If You Smell This, Your Risk of Seizures May Be High, New Study Says

According to new research, these popular everyday items may not be as safe as advertised.

Whether it's turning on a diffuser or lighting scented candles, aromatherapy is a popular daily ritual that many use to unwind or relax. But it turns out that some scents could trigger a medical emergency. A new study from India has found that the smell of certain widely used products may increase your risk of having a seizure. Read on to see what you should be aware of the next time you're shopping for scents, and for more odor-related warnings, If Your Breath Smells Like This, Get Your Liver Checked, Experts Say.

Some essential oils can increase the risk of having a seizure.

Bottles of various essential oils sitting on a table top with flowers in the background

In a study published in the journal Epilepsy Research on March 26, researchers analyzed 350 seizure cases from across four South Indian hospitals over the span of four years. Results showed that 15.7 percent of the seizures—making up 55 patients from the group—could potentially have been induced by inhaling, ingesting, or applying eucalyptus or camphor essential oils.

Researchers found that while some patients in the group had histories of epilepsy, 40 percent had never experienced a seizure before. Also, once patients were advised to stop using essential oils, their follow-up visits with doctors over the following one to three years revealed that almost none experienced another seizure. And for more things to avoid, If You Take These 2 Supplements, Your Stroke Risk May Be High, Study Says.

Ingesting or inhaling eucalyptus or camphor essential oils could be risky for some.

A bottle of eucalyptus essential oil in front of a eucalyptus branch

The study notes that most patients had reported using toothpaste, balms, pills, or other items containing eucalyptus or camphor, which are popular products in India for treating everyday maladies such as pain, headaches, or cold symptoms. But in an interview with The Academic Times, Thomas Mathew, PhD, one of the study's authors and head of the neurology department at St. John's Medical College Hospital in Bengaluru, India, called the initial results of the study "surprising and shocking."

"Ingestion of eucalyptus and camphor has been reported to trigger seizures, while the topical application is generally perceived as safe. However, our observations from the current study indicate that this may not be true," the study's authors wrote. And for more on how to keep other vital organs safe, If You Drink This Much Coffee a Day, Your Heart's in Danger, Study Finds.

The study's authors say further research is needed to fully understand the connection between essential oils and seizures.

Female patient touches her temples while explaining her headache pain to a caring female doctor

Despite being "one of the largest studies on essential oil-related seizures in adults," the researchers were quick to emphasize the limitations of their research, saying that the small number of patients from one area of India meant a more widespread study would have to be conducted.

The "true incidence of these essential oil-related neurological disorders like seizures are difficult to ascertain as doctors rarely ask these in their history taking, as these are not mentioned in conventional textbooks or teaching curricula," Mathew told The Academic Times. "We need large epidemiological studies to find the true prevalence, which is unfortunately not available at present." And for more health news delivered straight to your inbox, sign up for our daily newsletter.

Some experts already warn people with epilepsy against using essential oils.

Essential oils

While the Indian study may have been the largest to date, it's not the first time the use of essential oils has been linked to seizures in some people. According to the Epilepsy Society in the U.K., there are a few oils that anyone who has epilepsy should avoid, including rosemary, fennel, sage, eucalyptus, hyssop, wormwood, camphor, and spike lavender. And for more on how you can keep your brain healthy, Doing This One Thing Twice a Day Lowers Your Dementia Risk, Study Says.

Zachary Mack
Zach is a freelance writer specializing in beer, wine, food, spirits, and travel. He is based in Manhattan. Read more
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