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Stop Creating So Many Free Radicals in Your Colon

Colon cancer risk in Westernized populations may be reduced by decreasing animal product intake and thereby decreasing  “aggressive” factors as animal protein and fat. I’ve explored how animal protein can putrefy and produce the rotten egg gas that may be toxic to DNA (see Putrefying Protein and “Toxifying” Enzymes), but what about the fat? It can stimulate the synthesis and secretion of bile acids into the intestine.

Bile helps the body digest fats. So, more fat in the intestines means more bile in the intestines, which wouldn’t be a problem except bile acids, especially secondary bile acids, have long been suspected as being carcinogenic. Bile acids stimulate the growth of bacteria, which convert the primary bile acids our livers make into secondary bile acids. And, secondary bile acids have been shown to be cancer-causing.

As described in my How to Reduce Carcinogenic Bile Acid Production video, this could help explain why fat-rich diets are correlated with colon cancer. High saturated fat intake is associated with elevated levels of bile, which is what you tend to see in people with colon cancer. As such, they are considered tumor-producing factors in colorectal cancer development and perhaps also breast cancer, as these secondary bile acids can get absorbed into the blood stream and circulate throughout the body. (See Breast Cancer and Constipation for more on this.)

This may help explain the extraordinarily low rates of colon cancer in sub-Saharan Africa, with native Africans putting out just a fraction of the secondary bile acids of African Americans. Well, if a diet high in animal fat stimulates the growth of these toxic and carcinogenic secondary bile salt-producing bacteria, what about diets that don’t include any animal fat? We’ve known for more than 40 years that those eating plant-based diets have less bile in their stools and a reduced capacity to create colon carcinogens. Those eating vegetarian produce just a fraction of some of the secondary bile acids implicated in cancer—about 70% less. Within just one week on a plant-based diet, the bacterial enzyme activity to produce these secondary bile acids is cut in half. Within a month, their presence is cut in half, as well.

One of the most important toxic effects of these bile acids—the BAs in our BMs—is the increased production of free radicals. That’s one of the ways they can damage our DNA and undermine our DNA repair pathways.

Hydroxyl radicals are one of the most destructive free radicals, which may increase colon cancer risk. They only last about a billionth of a second but, in that time, can convert harmless substances in the bowel to DNA-damaging, mutagenic substances, and bile acids are believed to promote this process. But, if you switch people to a vegetarian diet for only 12 days, you can get a 13-fold drop in hydroxyl free radical production.

So, fecal free radicals may activate carcinogens in the colon. On a standard American diet, the amount of free radicals produced in the stool is quite remarkable, corresponding to that which would be produced by a fatal dose of gamma radiation. So, what do we do about it? What’s an achievable, practical measure to decrease free radical formation in our colon? We could attempt to “colonize the colons of high risk patients with genetically engineered, antioxidant-producing bacteria,” but why not just eat a more plant-based diet?

What about fiber? See Fiber vs. Breast Cancer for more information on why fiber may be so protective.

You can find more on the microbiome in Stool pH and Colon Cancer, Preventing Ulcerative Colitis with Diet, and Why Do Plant-Based Diets Help Rheumatoid Arthritis?.

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:

Discuss

Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, 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.


76 responses to “Stop Creating So Many Free Radicals in Your Colon

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    1. Note please that Dr. G specifies that ANIMAL fats are the culprit. Lumping all lipids together is disingenuous.

      ALL cells, whether animal or plant, contain fat. Otherwise cell membranes and organelles would dissolve into their cytoplasm. The human brain and nervous system are composed primarily of fat.




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    2. [Kind of OT] If TG had listened to this “non doctor” then he would not be sick as he is now.

      I cannot post the following link so just google for it.

      Google:

      draxe lipitor-side-effects




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      1. Thank you for your concern Jerry but apart from (inherited) glaucoma and some occasional, mild osteoarthritic symptoms, I am not sick.

        Yes, I experienced hepatitis as a reaction to statins many years ago but I am fully recovered now, Some people do react badly to statins and aspirin and pennicillin ( I am sensitive to all three) but those drugs have saved countless lives.

        There is another point worth raising – mental and cognitive health. Mine is fine and I am entirely rational. can you claim the same?

