May lower risk
Onions
red, yellow and white onions. Vegetables & fruit.
- Verdict
- May lower riskSome studies point to lower risk, but it isn't confirmed.
- How sure
- Rung 2 · LimitedFew, small or conflicting human studies, or only indirect measures such as blood markers.
- How big
- 31% lower odds of stomach cancer at the highest intake, in pooled case-control studies.
The rung shows how sure the science is, not how big the effect is. How to read these ratings
Cancers affected
Stomach (case-control studies)
What the evidence shows
In a pooled analysis of 17 studies (6,097 people with stomach cancer, 13,017 without), people who ate the most onions had 31% lower odds of stomach cancer. The authors urge caution: results varied by region and could partly reflect other habits.
What to do
Eat them often as part of a vegetable-rich diet. Quercetin pills are rated separately.
Sources
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Related
Every food we rated, or follow one cancer step by step: breast cancer, colorectal cancer, lung cancer and prostate cancer.