In people without a personal history of cardiovascular disease, the “risks of aspirin [may] outweigh [the] benefits.” But, aspirin may have additional benefits, as well.
“We have long recognized the preventative role of daily aspirin for patients with [heart] disease; however, it now appears that we can [hatch two birds from one egg].” Daily low-dose aspirin may also help prevent certain forms of cancer, as well.
In an analysis of eight different studies “involving more than 25,000 [people], the authors found a 20% decrease in risk of death from cancer among those…randomized to [a] daily aspirin.” You know, the search for effective and safe treatments for cancer remains an enormous, burdensome challenge. “If only we could stop cancer in its tracks—prevent it before it strikes.” Well, “[p]erhaps we can,” with this plant phytonutrient—salicylic acid—found in aspirin.
How does it affect cancer? Well, the Nobel Prize in Medicine went to the team that discovered how aspirin works. Enzymes named COX, cyclooxygenase, take the pro-inflammatory omega-6 fatty acid arachidonic acid that our body makes—or, we get directly in our diet, from mainly chicken and eggs—our enzymes take the arachidonic acid and turn it into inflammatory mediators, like thromboxane, which produces thrombosis (clots), and prostaglandins, which cause inflammation.
Aspirin suppresses these enzymes, though. So, less thromboxane means fewer clots. And, less prostaglandin means less pain, swelling, and fever. But, prostaglandins can also dilate the lymphatic vessels inside tumors, allowing cancer cells to spread. So, one of the ways cancer tries to kill us is by boosting COX activity.
That’s one of the ways we think aspirin can help prevent cancer—by counteracting tumor attempts to pry open the lymphatic bars on its cage, and spread throughout the body—because “the reduction in mortality due to some cancers occurred within 2 to 3 years after [aspirin was started].” That seems “too quick to be accounted for by an effect only on” the genesis (formation) of cancer. Cancer can take decades to develop.
So, the only way aspirin could save us that fast is by suppressing the growth and spread of tumors that already exist. Aspirin appeared to cut the risk of metastases in half—particularly for adenocarcinomas, like colon cancer.
So now, what about everyone taking a daily baby aspirin? Previous risk/benefit analyses did not consider the effects of aspirin on cancer, instead just balancing cardiovascular benefits with bleeding risks. But, these new cancer findings may change things.
If this was just the reduction of colon cancer risk, then the benefits might not outweigh the harms for the general public. But, now we have evidence that it works against other cancers, too. Even a 10% reduction in overall cancer incidence “could tip the balance” in favor of benefits over risks.
So, how does the cancer benefit compare? As we saw before, using aspirin in healthy people just for cardiovascular protection is kind of a wash. By contrast, the cancer prevention rates might save twice as many lives. So, the benefits may outweigh the risks. If you put it all together, heart attacks, strokes, cancer, and bleeding, aspirin comes out looking protective overall—potentially extending our lifespan.
Yes, higher risk of major bleeding, even at low-dose aspirin, but fewer heart attacks, clotting strokes, and cancers. So, it may be beneficial overall.
Now, note these age categories only go up to 74 years old, though. That’s because the risk of bleeding on aspirin increases steeply with age; and so, may tip the balance the other way. But, in younger folks, this data certainly has the research community buzzing. “The emerging evidence on aspirin’s cancer protection highlights an exciting time for cancer prevention.”
“In light of low-dose aspirin’s ability to reduce mortality from both vascular events and cancer to a very notable degree, it is tempting to recommend” low-dose aspirin for nearly everybody. However, aspirin pills, even at low doses, have “a propensity to damage [the lining of our stomach and intestines], and increase [the] risk for gastrointestinal bleeding; this fact may constrain health authorities from recommending aspirin for [the general population].” Recent meta-analyses estimate that just a single “year of low-dose aspirin therapy will induce major gastrointestinal bleeding…in one…out of 833 [people].”
If only there were a way to get the benefits, without the risks. Those who remember this video already know the answer. The aspirin phytonutrient isn’t just found in willow trees, but throughout the plant kingdom. This explains why the active ingredient in aspirin is found normally in the bloodstream even in people not taking aspirin.
Here’s the levels of aspirin in people that eat fruits and vegetables, and here’s the levels found in those that don’t. Then, just drink one fruit smoothie, and within an hour and a half, your levels rise. As you can see, one smoothie ain’t going to do it; you have to regularly eat daily fruit and vegetable consumption.
But, are these kinds of aspirin levels sufficient to suppress the expression of that inflammatory enzyme implicated in cancer growth and spread? Well, using umbilical cord and foreskins—where else are you going to get human tissue?—they found that even those low levels caused by smoothie consumption significantly suppressed the expression of that inflammatory enzyme at a genetic level.
Well, if this aspirin phytonutrient is made by plants, we might expect plant-eaters to have higher levels. And, indeed, not only did they find higher blood levels in vegetarians; there was an overlap with people taking aspirin pills. Some vegetarians had the same level in their blood as people actually taking aspirin. Vegetarians pee out as much of the active metabolite of aspirin as aspirin-users do, just because they’re eating so many fruits and vegetables.
“Because the anti-inflammatory action of aspirin is probably the result of [this active ingredient in aspirin—salicylic acid—], and the concentrations of [salicylic acid] seen in vegetarians [has] been shown to inhibit [that inflammatory COX enzyme] in vitro, [it’s] plausible that dietary salicylates may contribute to the beneficial effects of a vegetarian diet, although [they say] it seems unlikely that most omnivores would be able to achieve sufficient dietary intake of salicylates to have a therapeutic effect.” Though, they could certainly eat more fruits and veggies, too.
With effectively all that aspirin flowing through their systems, plant-eaters must have high ulcer rates, right? Aspirin can just chew through our gut. But no, vegetarians appear to have a significantly lower risk of ulcers, for both men and women.
So, for the general population, by eating plants instead of taking aspirin, we may not just get the benefits without the risks, we can get benefits—with benefits! How is that possible? Because in plants, the salicylic acid may come naturally pre-packaged with gut-protective nutrients.
For example, nitric oxide from dietary nitrates exerts stomach-protective effects by “boosting blood flow” and protective “mucus production” in the lining of the stomach—”effects [that] demonstrably oppose the pro-ulcerative impact of aspirin…”
“Dark green leafy vegetables…are among the richest dietary sources of nitrate.” But, of course, the researcher goes on to say that, “Since it may be unrealistic to expect people to eat ample servings of [greens] every day,” we should just give people pills with their pills, right? Nitrate pills with their aspirin pills.
But, why not just eat our greens? People who’ve had a heart attack should follow their physician’s advice, which probably includes taking aspirin every day. What about everyone else? I think everyone should take aspirin—but, in produce, not pill form.
To see the pros versus cons for people trying to prevent or treat heart attacks and stroke, see my previous video, Should We All Take Aspirin to Prevent Heart Disease?
If the COX enzyme sounds familiar, I talked about it in my Anti-inflammatory Life is a Bowl of Cherries video.
Where does one get “dietary nitrates” from? See: Vegetables Rate by Nitrate.
Do some plant foods have more aspirin than others? Definitely. In fact, some foods have the same amount as a “baby” aspirin. Check out my next video: Plants with Aspirin Aspirations.
Michael Greger, M.D.
Michael Greger, M.D., is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United