The aspirin compounds naturally found in plant foods may help explain the lower cancer rates among those eating plant-based diets.
Should We All Take Aspirin to Prevent Cancer?
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
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, 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” 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 need regular, 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 cords 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 [have] 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.
Please consider volunteering to help out on the site.
- Rinelli S, Spadafranca A, Fiorillo G, Cocucci M, Bertoli S, Battezzati A. Circulating salicylic acid and metabolic and inflammatory responses after fruit ingestion. Plant Foods Hum Nutr. 2012 Mar;67(1):100-4.
- Xu XM, Sansores-Garcia L, Chen XM, Matijevic-Aleksic N, Du M, Wu KK. Suppression of inducible cyclooxygenase 2 gene transcription by aspirin and sodium salicylate. Proc Natl Acad Sci U S A. 1999 Apr 27;96(9):5292-7.
- McCarty MF. Dietary nitrate and reductive polyphenols may potentiate the vascular benefitand alleviate the ulcerative risk of low-dose aspirin. Med Hypotheses. 2013 Feb;80(2):186-90.
- Rothwell PM, Wilson M, Price JF, Belch JF, Meade TW, Mehta Z. Effect of daily aspirin on risk of cancer metastasis: a study of incident cancers during randomised controlled trials. Lancet. 2012 Apr 28;379(9826):1591-601.
- Antonoff MB, D'Cunha J. Killing two birds with one salicylate: aspirin's dual roles in preventative health. Semin Thorac Cardiovasc Surg. 2011 Summer;23(2):96-8.
- Duthie GG, Wood AD. Natural salicylates: foods, functions and disease prevention. Food Funct. 2011 Sep;2(9):515-20.
- Thun MJ, Jacobs EJ, Patrono C. The role of aspirin in cancer prevention. Nat Rev Clin Oncol. 2012 Apr 3;9(5):259-67.
- Mayor S. Risks of aspirin outweigh benefits in people without cardiovascular disease, shows analysis. BMJ. 2012 Jan 9;344:e241.
- Rothwell PM, Price JF, Fowkes FG, Zanchetti A, Roncaglioni MC, Tognoni G, Lee R, Belch JF, Wilson M, Mehta Z, Meade TW. Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled trials. Lancet. 2012 Apr 28;379(9826):1602-12.
- Chan AT, Ogino S, Fuchs CS. Aspirin and the risk of colorectal cancer in relation to the expression of COX-2. N Engl J Med. 2007 May 24;356(21):2131-42.
- Opie LH. Aspirin in the prevention of cancer. The Lancet Volume 377, No. 9778, p1651,14 May 2011.
- Swain AR, Dutton SP, Truswell AS. Salicylates in foods. J Am Diet Assoc. 1985 Aug;85(8):950-60.
- Rothwell PM, Fowkes FG, Belch JF, Ogawa H, Warlow CP, Meade TW. Effect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials. Lancet. 2011 Jan 1;377(9759):31-41.
- Mills EJ, Wu P, Alberton M, Kanters S, Lanas A, Lester R. Low-dose aspirin and cancer mortality: a meta-analysis of randomized trials. Am J Med. 2012 Jun;125(6):560-7.
- Knutsen SF. Lifestyle and the use of health services. Am J Clin Nutr. 1994 May;59(5 Suppl):1171S-1175S.
- Vane JR. The mode of action of aspirin and similar compounds. J Allergy Clin Immunol. 1976 Dec;58(6):691-712.
- Karnezis T, Shayan R, Fox S, Achen MG, Stacker SA. The connection between lymphangiogenic signalling and prostaglandin biology: a missing link in the metastatic pathway. Oncotarget. 2012 Aug;3(8):893-906.
- Paterson JR, Blacklock C, Campbell G, Wiles D, Lawrence JR. The identification of salicylates as normal constituents of serum: a link between diet and health? J Clin Pathol. 1998 Jul;51(7):502-5.
- Blacklock CJ, Lawrence JR, Wiles D, Malcolm EA, Gibson IH, Kelly CJ, Paterson JR. Salicylic acid in the serum of subjects not taking aspirin. Comparison of salicylic acid concentrations in the serum of vegetarians, non-vegetarians, and patients taking low dose aspirin. J Clin Pathol. 2001 Jul;54(7):553-5.
- Hare LG, Woodside JV, Young IS. Dietary salicylates. J Clin Pathol. 2003 Sep;56(9):649-50.
Image credits: Curtis Gregory Perry, 100777, ragesoss, and SciTechMuseum via flickr. Images have been modified.
