Fact Check: Aspirin Can Help Prevent Cancer
What We Know
The claim that aspirin can help prevent cancer has been supported by various studies, particularly regarding its effects on specific types of cancer. A comprehensive 20-year cohort study conducted in Denmark found that long-term low-dose aspirin use was associated with a slight to moderate reduction in the risk of several cancers, notably colorectal cancer. However, the study also highlighted that overall cancer risk did not significantly decrease with low-dose aspirin, as there was an increased risk for some cancers, including lung and bladder cancer.
Additionally, a review article suggests that aspirin may prevent cancer deaths primarily by inhibiting metastasis rather than preventing cancer development itself. This mechanism is thought to involve the inhibition of Thromboxane A2 (TXA2), which can suppress T cell immunity against metastasis (Thorat, 2025). The evidence indicates that while aspirin may reduce the incidence of certain cancers, its effects are not uniform across all cancer types.
Analysis
The evidence supporting the claim is mixed. The 20-year cohort study provides substantial data indicating that while low-dose aspirin can reduce the risk of specific cancers, it does not lower the overall cancer risk. This suggests that while aspirin has protective effects against certain cancers, it may also pose risks for others, complicating the narrative that aspirin is a blanket preventive measure against cancer.
The review by Thorat (2025) reinforces the notion that aspirin's benefits may be more pronounced in preventing metastasis rather than in preventing cancer from developing in the first place. This distinction is crucial, as it indicates that the protective effects of aspirin are not universally applicable to all cancers. Furthermore, the mechanisms by which aspirin may exert these effects are still being explored, and the clinical doses required for effective prevention remain uncertain.
The reliability of these sources is generally high, as they are published in reputable journals and involve extensive research. However, the complexity of cancer biology and the variability in individual responses to aspirin must be considered when interpreting these findings.
Conclusion
The claim that "aspirin can help prevent cancer" is Partially True. While there is credible evidence that long-term low-dose aspirin use can reduce the risk of certain cancers, particularly colorectal cancer, it does not significantly lower the overall risk of cancer and may increase the risk of others. Additionally, the protective effects seem more related to preventing metastasis rather than preventing cancer development outright. Therefore, while aspirin may have a role in cancer prevention, it is not a universal solution.
Sources
- Long-term aspirin use and cancer risk: a 20-year cohort study - PubMed
- An aspirin a day keeps cancer at bay - PMC - PMC
- Aspirin and cancer treatment: systematic reviews and meta - Nature
- Aspirin Uses, Dosage, Side Effects & Interactions - Drugs.com - Drugs.com
- Aspirin Dosage Guide + Max Dose, Adjustments - Drugs.com - Drugs.com
- Aspirin Patient Tips: 7 things you should know - Drugs.com - Drugs.com
- Scientists discover how aspirin could prevent some - Medical Xpress
- Aspirin Monograph for Professionals - Drugs.com - Drugs.com
