Aspirin Research May Amount to a Conclusion in Search of a Study

Here’s an understatement: research on the benefits of aspirin for women is mixed. One large study after another about women and aspirin has been published, each with a slightly different conflicting conclusion. Most of the research is about heart disease. Here are a few of the published and supposedly scientific conclusions about women, aspirin and heart disease: aspirin doesn’t help at all and increases the risk of stomach and brain bleeding, which can be fatal; it lowers the overall risk of death but not the risk of dying from a heart attack; it doesn’t help prevent heart attacks but does help prevent strokes; it helps women of certain ages but not others; it only helps women without heart disease; it only helps women with existing heart disease, except for those with diabetes. Confused yet?

The most recent batch of claims is enough to give a woman a headache! In spite of impossibly murky research with ambiguous findings, the latest published conclusions are that low dose aspirin should be taken daily by both men and women of certain ages to prevent heart attacks. In one case, network TV reportage of these findings was accompanied by large images of a commercial aspirin product. Whenever I see (so-called) TV news accompanied by a brand name product I get suspicious.

The Women’s Health Initiative Study (WHI) and the U.S. Preventive Services Task Force guidelines study are perfect examples.

The WHI Aspirin Study
Out of the 93,676 WHI women between 50 and 79 years of age enrolled in this ongoing study of many health issues, just under 9,000 carefully screened participants were chosen for the aspirin study. Half were chosen because they were already taking aspirin, and the other half were chosen because they matched the aspirin takers in age, risk factors etc. The women chosen were also postmenopausal and had stable cardiovascular disease (CVD).

The researchers were looking for differences in the aspirin and non-aspirin group relating to all-cause mortality (death) and cardiovascular events, which included myocardial infarction (heart attack), stroke, and cardiovascular death. In other words, does taking aspirin daily lower a postmenopausal woman’s risk of dying, or her risk of having a heart disease “event” such as a heart attack or stroke. Their conclusion is:

“…we found that aspirin therapy was associated with a significantly lower risk of all-cause mortality and cardiovascular mortality, raising the hypothesis that aspirin may improve survival in postmenopausal women with stable CVD.”

Obvious Objections to a Dubious Conclusion

Objection #1: The study didn’t track the serious aspirin side effect of gastrointestinal and brain bleeding, which can be fatal. Out of the approximately 4,000 women taking aspirin, how many of them had bleeding caused by taking aspirin? Informed women want to know! This is a strikingly odd omission.

Objection #2: The aspirin group with the greatest reduction in overall death rate was taking hormone replacement therapy (HRT)—presumably PremPro although the researchers are not specific. This finding makes sense, because the WHI proved in 2003 that PremPro increases the risk of strokes caused by blood clots, and aspirin thins the blood, which would help prevent those types of strokes. If women on HRT were taken out of the equation, would the benefit of aspirin for women still be significant? We don’t know because the researchers do not share this information. Again, a strikingly odd omission.

Objection #3: The authors of the study and the media reports did not make it clear that a very narrow group of women may have some benefit from taking aspirin every day. Here's the truth: To very modestly decrease the risk of heart disease by taking an aspirin a day, a woman has to have stable cardiovascular disease and be aged 70 to 79. She will be helped slightly more by aspirin if she’s taking HRT, is taking a statin drug (for lowering cholesterol) and has never smoked. African-American women taking aspirin had an increased risk of overall mortality and cardiovascular events.

The U.S. Preventive Services Task Force (USPSTF) Study
The other study, which had more media attention, was undertaken by the U.S. Preventive Services Task Force (USPSTF). This group looked at a lot of past aspirin research, threw out the research they didn’t like, crunched and tweaked a lot of data, and then concluded, complete with full-color brand-name boxes of aspirin on the TV “news,” that according to new guidelines from the USPSTF, Americans should be taking a low dose aspirin daily to prevent heart attacks. (They used to say “baby aspirin” – it sounded so safe.)

Unlike the WHI study, this research concluded that aspirin only helps women aged 55 to 79 without heart disease, except those with an increased risk of ischemic stroke (the kind caused by a blood clot, and increased by the use of PremPro). Furthermore, it doesn’t have much benefit in men or women with diabetes. And it doesn’t decrease your risk of dying from CVD, just your risk of having a CVD “event.” And it increases your risk of having a hemorrhagic stroke (caused by bleeding in the brain). I could go on, but I think we’re already confused enough.

Aspirin and Bleeding
Add murky research and ambiguous conclusions to aspirin’s tendency to cause bleeding in the stomach and the brain and, well, why go there? If you’re in the middle of a heart attack, popping a few aspirin could save your life because it might rapidly dissolve the clots that are blocking your heart. However, if you’re a postmenopausal woman you’re more likely to have a heart attack that involves spasms of the heart muscle.

