Sensationalism and misinterpretation: How scientific papers are often misreported

Can Listerine mouthwash cause cancer, or can your multivitamins kill you? If you were to Google either of these two, it’s likely that you’ll come across a multitude of headlines suggesting so, attributing the information to scientific research. 

It’s essential to understand how one reads these studies. Headlines often highlight the most ‘sensational’ part of a study, omitting the context, disclaimers, and other research findings that need to be viewed in its entirety. In isolation, studies have been quoted to highlight the cancer-causing effects of substances, harms associated with vaccines, and even cures for certain diseases. 

A research published in PLOS One, a peer-reviewed journal, in February 2017 investigated how scientific studies are reported on by newspapers. It concluded, “Journalists preferentially cover initial findings although they are often contradicted by meta-analyses and rarely inform the public when they are disconfirmed.” The research also highlighted that biomedical studies often mature and that they may or may not be very accurate to scientific consensus built on follow-up studies, and quantified by meta-analyses.

What’s important to understand is that single studies do not always have the exact answer. There are limitations, and sometimes press releases exaggerate the findings. Pranav Radhakrishnan, a science communicator popularly known as ‘Science is Dope’ on Instagram underscored how content that incites fear has the potential of going viral, and influencers often make extreme situations to grab eyeballs.

Headlines and social media posts linking mouthwash use to cancer and multivitamins use to increased mortality risk. (Source: News headlines) 

For instance: Two studies published in June 2024 garnered a lot of interest with headlines and social media posts highlighting how using “Listerine mouthwash may cause cancer” and “multivitamins may lead to high mortality.” 

But is that what the studies actually highlighted? Let’s unravel to understand why context is key to research.

‘Listerine mouthwash may cause cancer’ 

A recent study published in the peer-reviewed Journal of Medical Microbiology on June 4, 2024, by a group of researchers from the Institute of Tropical Medicine in Antwerp, Belgium, found that two species of opportunistic bacteria were significantly abundant in the mouth after three months of daily use of the alcohol-based mouthwash.  

But what was highlighted through the headlines was how Listerine, a household mouthwash, may cause oral cancer. 

The study: The study looked at mouthwashes and the oral microbiome, the small amount of bacteria that live in a human mouth. It examined a subset of 59 MSM (men who have sex with men) from a previous study that analyzed whether Listerine Cool Mint reduced the risk of sexually transmitted infections (STI) or not. It must also be noted that the sample included MSM who were taking PrEP, a medicine to prevent getting HIV.

In a nutshell:

The study concluded 

1. Listerine Cool Mint didn’t prevent STIs.
2. Listerine use was associated with an increase in two types of common oral opportunistic bacteria, which takes advantage of a weakened or compromised immune system.

But the study has not found any direct correlation between Listerine use and oral cancer, and more studies are needed to understand this.

The author explains: Speaking to Logically Facts, Prof. Chris Kenyon, one of the authors of the study, noted, “We found that MW [mouthwash] leads to an enrichment of bacteria that have been associated with mouth cancer. Other studies have found a link between alcohol use, including mouthwash with alcohol, such as the one we tested, and mouth cancers.” On being questioned about whether the paper studied any link between Listerine use and cancer, he responded in the negative and added, “Long-term use [of mouthwash] is probably not advised unless for a clear indication.” He also clarified in his email response that the sample size was not screened for smoking and alcohol intake. 

Doctor’s take: Dr. Sonakshi Varun, a periodontist at the Centre for Smile and Heart Clinic in Faridabad, said, “Co-relating the use of mouthwashes to cancer has not been highlighted in the study. It’s simply trying to identify the presence of oral microbiomes.”

‘Multivitamins kill people’ 

Nutrition and supplements are two areas often discussed in health news reports. Another study published in the peer-reviewed Journal of the American Medical Association (JAMA) on June 26, 2024, led by the researchers at the National Institutes of Health’s National Cancer Institute examined whether taking multivitamins (MV) lowers the risk of death in healthy adults.

But what was highlighted on social media was how multivitamins were linked to higher mortality. 

The study: The study analyzed health records of 390,124 adults in the U.S., who were followed for more than 20 years and had no significant long-term diseases. The study participants had lower Body Mass Index (BMI), better sleep quality, and were slightly more likely to be college-educated. It highlighted that “findings suggest that multivitamin use to improve longevity is not supported.” 

In a nutshell: The study did not find association between regular multivitamin and mortality benefits, but noted that many U.S. adults use multivitamins to maintain or improve health.

It also highlighted, “In the meta-analysis incorporating the time-varying estimates from all 3 cohorts, daily MV use, compared with nonuse, was associated with a 4 percent higher risk of all-cause mortality.” 

What’s this four percent number?:  Writer and science communicator Krish Ashok highlighted how this “completely inconsequential four percent was picked up. Firstly, the number is not statistically significant in an extensive analysis of data and does not mean vitamins caused a four percent increase.” He also said that the “absence of benefit does not imply the presence of harm.”

It must also be noted that daily multivitamin use was associated with a four percent higher risk of all-cause mortality in follow-up period one (which was initial 12 years). However, there was no mortality risk associated with follow-up period two (which was the last 15 years). Also, four percent is too small in a large population study like this. 

Expert’s take: “There is no suggestion that MVs cause harm. They may be a waste of money for most people,” said award-winning dietitian, writer, and nutritionist Ursula Arens. Arens highlighted how “for most people in the U.S., MVs cannot make a significant link to mortality, but may benefit some markers of morbidity.” 

She added that different groups of people in different demographics may have varied requirements. "There are proven benefits for some people: those with poor and unbalanced diets, pregnant women, and vitamin D during winter months in cold climates (UK government official guidance = 10 ug vitamin D daily for everyone October to April),” she added.

According to a media advisory by the National Cancer Institute, the analysis showed that people who took daily multivitamins did not have a lower risk of death. This simply means that multivitamins won't help extend one's life, but it doesn’t translate to a higher risk of mortality. 

Moreover, the researchers noted that it’s important to “evaluate multivitamin use and risk of death” among different groups, such as people with nutrient deficiencies.

Both these cases highlight how these scientific papers were (mis)reported, leading to confusion, and a state of fear and panic on social media. They underscore the need to understand science before jumping to conclusions.

(Edited by Kritika Goel)