A 2024 observational study of more than 470,000 adults in Britain found that people with higher salt intake are more likely to develop certain stomach cancers than those who ate little or no salt. However, the researchers noted that the findings cannot be generalized to broader populations due to the study's limitations.
In May 2024, a post on Reddit's r/science subreddit claimed that people who always or often added salt to their food were much likely to develop stomach cancer than people who rarely or never did so. The post had more than 2,700 upvotes at the time of this publication.
Through a Google keyword search, Snopes found several news publications that wrote about the study the Reddit post referenced, including News Medical Life Sciences, Newsweek, Technology Networks, and Medical News Today. The study, "Adding salt to food at table as an indicator of gastric cancer risk among adults: a prospective study," was published in the peer-reviewed scientific journal Gastric Cancer on April 17, 2024.
Researchers at the Center for Public Health, Medical University of Vienna analyzed the data of more than 470,000 adults from UK-Biobank, a large-scale British biomedical database. Questionnaires administered between 2006 and 2010 included questions like, "How often do you add salt to your food?" Responses were compared with measurements of study participants' salt excretion in urine, as well as data from national cancer registries.
According to a news release published by the institution, people who said they regularly salted their food were "41% more likely to develop stomach cancer than those who left their saltshakers untouched" over 11 years. (An English-language version of the news release is also available on the science news website, EurekAlert.)
"Our results also stood up to the consideration of demographic, socioeconomic and lifestyle factors and were just as valid for prevailing comorbidities," study author Selma Kronsteiner-Gicevic said in the news release.
Researchers noted several limitations with their research. For example, they could not evaluate the influence of certain characteristics such as sex, age, ethnicity or smoking status. It also was an observational study, which means other outside influences may not have been fully accounted for. Because the study participants volunteered, the findings cannot be generalized to the general U.K. population — or beyond — because of participation and age restrictions present with the UK Biobank cohort.
Regardless of the limitations, the findings add to a growing body of evidence supporting salt's potential role in gastroenterological cancers. For example, research published in 2009 in the World Journal of Gastroenterology found that salt may "cause stomach cancer through directly damaging gastric mucus" and that "considerable evidence" suggests limiting salted foods is a "practical strategy for preventing gastric cancer"
Similarly, in 2021 a systematic review published in the journal Frontiers in Nutrition found that "High intakes of salt, pickled food, and processed meat are associated with significantly increased risks of gastric cancer; these increased risks are also seen when participants consumed moderate amounts of salt."
In 2022, scientists concluded in the journal Nutrients that higher dietary salt intake increases the risk of gastric cancer.
As of this publication, stomach cancer is the fifth-most-common type of cancer worldwide, according to the World Cancer Research Fund International. The agency notes that there is strong evidence that consuming salt-preserved foods increases the risk of stomach cancer.
Though the risk of stomach cancer increases with age, experts have noted an increase in gastrointestinal cancers, like those of the stomach, liver, pancreas, and colon, in younger people, particularly women. The cause is not entirely clear, but researchers speculated in 2023 it could be connected to shifts in dietary habits, increased intake of processed foods and higher rates of obesity, as well as other unhealthy behaviors, diet and physical activity.
The 2024 study authors say the findings will help highlight stomach health and its relationship to diets.
"With our study, we want to raise awareness of the negative effects of extremely high salt consumption and provide a basis for measures to prevent stomach cancer," researcher Tilman Kühn said.