Does kimchi cause cancer? Experts say it shouldn't be lumped in with salted vegetables

"Wait — kimchi isn't a health food?"

Kim, a woman in her 40s, said she was taken aback when she heard that kimchi had been included in research linking certain foods to cancer risk — a finding that seemed to contradict the dish's growing global reputation as a health food.

A string of conflicting findings about kimchi has left many consumers confused. Kimchi experts agree that the dish should be understood not as a simple pickled vegetable but as a "complex fermented food." They also say the question of kimchi and stomach cancer is not a matter of "kimchi versus no kimchi," but one of sodium management, portion size and overall dietary patterns.

The study at the center of the debate was published earlier this year in the international journal Epidemiology and Health by Korean researchers. It identified "salted vegetables" — a category covering various pickled vegetables — as the single largest dietary factor affecting cancer risk among Koreans. The researchers estimated that salted vegetable consumption accounted for 2.1 percent of cancer incidence and 1.7 percent of cancer deaths. The link to stomach cancer was particularly pronounced, with the study concluding that a salt-heavy diet has long driven the stomach cancer burden in South Korea.

The controversy stems from the fact that kimchi was included in that salted-vegetable category. Critics argue that fermented foods like kimchi are fundamentally different from simple salted vegetables and must be clearly distinguished from them.

Lee Woo-je, head of the Kimchi Healthcare Research Division at the World Institute of Kimchi, said classifying kimchi in the same category as pickled vegetables such as jangajji "has limitations in that it does not adequately reflect kimchi's fermentation characteristics." Kimchi is made with a seasoning blend of aromatic vegetables — green onions, garlic, ginger and chili peppers — and the fermentation process generates a range of functional nutrients not found in the raw ingredients. The complex co-fermentation of animal-based jeotgal and plant-based ingredients is a defining feature unique to kimchi. According to the World Institute of Kimchi, a government-funded research institute under the Ministry of Science and ICT, kimchi is the only food in the world in which vegetables are salted, combined with various secondary ingredients and a seasoning paste, and then fermented.

As for stomach cancer, a direct causal link to kimchi has not yet been clearly established by science. Some studies have found that consuming kimchi in excessive amounts or at very high sodium levels may modestly raise stomach cancer risk. However, a study published in the International Journal of Cancer in 2002 found that moderate kimchi consumption was actually associated with lower stomach cancer risk.

A study in the Journal of Medicinal Food in 2014 similarly concluded that beneficial bacteria and antioxidants produced during kimchi fermentation may support stomach health. Research published last year by the World Institute of Kimchi, which analyzed data from the 2022–2023 Korea National Health and Nutrition Examination Survey, found that higher kimchi consumption was associated with higher sodium intake — but also with increased intake of potassium and dietary fiber, nutrients that can help offset the negative effects of sodium.

"The relevant research suggests that kimchi is not an absolute carcinogen, but that various factors — including excessive consumption, high-sodium preparation methods or an individual's health condition — may play a role," Lee said. He added that strategies for kimchi consumption and sodium management need to be reexamined.

The United States government has formally recognized kimchi's functional value by naming it explicitly in its new national dietary framework. Lee said kimchi should be evaluated holistically for its effects on health rather than simply labeled a "high-sodium food." "If eaten in appropriate amounts and at a suitable sodium level, kimchi is an important cultural asset of our country that also carries health benefits," he said.