 It's crazy when you think about all the different kinds of foods we eat. We just swallow and hope it all works out for the best. Well, it turns out there are better ways to think about keeping our bodies humming healthfully along. Welcome to Nutrition Facts. I'm your host, Dr. Michael Greger. Feeling lousy? Take two aspirin and call me in the morning or not. Today on the podcast we take a closer look at the health effects of regular aspirin use. In our first story, we weigh daily aspirin use against the risk of internal bleeding. Salicylic acid, the active ingredient in aspirin, has been used for thousands of years as an anti-inflammatory painkiller in the form of willow tree bark extract, which Hippocrates use to treat fever and to alleviate pain during childbirth. It became trademarked as a drug in 1899 and remains to this day probably the most commonly used drug in the world. One of the reasons it remains so popular, despite the fact that we have better painkillers now, is that it also acts as a blood thinner. Millions of people now take aspirin on a daily basis to treat or prevent heart disease. It all started back in 1953 with the publication of this landmark study in the New England Journal of Medicine, Length of Life and Cause of Death in Rheumatoid Arthritis. Paper started out with the sense it has often been said that the way to live a long life is to acquire rheumatism. They found fewer deaths than expected from accidents, which could be explained by the fact that people with arthritis probably aren't out going skiing, but also significantly fewer deaths from heart attacks. Maybe it was all the aspirin they were taking for their joints that was thinning their blood and preventing clots forming in their coronary arteries in their heart. And so in the 1960s there were calls to study whether aspirin would help those at risk for blood clots and in the 1970s we got our wish. Studies suggesting regular aspirin intake protects against heart attacks. Today the official recommendation is that low dose aspirin is recommended for all patients with heart disease, but in the general population for those without a known history of heart disease or stroke, daily aspirin is only recommended when the heart disease benefits outweigh the risks of bleeding. The bleeding complications associated with aspirin use may be considered an underestimated hazard in clinical medical practice. For those who've already had a heart attack, the risk-benefit analysis is clear. If you took 10,000 patients, daily low-dose aspirin use would be expected to prevent approximately 250 major vascular events such as heart attacks, strokes, or the most major event of all, death. But that same aspirin would be expected to cause approximately 40 major extra-cranial bleeding events, meaning bleeding so bad you have to be hospitalized. Thus the net benefit of aspirin for secondary prevention, meaning like preventing your second heart attack, would substantially exceed the bleeding hazard. For every six major vascular events prevented, only about one major bleeding event would occur, so the value of aspirin for secondary prevention is not disputed. But if you instead took 10,000 patients who had never had a heart attack or stroke yet, and tried to use aspirin to prevent clots in the first place, so-called primary prevention, daily low-dose aspirin would only be expected to prevent seven major vascular events at the cost of causing a hemorrhagic stroke, bleeding within the brain, along with three other major bleeding events. So then the benefits are only like two to one, there's a little too close for comfort, which is why the new European guidelines do not recommend aspirin for the general population, especially given the additional risk of aspirin causing smaller bleeds within the brain as well. If only there were a safe, simple side-effect-free solution, and there is. Ornish and Esselstyn prove that even advanced crippling heart disease could not just be prevented and treated, but reversed with a plant-based diet centered around grains, beans, vegetables, fruits, with nuts and seeds treated as condiments, and no oils, dairy, meat, poultry, or fish. Bill Castelli, the longtime director of the longest running epidemiological study in the world, a famous Framingham heart study, was once asked, what he would do to reverse the coronary artery disease epidemic if he were omnipotent? His answer? Have the public eat the diet described by Dr. T. Colin Campbell. In other words, he told PBS if Americans ate healthy enough, the whole heart disease epidemic would disappear. Though Esselstyn clarifies, we're not just talking about vegetarianism, this new paradigm of heart disease reversal means exclusively plant-based nutrition. Next up, we discover how the aspirin compounds naturally found in plant foods may help explain the lower cancer rates among those eating plant-based diets. 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 we can now hatch two birds from one egg. Daily low dose aspirin may also help prevent certain forms of cancer as well. In 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 with daily aspirin. You know, the search for effective and safe treatments for cancer remains an enormous burden, some challenge. If only we could stop cancer in its tracks, prevent it before it strikes. Well, perhaps 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, the 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, of course, 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 two to three 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 versus 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 that 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 cancer, so maybe beneficial overall. None of 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's tempting to recommend low-dose aspirin for nearly everybody. However, aspirin pills, even at low doses, has propensity to damage the lining of our stomach and intestines, increase the risk of 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 are a way to get the benefits without the risks. The aspirin phytoneutrient 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. Then drink just one fruit smoothie when an hour and a half your levels rise. One smoothie ain't going to do it. You have to regularly eat daily fruit and vegetable consumption. But are these kind