When cold and flu season comes around, what can you do to prevent the coughs, sneezes, or even worse symptoms that come with a cold or flu virus? This is an even more important question to address when the backdrop of a viral outbreak is also top of mind.

‌‌‌‌Some Key Immunity Tips:

  • Wash your hands frequently.
  • Avoid touching your face (or at least wash your hands beforehand).
  • Avoid close contact with sick people (keeping a distance of at least 6 feet).
  • Carry hand sanitizer for those times when soap and water are not nearby. The CDC (The Centers for Disease Control and Prevention) recommends an alcohol content of at least 60%.
  • Speak with your health care provider to determine if the flu vaccine is appropriate for you.

Some of the best cold and flu prevention strategies, however, are actually the same as you would implement to achieve general health throughout the year. 

“These are lifestyle issues,” describes Dr. Carol Shwery, owner of Pleasure Point Wellness and Functional Medicine. When concerned about one’s immunity, she believes it’s an opportunity to say, “I really need to focus on my body and my health – mentally, emotionally, and physically – in order to be strong and to bolster my immune system as much as possible.”

‌‌‌‌Lifestyle Tips For Optimal Immune Health:

  • Manage stress appropriately.
  • Get adequate restorative sleep (at least seven hours each night).
  • Support your immune system with nutrient-filled fruits and vegetables.
  • Maintain a regular exercise plan which includes moderate amounts of aerobic activity.

But there are a few more things you may want to include in your immune health game plan. Just as you would keep a first aid kit in your home for emergency purposes, you should also put together an “immunity toolkit.” You can start using this kit right away so your immune system is prepared when cold and flu season arrives.

Remember, it’s wise to consult with your health care provider before starting any supplement, especially if you are taking medications or have a medical condition.

6 Things To Put In Your Immunity Toolkit 

‌‌‌‌Vitamin D is Essential for Immune Health

Your body requires vitamin D for normal growth and function, but cannot make it. So vitamin D is considered an essential nutrient. As a major regulator of your immune system, it is one of the most important vitamins that contribute to your immune health.

Your skin is actually able to use ultraviolet B (UVB) light from the sun to make vitamin D. However, it can be difficult to expose your skin to enough sunlight to maintain sufficient vitamin D levels due to the risks of prolonged sun exposure, namely sunburn, heatstroke, and skin cancer.

To maintain a healthy immune system, it’s a good idea to check your vitamin D level and make sure it is optimal. The form of vitamin D that is measured in lab tests is 25-hydroxycholecalciferol (or 25-hydroxy vitamin D).  The Endocrine Society, a leading endocrine research organization, recommends a minimum blood level of 30 ng/mL and, if levels are below that, a daily vitamin D supplement of 1500 to 2000 IU. 

There are five types of vitamin D, however, the body primarily uses vitamin D2 (also called ergocalciferol) and vitamin D3 (cholecalciferol). Because the body converts vitamin D3 more quickly and effectively than it converts vitamin D2, the recommended supplement form is D3.

Taken at appropriate doses, vitamin D does not commonly cause ill effects. Because vitamin D helps your body absorb calcium from the food you eat, symptoms of too much vitamin D are often the same as those associated with excess calcium. These include nausea, abdominal pain, fatigue, dizziness, confusion, increased thirst, and frequent urination.

‌‌‌‌Vitamin C and Combating Colds

Another essential nutrient that can be very beneficial for your immune system is vitamin C. For those under significant physical stress, studies have found that vitamin C can decrease the risk of developing the common cold by 50%. 

For the average population, however, there is little evidence that it prevents colds.

But there is still a valid reason to include vitamin C in your supplementation plan for cold and flu season. Research does show that regularly taking a daily dose of at least 200mg can reduce a cold’s duration and severity. In studies of people taking vitamin C only after contracting a cold, symptom improvement did not occur.

Dr. Melissa Sophia Joy – a naturopathic doctor and founder of Somatic Awakening, a mind-body-spirit healing modality – suggests a specific type of vitamin C over others. “What I like to recommend is liposomal vitamin C, ideally, because it’s the most absorbed in our body without causing a lot of gastrointestinal distress.”

Vitamin C is generally safe as a supplement. At higher doses, you may experience gastrointestinal side effects like nausea and diarrhea. If you have a history of kidney stones or a condition in which iron accumulates in the body, then you should be cautious about vitamin C supplementation.

‌‌‌‌Zinc and Immune Cell Benefits 

Zinc is an essential mineral that contributes to the normal function and development of some types of immune cells. Research has demonstrated that certain white blood cell activities are impaired when there is a deficiency of zinc.

There is evidence that zinc has anti-viral activity. In vitro studies show that it can inhibit the replication of certain viruses. It can also improve the anti-viral response of the immune system in those who are zinc-deficient.

Looking at the studies to evaluate the effect of zinc on cold symptoms, the results have been conflicting. However, overall, it seems that zinc supplementation can be beneficial in this regard. A Cochrane review found that zinc given “within 24 hours of the onset of symptoms reduces the duration and severity of the common cold in healthy people.”

