An aspirin a day keeps the doctor away?
The old addage “an apple a day keeps the doctor away” has long been applied to aspirin. And on the surface it sounds like a not so bad idea. Aspirin is acetylsalicylic acid, derived from the bark and leaves of willow trees. We use white willow bark ground up and encapsulated in Naturopathic Medicine for a lot of the same reasons that aspirin is used.
Salicylic acid inhibits the action of an enzyme called cyclooxygenase that are responsible for creating little signaling molecules that come from certain fats that we eat. These signaling molecules regulate inflammation, pain sensation, clotting, muscle activity and several other processes.
Oftentimes you’ll reach for an aspirin for a headache, cramps, fever or other common malady. Transient uses in healthy individuals are likely no big deal. But what about daily use over long periods of time?
One of our greatest issues in terms of adverse health outcomes are heart attacks and cerebrovascular events. Every 34 seconds, someone in the U.S. has a severe adverse event.
It’s thought that the pathogenesis of cardiovascular disease is the result of inflammation run amok and that this lack of regulation can be helped by aspirin. Our health authorities have declared that aspirin use is critical for the primary prevention of heart attacks and strokes.
The U.S. Preventative task force recommends that adults initiate low dose aspirin therapy at the ages of 50 and wiser [1]. And the CDC recently announced that millions more Americans should be taking aspirin for the same reason [2].
Primary versus Secondary Prevention
You need to understand these terms so that you can make sense of the information that is out there. Let’s keep it on the note of cardiovascular disease, which we’re all at risk for. Starting a daily aspirin as a primary preventative strategy would be using it in folks who do not have a history of heart attack or stroke. Doing so as a secondary preventative strategy would be waiting until we had a heart attack or stroke and then starting aspirin as treatment.
You might say, as someone who hasn’t had a heart attack or stroke, start me up now! And that seems reasonable, since we always want to be more sensitive in the way we address disease, that is, an ounce of prevention is worth a pound of cure. But, we also want to make sure that said treatment is effective and safe as a primary preventative agent. In addition, if any side effects arise we want to know if the benefits outweigh the costs.
The science on aspirin for primary preventative care
The earliest data suggesting Aspirin was of benefit were the Physicians Health Study and the Womens Health Study, published back in the late 80s and early 90s, which revealed small-to-modest cardiovascular benefits in high risk patients [3].
One important thing to note is that the times were different, and the preventative efficacy of aspirin in the backdrop of the population’s current set of cardiovascular insult is uncertain. We didn’t have the same approaches we had in managing other risk factors for cardiovascular disease, including the management of lipids, hypertension, diabetes and other comorbidities. Additionally, not as many people smoke now as they did 30 years ago.
The three most recent trials consisting of over 20,000 individuals include ASPREE, ASCEND and ARRIVE, all of which demonstrated increased risk of bleeding and minimal cardiovascular benefit. Two of these trials included individuals considered at high risk for a first cardiovascular event. One of the studies showed an increase risk of all types of cancer.
The benefit/detriment findings in these three trials is consistent with what 11 other studies performed since the 80s collectively reveal [4], little benefit and significant bleeding risk.
Another collection of studies reviewed in the Journal of the American Medical Association looking at low risk men and women found sex specific benefits with aspirin treatment [5]. It seemed to prevent ischemic strokes in women but not heart attacks, and heart attacks in men but not strokes. The benefits were pretty modest, with 3 and 4 events prevented per 1000 women and men treated respectively. This is in contrast to major bleeding events which occurred in 1 per 400 women and 1 per 300 men respectively. So a pretty small protective effect for your vasculature and a pretty susbstantial increase in major bleeding events.
A more recent analysis showed that the numbers needed to treat over 6 years to prevent one stroke was 120 and the to prevent one heart attack was 160. The number needed to harm over this same time period, harm being major bleeding events was one per 70 people [6].
This of course, is removed from the lesser harm aspirin may inflict on your digestive tract in ways that have not been studied very well [7]. One thing we give a little more credence to in good medicine is the concept referred to as “leaky gut” or increased intestinal permeability, which turns out to be a contributing factor to many chronic health maladies.
Please note that the primary adverse event tracked in these studies it what authors call “nontrivial bleeds,” which are brain bleeds, eye bleeds, GI bleeds that result in hospital. So in the same vein as lesser harm, leaky gut component I mentioned, what about the impact of aspirin on all these other body systems. No one is studying that. More discussion for another time.
So what gives?
An aspirin per day… we may have been barking up the wrong tree for quite some time. You can certainly make a much better argument for aspirin in the case of secondary prevention. Again, that’s in the case where someone has already had a heart attack or a stroke. But the data just isn’t that impressive for primary prevention, and the harm seems to be too great.
Still you can go on the U.S. Preventative Task Force website and see that the guidelines still push aspirin in folks aged 50+ despite lack of serious adverse event. I’m curious about how many folks without a history of heart attack or stroke are actually on aspirin therapy and how many physicians are recommending it. In a local rheumatology clinic I got to spend time at turning through 25-30 encounters a day, it seemed like every other person had aspirin in their long list of medications.
Rheumatology is an area where aspirin is also an interesting discussion. Aspirin at a dose of 20 100mg tablets per day was actually considered a DMARD treatment for lupus. It was pretty dismal, only helping a minority of patients with maybe 30% improvement according to this old timer I was listening to. Sorry, I’m getting off track, now.
