Onions and Garlic May Help Reduce Stomach Cancer Risk

Zhifei Zeng ’23

Figure 1: A study found higher intake of allium vegetables beneficial in reducing stomach cancer risk.

Stomach cancer, or gastric cancer, is the fourth leading cause of cancer deaths worldwide, and dietary habits play an important role in the development of this cancer. For example, heavy alcohol consumption or high consumption of salt-preserved foods increases the risk of stomach cancer, while diets rich in fruits or vegetables decrease the risk. However, the specific types of vegetables that are effective in preventing stomach cancer need to be further investigated. A team led by Stony Brook University professor Dr. Paolo Boffettais is interested in the effects of consuming allium vegetables, such as onions and garlic, on stomach cancer. Through the Stomach Cancer Pooling (StoP) Project, a global collaborative consortium for the epidemiological investigation of gastric cancer, this team evaluated whether a higher intake of allium vegetables is associated with a lower risk of gastric cancer.

The StoP project includes previous research data that can help to quantify the role of lifestyle and genetic determinants in the etiology of gastric cancer, including the impact of dietary patterns and lifestyle on the incidence of stomach cancer. The researchers selected 17 of these studies, including a total of 6097 gastric cancer cases and 13,017 healthy volunteers from 10 countries, to analyze information on the intake of allium vegetables. All studies assessed dietary intake via a food frequency questionnaire that asked participants to report weekly intake of onion and garlic for at least 1 year before cancer diagnosis. The researchers also evaluated whether the effects of allium vegetable intake on gastric cancer differed by geographic region. The results showed that a trend towards a lower risk of stomach cancer emerged as onion intake increased, and the favorable effect of garlic intake gradually increased, leveling off after reaching 50-60 g per day. This favorable effect was more pronounced in people living in Asian countries, which may be related to differences in the genetic background of patients or in the preparation or processing methods of allium vegetables.

This study investigated the effect of a single type of vegetable on reducing cancer risk from an epidemiological perspective, and future studies should further explore whether the way vegetables are cooked and handled may have an effect on their beneficial effects. This series of studies will be able to further refine dietary guidance protocols for cancer prevention and alert people to avoid potentially cancer-causing dietary habits.

Works Cited: 

[1] M. Dalmartello, et al., Allium vegetables intake and the risk of gastric cancer in the Stomach cancer Pooling (StoP) Project. Br J Cancer (2022). https://doi.org/10.1038/s41416-022-01750-5

[2] Image retrieved from:


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