If I were having a heart attack, I would wash down a few aspirin with a few glasses of red wine, which has the potential to both bust up a clot and relax the heart muscles. Other than treatment for an imminent heart attack, ibuprofen seems to be an overall better painkiller for women. We all know it works better for menstrual cramps. Ibuprofen can also cause gastrointestinal bleeding, but the risks are smaller.

Aspirin helps thin the blood and reduces inflammation. Overall, that’s good for the heart. But exercise, a good diet, and enough sleep are even better. Add some fish oil supplements to that, and we have a recipe for heart health that beats aspirin hands down.

Below is an excerpt from my book Prescription Alternatives, which gives another spin to the aspirin vs. no aspirin debate.

Should You be Taking an Aspirin a Day?
If you read the headlines and listen to conventional physicians, you’ll be convinced that aspirin is the miracle drug of the century. Not only does it banish pain and reduce inflammation and fever, it prevents heart disease. And now we’re hearing that it prevents colon cancer. Yes, aspirin is a wonder drug. For short-term use there’s nothing like a couple of aspirin to knock out a headache, reduce the pain of a sprain, and even to quickly reduce heart disease risk while working on safer and more effective long-term solutions.

Used long term, aspirin often does more harm than good. It causes gastric bleeding and ulcers, suppresses the immune system, and promotes macular degeneration, an irreversible eye disease that is the leading cause of blindness in the United States. A study published in the British Medical Journal found that the risk of gastrointestinal hemorrhage (bleeding) with aspirin doesn’t change whether the dose is 50 mg or 1,500 mg. In other words, lowering your dose won’t decrease the risk of this adverse effect. Taking buffered aspirin slightly helps to counteract these side effects, but not significantly enough to make it safe to take long term. And while aspirin decreases the risk of some types of strokes, it increases the risk of other types.

Aspirin Blocks Good and Bad Prostaglandins
Aspirin essentially works by blocking the production of hormone-like substances called prostaglandins, which constantly regulate every cell in the body in many of their complex interactions. Some prostaglandins, when made in the body in excess, play a role in promoting heart disease, inflammation, and pain. The fact that aspirin very effectively blocks these prostaglandins would be good news, except that it blocks the formation of both “good” and “bad” prostaglandins, and in the process of suppressing the good prostaglandins, also suppresses the immune system.

While the bad prostaglandins can make your blood more likely to get sticky and clump together and cause a stroke or heart attack, good prostaglandins lower blood pressure, inhibit blood aggregation and the production of cholesterol, and reduce inflammation reactions. Hmmmm. Sounds like “good” prostaglandins provide the same heart benefits that aspirin does. And they do. Much of heart disease has to do with the fact that bad prostaglandins are outweighing good prostaglandins.

The rest of the Drugs for Heart Disease and their Natural Alternatives chapter in Prescription Alternatives goes into detail about what can be done to reduce inflammation and encourage good prostaglandins. Bottom line, the number one natural remedy for reducing inflammation is omega-3 fish oil.

Many Diseases are Associated with Inflammation
In another arm of the WHI, women who took NSAIDs such as aspirin or ibuprofen had a significantly lower risk of breast cancer. You can read more about this in the article Breast Cancer Risk Factors—New Findings. If you're interested in the biochemical details of how inflammation contributes to breast cancer, please read our book, What Your Doctor May Not Tell You about Breast Cancer.

The bottom line is that NSAIDs effectively reduce inflammation, which is closely tied to heart disease, arthritis and many types of cancer, including breast cancer and prostate cancer. In my article Update on the Prostate, there’s a section titled Dousing the Fires of Inflammation, which suggests a myriad of ways that inflammation can be reduced without resorting to drugs that, when taken daily, can cause so many negative side effects.

To test heart disease-related inflammation risk markers with a home test kit, use the Cardio-Metabolic Profile blood spot test.

Here's a great article by John R. Lee, M.D., Women and Heart Disease.

References

Antithrombotic Trialists' Collaboration, “Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients,” BMJ 2002;324:71-86.

Berger JS, Brown DL, Burke GL et al, “Aspirin Use, Dose, and Clinical Outcomes in Postmenopausal Women With Stable Cardiovascular Disease,” Circulation: Cardiovascular Quality and Outcomes. The Women’s Health Initiative Observational Study 2009;2:78-87.

Hernández-Díaz S, García Rodríguez LA, “Cardioprotective aspirin users and their excess risk of upper gastrointestinal complications,” BMC Med 2006;4:22.

Ridker PM, Cook NR, Lee IM et al, “A randomized trial of low-dose aspirin in the primary prevention of cardiovascular disease in women,” N Engl J Med 2005;352:1293-304.

Wolff T, Miller T, Ko S, “Aspirin for the primary prevention of cardiovascular events: an update of the evidence for the U.S. Preventive Services Task Force,” Ann Intern Med 2009;150:405-10.