Researchers at Seoul National University (SNU) College of Medicine found that those who consistently consumed foods made from soybeans such as tofu and soybean paste have a significantly lower risk of developing stomach cancer.

A joint research team led by Professors Shin Woo-kyoung and Kang Dae-hee of the Preventive Medicine Department at SNU conducted a follow-up study on 139,267 people aged 40 to 69 years who participated in the HEXA Study between 2004 and 2013.

The research team examined the effects of the ingestion of soybeans, soybean paste, and tofu on gastric cancer in 767 people who developed gastric cancer compared to those who did not.

Consequently, men who consumed tofu more than twice a week had a 37 percent lower risk of developing gastric cancer than men who consumed little tofu. The results also showed that greater tofu consumption resulted in a lower risk of gastric cancer.

Genistein, isoflavone in soybeans are the key

The research team analyzed that foods made of soybeans lower the risk of stomach cancer due to the effect of genistein and isoflavone, which has anti-inflammatory and antioxidant properties.

Previous studies have also highlighted that these substances not only reduce cell proliferation and angiogenesis in the mucous membrane but also inhibit the growth of Helicobacter pylori, which affects gastric cancer.

In addition, the research team suggested that the effect of soybean paste, which is known to have a relatively high sodium content, was due to the production of bioactive substances that are good for the body during the fermentation process.

"The soybean paste made in Korea is thought to have a better effect on preventing stomach cancer as more physiologically active substances are produced during the long fermentation process," said Professor Shin.

Professor Kang Dae-hee added that the physiologically active substance contained in soybeans not only activates NK cells, immune cells that directly destroy virus-infected or cancer cells, but also suppresses DNA damage and improves DNA recovery.

However, the study also pointed out that the incidence of ingestion of tofu and soybean paste on gastric cancer differed according to an individual’s weight. 

For example, in men who did not exceed the normal body mass index (BMI) weight, more frequent consumption of soybean paste, and tofu proved to have a lower gastric cancer risk. However, this association was not observed in overweight or obese men.