How to Get the Benefits of Aspirin Without the Risks

For people without a personal history of cardiovascular disease, aspirin’s risks may outweigh its benefits, but aspirin may have additional benefits. “We have long recognized the preventative role of daily aspirin for patients with atherosclerotic [heart] disease; however, it now appears that we can hatch 2 birds from 1 egg. Daily low-dose aspirin may help prevent certain forms of cancer, as well, as I discuss in my video Should We All Take Aspirin to Prevent Cancer? In an analysis of eight different studies involving more than 25,000 people, “the authors found a 20 percent decrease in risk of death from cancer among those randomized to daily aspirin…” The researchers wrote, “[T]he search for the most efficacious and safe treatments for malignant disease remains an enormous and burdensome challenge. If only we could just stop cancer in its tracks—prevent it before it strikes. Perhaps we can.” Indeed, perhaps we can with salicylic acid, the plant phytonutrient that’s marketed as aspirin.

How does aspirin affect cancer? The Nobel Prize for Medicine was awarded to the team who discovered how aspirin works. Enzymes named COX (cyclooxygenase) take the pro-inflammatory, omega-6, fatty-acid arachidonic acid our body makes or we get directly in our diet (primarily from eating chicken and eggs), and turns it into inflammatory mediators, such as thromboxane, which produces thrombosis (clots), and prostaglandins, which cause inflammation. Aspirin suppresses these COX enzymes. Less thromboxane means fewer clots, and less prostaglandin means less pain, swelling, and fever. However, prostaglandins can also dilate the lymphatic vessels inside tumors, allowing cancer cells to spread. So, one way cancer tries to kill us is by boosting COX activity.

We think one way aspirin can prevent cancer is by counteracting the tumor’s attempts to pry open the lymphatic bars on its cage and spread throughout the body. Indeed, reduction in mortality due to some cancers occurred within two to three years after aspirin was started. That seems too quick to be accounted for by an effect only on tumor formation . Cancer can take decades to develop, so the only way aspirin could work 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.

Given this, should we all take 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 daily aspirin use were only associated with a reduction of colon cancer risk, then the benefits might not outweigh the harms for the general population, but we now have evidence that it works against other cancers, too. “[E]ven a 10% reduction in overall cancer incidence…could tip the balance” in favor of benefits over risks.

How does the cancer benefit compare? We know that using aspirin in healthy people just for cardiovascular protection is kind of a wash, but, by contrast, the cancer prevention rates might save twice as many lives, so the benefits may outweigh the risks. If we put it all together—heart attacks, strokes, cancer, and bleeding—aspirin comes out as protective overall, potentially extending our lifespan. There is a higher risk of major bleeding even on low-dose aspirin, but there are fewer heart attacks, clotting strokes, and cancers. So, overall, aspirin may be beneficial.

It’s important to note that the age categories in that study only went up to 74 years, though. Why? Because the “risk of bleeding on aspirin increases steeply with age,” so the balance may be tipped the other way at 75 years and older. But, in younger folks, these data certainly have 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 this measure…for most healthy adults…However, oral aspirin, even in low doses, has a propensity to damage the gastroduodenal mucosa [linings of our stomachs] and increase risk for gastrointestinal bleeding; this fact may constrain health authorities from recommending aspirin use for subjects deemed to be at low cardiovascular risk”—that is, for the general population. “Recent meta-analyses estimate that a year of low-dose aspirin therapy will induce major gastrointestinal bleeding (requiring hospitalization) in one subject out of 833…”

If only there were a way to get the benefits without the risks.

Those who remember my video Aspirin Levels in Plant Foods already know there is. The aspirin phytonutrient salicylic acid isn’t just found in willow trees, but throughout the plant kingdom, from blackberries and white onions to green apples, green beans, and beyond. This explains why the active ingredient in aspirin is found normally in the bloodstream even in people not taking aspirin. The levels of aspirin in people who eat fruits and vegetables are significantly higher than the levels of those who don’t. If we drink just one fruit smoothie, our levels rise within only 90 minutes. But, one smoothie isn’t going to do it, of course. We need to have regular fruit and vegetable consumption every day. Are these kinds of aspirin levels sufficient to suppress the expression of the inflammatory enzyme implicated in cancer growth and spread, though? Using umbilical cord and foreskin cells—where else would researchers get human tissue?—they found that even those low levels caused by smoothie consumption significantly suppressed the expression of this inflammatory enzyme on a genetic level.

