I think I’m coming down with something.
Usually that means I prepare a mug of tea, add a spoonful of honey kept solely for such occasions, and add a dash of lemon juice. This elixir, I’ve been told, will soothe my sore throat and coax my raspy voice back to normalcy. But does it actually work?
“I have to say, when I have patients that are sick, I often ask them to sip hot tea,” says Dr. Edward Damrose, chief of laryngology at Stanford Health Care. “But I’m not sure that it’s the tea itself that has the beneficial property, or that the warm water cuts through the phlegm and makes patients feel good.”
To figure out whether the classic tea drink alleviates a sore throat, it helps to know what causes a sore throat in the first place. As Damrose explains, the throat is divided into two parts: a pharynx and a larynx, and both can be infected at the same time or separately. We use our pharynx when we swallow food or liquid. Bacterial or viral infections can cause the pharynx to swell and lead to a sore throat.
When we speak, on the other hand, we use our larynx, the part of the throat that contains our vocal cords. Viral infections make it more difficult for the vocal cords to vibrate, causing us to lose our voices.
How exactly this happens is something of a mystery. “We have a lot of ideas but not a definite answer,” says Dr. Jennifer Long, assistant professor of head and neck surgery at the David Geffen School of Medicine at UCLA. One theory suggests that white blood cells storm the vocal cords, causing them to swell and preventing vibration. Another theory is that viruses injure the surface of the vocal cords, making it difficult to vibrate. “For being a common problem, it’s surprising how little we know,” Long says.
On top of this uncertainty, there’s not a lot of good research on whether tea or honey can help a sore throat or lost voice, according to Dr. Maya Sardesai, an associate professor of otolaryngology and surgery at the University of Washington School of Medicine. High-quality health studies typically use placebos, but that’s difficult in this case, Sardesai explains. Most people can tell whether they’re drinking tea and honey, so creating placebos for study participants is challenging.
These difficulties aside, all three doctors are willing to speculate about whether tea, honey and lemon help a sore throat and voice loss.
Let’s start with tea. Because liquids and food go down our pharynx, not our larynx, Damrose points out that any beverage is unlikely to have a direct effect on our vocal cords. But tea could still help a sore throat that results from a swelled pharynx. Research has shown green tea has anti-inflammatory properties, which could help decrease a sore throat’s swelling. Perhaps more importantly, according to Damrose, when people drink a liquid like tea, the act of sipping and swallowing prevents irritating coughing. Warm liquid can also help remove throat phlegm. Long and Sardesai recommend teas with low caffeine, because caffeine may lead to greater acid production and irritate the throat further.
As for honey, “it’s really very speculative” whether honey helps throat pain, according to Long. Honey might be a natural anti-coughing agent, but so far research is inconclusive. On the other hand, none of the doctors suggest that honey might harm the throat.
That’s not the case for lemon. “I actually worry about too much lemon because it’s so acidic, and acids can be irritating” to the throat, says Long. Sardesai agrees, though she notes that “lemon does have vitamin C, and vitamin C is thought to be helpful early in some infections.” Damrose notes another plus: Lemon has antibacterial properties, which could fight off bacterial sore throat.
The tea-honey-lemon trifecta has a mixed report card. For more tested treatments, the doctors recommend resting, inhaling steam and — in the case of voice loss — speaking as little as possible (yes, that includes cutting back on whispering). Symptoms should subside within two weeks, and if not, a trip to the doctor is warranted.
I’ll do my best to follow the doctors’ advice. Just as soon as I finish my cup of tea.
Natalie Jacewicz is a science writer based in New York City. You can find more of her work here. Gnawing Questions is a semi-regular column answering the food mysteries puzzling us and our readers. Got a question you want us to explore? Let us know via our contact form.