Everyday foods, an intriguing breast cancer study, and what its striking numbers really mean.
Mushrooms in a curry and a cup of green tea are simple pleasures. Could they also help protect our health? A Chinese study attracted attention because women who consumed both had substantially lower odds of breast cancer. The findings deserve a closer look—especially the often-repeated “89%” figure.
What the researchers found
Published in the International Journal of Cancer in 2009, the study compared 1,009 women with breast cancer with 1,009 women without it. Researchers interviewed participants about their diet and lifestyle.
Women reporting at least 10 grams of fresh mushrooms daily had lower breast cancer odds than non-consumers. The strongest association appeared among women consuming mushrooms together with green tea.
For higher fresh-mushroom intake combined with tea, the reported odds ratio was 0.11, compared with consuming neither. That represents 89% lower odds. The corresponding estimate for dried mushrooms combined with tea was 0.18, or 82% lower odds. These were separate comparisons, not evidence that people must eat fresh and dried mushrooms together. [1]
Does that mean 89% of breast cancers could be prevented?
No. This was a case-control study: researchers compared existing cases with controls and looked back at reported habits. They did not randomly assign diets and follow participants to see who developed cancer.
An odds ratio is not an absolute reduction in the chance of developing a disease. The study cannot tell an individual how many percentage points their risk would fall after changing their meals.
People who regularly eat mushrooms and drink tea may differ in other ways. Statistical adjustments help, but cannot remove every difference. Remembering past meals can also be imperfect, and the choice of control participants can affect the results.
The association is evidence worth investigating. Establishing that the foods caused the difference requires stronger confirmation.
What about men and other cancers?
This particular study investigated breast cancer in Chinese women. It cannot establish the same benefit for men, prostate cancer, or cancer overall. Nor does it demonstrate that adding mushrooms and tea in later life produces the same association.
For HealthyRetired readers, the useful message is that ordinary foods can be interesting subjects of research without becoming guaranteed cancer-prevention treatments.
Bringing them to the table
Here is a meal idea rather than a medical prescription: cook familiar edible mushrooms with tofu, garlic and vegetables, serve with brown rice, and enjoy unsweetened green tea if you like it.
Choose cultivated mushrooms from a trusted seller. There is no need to seek exotic varieties or turn a modest dietary habit into an expensive supplement routine.
Tea contains caffeine, so consider your sleep and sensitivity. Concentrated green tea extracts are different from brewed tea: uncommon liver injuries have been reported, primarily with extract tablets or capsules. Green tea can also interact with medicines; ask a pharmacist about your particular treatment. [2]
A thoughtful addition to everyday eating
Mushrooms and green tea can be enjoyable parts of a varied diet. This research provides a reason for curiosity, while leaving important questions open. Enjoy the meal and the cup of tea; keep screening and medical care in your health routine.
This article provides general information, not personal medical advice. Before making substantial dietary changes, consult a qualified healthcare practitioner, particularly if you take medication or have a medical condition. Food does not replace cancer treatment.
Sources
- Zhang M, Huang J, Xie X, Holman CDJ. Dietary intakes of mushrooms and green tea combine to reduce the risk of breast cancer in Chinese women. International Journal of Cancer. 2009;124:1404–1408. https://pubmed.ncbi.nlm.nih.gov/19048616/
- US National Center for Complementary and Integrative Health. Green Tea: Usefulness and Safety. https://www.nccih.nih.gov/health/green-tea
Prepared for HealthyRetired. Sources checked 27 October 2026.