Since this aspirin phytonutrient is made by plants, we might expect plant-eaters to have higher levels. Indeed, not only did researchers find higher blood levels in vegetarians, but there was an overlap between people taking aspirin pills. Some vegetarians had the same level in their blood as people actually taking aspirin. Vegetarians may pee out as much of the active metabolite of aspirin as those who take aspirin do, simply because vegetarians eat so many fruits and vegetables. “Because the anti-inflammatory action of aspirin is probably the result of SA [salicylic acid, the active ingredient in aspirin], and the concentrations of SA seen in vegetarians have been shown to inhibit [that inflammatory enzyme] COX-2 in vitro, it is plausible that dietary salicylates may contribute to the beneficial effects of a vegetarian diet, although it seems unlikely that most [omnivores] will achieve sufficient dietary intake of salicylates to have a therapeutic effect.”

Aspirin can chew away at our gut. With all that salicylic acid flowing through their systems, plant-eaters must have higher ulcer rates, right? No. Both vegetarian women and men appear to have a significantly lower risk of ulcers. So, for the general population, by eating plants instead of taking aspirin, we may not only get the benefits without the risks, we can get the benefits with even more benefits. How is this possible? In plants, the salicylic acid can 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 which demonstrably oppose the pro-ulcerative impact of aspirin and other NSAIDs.”

The researcher notes that while “[d]ark green leafy vegetables…are among the richest dietary sources of nitrate…it may be unrealistic to expect people to eat ample servings of these every day,” so we should just give people pills with their pills, but I say we should just eat our greens. People who’ve had a heart attack should follow their physician’s advice, which probably includes taking aspirin every day, but what about everyone else? I think everyone should take aspirin—but in the form of produce, not a pill.


To see the pros versus cons for people trying to prevent or treat heart attacks and stroke, see my video Should We All Take Aspirin to Prevent Heart Disease?.

Does the COX enzyme sound familiar? I talked about it in my Anti-Inflammatory Life Is a Bowl of Cherries video.

Where does one get “dietary nitrates”? See Vegetables Rate by Nitrate and Veg-Table Dietary Nitrate Scoring Method. I also discuss nitrates in Slowing Our Metabolism with Nitrate-Rich Vegetables and Oxygenating Blood with Nitrate-Rich Vegetables.

Do some plant foods have more aspirin than others? Definitely. In fact, some foods have the same amount as a “baby” aspirin. Check out Plants with Aspirin Aspirations.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Why We Should Cut Down on Salt Independently of Blood Pressure

If you put people on a low-salt diet, meaning only getting twice as much sodium as they need, as opposed to a usual salt diet where they’re getting five times more, you get a significant improvement in artery function. Lower salt begets better arterial function, suggesting heart-protective effects beyond just blood pressure reduction. Now, this was after dropping people’s salt intake by about a teaspoon a day for two weeks. What if you only dropped salt intake by a half teaspoon or so a day? You still get a significant improvement in artery function, and it happens within just two days of reducing one’s salt intake—or, even after a single meal. A high-salt meal, which is to say just a “typical amount of salt consumed in a commonly eaten meal, can significantly suppress [artery function] within 30 [minutes].” In my video Sodium and Arterial Function: A-Salting Our Endothelium, I show what happens 30, 60, 90, and 120 minutes after consuming a meal with just a pinch of salt in it versus eating the same meal, but made with a quarter teaspoon of salt rather than a pinch: a significant suppression of arterial function. Now, is this in addition to the spike in blood pressure from salt or because of the spike in blood pressure?