According to the National Institutes of Health, the upper limit dose for adults is 40 mg per day. For infants under six months old, it is 4 mg.

Taking too much zinc can be associated with gastrointestinal side effects like nausea, diarrhea, and indigestion. Headache can also occur.

Since zinc competes with copper for absorption in the gastrointestinal tract, there is a risk of copper deficiency. So for long-term supplementation, it’s wise to avoid taking zinc in high doses. Daily zinc doses of 50 to 180 mg for one to two weeks has not been shown to result in serious adverse effects.

‌‌‌‌Probiotics and Gut Health

A huge amount of immune cells reside in your gut. These cells form your gut-associated lymphoid tissue, or GALT, which represents about 70% of your immune system. So when the gut is not healthy, the immune system may falter and inflammation can become a problem. To restore or maintain gut health, the goal is to achieve the proper balance of "good bacteria" and “bad bacteria" in the gut.

Probiotics are beneficial bacteria that make up the naturally occurring flora of the digestive tract. These "good bacteria" work to prevent invasion by harmful organisms, support the immune system, maintain the gut lining, and increase the absorption of various vitamins, minerals, and amino acids.

However, when there is an overgrowth of "bad bacteria" in the gut, these bacteria produce substances that can increase inflammation throughout the body. Causes of this overgrowth can be stress, alcohol consumption, processed foods, and excess carbohydrate intake.

Consuming probiotic foods can help you restore or maintain the balance of "good" versus "bad" bacteria. Look for fermented foods like kimchi, sauerkraut, kombucha, and green olives (that are salt water-brined). You can also eat prebiotics which are indigestible dietary fibers that nourish the "good bacteria" of the gut.

Examples of prebiotic foods:

Here’s a tasty tip: Dark chocolate is a source of both prebiotics and probiotics. The recommendation is to limit dark chocolate to 3/4 ounce per day and to opt for varieties that contain at least 70% cacao.

Note: If you have immunodeficiency or are being treated for cancer, you should be cautious about taking probiotics. It’s a good idea to consult your physician in this case.

‌‌‌‌Manuka Honey’s Antiviral and Antibacterial Properties

The honey produced by bees that pollinate the white-flowered manuka bush (native to New Zealand) has antiviral and antibacterial properties that distinguish it from traditional honey. So Manuka honey may help your immune system defend your body against infections.

Two substances found in manuka honey, methylglyoxal (MGO) and dihydroxyacetone (DHA), have strong antimicrobial effects. Flavonoids and polyphenols are also compounds in the honey that contribute to its healing potency.

Moreover, manuka honey offers specific benefits in alleviating flu and cold symptoms. Research has shown that it reduces cough frequency and severity. It can help relieve sore throat, too. Not only does it combat the infection causing the pain, but it also coats the lining of the throat creating a soothing effect.

Manuka honey’s antimicrobial strength generally appears as a rating on its label. You may see "NPA" (non-peroxide activity), "UMF" (Unique Manuka Factor), or "MGO/MG" (methylglyoxal) on a label. Generally, the higher the number, the higher the antimicrobial activity.

The MGO concentration ranges from 0 mg/kg to 1000 mg/kg. If you see MGO 100+, then the manuka honey contains at least 100 mg of methylglyoxal. When MGO is above 100 mg/kg, it is considered antibacterial.

When UMF is in the range of 0 to 5+, then the manuka honey has low antimicrobial activity, similar to that of regular honey. The NPA rating is essentially equivalent to UMF.

Manuka honey is generally safe to consume. However, it is not recommended to give to children younger than 12 months old because of the risk of botulism. Furthermore, individuals who have diabetic conditions, and those who are allergic to bees or other types of honey should consult a physician before using it.

‌‌‌‌Green Tea Has Immune Boosting Polyphenols

Consuming green tea can have a positive impact on your immune health. Research has demonstrated that polyphenols in the tea – particularly epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) – have the ability to suppress viral and bacterial activities.

The amino acid L-theanine is also found in green tea and has been shown to enhance immune responses. It contributes to the production of certain white blood cells. L-theanine also helps to make interferon-gamma, which is an important signaling protein for the immune system.

You can choose to drink green tea as a beverage or take it as a capsule or liquid extract. When consumed in moderate amounts as a beverage, it is believed to be safe. Kidney and liver damage, however, can be caused by polyphenol toxicity at doses higher than 800 mg.

Unless decaffeinated, green tea contains a significant amount of caffeine which can be associated with its own side effects like headaches, anxiety, feeling jittery, sleep disruption, increased heart rate, and elevated blood pressure. 

References:
  1. https://www.fda.gov/drugs/information-drug-class/qa-consumers-hand-sanitizers-and-covid-19
  2. https://academic.oup.com/jcem/article/96/7/1911/2833671
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124957/
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1160577/
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2277319/
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6628855/
  7. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001364.pub4/full
  8. https://ods.od.nih.gov/factsheets/Zinc-Consumer/
  9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4837971/
  10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763290/