My experience may have been a lucky coincidence, but it opened my mind to the world of natural medicines. Folk remedies like my friend’s ginger tea have been around for centuries, but they’ve been eclipsed by over-the-counter cold solutions. While these may be effective, they can carry unpleasant side effects and be full of undesirable ingredients. Natural immune boosters almost never have these problems—and some may even be preventive.
Of course, nearly any doctor will say that eating right, drinking lots of fluids and getting enough sleep are the best ways to strengthen your immune system. Dr. Mary Hardy is medical director of the Simms/Mann UCLA Integrative Oncology program and has studied botanical medicine on four continents. She recommended more water for everyone, saying “people don’t drink enough water. Period.” In addition, she suggested avoiding diuretics like caffeine, and using a humidifier by the bed.
The Antimicrobial Kitchen
When colds and flu circumvent a healthy lifestyle and standard vitamin C supplements, there are a multitude of options outside of the conventional medicine cabinet and handier than the drugstore. Hardy said science has, to some extent, validated the folk remedies our grandparents trusted. They include many kitchen staples, even ordinary chicken soup.
“It’s not just the warm water; the onions and garlic make a difference as well,” she explained. “[And] if you have a spicy soup . . . hot foods can empty out the nasal passages.”
Garlic and onions are both members of the allium family of plants, which scientists have found to have antimicrobial properties. In laboratory studies, garlic in particular has been shown to have strong antimicrobial effects, and spices confer benefits as well. Studies have found that many spices contain an antimicrobial, anesthetic and antiseptic chemical called “eugenol.” Eugenol is particularly abundant in cloves, oil of which is traditionally used as a painkiller in dentistry, but other good sources include bay leaves, basil, oregano, cinnamon and allspice. Studies are looking into eugenol as a COX-2 inhibitor, a class of painkilling and anti-inflammatory chemicals.
Sage, another common chicken soup ingredient, is a traditional sore throat treatment in Europe. Hardy recommended gargles and mouthwashes made with sage for acute sore throats. And the bright yellow spice turmeric gets its antibacterial effects from the chemical curcumin, which is also an anti-inflammatory.
Another home remedy backed by science is honey. Used for centuries to dress wounds, honey has been found in laboratories to have antibacterial, antiseptic and antifungal properties. It’s also good for a sore throat, she said; one study found that it had a throat coating effect. And unlike raw garlic, it tastes pleasant.
As Hardy noted, spicy foods like chiles and horseradish are good for clearing a stuffy nose and throat. Like spices, chilies are also antimicrobial. And capsaicin, the chemical that gives them their heat, has been found effective as a topical painkiller.
Science hasn’t explained my experience with ginger—to date it’s shown only limited antimicrobial properties—but scientists have found that ginger combats nausea and vomiting in some patients, confirming its widespread use against morning sickness. Studies have also declared it effective as an anti-inflammatory for arthritis patients.
Hardy also recommended several herbs you’re less likely to have on hand, but that have shown promise in scientific studies. Among these are:
An Asian herb with the Latin name andrographis paniculata, which some studies have found can actually stop colds before they start. It’s available as a supplement, alone or in combinations.
Any species of elderflower and elderberry. Israeli researchers found that people taking an elder product called Sambucol recovered from Influenza B about twice as quickly as people taking placebos.
American ginseng (not panax ginseng). A study funded by a Canadian ginseng supplement manufacturer found that it significantly lowered the incidence, amount and duration of colds.
Pelargonium. Used as folk medicine in southern Africa, this is the genus of plants containing ordinary geraniums, which scientists have found have strong antibacterial effects. Pelargonium is available as a dietary supplement as well as an essential oil, or you can make a tea from fresh, well-scrubbed geranium leaves—if you don’t mind the strong taste.
Another herbal cure you may not have around the house is Thai holy basil— known in Thailand as kha phrao and in India as tulsi or tulasi. A relative of the more familiar Italian basil, it’s used in Ayurvedic medicine and as a folk remedy for colds and a variety of other ailments throughout Asia. Multiple scientific studies have found that tulsi is a good source of eugenol, the antimicrobial chemical in cloves.
Most natural cures that aren’t sold as supplements can be consumed as part of an herbal tea. Boil them until the water changes color; add honey if you’re using it, plus lemon juice or other flavorings; and drink. Hardy said that when she has trouble kicking a cold, she makes a cup of strong ginger tea and adds a syrup of garlic and onions, with a little honey to make it more palatable. Medicinal herbs can also be eaten straight if you can tolerate the strong flavors.
Hardy said most natural immune boosters aren’t dangerous, especially since some may be too unpleasant to really go overboard.
“Most of these things have kind of a natural self-limitation,” she said. “If you take too much, you’re going to irritate your stomach. “The real trouble is thinking you don’t need to go home and rest and be sensible.”
—Lorelei Laird, a freelance writer and editor, still makes ginger tea whenever she feels a sore throat coming.
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