If you take people with normal blood pressure and give them a bowl of soup containing the amount of salt a regular meal might contain, their blood pressure goes up over the next three hours compared to the same soup with no added salt. Now, this doesn’t happen to everyone; this is just the average response. Some people are resistant to the effects of salt on their blood pressure. So what if you repeated the artery function experiment on them? You get a paper entitled (*spoiler alert*): “High dietary sodium intake impairs endothelium-dependent dilation in healthy salt-resistant humans.” Indeed, even in people whose blood pressure is unresponsive to salt intake, they still suffer significant suppression of their artery function. So, independent of any effects on blood pressure, salt hurts our arteries, and that harm begins within minutes of consumption for our major arteries and even our tiny blood vessels.

Using something called laser Doppler flowmetry, you can measure blood flow in the tiny vessels in our skin. In the video, you can see the measurement of blood flow at baseline. Now, to get the blood vessels to open up, they warmed the skin. The reason we may turn pink when we get into a hot bath is that the blood vessels in our skin are opening up, and that’s what happened: a big increase in blood flow with the warming. That was on the low-salt diet, however. A high-salt diet starts out the same, but after the same warming, there’s significantly less blood flow. The arteries just don’t seem to open up as well on a high-salt diet, unless you inject vitamin C into the skin. That seems to reverse the salt-induced suppression of blood vessel function. So if an antioxidant reverses the salt effect, then the way salt may be damaging our artery function is through oxidative stress, the formation of free radicals in our blood stream. But, how?

There’s an enzyme in our body that can detoxify a million free radicals per second (!), 24 hours a day, 7 days a week. But, compared to a low-salt diet, if we consume a normal-salt diet, we suppress the activity of this detoxifying powerhouse of an enzyme. That may help explain why our artery function is much lower on salt. With our antioxidant enzymes crippled by the salt, all the excess free radicals may be crippling our arteries. Mop up those extra free radicals by infusing vitamin C into the bloodstream, however, and artery function returns to normal. In contrast, on a low-salt diet, if you drip vitamin C into people’s veins, nothing happens because our antioxidant enzymes are already taking care of business and haven’t been shackled by the sodium of a normal-salt diet.

Whereas potassium, concentrated in fruits and vegetables, softens the cells that line our arteries and increases the release of nitric oxide that allows our arteries to relax, sodium in our blood stiffens the artery lining within minutes and reduces nitric oxide release. The more salt, the less nitric oxide is produced. Consume one salty meal, and not only does our blood pressure go up, but our arteries literally stiffen. That’s why we could figure out four thousand years ago that too much salt was bad for us. Maybe we don’t need a double-blind trial. Maybe we don’t need to follow people around for a decade. We may just have to feed someone a bag of potato chips and take their pulse.


My video Sodium and Arterial Function: A-Salting Our Endothelium is part of an extended video series on sodium, trying to set the record straight on the “controversy” manufactured by the processed food industries. Check out the other installments:

Other salt-related videos of interest include:

I touched on potassium in Preventing Strokes with Diet and Lowering our Sodium-to-Potassium Ratio to Reduce Stroke Risk, but I’m looking forward to doing a deep dive into the mineral when I get a chance.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

The Best Source of Vitamin D

If one is going to make an evolutionary argument for what a “natural” vitamin D level may be, how about getting vitamin D in the way nature intended—that is, from the sun instead of supplements? I run through the pros and cons in my video The Best Way to Get Vitamin D: Sun, Supplements, or Salons?. Though supplements may only cost about 10 dollars a year, sunlight is free. We never have to worry about getting too much vitamin D from sunlight, since our body has a way to regulate production in the skin, so if we get our D from the sun, we don’t have to trust poorly regulated supplement companies not to mislabel their products. Indeed, only about half the supplement brands that researchers tested came within 10 percent of their labeled amount.

Sunlight may also have benefits beyond vitamin D, such as how our body may use the sun’s near-infra-red rays that penetrate our skin to activate chlorophyll by-products in our bloodstream to make Co-Q10. (See my video How to Regenerate Coenzyme Q10 (CoQ10) Naturally for more on this.) There’s another way our body appears to use the sun’s rays to maximize the effects of the greens we eat: Within 30 minutes of exposure to the ultraviolet (UV) rays in sunlight, we can get a significant drop in blood pressure and improvement in artery function, thanks to a burst of nitric oxide-releasing compounds that flow into our bloodstream. We can even measure the nitric oxide gas coming straight off our skin. Of course, we have to eat greens or beets in the first place, but that combo of greens and sunlight may help explain some of the protection that plant-based eaters experience.

