Science behind home remedies
Some age-old methods to beat flu, cold may actually work
Experts are already predicting that this year’s flu season will be a rough one and are reporting a rise in a variety of other respiratory illnesses as well, after two years of relative quiet.
The best precaution against influenza is getting vaccinated. There is little you can do once you get sick beyond managing your symptoms. The flu, common cold and most other upper respiratory illnesses are caused by viruses, so you cannot cure them with antibiotics, which are used to treat bacterial infections.
Antiviral drugs for treating influenza, like Tamiflu, are usually reserved for people who have tested positive for the flu and are at risk of developing severe complications, such as those who are pregnant, elderly or immunocompromised. For everyone else, doctors suggest resting and waiting out your symptoms — which for flu can include a fever, headache, body aches and a stuffy or runny nose that lasts three to five days. Some people might also develop a cough or sore throat or experience fatigue, which can last a little longer, said Dr. H. Keipp Talbot, an associate professor of medicine at Vanderbilt University Medical Center.
Cold symptoms are similar, but they are generally slower to build, milder than what you would experience with the flu and unlikely to result in serious health problems. (People with COVID
-19 also experience respiratory symptoms; testing is the best way to know which virus you have.)
“There’s a saying that if you treat a cold, it goes away in seven days; if you leave it alone, it goes away in a week,” said Dr. Aviva Romm, who specializes in integrative medicine.
But for generations, countless home remedies have helped manage cold and flu symptoms. Scientists have conducted research attempting to quantify how effective those remedies are, how frequently they should be used and what formulations work best. But the studies are often small or don’t show much efficacy.
Here’s what we know about some popular remedies that show at least a little promise.
Bolstering the immune system
There is some evidence to suggest that certain vitamins and ingredients in home remedies — like vitamin C, elderberry and zinc — can, at the very least, stimulate the immune system and slightly shorten the duration of symptoms.
The idea that vitamin C can help with a cold was popularized by Nobel laureate Linus Pauling in the 1970s. Since then, scientists tied to the supplements industry have suggested that vitamin C supports immune cells’ ability to fight off infection.
The nutrient’s effectiveness is still debated. The body is not able to store high doses of vitamin C, like those found in supplements. A comprehensive meta-analysis of vitamin C trials published in 2013 suggests that regular supplementation, even before you start to feel sick, can shorten colds by a day or so. But taking vitamin C after you’ve developed symptoms does not show consistent benefits.
In some studies, elderberry, a common ingredient in cold and flu syrups, shortened the duration of symptoms when taken at the start of an illness. But it’s a very limited amount of data, Romm said. Elderberries contain antioxidants and chemicals known as anthocyanins, which have been shown to help immune function.
Similarly, research on zinc suggests that taking syrups and lozenges containing the trace element every three to four hours might reduce the length of a cold or flu by a day or two, potentially by preventing viruses from multiplying. Other analyses have concluded there is not enough evidence to say it is any better than a placebo.
Most formulations of zinc have side effects. Some people who used zinc nasal sprays have experienced a permanent loss of smell. Those who take it orally can get a lasting metallic taste in their mouth.
Hydrating and soothing a sore throat
A sore throat is often the result of inflammation created when your immune system is fighting off a virus lodged in your upper airways. The swelling and pain can make it more difficult to swallow food and stay hydrated. Drinking water, hot teas, broths or soups can help you feel more comfortable.
In many cultures, ginger is one of the first things people reach for when faced with a sore throat. It’s often steeped in boiling water along with other herbs to make soothing teas, or added to chicken soup. There might be some science to back up these age-old practices: A handful of studies has found that ginger may have antiinflammatory properties that can ease swelling.
Turmeric root, a plant in the ginger family long used in ayurvedic medicine, can also reduce inflammation. But its effects have been challenging to prove because the main compound in the root, curcumin, isn’t easily absorbed in the body. Eating turmeric in food or mixing it with a fatty substance, such as cooking oil or warm milk, may help you absorb more curcumin. Adding black pepper can also aid in its absorption, Romm said.
Controlling a cough
Gargling with salt water might calm a cough. Mix half a teaspoon of salt in a glass of warm water and swish it around your mouth and throat for a few seconds before spitting it out. Any type of salt you have at home can work.
Adding honey to your gargling solution, or to any warm drink, can also have a soothing effect. Honey calms down irritated tissues by coating them.
Relieving congestion
Keeping your nasal passages moisturized might also help with relief.
The use of neti pots and nasal irrigation can be traced back thousands of years to ayurvedic medicine. Much like gargling with salt water, nasal rinsing might help remove some virus and mucus from your body, while reducing the swelling that can cause congestion. One study from 2019 showed that this process may help shorten the duration of illness as well as reduce the transmission of germs to others.
Use only distilled, sterile or boiled water for your rinses, as tap water can contain small amounts of bacteria that carry the risk of other infections. Alternatively, you can try commercial nasal saline sprays.
Dr. Fadel Hind, an infectious-disease physician at the Mayo Clinic, keeps a humidifier running in her house during winter. Her research has shown that keeping rooms at a humidity level of about 40% to 60% reduces the transmission of respiratory viruses.
Menthol, a chemical found in peppermint and other mint plants, can give the sensation of easier breathing. You can dab a store-bought menthol ointment like Vicks VapoRub under your nose or on your neck and throat. Some people also use the fresh or dried herbs in steam therapies for clearing congestion. Steep herbs, like eucalyptus or thyme, in boiling water for five to 10 minutes, then cover your head with a towel and breathe in the steam. You can also hang the dried leaves in a steamy shower.