As weather gets colder, some of us start to feel that little “nip” of something—a scratch at the back of the throat, a little cough, or maybe just feeling more tired than usual.
You know the feeling well. Cold and flu season is right around the corner, as soon as winter begins. What’s worse, there’s no way to directly cure or prevent colds. The most we can do is to stock up on plenty of fluids, vitamin C, a humidifier, and maybe some cough drops to get us through.
But there’s one thing you can proactively do for health with the help of both nutrition and herbs: support the immune system.
Eating plenty of vitamin- and mineral-rich foods is a start, which helps maintain a healthy immune system, your #1 natural helper for getting through winter smoothly and easily.
But beyond nutrition, there are a few herbs you can turn to for a little immune system help.
A dainty plant whose home is the lush, damp forests of Southeastern Asia, andrographis—also called green chiretta—has been cultivated for thousands of years for traditional health purposes. These include fighting infection, aiding digestion, and helping liver issues.
Andrographis has also been prominent in Ayurveda and Traditional Chinese Medicine (TCM). In line with its historical uses, research suggests that andrographis may help boost immunity to fight foreign invaders, making this plant an excellent winter helper.
One study of the plant in 2010 specifically found that it may stimulate macrophages and antibodies, parts of the immune system that help battle infections and viruses.
Can andrographis kill a cold? Not directly. But it can be a small part of building healthy immunity, which is important to health especially in winter.
Another helpful ally in one’s wintertime immune arsenal: elderberry (Sambucus nigra).
This botanical comes from Europe, where the berries were specifically used as a health-boosting tonic. Unlike most berries, elderberry must be consumed differently—the berries cannot be directly eaten since the seeds make people ill. Instead, an infusion, decoction, or extract must be made of the berries, which is then safely consumed.
These preparations—rich in vitamin C, antioxidants, and phytonutrients—were traditionally taken as a tonic before and during the winter. It was thought that elderberry could keep viral sicknesses at bay, like colds and flu.
Studies may support this idea. One recent trial in 2016 demonstrated that elderberry, when taken by travelers developing colds, helped shortened the duration of the illness in most.
While elderberry cannot kill a cold or flu, research suggests it may be a healthy herb that helps your immune system cope.
Astragalus (Astragalus membranaceous) is a fern-like plant closely related to peas and beans. Like elderberry and andrographis, it has its own background in folk medicine for helping people through tuff times.
Though it’s never been proven to cure colds, studies show positive signs that astragalus could be great for immunity and helping to keep healthy.
As it turns out, research suggests astragalus immune properties may be very effective. An animal study in 2013 found that the botanical could prevent the growth and spread of bird flu in the body, which is a powerful virus. This could mean that astragalus may be effective against colds also—though more research is certainly needed.
Not coincidentally, traditional healers in Asia tended to use astragalus for just that: to prevent illness and boost overall health and immunity.
Ever heard of acerola cherry? A berry that is super-rich in vitamin C from the West Indies, it may just have a competitor—a berry-bearing plant from Brazil in South America called camu camu (Myrciaria dubia).
Research on the berry shows that it is incredibly rich in vitamin C, as well as minerals like iron, potassium, and calcium. It also contains healthful amino acids leucine, serine, and valine. Beyond that, a 2010 study of various antioxidant-rich fruits found that it was quite similar to acerola cherry when it came to phytonutrient and antioxidant content.
However, it may have even more vitamin C than acerola cherry, one of the most famous vitamin C-rich foods. NutritionData says that acerola cherry contains an average of around 1600 mg per about 100-gram serving. Camu camu, on the other hand, contains anywhere between 1800 to 2300 mg per 100 grams.
While vitamin C has not been shown to have strong effects on the duration of wintertime illnesses, the vitamin is nevertheless an essential nutrient to the human diet for maintaining a healthy immune system and camu camu could be a great source of the vitamin.
Wintertime support doesn’t have to be found solely from nutritious berries and herbal remedies. It may surprise some that you can find similar benefits in unlikely mushrooms—and reishi mushroom is one of the best-known of all healing mushrooms.
This tough fungus grows on trees in woods all around the world, including Asia, Europe, and North America. It usually exhibits bright colors like reds, golds, oranges, and even mauves and purples.
The stories of its traditional use for viral illnesses are even more vibrant than its appearance. In China it was known as the Lingzhi mushroom, famous for strengthening all-around health and immunity and preventing all sorts of diseases as a legendary medicine.
While reishi is not guaranteed to fight or cure any disease today, studies on its immune-boosting benefits are numerous. Though the fungus has yet to be proven for therapeutic use, it may be helpful to the immune system during seasonal change. Just make sure to use an extract as the mushroom or raw powder have such a thick cell wall they cannot be digested in these forms.
We savor olives in our favorite dishes, and even use olive oil for cooking and meal prep. There are certainly benefits to olives—but did you know that there are interesting properties in the olive leaf?
Specifically, studies (like this one in 2010) reveal great antioxidant content in olive leaves. While this hasn’t been connected to any ability to cure or prevent colds and flus, it has shown some immune-boosting properties, such as in this 2010 piece of research.
Adrian White is a certified herbalist based in Iowa, and has completed two separate herbalist training programs. She’s also an organic farmer of near a decade. She is co-owner of Jupiter Ridge Farm, producer of mushrooms and vegetables. Adrian freelance writes and has contributed to publications such as The Guardian, Civil Eats, and Gardening Know-How. She currently regularly contributes to Rodale’s Organic Life and Healthline.