Morning sun exposure may help those with seasonal affective disorder, as well as improve the mood of wheelchair-bound nursing home residents. Previously, I’ve talked about the benefits of avoiding light at night—see my video Melatonin and Breast Cancer if you’d like to know more—but underexposure to daytime sunlight may also affect our melatonin levels, which don’t only regulate our circadian rhythms but may also be helpful in the prevention of cancer and other diseases. Older men and women getting two hours of outside light during the day appear to secrete 13 percent more melatonin at night, though we’re not sure what, if any, clinical significance this has.

The downsides of sun exposure include increased risk of cataracts, a leading cause of vision loss, though this risk can be minimized by wearing a brimmed hat and sunglasses. Sunlight also ages our skin. In my The Best Way to Get Vitamin D: Sun, Supplements, or Salons? video, you can see a dramatic photo of a truck driver who spent decades getting more sun on the left side of his face—though his driver’s side window. “The effects of sunlight on the skin are profound, and are estimated to account for up to 90% of visible skin aging”—that is, wrinkles, thickening, and loss of elasticity. Things like sun exposure and smoking can make us look 11 years older. Cosmetic surgery can make us look up to eight years younger, but a healthy lifestyle may work even better. Doctors don’t preach about sun protection for youthful facial looks, though, but because of skin cancer. Medical authorities from the World Health Organization, the American Cancer Society, to the Surgeon General warn about excess sun exposure and for good reason, given the millions of skin cancers and thousands of deaths diagnosed every year in the United States alone.

The UV rays in sunlight are considered a complete carcinogen, meaning they can not only initiate cancer, but promote its progression and spread. Melanoma is the scariest, which “makes the rising incidence of melanoma in young women particularly alarming.” This increase has been blamed on the increased usage of tanning salons. Tanning beds and UV rays in general are considered class 1 carcinogens, like processed meat, accounting for as many as three quarters of melanoma cases among young people and six times the risk of melanoma for those who visited tanning salons ten or more times before the age of 30.

The tanning industry is big business, bringing in billions of dollars. There may be more tanning salons than there are Starbucks, and they use those dollars like the tobacco industry: to downplay the risks of their products. Laws are being passed to regulate tanning salons, from complete prohibitions, like in the country of Brazil, to age restrictions for minors. But, unlike tobacco, tanning isn’t addictive. Or is it?

Have you heard of “tanorexia”? Some people tan compulsively and report a so-called tanner’s high. Describing tanning behavior like a substance abuse disorder might seem a little silly—that is, until you stick people in a brain scanner and can show the same kind of reward pathways light up in the brain, thanks to endorphins that are released by our skin when we’re exposed to UV rays. In fact, we can even induce withdrawal-like symptoms by giving tanners opiate-blocking drugs. So, tanning is potentially addictive and dangerous. Harvard researchers suggest that we should “view recreational tanning and opioid drug abuse as engaging in the same biological pathway.” But there’s a reason sun exposure feels good. Sunlight is the primary natural source of vitamin D, and, evolutionarily, it’s more important, in terms of passing along our genes, not to die of rickets in childhood. Unlike natural sunlight, tanning bed lights emit mostly UVA, which is the worst of both worlds: cancer risk with no vitamin D production. The small amount of UVB many tanning beds do emit, however, may be enough to raise vitamin D levels. Is there a way to raise D levels without risking cancer? Yes: vitamin D supplements.


Indeed, we can get some of the benefits of sun exposure without the risks by taking vitamin D supplements. But, for the sake of argument, what if such supplements didn’t exist? Would the benefits of sun exposure outweigh the risks? That’s the subject of my video The Risks and Benefits of Sensible Sun Exposure.

For other videos in this vitamin D series, see:

I also explore Vitamin D as it relates to specific diseases:

Here’s the video about that amazing chlorophyll activation: How to Regenerate Coenzyme Q10 (CoQ10) Naturally.

What do greens and beets have to do with artery function? Check out some of my latest videos on the wonders of nitrate-rich vegetables:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: