How to Strengthen Your Immune System

How to Strengthen Your Immune System

Common as they are during winter months, colds and flu aren’t inevitable. That’s especially true once we reach our late 20s or early 30s, when the immune system becomes most effective against these types of bugs. Although resistance starts to drop after age 80, most of our lives should be relatively free of these annoying experiences.

“If you’re a 45-year-old and you’re catching colds three times a winter, you’re doing something wrong in terms of caring for yourself,” says Wendy Warner, MD, a holistic physician in Langhorne, Pa., and author of Boosting Your Immunity for Dummies. “So you should stop and think, what could I be doing differently?”

Adequate sleep and good food are the best protection. “If you’re eating crap, you can’t expect your immune system to work right, and sugar’s really bad for the immune system,” says Warner. Eat whole foods, especially lots of veggies, and include an orange a day for vitamin C. In addition, she offers the following helpful tips and supplement recommendations.

1. Eight Hours of Sleep May Not Be Enough

It’s most important to sleep between the hours of 10 p.m. and 2 a.m. “That’s when the immune system revs up, runs around, and cleans up all the stuff you’ve been exposed to that day,” says Warner, “but you have to be asleep for that to happen.” If you tend to sleep between 1 a.m. and 9 a.m., for example, your immune system gets short-changed, even though you're getting the recommended eight hours of sleep.

2. Mushroom Extracts Can Keep You Healthy

Different mushrooms enhance different parts of the immune system, boosting its ability to resist seasonal bugs and, if you do get sick, speeding recovery. Look for a combination of maitake, cordyceps, and reishi extracts, and take it daily during the winter season.

3. Vitamin D Beats Bugs

Studies of more than 11,000 people, from infants to 95-year-olds, show that low levels of vitamin D increase the odds of winter respiratory infections. So make sure you're getting enough of the "sunshine vitamin," especially in the winter when you're less likely to spend time outdoors.

4. An Herbal Bath Clears Congestion

A hot, steamy shower or bath with some herbs is a pleasant and relaxing way to decongest sinuses and lungs. Take fresh rosemary or oregano, or dried eucalyptus, into a hot shower. Get the herb wet, squeeze or stomp on it to release its oils, and inhale. Or, put essential oil of eucalyptus on a hot, wet washcloth and squeeze it to release more active components. An alternative to flushing sinuses with a Netti Pot, taking herbal showers or baths can be effective for all ages,including kids.

5. The Mistake Most People Make with Echinacea

“Echinacea is great, but you have to take it the minute you get a sniffle, if it even crosses your mind that you’re getting a scratchy throat,” says Warner, adding that you need to take about four times the dose recommended on most products. That way, she says, whether you are getting a cold or the flu, “It will knock it out really quickly.”

6. Why Andrographis Is a Go-to Remedy

Andrographis will work even if you start taking it a day or two after symptoms strike. It may also be effective for prevention, especially if you’re exposed to bugs from sick coworkers, family, or a sniffling passenger sitting next to you on an airplane.

7. Why a Popular Flu Remedy also Works for Colds

Viruses are continually mutating, and it’s getting more difficult to tell whether symptoms indicate a cold or flu. For example, says Warner, “sniffles could be either one.” Unlike flu vaccines, which aim to target specific viruses (and may not work because of incorrect predictions on which flu virus will be active in a given season), natural remedies help
the immune system knock out any virus. Consequently, Oscillococcinum, a popular homeopathic remedy for flu, can also work for colds.

8. How Exercise Can Help or Harm

A moderate amount of exercise—the kind that leaves you less stressed and revitalized—makes you less susceptible to seasonal bugs. However, cautions Warner, “When you overdo exercise, you increase your cortisol, your main stress hormone, and that negatively impacts the immune system.” If you’re always trying to push yourself past the limit, winter is a good time to try yoga or Pilates.

9. Achiness and Fever Are Not Cold or Flu Symptoms

If a fever or achiness makes you want to hide under the covers, that’s the best thing to do. Aches and fever aren’t actually caused by cold or flu viruses, but by inflammatory chemicals released by our immune system, indicating it’s fighting the virus—a good thing, under the circumstances.

Don’t take an aspirin to suppress the bug-fighting process. Rather, take natural remedies that enhance your ability to beat the virus, and get some rest. “If you don’t rest when you need to,” warns Warner, “it’ll take longer to recover.”

10. Viruses Aren’t the Only Culprits

Colds and flu are viral infections, but once they strike, a bacterial infection—a “secondary” infection in medical terms—can also develop. A wet cough or yellowish-greenish nasal discharge may be symptoms. Because natural remedies enhance our immune system’s ability to knock out all types of pathogens, they can work on both, and herbs that contain berberine, such as Oregon grape, yellow root, and barberry are especially good at knocking out bacteria. 

