Should We All Take Aspirin to Prevent Cancer?

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.

Doctor’s Note

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.

In health,
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

Try This Diet Plan To Shrink Cancerous Tumors

Shrink Breast Cancer Tumors With Vegan DietProbably about a third of common cancers can be prevented by eating a healthy, plant-based diet, being physically active, and maintaining a healthy weight. One of the ways plants may help is by cutting off the supply lines to cancerous tumors.

A tumor cannot grow without a blood supply. Currently, it is believed that a tumor mass cannot exist in a volume greater than about size of the ball at the tip of a ballpoint pen without a proper blood supply, which indicates that angiogenesis—angio means vessel, so the genesis—the creation of new blood vessels is critical to tumor growth. Each one of us has cancer cells in us right now. By age 70, microscopic cancers are detected in the thyroid glands of virtually everyone, for example. Most of these tumors never cause problems, never become clinically significant, leading to the concept of “cancer without disease” as a normal state during aging. Cancer cells are commonly present in the body, but they can’t grow into tumors any bigger than that tiny dot size, no more than 10 million cancer cells before needing to get hooked up to a blood supply. So tumors diabolically release angiogenic factors, chemicals that cause new blood vessels to sprout into the tumor. The most important one is called VEGF, vascular endothelial growth factor. But we can suppress VEGF with Ve-ggies.

Many of the phytonutrients we know and love in tea and spices and fruit and berries and broccoli and beans can block cancer’s stimulation of new blood vessels. They’re ideal for prophylactic long-term use against breast cancer because of their reliability, availability, safety, and affordable price. Dietary agents used to suppress angiogenesis may be an important step in the prevention and treatment of breast cancer, and in fact all types of tumors. The review concludes that we now have convincing evidence that dietary plant constituents possess the unique ability to affect tumor angiogenesis, which may be deemed advantageous in the prevention and treatment of human breast cancer.

Most of these studies have only been done in a petri dish, though. You stimulate human blood vessel cells and they start forming these tubular structures trying to make new capillaries to feed the tumor, but if you add plant flavones like apigen or luteolin, found thoughout the plant kigdom—like in citrus, celery, and peppers, you can see they help block the tube formation. Here’s the effect of fisitin, a phytonutrient found in strawberries and other fruits and veggies. It just shrinks the beginnings of new blood vessel formation right down.

Where do researchers get their hands on human blood vessels? Human umbilical vein endothelial cells. They get them from discarded umbilical cords, or, more controversially, from the eyes of aborted fetuses. But either way you can stimulate blood vessel formation with the tumor compound VEGF and then abolish that effect with plant compounds, in this case from purple rice. Therefore, the daily consumption of natural foods containing adequate flavonoids could be beneficial for the prevention of cancer metastasis or could improve cancer prognosis.

Given the power of plants, one might speculate that the foundation of an anti-angiogenic approach to cancer might be a whole food vegan diet.

Doctor’s Note

The cancer-promoting growth hormone IGF-1 is another angiogenic factor, helping tumors turn on the gravy train. This may be another reason plant-based diets protect against cancer, since as few as two weeks on a healthy diet can lower IGF-1 levels. See my series on the elegant experiments that discovered this:

One way cancer turns on the tap is silencing certain tumor suppressor genes. How do you turn them back on? See, for example, Apple Skin: Peeling Back Cancer.

How else can strawberries smack on the cancer kibosh? See Strawberries versus Esophageal Cancer and Cancer Fighting Berries.

Because we all likely have cancer cells inside us, Cancer Prevention and Treatment May Be the Same Thing. To die with cancer rather than from cancer, we need to slow down cancer doubling time. Check out one of my oldie-but-goodie video Slowing the Growth of Cancer.

For more context, check out my associated blog post: Flax and Breast Cancer Survival and Starving Tumors of Their Blood Supply.


In health,
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

#1 Anticancer Vegetable

#1 Anti-Cancer VegetableBy: Dr. Michael Greger, Director of Public Health and Animal Agriculture at the Humane Society of the United States.

But anyway, back to beans. In terms of nutrient density, nutrients per calorie: are beans the most nutritious class of whole foods? Or is it fruit, nuts and seeds, vegetables, or whole grains? What should go on the base of a healthy eating pyramid? Beans, fruits, nuts, veggies, or grains?

Definitely vegetables, but which are the healthiest ones? A major advance was made this year ranking vegetables. Graphs like this that I’ve shared over the years that compare the antioxidant power of foods were all based on very primitive methods—basically just measuring how much a food slows down an oxidation reaction between two chemicals in a machine. That was the best we had, but it required a leap of faith that what was happening in the test tube could be extrapolated to what might happen in living human tissue.

This year, though, a landmark study was published, pitting 34 common vegetables against 8 different types of human cancers. Breast cancer, brain tumors, kidney cancer, lung cancer, childhood brain tumors, pancreatic cancer, prostate cancer, and stomach cancer.

Let’s look at breast cancer—I’ll cover up the. What’s being measured is tumor cell proliferation. Here’s the control. You drip some water on a human breast tumor, and nothing happens—it’s still powering away at 100% growth rate. And these 7 vegetables appear useless against breast cancer, no different than placebo. But these 6 cut the cancer growth rate in half. And these 5 at the end stopped cancer growth completely—stopped these tumor cells dead in their tracks.