        For example, I can read and accurately report scientific papers on nutrition and health. You can’t – remember when you insisted that a paper comparing silicon and collagen plugs, actually was about eating collagen when it never mentioned dietary collagen at all? I am also rational and don’t believe in world-wide conspiracies that have operated in perfect secrecy for generations to “fake” tens of thousands of scientific papers by respected scientists and institutions for reasons that are entirely unclear. You do.

        I think that you would do better to worry about your own health Jerry. High saturated fat consumption has been associated with increased risk for cardiovascular disease, type 2 diabetes, certain cancers, Alzheimer’s and cognitive impairment. Yet you argue on the basis of a well-known logical fallacy (the Appeal to Antiquity Fallacy) that it must be harmless or even healthy, so we should ignore all the evidence (which is “faked” or “bogus” according to you. That does not sound rational and raises legitimate questions about your neurological/cognitive health. You choose to consume saturated fat yet

        “diets that are high in saturated fat are becoming notorious for reducing molecular substrates that support cognitive processing and increasing the risk of neurological dysfunction in both humans3 and animals4.”
        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805706/




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        1. Re: Some people do react badly to statins and aspirin and pennicillin ( I am sensitive to all three) but those drugs have saved countless lives.

          Sadly, I don’t know what kind of “researches” and statistics he read, but to say that statins save countless of lives, is unbelievable. You are beyond help, TG.

          Such drugs should be lumped with opioids as the number one legal poisons that killed more people than even wars. Sigh!




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          1. Jerry You wrote ” to say that statins save countless of lives, is unbelievable. You are beyond help, TG.”

            This sort of thing is why I worry about your cognitive health. You seem willing to believe any internet marketer, snakeoil salesperson or deranged crank with a website, book or YouTube video promoting sensational saturated fat and/or cholesterol claims. Or claims about whole grains being unhealthy. What you absolutely refuse to believe is actual evidence.

            And of course you seldom if ever dignify your false assertions with any kind of credible evidence. That is of course because there isn’t any. If you bothered to do any actual research instead of just believing internet marketers like Axe and Hyman, you would know this. A quick one minute Google turned up these for example
            http://www.theaustralian.com.au/news/health-science/cholesterollowering-statins-do-save-lives-says-us-study/news-story/

            “Across all 26 trials, all-cause mortality was reduced by 10% per 1·0 mmol/L LDL reduction (RR 0·90, 95% CI 0·87-0·93; p<0·0001), largely reflecting significant reductions in deaths due to coronary heart disease (RR 0·80, 99% CI 0·74-0·87; p<0·0001) and other cardiac causes (RR 0·89, 99% CI 0·81-0·98; p=0·002), "
            https://www.ncbi.nlm.nih.gov/pubmed/21067804

            And it is not just deaths that statins prevent, they also prevent heart attacks and strokes.

            “Controversy over the safety and efficacy of statins has harmed the health of potentially thousands of people in the UK,” he wrote in a comment published with the review. In six months after the publication of “disputed research and tendentious opinion” on the side-effects of statins in 2013, a study estimated that over 200,000 patients stopped taking a statin. It predicted there would be 2,000 extra heart attacks and strokes over the next decade as a result."
            https://www.theguardian.com/society/2016/sep/08/statins-prevent-80000-heart-attacks-and-strokes-a-year-in-uk-study-finds

            That is why in the UK, the national NICE guidance still recommended statin use in particular target groups where mortality reduction (in the short term) was low but the reduction in adverse events was significant.

            Jerry – your continued insistence on ignoring hard evidence and instead believing claims made by people selling stuff (and claims by opinionated crackpots on the internet) continues to mystify. As I have suggested before, you should consider having yourself assessed

            Somebody once said that Atkins (and his ilk) were responsible for more deaths than WW2. I can easily believe it. People like you are a menace to the public's health by constantly spreading false assertions.




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  1. Jerry has become so famous that people are posting pre-emptive strikes without even reading what he may have to say.

    Jerry’s probably thinking “Say what you will… just spell my name right”. ‘-)




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    1. They are so scared of me that they have to preempt me even before I read the daily blog or video.

