Study Links High Chili Pepper Consumption to Increased Esophageal Cancer Risk

Can your love for spicy food increase cancer risk? A new review suggests that people who eat the most chili peppers may have a higher risk of certain digestive cancers, particularly esophageal cancer, but researchers say the evidence does not prove that chili peppers directly cause cancer.

Published in Frontiers in Nutrition, the review analyzed 14 observational studies involving more than 11,000 participants, including over 5,000 people with gastrointestinal (GI) cancers.

Compared with those who consumed the least chili peppers, people with the highest intake were 64% more likely to develop GI cancers overall. The strongest association was seen with esophageal cancer, where heavy chili pepper consumers were nearly three times more likely to develop the disease than those with the lowest intake.

For stomach and colorectal cancers, however, the results were less clear. Although stomach cancer showed a trend toward higher risk among heavy chili pepper consumers, the association was not statistically significant, and no significant increase was found for colorectal cancer.

Researchers noted that findings differed across regions. Studies from Asia, Africa, and North America generally reported higher cancer risks with heavy chili consumption, whereas studies from Europe and South America found little or no increased risk. Differences in cooking methods, pepper varieties, genetics, smoking, alcohol use, and overall diet may partly explain these variations.

Scientists believe repeated exposure to capsaicin, the compound that gives chili peppers their heat, may irritate the lining of the esophagus in some people, but this theory has not been proven.

Importantly, all studies included in the review were observational, meaning they can only show an association, not cause and effect. Other lifestyle factors could also influence cancer risk.

Researchers say more long-term studies are needed to determine whether chili peppers themselves increase cancer risk or whether the observed associations are driven by other dietary and environmental factors.

REFERENCE: Changchang Chen, Man Zhang, Xutong Zheng, Hongjuan Lang. Association between chili pepper consumption and risk of gastrointestinal-tract cancers: A meta-analysis. Frontiers in Nutrition, 2022; 9 DOI: 10.3389/fnut.2022.935865