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Cancer Explained
Beginner 4 min read Verified

Stomach Cancer Risk Factors

A plain-language explanation of what raises the risk of stomach cancer, including H. pylori infection. Based on the National Cancer Institute.

NCI source

Last reviewed: 2026-07-07

The short answer

Long-term infection with H. pylori bacteria is a major risk factor for stomach cancer. Smoking, certain diets high in salted or smoked foods, older age, and family history also raise risk. Treating H. pylori can lower risk.

  • Long-term H. pylori bacterial infection is a major risk factor.

  • Smoking raises the risk of stomach cancer.

  • Diets high in salted, smoked, or pickled foods are linked to higher risk.

  • Older age, being male, and family history raise risk.

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The full explanation.

The simple version

A risk factor is anything that raises the chance of developing a disease. For stomach cancer, long-term infection with H. pylori bacteria is a major factor. Having risk factors does not mean you will get stomach cancer.

H. pylori and diet

Long-term H. pylori infection causes lasting inflammation that can lead to cancer over years. Diets high in salted, smoked, or pickled foods, and low in fruits and vegetables, also raise risk.

Long-term H. pylori infection is a major, treatable risk factor for stomach cancer.

Other factors

Risk also rises with age and is higher in men. Smoking, a family history of stomach cancer, and certain stomach conditions raise risk too.

Lowering your risk

Treating H. pylori infection, not smoking, and eating a diet rich in fruits and vegetables may help lower risk. Ask your doctor about testing if you have persistent stomach symptoms.

Words to know

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Common questions

What is the biggest risk factor?

Long-term infection with H. pylori, a common stomach bacterium, is a major risk factor. It causes long-lasting inflammation that can lead to cancer over many years.

What dietary factors matter?

Diets high in salted, smoked, or pickled foods, and low in fruits and vegetables, are linked to higher stomach cancer risk.

Who else is at higher risk?

Risk rises with age and is higher in men. Smoking, a family history of stomach cancer, and certain stomach conditions also raise risk.

Can risk be lowered?

Treating H. pylori infection, not smoking, and a diet rich in fruits and vegetables may help lower risk.

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  1. Q1.Which infection is a major stomach cancer risk factor?
  2. Q2.Which diet is linked to higher risk?
  3. Q3.How can risk be lowered?

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Related learning map

How this explanation connects to 9 other things you can explore — related topics, terms, questions, practice, and its NCI source.

Stomach Cancer Risk Factors