5 Immune Boosting Foods, Herbs, and Nutrients for Flu and Travel Season
Written by Delilah Bisase, RD
We are still technically in the midst of cold/flu season because it lasts from approximately October through March. This year’s cold/flu season is definitely compounded by the fact that we are (still) in the midst of the ‘Rona pandemic. Here are some foods and herbs to keep in your kitchen to help your immune system stay in its best shape throughout flu season and spring/summer travel time, because people are back to traveling likes it’s 2019!
Note: Although the items listed here can help promote optimal immune function, they are not guaranteed to prevent or cure a COVID-19 infection. As always, consult your medical doctor before introducing any new supplements into your diet.
1. Raw Garlic
Raw garlic is a great antimicrobial, and it’s the most accessible item on this list. However, to maximize the antiviral effects it must be consumed in the fresh, raw form because the allicin contained in garlic is volatile (although this nutritionist shares a tip to preserve the goodness). Allicin is the most researched antimicrobial component in garlic and it gets released when it’s crushed, sliced, or chewed. So instead of the powdered and the pre-sliced/pre-peeled jars of garlic, it’s best to buy a fresh bulb of garlic. One option would be to just chew the raw cloves with a bit of agave or honey. Or if you’re like me with sensitive taste buds, you can try this garlic smoothie to help mask the intense bite that raw garlic has.
Dee’s Raw Garlic Smoothie
2 cloves raw garlic
1 handful raw spinach or kale
½-¾ cup frozen pineapple
1 banana (optional)
1 cup your liquid of choice (I typically go with a non dairy milk with a bit of coconut water)
2. Reishi (medicinal) Mushroom
Reishi is an adaptogen, and adaptogens are plants which contain certain naturally occurring plant chemicals that help our body adapt to stress and reduce the harm that stress does to the body. They work in a non-specific way on our body’s stress response system. Essentially, they make our body more resilient in the face of stress (ie: they help us bounce back!). There are many kinds of adaptogens (ex: ashwagandha, rhodiola root, maca root, tulsi, various kinds of ginseng, chaga, lion's mane…just to name a few).
Reishi has a long history of use in Traditional Chinese Medicine. It is quite interesting because it has natural antihistamine effects which makes it a perfect go-to for cold/flu season. Antihistamines are drugs used to treat the classic symptoms of allergies such as a runny nose/nasal congestion and sneezing. Some well known examples of antihistamine drugs are Claritin and Zyrtec. Reishi is also known to stimulate the immune system and has been found to increase certain types of lymphocytes. These are white blood cells that function as a part of our immune system and help the body fight off infections. Reishi has also been widely researched for potential anti-cancer properties.
The most common way to consume reishi is either in the form of tea or in a capsule.
3. Cruciferous Vegetables
Dark green leafy vegetables are nutritional powerhouses in general simply because they are loaded with antioxidants. Antioxidants help your body fight off inflammation and keep your whole body system thriving. So it’s best to keep these veggies in your diet year round.
Cruciferous vegetables are the family of vegetables that include:
Broccoli, Kale, Bok Choy, Collard Greens, Cauliflower, Mustard greens, Brussel Sprouts, Swiss Chard, Radishes, Turnips, Kohlrabi
The reason I’ve highlighted cruciferous veggies for this post is because they are overall great for respiratory health, especially broccoli. Vegetables in this family are concentrated in a plant compound called sulforaphane which has been found to be protective to the lungs. To maximize sulforaphane absorption, opt for raw broccoli versus cooked broccoli. Fun fact, this chemical also boosts the activity of natural detoxifying enzymes in the liver, hence it has gotten a lot of attention for its potential role in cancer prevention. Additionally, these vegetables are typically rich in other nutrients such as folate, vitamins C, K, and E, calcium, selenium, and potassium. An easy way I like to get broccoli in it’s raw form is by adding broccoli slaw to my salads, wraps, and even on top of Asian style noodles.
4. Vitamin D
This vitamin has gotten so much attention during the pandemic, and it’s not without reason. Long before the COVID panny, it was already well known that Vitamin D can stimulate the immune system and help bolster its functions. Because of this it continues to be used (often in conjunction with zinc) as a means to reduce the severity and duration of a COVID-19 infection. Pandemic or not, vitamin D is an important nutrient to ensure you are consuming adequate amounts of year round for a healthy immune system.
How to Supplement vitamin D
First consult with your doctor to check your levels and advise proper dosage. A wide range of dosages are on the market, from 500-5000 IU (IU= international units)
The RDA (recommended dietary allowance) for ages 1 to >70 yrs ranges from 400-600 IU per day
It’s recommended to choose the D3 form instead of D2 because D3 is better at raising and maintaining vitamin D levels. However, still consult your doctor because your past medical history can affect which form is most appropriate for you.
Vitamin D is a fat soluble vitamin, meaning that it’s best absorbed in the presence of fat. Take it in the same sitting with food/meal that contains fat. Or you can take it alongside an omega-3 fat supplement.
Keep it vegan: most commercial vitamin D3 supplements are sourced from lanolin which comes from sheep’s wool. Vegan forms of vitamin D3 are sourced from lichen, a type of fungus. There are many brands to choose from, lately I’ve been using Naturelo.
An interesting note about vitamin D and dark skin:
Some research suggests that the current testing standards may not be the best fitting assessment for Black people. The speculation is that the current test (hydroxy vitamin D) measures the vitamin D in a form that doesn’t accurately reflect the way it is stored in people with dark skin.
5. Echinacea
Echinacea is known as an immunostimulant, meaning that it stimulates or increases the activity of the immune system. This herb is known to increase both innate and specific immunity. It’s been found to decrease the chance of developing a common cold by 58%. Overall, it has the potential to shorten the duration and/or reduce the severity of the cold. The most common way to consume this herb is in the form of tea, however capsules are available widely as well.