By Tom Cowan, M.D.
A few weeks ago, a patient, who came to me to discuss possible alternative treatments for his heart, said that he was completely against taking cardiology drugs, and that all he used was one aspirin a day. I have heard similar comments from other patients: “My cardiologist practically begged me to take aspirin,” or, “No, I never take drugs of any sort, only the one aspirin per day." Generally, I let these comments slide because I believed that we had more important issues to decide than whether the patient should take aspirin.
I have heard aspirin described as one of the greatest medical interventions of the 20th century, almost as important as the discovery of penicillin. On the other hand, I have read credible accounts that link the widespread and aggressive use of aspirin to the tragic outcomes in the 1918 "flu" pandemic, and that suggest if aspirin were a new drug, it would never pass FDA scrutiny because of its significant toxicity. Ironically and tragically, I am sure my mother’s fatal hemorraghic (bleeding) stroke three years ago was caused by the combination of statins, fish oil, and daily aspirin use.
During the past few months, I decided to finally look into the actual studies on aspirin use to see whether I could find out whether everyone older than 60 should really take an aspirin a day, and, if not, whether downsides to its use exist.
Generally, the most common indications for the widespread use of aspirin is to prevent clotting (or thrombosis) of the blood, considered an integral step in the development of heart attacks and strokes. Second, as aspirin is a prostaglandin inhibitor, therefore an anti-inflammatory, it is used in the primary prevention of diseases that are thought to be caused by chronic inflammation, including colon cancer. Tens of millions of Americans take an aspirin a day mainly for these two indications. So what do the actual studies find?
The first study comes from the journal Expert Opinion on Pharmacotherapy (2010 Jun;11 (9):1459-66), which studied the role of aspirin in the primary prevention of cardiovascular disease in patients with diabetes. Primary prevention means that these patients were diabetic but had no history or evidence of heart disease. The fact that they had diabetes put them at high risk for heart disease, and aspirin was studied as a low-risk, low-cost primary prevention therapy. Here is the conclusion of the study:
“Aspirin therapy did not reduce the risk of cardiovascular events…The use of aspirin cannot be routinely recommended for primary prevention of cardiovascular events in diabetes.”
In other words, aspirin was found to be ineffective in preventing cardiovascular disease in patients who had diabetes but no existing heart disease at the time.
The second study comes from the prestigious Journal of the American College of Cardiology (J Am Coll Cardiol. 2010 Oct 19;56 (17):1376-85. PMID: 20946994). The study was designed to determine the outcome for patients taking aspirin when they happened to have a coronary event. This focus is important, because it is the predominant indication doctors use in prescribing aspirin therapy. Here is that actual conclusion of the study:
“Prior aspirin use was associated with more comorbidities and coronary disease and a higher risk of recurrent MI, but not mortality.”
In other words, people taking aspirin had worse outcomes and a higher risk of having a heart attack than those not taking aspirin — exactly the opposite of what they were told.
The third study, coming from the gold-standard New England Journal of Medicine (N Engl J Med. 2005 Mar 31;352 (13):1293-304. Epub 2005 Mar 7. PMID: 15753114), examined whether aspirin use lowered the cardiovascular risk for women in general. The conclusion of the study:
“In this large, primary-prevention trial among women, aspirin lowered the risk of stroke without affecting the risk of myocardial infarction or death from cardiovascular causes, leading to a nonsignificant finding with respect to the primary end point.”
In this study, a lowered risk for stroke (only ischemic, or clot, strokes) was found; however, the overall death rate from cardiovascular events was not affected.
And, finally, this study found no clear evidence that aspirin helped prevent ischemic strokes, while clear evidence emerged in another study that taking daily aspirin does increase the risk of having a bleeding stroke. This study is from the journal Stroke (Stroke. 1998 May; 29(5):887-94. PMID: 9596230). The conclusion states:
“Aspirin use was associated with increased risks of ischemic stroke in women and hemorrhagic stroke overall in this elderly cohort, after adjustment for other stroke predictors.”
In other words, at least with women older than 65, daily aspirin use was shown to increase the risk for strokes.
Some positive trials do exist in regard to men with secondary prevention (those who have already had a heart attack or stroke). However, this strategy is not without a significant downside. Again, studies that show that aspirin is far from a benign drug.
The first one from the American Journal of Medicine (Am J Med. 2010 Mar;123 (3):231-7. PMID: 20193831) shows that chronic aspirin use is associated with significant hearing loss in men:
“Regular use of aspirin, NSAIDs, or acetaminophen increases the risk of hearing loss in men, and the impact is larger on younger individuals.”
Another study, from the journal Current Medical Research (Curr Med Res Opin. 2009 Nov; 25 (11):2785-93. PMID: 197), shows that even low-dose aspirin therapy is associated with significant gastrointestinal toxicity:
“Data suggest that ASA causes significant gastroduodenal damage even at the low doses used for cardiovascular protection. These effects (both systemic and possibly local) may be pharmacodynamically distinct from the gastroduodenal toxicity seen with NSAIDs.”
Finally, daily aspirin use is associated with the development of Crohn’s disease (CD), an illness becoming increasingly prominent in our medical landscape. This is from Alimentary Pharmacology & Therapeutics (2011 Sep ;34(6):649-55. Epub 2011 Jul 26. PMID: 21790683) and concludes:
“A strong positive association between regular aspirin use and CD, but not UC, was observed.”
I could go on for pages, but the conclusion is clear: while low-dose daily aspirin therapy has been shown to have some usefulness in very specific situations, it is far from a safe, effective medicine for all those who use this therapy.
Are there alternatives to low-dose aspirin therapy? Many natural medicines inhibit platelet aggregation, thin the blood and reduce inflammation without any of the risks incurred by low-dose aspirin therapy. Some of my favorite choices include the use of the enzymes Nattokinase or Lumbrokinase, both of which have shown anti-clotting effects as well as heart-strengthening properties. Pycnogenol, the French pine bark extract, was shown in a 1999 study published in the journal Thrombotic Research to not only inhibit platelet aggregation in smokers (a high-risk group) as effectively as aspirin, but also to do it without adversely affecting bleeding time:
"Thus, smoking-induced enhanced platelet aggregation was inhibited by 500 mg aspirin as well as by a lower range of 100-125 mg Pycnogenol. Aspirin significantly (p<0.001) increased bleeding time from 167 to 236 seconds while Pycnogenol did not. These observations suggest an advantageous risk-benefit ratio for Pycnogenol."
In sum, the daily use of even low-dose aspirin is an important medical decision, one not without significant risk. Please discuss the risks and benefits with your primary physician and cardiologist, and make sure they are aware of both the downsides of this therapy as well as safer alternatives.