Sesame oil? Granite baths? Sea lettuce? COVID-19 rumors spread like a virus in Japan

Can applying sesame oil stop the new coronavirus from entering the body? Is it true that a hot water and granite rock bath will help kill the virus? Does taking vitamin D make people less susceptible to the pathogen?

In a nation gripped by fear amid the COVID-19 outbreak, rumors swirling online that appear to have little or no scientific justification have, at times, persuaded people to flock to e-commerce websites in search of items touted — often falsely — as effective against the new coronavirus.

Some of these claims are simple misconceptions, but others are more sinister and deliberate, finding their way into inboxes as spam email containing malware.

The health ministry and cybersecurity firm Trend Micro are already urging caution against a few examples of what they say is a campaign of disinformation, including a text message claiming to give away free face masks, and encouraging recipients to click a link leading to an illicit site.

Be it misinformation or disinformation, what are some of the most prominent COVID-19 myths that have caught the attention of the Japanese public so far? Are they all absolute nonsense or is there a kernel of truth somewhere? And what health tips do experts have to offer in lieu of those misguided bits of knowledge to help us better fight the virus?

Rumor 1: Drinking lukewarm water of 26 degrees to 27 degrees will kill the virus

One spam message circulating on the Line messaging app peddles the idea that the new virus is vulnerable to heat, and encourages people to drink “as much hot water as possible,” specifically heated to a range of 26°C to 27°C.

Koichiro Yoshida, a professor of infectious disease studies at Kindai University, says the claim has no scientific basis, and that given the recommended heat range is lower than average body temperature, it is nearly impossible that such lukewarm water will do anything to destroy the new coronavirus.

In comparison, when the SARS (severe acute respiratory syndrome) crisis broke out in 2003, the National Institute of Infectious Diseases said that particular coronavirus could be killed with water boiled for 15 minutes at 98 degrees or higher.

Rumor 2: Intake of vitamin D is effective against the new coronavirus

The National Institute of Health and Nutrition rebutted this as false on its official Twitter account. The organization cautioned that the rumor, which it said was based on a past academic paper that asserted the vitamin’s effectiveness against influenza, has not yet been corroborated by any scientific data.

Hiroshi Yotsuyanagi, a professor at the University of Tokyo who studies infectious diseases, agreed, although he said vitamin D is generally thought to be helpful in boosting immunity against viruses.

“But the extent to which vitamin D can increase immunity is very subtle, so there is no way that just taking vitamin supplements will be able to prevent you from contracting” the new coronavirus, Yotsuyanagi said.

Rumor 3: Face masks can be reused if sterilized in a microwave

Both Yoshida and Yotsuyanagi expressed skepticism about this method, citing a lack of scientific evidence backing up the claim. Yotsuyanagi said heating up dirty face masks would only risk contaminating the inside of microwave ovens, while Yoshida wondered if the wire inside masks would spark a fire if microwaved. An industry group of Japanese mask manufacturers said in a statement Wednesday that face masks should not be reused unless advertised as washable.

But if current shortages force one to use nonwashable types more than once, one is advised to wash them by gently “pushing” — instead of scrubbing — them multiple times in water mixed with a neutral detergent, the group said. One should then rinse them sufficiently and dry them, avoiding the use of a machine dryer in order to minimize damage, it added.

Rumor 4 : Vodka can stand in as a homemade hand sanitizer

Spirytus Rektyfikowany, a Polish vodka touted as the world’s strongest booze with a whopping 96 percent alcohol content, is reportedly in short supply in Japan as people frantically search for alternatives to hand sanitizers, which are also fast disappearing from store shelves amid the outbreak.

Million Trading Co., a Tokyo-based importer of foreign alcoholic beverages, saw shipments of the Polish vodka soar in late February, so much so they more than doubled from the level seen in regular years, according to Jiji Press. Both Yoshida and Yotsuyanagi said it is “possible” that the Polish drink could be a replacement for hand sanitizers, given its extremely high percentage of alcohol, although neither could vouch for its efficacy.

A resurgence of vodka’s popularity amid the coronavirus outbreak is not peculiar to Japan. Texas-based distiller Tito’s recently reached out to a number of Twitter users who expressed an interest in concocting their own hand sanitizers out of vodka. The maker noted that its beverage is not strong enough, citing a U.S. Centers for Disease Control and Prevention (CDC) guideline that says hand sanitizers need to contain at least 60 percent alcohol. “Tito’s Handmade Vodka is 40 percent alcohol,” it said.

As far as a sanitizer replacement goes, Yoshida recommended diluting Haiter, a popular brand of bleach produced by chemical and cosmetics company Kao, to 0.02 percent to 0.05 percent by mixing it with water. The makeshift sanitizer, however, is damaging if sprayed on human skin, so its use should be limited to certain objects and surfaces, he said.

Rumor 5: Applying sesame oil to the body blocks the entry of the new coronavirus

The World Health Organization unequivocally denies this, urging caution on its website: “Sesame oil does not kill the new coronavirus.”

Some chemical disinfectants, the WHO said, can kill the new virus on surfaces, including bleach/chlorine-based disinfectants, those with 75 percent ethanol, peracetic acid and chloroform. But those chemicals, it said, have “little or no” impact on the virus and can even cause harm if they come in contact with skin or a person’s nose.

Kawasaki-based cosmetics firm Shimura Co. said it has witnessed a surge in inquiries from customers asking for sesame oil’s ability to fend off the novel coronavirus.

“Although our products with sesame oil can prevent a cold or hay fever if applied to your nose or used to rinse your mouth, their effectiveness against the new coronavirus is not verified yet,” the firm said in a statement earlier this month.

Rumor 6: Granite is effective against the new coronavirus

Talk of granite as a possible weapon against COVID-19 has reportedly led to rocks being auctioned at sky-high prices on shopping websites such as Mercari. According to Fuji TV, granite rocks, some priced at around ¥5,000, were selling briskly on one flea market website, while on Mercari, a seller was claiming the rock can destroy the virus if used when bathing.

Most of these items are no longer being promoted on e-commerce sites now that they have started cracking down on those who are attempting to cash in on virus fears. Mercari spokeswoman Ayaka Suzuki neither denied nor confirmed the reports, but acknowledged that “it is true that some sellers were auctioning items that they are touting as being effective against the coronavirus.”

Yoshida said he had never heard of granite’s ability to kill a virus.

Rumor 7: Aosa, a type of edible green seaweed, is effective against the new coronavirus

The rumor originated from a now-deleted press release published by Chubu University in Aichi Prefecture that reportedly boasted that recent research co-led by professors from the school had discovered the sea lettuce’s potential ability to stem the proliferation of the new coronavirus — although the research itself was primarily focused on a different type of coronavirus.

The announcement, however, quickly fueled the narrative that eating aosa would help counter COVID-19, generating a spike in demand for the seaweed on shopping websites.

When contacted by The Japan Times, Chubu University refused to confirm any details of the original press release.

“The press release’s use of misleading language ended up emphasizing parts that were not based on facts,” the school’s public relations department said in a statement. “We are currently considering rewriting our press release to describe more accurately the conclusions of the research.”

More resources to inoculate yourself against misinformation

• WHO’s myth busters page
• Buzzfeed’s list of virus-related disinformation
• The Guardian’s coronavirus fact checker
• John Hopkins’ myth vs. fact list
• 14 bogus claims from Business Insider
• FactCheck.org’s coronavirus collection