Supplements for Preventing Colds & Flu: Dosage Guidelines

To stay healthy, Warner recommends taking these daily during cold and flu season:

Mushroom extracts: 

Take a combination of maitake, cordyceps, and reishi or, if you opt for a single mushroom, choose reishi, which also helps balance stress. Look for an extract from the fruiting body (the top part) or, next best, mycelium (the underground part) grown in liquid nutrients.

Probiotics and prebiotics: 

Preferably, get probiotics by drinking kefir or kombucha, and prebiotics (food for beneficial gut bugs) by eating jicama, asparagus, and artichokes. A high-quality supplement is the next-best alternative. 


Take 200 mg of dried extract 1–2 times daily, especially when traveling or when you know that you’ll be around people with colds or flu.

Vitamin D: 

Get your levels tested. Failing that, take at 2,000–4,000 IU daily—the higher dose
if you live north of the sunny southern states.

Fish oils: 

Get 1–2 grams daily of an EPA/DHA combination to reduce chronic inflammation, which makes you more susceptible to seasonal bugs.

Vitamin C: 

One of the most acknowledged immune health remedies on the planet, vitamin C may help keep colds at bay, according to several studies. For those who succumb to the sniffles, increasing vitamin C may shorten the number of days they're symptomatic. When Israeli doctors gave vitamin C to a group of competitive swimmers with upper respiratory infections, 47 percent of those taking a daily dose of C experienced less severe symptoms and recovered faster than those who didn't supplement with C. Use 250 mg daily for kids and 500–1,000 mg daily for adults. 

The Hand-Washing Pitfall

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If you don’t wash your hands properly, they will keep spreading bugs—both to other people and into your own mouth and nose. The CDC recommends scrubbing with soap and water for 20 seconds, or the time it takes to sing “Happy Birthday” twice. 

Why Alcohol Wipes Best 

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Wiping off keyboards, phones, and door knobs helps stop the spread of bad bugs, but antibacterial wipes can also contain toxins. Alcohol wipes are effective and benign.

Natural Remedies for What Ails You

To treat any combination of cold or flu symptoms, Warner recommends:


Take 200 mg of dried extract every 2 hours for the first 12 hours, and then 3 times daily until symptoms abate and you feel normal for 1–2 days.

Vitamin D: 

For 7–10 days, take 10,000 IU daily, or double your usual dose if it’s based on blood tests.


For a cold or flu, each vial can be divided into 3–4 doses.


Must be taken at the very first sign of a cold. Warner recommends four times the echinacea dose suggested on product labels. Take a tincture every two hours (it should make your tongue tingle) or drink an echinacea tea throughout the day.


Lozenges are an effective way to shorten the duration of colds and flu. 

For specific symptoms:

Dry cough: 

Allergies may play a part. Take fish oil, enough to get 4 grams of EPA and DHA daily, and natural antihistamines and anti-inflammatories such as stinging nettle, quercetin, bromelain, and turmeric, available in combination formulas.

Wet cough and Congestion: 

Wet coughs can be viral, bacterial, or a combination of the two. Elderberry (Sambucus) in syrup, gummies, or lozenges helps fight both viruses and bacteria. Additional antibacterial cough remedies include herbs that contain berberine, such as Oregon grape, yellow root, goldenseal, and/or barberry, in capsules or tinctures.

For congestion, take an herbal bath or shower (see No. 4), or flush sinuses using a Netti Pot with salt and a drop of rosemary. Take andrographis, and if you notice a yellowish or greenish discharge, there could be a bacterial infection on top of the cold or flu virus. Herbs that contain berberine, such as Oregon grape and goldenseal, are natural antibiotics. 

Sore throat: 

Gargling with salt water reduces mucus, and herbs can coat and soothe the throat. Choose teas with slippery elm, marshmallow root, and ginger. To make your own ginger tea, chop fresh ginger root, brew for 10 minutes in a tea ball, and sip it throughout the day. Throat sprays and respiratory tonics may also include other herbs such as osha and elecampane.

Feeling weak or tired: 

Take the above remedies, and get plenty of rest. Among the mushrooms, cordyceps is especially good for enhancing energy. 

Lingering symptoms:  

If you’ve been taking natural remedies and feel better, but some symptoms just won’t go away, Warner recommends trying acupuncture or shiatsu (or just getting a massage) to help the immune system beat the last of it.

Written by vera-tweed for Better Nutrition and legally licensed through the Matcha publisher network. Please direct all licensing questions to

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