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
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, 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” 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 need regular, 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 cords 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 [have] 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.
Please consider volunteering to help out on the site.
- Rinelli S, Spadafranca A, Fiorillo G, Cocucci M, Bertoli S, Battezzati A. Circulating salicylic acid and metabolic and inflammatory responses after fruit ingestion. Plant Foods Hum Nutr. 2012 Mar;67(1):100-4.
- Xu XM, Sansores-Garcia L, Chen XM, Matijevic-Aleksic N, Du M, Wu KK. Suppression of inducible cyclooxygenase 2 gene transcription by aspirin and sodium salicylate. Proc Natl Acad Sci U S A. 1999 Apr 27;96(9):5292-7.
- McCarty MF. Dietary nitrate and reductive polyphenols may potentiate the vascular benefitand alleviate the ulcerative risk of low-dose aspirin. Med Hypotheses. 2013 Feb;80(2):186-90.
- Rothwell PM, Wilson M, Price JF, Belch JF, Meade TW, Mehta Z. Effect of daily aspirin on risk of cancer metastasis: a study of incident cancers during randomised controlled trials. Lancet. 2012 Apr 28;379(9826):1591-601.
- Antonoff MB, D'Cunha J. Killing two birds with one salicylate: aspirin's dual roles in preventative health. Semin Thorac Cardiovasc Surg. 2011 Summer;23(2):96-8.
- Duthie GG, Wood AD. Natural salicylates: foods, functions and disease prevention. Food Funct. 2011 Sep;2(9):515-20.
- Thun MJ, Jacobs EJ, Patrono C. The role of aspirin in cancer prevention. Nat Rev Clin Oncol. 2012 Apr 3;9(5):259-67.
- Mayor S. Risks of aspirin outweigh benefits in people without cardiovascular disease, shows analysis. BMJ. 2012 Jan 9;344:e241.
- Rothwell PM, Price JF, Fowkes FG, Zanchetti A, Roncaglioni MC, Tognoni G, Lee R, Belch JF, Wilson M, Mehta Z, Meade TW. Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled trials. Lancet. 2012 Apr 28;379(9826):1602-12.
- Chan AT, Ogino S, Fuchs CS. Aspirin and the risk of colorectal cancer in relation to the expression of COX-2. N Engl J Med. 2007 May 24;356(21):2131-42.
- Opie LH. Aspirin in the prevention of cancer. The Lancet Volume 377, No. 9778, p1651,14 May 2011.
- Swain AR, Dutton SP, Truswell AS. Salicylates in foods. J Am Diet Assoc. 1985 Aug;85(8):950-60.
- Rothwell PM, Fowkes FG, Belch JF, Ogawa H, Warlow CP, Meade TW. Effect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials. Lancet. 2011 Jan 1;377(9759):31-41.
- Mills EJ, Wu P, Alberton M, Kanters S, Lanas A, Lester R. Low-dose aspirin and cancer mortality: a meta-analysis of randomized trials. Am J Med. 2012 Jun;125(6):560-7.
- Knutsen SF. Lifestyle and the use of health services. Am J Clin Nutr. 1994 May;59(5 Suppl):1171S-1175S.
- Vane JR. The mode of action of aspirin and similar compounds. J Allergy Clin Immunol. 1976 Dec;58(6):691-712.
- Karnezis T, Shayan R, Fox S, Achen MG, Stacker SA. The connection between lymphangiogenic signalling and prostaglandin biology: a missing link in the metastatic pathway. Oncotarget. 2012 Aug;3(8):893-906.
- Paterson JR, Blacklock C, Campbell G, Wiles D, Lawrence JR. The identification of salicylates as normal constituents of serum: a link between diet and health? J Clin Pathol. 1998 Jul;51(7):502-5.
- Blacklock CJ, Lawrence JR, Wiles D, Malcolm EA, Gibson IH, Kelly CJ, Paterson JR. Salicylic acid in the serum of subjects not taking aspirin. Comparison of salicylic acid concentrations in the serum of vegetarians, non-vegetarians, and patients taking low dose aspirin. J Clin Pathol. 2001 Jul;54(7):553-5.
- Hare LG, Woodside JV, Young IS. Dietary salicylates. J Clin Pathol. 2003 Sep;56(9):649-50.
Image credits: Curtis Gregory Perry, 100777, ragesoss, and SciTechMuseum via flickr. Images have been modified.
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Should We All Take Aspirin to Prevent Cancer?
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Content URLDoctor'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.
If you haven’t yet, you can subscribe to my videos for free by clicking here. Read our important information about translations here.