Most people are familiar with the nutrients that can help ward off or shorten the duration of the common cold or flu, namely vitamins A, C, and D, and the mineral zinc. Perhaps less familiar to some people are the many plants that also may be beneficial by stimulating the immune system or by other means such as enhancing the elimination of toxins by increasing sweating or loosening phlegm in the respiratory tract, for example. Though there are many that could be talked about, in this article I will focus on a handful of my favorites that have a direct effect on the immune system.
Echinacea - A classic immune herb native to the United States. It stimulates the activity of white blood cells in their attack against viruses as well as speeding up the rate of replication of a type of white blood cell known as lymphocytes which translates into quicker resolution of the infection. There is a common misconception that echinacea should only be used for short periods of time, but the vast majority of research supports the idea that it is best used prophylactically as a safe and effective preventative treatment over the course of months.
The form of the herb is important to take into consideration. A tincture (alcohol-based extract) of the fresh plant captures many of the plant's active constituents but not the important water-soluble polysaccharides. So to get the most potent effect from echinacea it is best to consume it in the form of tea with some tincture added to it.
Osha - Surprisingly, very little research has been published on this plant though in its traditional use it is highly revered as a medicine for viral infections, especially of the upper respiratory tract. It has some expectorant qualities and stimulates sweating so it is more than simply anti-viral. It has a close relative - Lomatium dissectum - that also has a great reputation as an anti-viral herb and was used extensively during the Spanish flu pandemic around the time of world war I. However, Lomatium can cause an itchy rash in some people (that goes away after discontinued use) so I believe Osha is a better choice.
Astragalus - The root of this plant has been used in Traditional Chinese Medicine (TCM) for thousands of years. Its value in treating colds and flu isn't as a directly anti-viral herb, but for its immune enhancing properties that increase a person's resistance and as such, does well as a preventative. Studies show it to increase the proliferation of T-cells and B-cells of the immune system and the production of IgM antibodies. It also enhances the body's initial non-specific immune response while also decreasing chronically high levels of inflammatory compounds such as cytokines.
Medicinal Mushrooms - I mention this group of botanicals because there are several that are potent immune enhancers and should be considered when looking for useful herbal supplements for the cold and flu season. Reishi mushroom, for example, increases the number and activity of several types of immune system cells and increases the body's production of interferon. It is considered to have anti-viral, anti-inflammatory, and anti-histamine effects. Shiitake, maitake, and turkey tail are some others that deserve mentioning that could strengthen a person's immune system and make one more resistant to invading pathogens. Mushrooms are fascinating and unique and may be the subject of a future blog post.
This is by no means an exhaustive list and there are many other herbs that can be helpful for staying healthy during the winter months. Honorable mention should be given to elderberry, boneset, garlic and andrographis just to name a few more.
I also have to add that it is very important to get a good quality brand. Unfortunately, there are plenty of not-so-good quality supplements on the market. I realize it is hard to know. A few brands that I like and trust are Supreme Nutrition Products, Gaia Herbs, and Herb Pharm.