A recent report in Pediatrics warns of the risks of lung damage from the "cinnamon challenge" — a stunt where someone attempts to swallow a tablespoon of cinnamon in 60 seconds without drinking fluids. Because the cinnamon absorbs saliva, people usually choke and cough out a cloud of cinnamon smoke to the amusement of their peers. (An exception was MythBuster Tory Belleci, who managed to swallow the cinnamon after tucking it squirrel-style into his cheek, but not within 60 seconds)
Online, cinnamon challenge clips beckon to fresh participants hoping to rocket to stardom on a plume of orange dust and saliva, with one clip by comedienne GloZell Green having received now 27 million views. The other 51,100 videos (as the Pediatrics report counted them), not so much. Alexa's rating for cinnamonchallenge.com, which promotes the challenge, has spiked in recent days to #133,379 in the United States, receiving visits from no less than 1.8 out of every million internet users during the past three months. Over the past three months only half as much traffic reached opposing site nocinnamonchallenge.com, but in recent days it has pulled into the lead as news outlets covered the story.
The bad news is that the stunt can result in an urgent call for help to poison control centers, as happened 122 times in the first half of 2012 — up roughly four-fold from 2011. Thirty of these cases required medical attention. Though usually the symptoms were brief, a few cases were placed on ventilator support with collapsed lungs or pneumonia. Cited by the Pediatrics article from a news broadcast and not explained in detail, the collapsed lungs may be atelectasis, a condition in which some of the tiny sacs in the lung fail to expand because a bronchiole is blocked or the surfactant covering the inner surface of the lung is disrupted. By analogy to a similar observation with inhaled talc, the cinnamon might absorb surfactant and fluid in the lungs just as it does in the mouth, disrupting the lung's expansion.
The worse news was that in two animal studies, particles of cinnamon introduced into the trachea could result in inflammation and immune reactions including fibrotic lesions (scarring) which some compare to emphysema. This is mostly the result of the cellulose fibers, many of which can neither be broken down nor expelled from the lungs by any means short of an all-out attack by the immune system. Granulomas very slowly break down the fibers in much the same way as bleach puts holes in a cotton shirt, but the process takes a toll on the lungs. In addition to cellulose, cinnamon contains cinnamaldehyde, a potential irritant that might contribute to the lung damage, but inhaled paprika has many of the same effects.
Because there is no comparable lab data for humans, it is not clear how many past participants in the challenge might suffer some long-term effect. Nonetheless, the workers in local cinnamon buyers' stores in Sri Lanka might have told us that breathing it is a bad idea. One small study reported that 37.5% of those tested had chronic coughs, and 22.5% had asthma, versus 6.4% and 2.2% asthma rates in tea and kapok workers.
Used properly, cinnamon can do more good than harm. There is concern that a variety frequently sold in the U.S. may contain enough coumarin to create a risk of liver damage in susceptible individuals who consume large amounts, but the compound also contributes to cinnamon's role as a natural appetite suppressant and anti-clotting agent, and might even help to protect the liver from effects of a high-fat diet.
Two varieties of cinnamon are among the fundamental herbs of traditional Chinese medicine, used from ancient times to treat conditions such as diabetes and gout. Modern data backs this up with evidence that cinnamon weakly inhibits xanthine oxidase, which is a known way to treat gout, and lowers fasting blood glucose while helping to stabilize blood glucose levels after eating. No matter how small the world may seem nowadays, we still have much left to learn from other cultures, even about what our most common foods can do to help or hurt us.