of aspirin levels sufficient to suppress the expression of that inflammatory enzyme implicated in cancer growth and spread? Using umbilical cords and foreskins, where else you're 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 phytoneutrient 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 at the same level in their blood as people actually taking aspirin. Vegetarians pee out as much of the active metabolite as aspirin, as aspirin users do, just because they're eating so many fruits and vegetables. Because the anti-inflammatory action of aspirin is part of the result of this active ingredient in aspirin, salt-silic acid. And the concentrations of salt-silic acid seen in vegetarians has been shown to inhibit that inflammatory cox enzyme in vitro. It's plausible that dietary solicilates may contribute to the beneficial effects of a vegetarian diet, although they seem unlikely the most omnivorous would be able to achieve sufficient dietary intake of solicilates to have a therapeutic effect, though. They could certainly eat more fruit 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 risk, we can get benefits with benefits. How is that possible? Because in plants, the salt-silic 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 and aligning the stomach, effects that demonstrably oppose the pro ulcerative impact of aspirin. Dark green leafy vegetables among the richest dietary sources of nitrate, but of course the researchers go on to say, 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. Finally, today we ask, should the active ingredient in aspirin be considered an essential vitamin? The results of the recent aspirin meta-analysis, suggesting a reduction of cancer mortality by about a third in subjects taking daily low-dose aspirin, can justly be called astounding. Yet the protection from Western cancers enjoyed by those eating more traditional plant-centered diets is even more dramatic, before the westernization of their diets. Animal products made up only about 5% or less of the Japanese diet. Note that age-adjusted death rates from cancers as a colon, prostate, breast, and ovary were on the order 5 to 10 times lower in Japan than in the US, with a mortality from pancreatic cancer, leukemia, and lymphomas 3 to 4-fold lower. But this phenomenon was by no means isolated to Japan. Western cancers were likewise comparatively rare in other societies where people ate plant-based diets. The cancer protection afforded by life-long consumption of a plant-based diet, in conjunction with the leanness and insulin sensitivity that tends to come along with it, may be very substantial. Indeed, therefore, a lifestyle protocol for minimizing cancer risk may include a whole-food, plant-based diet. Now, if part of this cancer protection arises out of the aspirin phytonutrients in plants, are there any plants in particular that are packed with the salicylates? Though salicylic acid, the main active ingredient in aspirin, is ubiquitously present in fruits and vegetables, herbs and spices contain the highest concentrations. Chili powder, paprika, turmeric have a lot, but cumin is like 1% aspirin by weight. Eating a teaspoon of cumin is like taking a baby aspirin. Consequently, populations that incorporate substantial amounts of spices in foods may have markedly higher daily intakes of salicylates. Indeed, it's been suggested that the low incidence of colorectal cancer among Indian populations may be ascribed in part to high exposure to dietary salicylates throughout life from spice consumption. The population in rural India is one of the lowest rates of colorectal cancer in the world. They have a diet that could be extremely rich in salicylic acid, given the substantial amounts of plant foods flavored with large quantities of herbs and spices. Some was proposed as the curcumin in the spice turmeric, but maybe as the salicylic acid in cumin and the spicier the better. A spicy veggie vindaloo may have four times the salicylates of a mild madrasa-style veggie dish. One meal and you get a spike in your bloodstream like you just took an aspirin. So, eating flavor-filled vegetarian meals with herbs and spices may be more chemo-protective, meaning more protective against cancer than just regular, more bland vegetarian meals. We may also want to eat organic, because salicylic acid is a defense hormone of plants. The concentration is increased when plants become stressed, like when plants are bitten by bugs, unlike pesticide-laden plants. And indeed, soups made from organic vegetables were found to have nearly six times more salicylic acid than soups prepared from conventionally grown ingredients. We should also choose whole foods. Whole grains breads, which are high in salicylic acid, contain about 100 times more phytochemicals than white bread, 800 perhaps compared to 8, that does raise the question, though what about the other 799? Interest in the potential beneficial effects of dietary salicylates has risen in part because the extensive literature on the disease-preventative effects of aspirin. However, it should not be forgotten that plant products found to contain salicylic acid are generally rich sources of a whole long list of other phytonutrients, many of which have marked anti-inflammatory and antioxidant activity as well. Their potential protective effects should therefore not be overlooked. In this context, the importance of dietary salicylic acid should not perhaps be overemphasized. Indeed, some believe that salicylic acid deficiency has such important public health implications that it should be classed as an essential vitamin, namely vitamin S. But what they're really saying is that we should all just have to eat a lot of plants. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to nutritionfacts.org slash testimonials. We may share it on our social media to help inspire others. To see any graphs, charts, graphics, images, or studies mentioned here, please go to the Nutrition Facts podcast landing page. There you'll find all the detailed information you need, plus links to all the sources we cite for each of these topics. For a timely text on the pathogens that cause pandemics, you can order the e-book out of your book or hard copy of my latest book, How to Survive a Pandemic. For recipes, check out my new How Not to Diet Cookbook. 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