We need to eat a portfolio of vegetables. Take a look: radishes, do nothing against pancreatic cancer, in fact if anything they might accelerate growth but, against stomach cancer, they completely eliminated tumor cell growth. On the other hand, orange bell peppers don’t do much for stomach cancer, but can cut prostate cancer growth by more than 75%. So we need to eat a variety of vegetables, because each one tends to target different cancers.

If you’re particularly concerned about a specific cancer, like if you have a strong family history of breast cancer, then you can narrow it down and really nail those 5 or 6 veggies every day that excel at targeting breast tissue. But otherwise, to fight against any kind of cancer, we’ve got to eat a portfolio of vegetables to cover all our bases.

That doesn’t mean some veggies aren’t better than others. Some of these vegetables target multiple cancers at the same time. So using this groundbreaking new data, let’s play “Which is healthier.”

Building An Anti-Cancer Salad

Imagine you’re standing in line at one of those custom made-to-order salad places, where you get to choose your lettuce, choose your toppings, then choose your dressing. Lets assume that you don’t have a strong family history of any particular cancer, and so aren’t trying to hone in on avoiding one tumor over another.

First, let’s choose our lettuce. Boston, endive, radicchio, romaine, or spinach?
Out of the five, spinach is #1 against breast cancer—remember, the farther right the better it is at slowing down these cancer cells. #1 against brain tumors, #1 against kidney cancer, #1 against lung cancer, #1 against pediatric brain tumors—feed your kids spinach! #1 against pancreatic cancer, prostate cancer, and #1 against stomach cancer.

Now note it’s not #1 overall—there are 16 vegetables more powerful at stopping stomach cancer growth than spinach, but out of those five salad greens, spinach wins out across the board, against every cancer type tested.

What if the salad place said they were out of spinach, though? Which comes in second out of the four left to choose from.
For breast cancer, radicchio is #2. against brain tumors. radicchio, kidney cancer, radicchio, radicchio, romaine, radicchio, radicchio, and radicchio. So overall, out of those choices for greens, radicchio is number 2.

Back to the menu. Next we get to choose 4 toppings. Now there’s a long line of people behind you, all staring at you to make your choice. You don’t have time to ponder and pick the 4 absolute best, but you can at least make a guess as to roughly where on the graph they are.

According to this amazing new data, do carrots slow cancer cell growth rates more than 50%? Yes or no?
The answer is no. So shredded carrots aren’t going to make our top four toppings choice.

What about shredded beets? Yes or no?
Yes. Super yes! Brain tumor? Just beet it. Kidney cancer is a no, close to 50%, but not quite there. And then yes, yes, yes, yes, yes. So overall, yes for beets.

Are we putting cucumber on out salad? Yes? No?
As tasty as they may be… no. For most cancers it suppressed tumor cell growth less than 50%

What about a tomato? Yes or no?
No tomato either.

What about a potato? You can actually put potatoes onto your salad. Yes or no?
No potato either. Wait a second, no iceberg lettuce, carrots, cucumber, tomatos, potatos—that’s all people eat! That’s the problem. Even people eating their vegetables, aren’t really eating their vegetables. The majority of veggies people commonly eat have little effect.

Cutting to the chase: The line at the salad place is now out the door at this point. In this study there was one clear winner. One vegetable that completely 100% stopped cancer growth in 7 out of the 8 tumor lines. One of the most important findings of the year: which vegetable was it?

Was it bok choi? Broccoli. Brussel sprouts, fiddlehead ferns, garlic, kale, or red cabbage?

Number one against breast cancer? Garlic. Number one against brain tumors: garlic. Number two against kidney cancer: garlic. Lung cancer: garlic. Childhood brain tumors: garlic. Pancreatic cancer: garlic. Prostate cancer: garlic. And stomach cancer? Garlic. So might I suggest a garlicky salad dressing?

Wait a second, though. Is it just that garlic is toxic to all cells? Yes, it stops the growth of cancer cells, but maybe it stops the growth of healthy cells too? That wouldn’t be good. They tested for that. The black bars are cancer cells; the white bars are normal cells. As you can see garlic slams cancer cells, but doesn’t touch normal cells, and the same thing with pretty much all the vegetables. They’re selective; they go after the cancer cells but leave the normal cells alone. Veggies are amazing.

Now if you didn’t pick garlic and instead chose one of those others you probably weren’t far off. The two best families of vegetables for cancer prevention are the cruciferous vegetables, like broccoli, kale, cabbage, and the allium family vegetables, like garlic, onions, and leeks. Let me just run through this one last time to highlight this important fact.

Starting from the beginning. Cruciferous vegetables in green; allium vegetables in yellow. What I want you to notice is the clustering of colors over on the right side, which illustrates the power of these two superfood classes of vegetables.

Whether for breast cancer, brain cancer, kidney cancer, lung cancer, or brain cancer. Interestingly you’ll notice that bok choy is often the odd one out, apparently the least healthy of the cruciferous vegetables. Pancreatic cancer, prostate cancer, and finally stomach cancer.

So you know all those recipes that start with garlic and onions and then throw you in some greens—that, is the way to eat.

The researchers conclude: “the inclusion of cruciferous and allium vegetables in the diet is essential for effective dietary-based chemopreventive strategies.”

Michael Greger M.D.About Michael Greger M.D.
Michael Greger, M.D., is a physician, 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 States.


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