One statistic I was able to come across based off of NHANES data states that 34% of men and 42% of women (who did not have a history of heart attack or stroke) report having their physician recommend aspirin therapy [7]. That’s potentially a lot of folks! In those for whom aspirin would be a secondary preventative measure, 74% were instructed to take daily aspirin. I wonder if the physcians of the previous demographic are aware of the data out there.
What does this all mean for you? And is there a better strategy
Certainly, the CDC is on the right track in it’s desire to implement behavior change, just not in the direction of having folks become more intimate with the aspirin in their medicine cabinets.
There are three major areas to focus on in reducing your risk of cardiovascular disease.
- First and foremost, modifying your diet in away that optimizes all of the following:
- Your intake of micronutrients
- Body composition (greater muscle: fat)
- Blood pressure
- LDL-P & Apo-B (advanced lipid screening)
- HgbA1c (glycemic control)
- Second would be cleaning up your sleeping habits. This doesn’t only mean going to bed on time, but ensuring you’re actually getting good sleep by removing obstacles that harm sleep efficiency (stimulants, light exposure, suboptimal temperature, noise, dirty air) and having any sleep disorders diagnosed.
- Third is regular exercise. Higher intensity gives you more bang for your buck, be that interval training while running, spinning, swimming or picking up something heavy. I tend to favor resistance training over cardio, but you have to do something you have fun doing and will still be doing a year from now.
What I’ve listed first and foremost is incredibly vague, and it should be. Nutrition is actually the domain that allows for the greatest degree of variance. The other two are more straightforward, need to be less individualized and can be easily researched. But we’ll talk about more of these three things in the future.
What about a pill?
The authors of one of the articles I linked to states that a better primary preventative strategy for cardiovascular disease would be statin therapy. Certainly, optimizing your lipids will reduce your cardiovascular risk.
I’m not the biggest fan of statins or supplements for that matter. In most cases, they’re going to move the needle to a much smaller degree than will the three things above that I mentioned in the context of heart disease prevention. I’ll arbitrarily say 5% for the supplements, herbs, etc and 95% for the lifestyle component. I don’t know to what degree statins actually change cardiovascular outcome for a number of reasons I won’t get into here.
But some alternatives to aspirin that might be helpful are curcumin, boswellia and devil’s claw. These haven’t been studied at all in cardiovascular disease prevention in a way that’s very telling. This is all based off of translational science.
Some other ways to target your lipids that has the same quality of evidence of the three herbs I mentioned are red yeast rice, policosanol, and soluble fiber supplements like acaia and inulin.
What if I go about listening to my adamant Primary Care Provider, the CDC or the U.S Preventative Task Force?
Some might call you a fool, but I won’t. It’s actually a pretty complex topic which you can read more about in this reference specifically. I think there’s enough data clearly demonstrating that the cost outweights the benefit, and that the benefit is very small. I certainly am in the camp of physicians that won’t be recommendeding aspirin to any of my patients, including the high-risk folks without history of cardiac events or stroke.
That being said, if you and your provider have decided to put the green light on aspirin consider your risk of bleeding. Some of areas you want to look at are going through any other medications you need to take with a fine-tooth comb, looking at any other health conditions you currently have and ruling out any others that may be hidden, looking closely at any supplements you’re taking, and doing a thorough analysis of your dietary habits.
Further Reading:
U.S Preventative Task Force Position on aspirin use
[1]https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/aspirin-to-prevent-cardiovascular-disease-and-cancer
Recent article by the CDC calling for behavior change to get 9 million more Americans on aspirin
[2] https://www.cdc.gov/mmwr/volumes/67/wr/mm6735a4.htm?s_cid=mm6735a4_w
One of the studies supporting the development of the idea that aspirin could help prevent heart attacks
[3] Final Report on the Aspirin Component of the Ongoing Physicians’ Health Study. “Steering Committee of the Physicians’ Health Study Research Group.” N Engl J Med321.3 (1989):
A commentary on the three latest trials ASPREE, ASCEND, ARRIVE, plus a brief look on at the outcomes found by 11 other trials since the 80s.
[4] Ridker, Paul M. “Should Aspirin Be Used for Primary Prevention in the Post-Statin Era?.” (2018): 1572-1574
Modest benefits of aspirin specific to men and women, but higher risk of nontrivial bleeding events.
[5] Berger, Jeffrey S., et al. “Aspirin for the primary prevention of cardiovascular events in women and men: a sex-specific meta-analysis of randomized controlled trials.”
A commentary on the data at large, opinions of expert groups, and disparities in aspirin related decision making among primary care providers
[6] Psotka, Mitchell A., and Kirsten E. Fleischmann. “Aspirin for Primary Prevention: What’s a Clinician to Do?.” (2015): 147-149
A potential effect of aspirin on the permeaibility of your intestine.
[7] Lambert, G. P., et al. “Effect of aspirin dose on gastrointestinal permeability.” International journal of sports medicine 33.06 (2012): 421-425.
Stats on aspirin recommendations by primary care providers
[8] Fiscella, Kevin, et al. “Do clinicians recommend aspirin to patients for primary prevention of cardiovascular disease?.” Journal of general internal medicine 30.2 (2015): 155-160
All that glitters isn’t gold.
[9] Krantz, Mori J., Jeffrey S. Berger, and William R. Hiatt. “An aspirin a day: are we barking up the wrong willow tree?.” Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy 30.2 (2010): 115-118
Dr. Mitchell is a physician practicing rheumatology in Gilbert, Arizona. His interests include clinical nutrition, autoimmune disease and environmental medicine.