you an extra antioxidant boost. When you’re getting sick, you have more oxidative stress and more free radicals to quench.
  • Zinc can help you kick a cold faster and decrease your symptoms, too…as long as you take it within 24 hours of the cold’s onset [11].



Turns out that your grandmother was right about soup, at least mostly. (there’s always room for upgrading your grandmother!)

  • Chicken soup. The old classic really does kill pathogens that cause upper respiratory infections [12]. Always get or make your chicken soup from the bones of pasture-raised chickens. You can also use beef or lamb bone broth bases with a dash of Brain Octane mixed in.
  • Ginger contains sesquiterpenes that specifically fight the rhinovirus – that’s the virus responsible for many colds [13]. To nab ginger’s benefits, you can make ginger tea, eat raw ginger, or add ginger to your chicken soup. I grate fresh ginger, a couple tablespoons, and put it in bone broth soup. When I finish crying, I feel great!
  • Garlic is a strong antiviral, antibacterial, antiparasitic, and antifungal. It also boosts your immune system [14]. It inhibits alpha brain waves and can make it harder to maintain emotional regularity, which is why it’s a suspect food on the Bulletproof Diet Roadmap. That said, if you’re sick, garlic is a great way to rev your immune system. If you’re hardcore, you can suck on a clove of raw garlic for 15-20 minutes to get its benefits (yum). You can also just add it to your meals – perhaps to your chicken/bone broth ginger soup.
  • Turmeric is full of antioxidants and curcuminoids, the most famous of which is curcumin.  Curcumin regulates your immune system and is a strong anti-inflammatory [15]. It makes up about 3% of turmeric, so if you want the full-on immune-boosting effects, I recommend curcumin extract. While curcumin’s bioavailability is low alone, you can buy it combined with black pepper extract, which boosts bioavailability considerably. Be sure you get a reputable brand – the black pepper extract can be moldy. Warning: turmeric will dye everything a nice yellow color, including your kids’ faces and your favorite shirt. I like fresh turmeric grated into my bone broth.  



  • Cold exposure boosts your metabolism [16], and faster metabolism correlates with increased immune power [17]. Try a blast of cold water at the end of your morning shower, or leave your windows open and the heat off for 30 minutes. Do this when you’re NOT sick; it’s counterproductive if you’re already fighting a cold.
  • Moderate exercise can also protect you from the cold or flu, although strenuous exercise to excess makes your immune system tank [18]. If you’re not sick, doing HIIT or resistance training is a good way to keep your defenses up. Bonus points if you do it outside in the cold and kill two birds with one stone. But don’t overtrain – that makes you more susceptible.


With these hacks you can thrive throughout the winter months. What else do you do to ward off the cold and flu? Let me know in the comments, and stay Bulletproof!


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