An Aspirin a Day...
June 10, 2005: The data supporting increased intake of fruits and vegetables to reduce the risk of cancer is so strong that the National Cancer Institute has promoted the intake of at least 5 servings (and 6 to 8 is probably better) a day.
I believe that a drug has now proven to be nearly as good as fruits and vegetables for cancer prevention. Remarkably, just as fruit and vegetables and low fat intake are good for your heart, this drug is also good for the heart. What is this "exciting, new cancer-preventing drug?" Aspirin. Yes, plain old aspirin.
In a meta-analysis Dr. Randall Harris and associates (Oncology Reports 13:559-583, 2005) reviewed 91 epidemiologic studies that examined NSAID (Non-Steroidal Anti-Inflammatory Drugs such as aspirin, ibuprophen, naproxen, Celebrex, Vioxx, etc.) taking 325 mg of aspirin or 200 mg of ibuprophen was found to reduce the risk of seven cancers, including the four major cancers: Colon (63% reduction), breast (39% reduction), prostate (39%) and lung (36%). The effect in bladder and kidney cancer was suggestive of benefit, but inconsistent. Major reductions in risk were also found in cancer of the esophagus (73%), stomach (62%), and ovary (47%).
How Does Aspirin Work?
Aspirin blocks both forms of the COX enzyme that are required for the synthesis of prostaglandin, a hormone-like molecule that, among other things, can produce fever, inflammation, and immune suppression. Many cancers produce both COX-1 and COX-2 enzymes, and this is thought to be an important step in the development, growth and spread of cancers. Suppression of these and other enzymes by NSAIDS such as aspirin may have many beneficial anticancer effects such as reversing immunosuppression, mutagenesis, mitogenesis, and angiogenesis, as well as inhibiting metastasis and permitting programmed cancer cell death through the process termed apoptosis.
The Down Side
Aspirin and other NSAIDS are generally safe, but serious and even fatal toxic reactions can occur. Aspirin in a dose of one 325 mg tablet a day impairs platelet function and reduces blood clotting. This can result in bleeding, and it is important to stop aspirin a week before undergoing elective surgery. Aspirin can also cause stomach irritation, ulceration and bleeding, so everyone cannot take it. The newer and more expensive selective COX-2 inhibitors such as Celebrex and Vioxx are less irritating to the stomach, but do not have the cardiac-protective effect of aspirin.
Should Everyone Take Aspirin?
An apple a day is a safe recommendation for the world at large, but even something as safe and inexpensive as aspirin should not be recommended without consideration of the relative risks and benefits. Young people who do not smoke and have no family history of cancer should maintain a healthy lifestyle and probably do not need chemoprevention with aspirin. Those with irritable stomachs should also probably pass on aspirin unless they have an increased risk of cancer. Considering the dreaded consequences of cancer as well as the benefit in reducing the risk of heart attach, I think an aspirin a day is worth the risk for those of us who have a family history of cancer and heart disease.
Created: 6/13/2005