      I already know without reading that as usual, this article will find a way to mix up free radicals discussion with fat eating, or animal foods eating, etc. as a way to confuse the issue to push for an agenda. I am trying to think about something funny to use as rebuttal but just for a start, saying that fat eating will cause more bile acid is like saying that eating broccoli will cause more bacteria to get rid of the natural toxin. It is totally unscientific.

      So how about eating fats from plant foods? Oh that is an exception.




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      1. Heh, Jerry, I think they just believe strongly that your beliefs are contrary to everything they believe… I don’t really see it as fear, rather standing up for their beliefs.

        I’ll even go so far as to say in a social setting you and Tom for instance, might end up talking something other than NF and find common ground.

        Nancy, um wellllllll… maybe.




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            1. Right, Lonie, because some people don’t want to believe in the science, emphasis on the word want. It’s a choice. Unfortunately for those people, the science is what it is, regardless of whether or not someone refuses to believe it or not.

              If people don’t want to believe in the science, that’s their business. But then why do they come here?




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                  1. I guess it all boils down to what one considers to be science. I get it that the true believers of plant based whole foods science will follow that science to the exclusion of all other science. There are many testimonials of that path serving them well and I applaud their devotion to their belief.

                    But personally I think by excluding the breakthroughs happening daily by scientists who aren’t just interested in survival, but good-health longevity through other means than WFPB, well, that person is missing out on some cutting edge discoveries that could have made their lives even better.




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      2. Yes indeed every article is agenda driven..all studies slanted to a point of view. Follow the money. Anyone who disagrees is demonized. One never knows the rest of the diet consumed by any of the studies on this site. Grass fed, not grass fed, organic, not organic, wild caught, farm raised. Each person needs to look at their body composition and blood work. Extremely difficult to build a muscular body on plant protein. I notice most vegans biceps are the same size as their forearms. Typically their heads appear large for their body. If that floats your boat, good sailing!




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        1. The big money is in meat, dairy and eggs. There;s not a lot of profit in beans. Even there, the great majority of the US soybean and corn crop is used for animal feed. That’s why the internet sites make these allegations about vegetarianism and “follow the money” never provide any facts and figures. the facts and figures show the exact opposite of what they allege.

          “Corn is the primary U.S. feed grain, accounting for more than 90 percent of total feed grain production and use. Around 80 million acres of land are planted to corn, with the majority of the crop grown in the Heartland region. Most of the crop is used as the main energy ingredient in livestock feed.”
          http://www.ers.usda.gov/topics/crops/corn/background.aspx

          Livestock feeds account for 98 percent of U.S. soybean meal consumption,
          http://www.ers.usda.gov/media/862896/ocs200601_lowres.pdf

          All this has been known for a long time eg this 1997 article from Cornell
          http://www.news.cornell.edu/stories/1997/08/us-could-feed-800-million-people-grain-livestock-eat

          The facts and figures show where the money really is and the people making these generalised claims are just the willing dupes of the big food businesses.
          https://www.theatlantic.com/business/archive/2016/03/the-economic-case-for-worldwide-vegetarianism/475524/

          Ditto for the claims about cherry picking. You guys never provide any evidence. That is because when claims and the totality of evidence are analysed it is the saturated fat, cholesterol and red meat apologists who engage in the most blatant and deceptive cherry picking.




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    2. It was a pun Lonie. Dr G noted “On a standard American diet, the amount of free radicals produced in the stool is quite remarkable, corresponding to that which would be produced by a fatal dose of gamma radiation.” People often describe stools as pooh pooh.

      And Jerry seldom bothers to provide any evidence to support his assertions (not surprising since they usually all false). Instead he pooh poohs the videos and the evidence they cite.

      “A pooh-pooh (also styled as poo-poo)[2] is a fallacy in informal logic that consists of dismissing an argument as being unworthy of serious consideration.[3] Scholars generally characterize the fallacy as a rhetorical device in which the speaker ridicules an argument without responding to the substance of the argument.[4]”
      https://en.wikipedia.org/wiki/Pooh-pooh




      2
  2. I just read this in my inbox a minute or so ago. It is a newsy type interpretation of a study and mentions colon cancer so I thought I would post it as a link.

    The upshot of the article says that people who take Warfarin as a blood thinner appear to have less cancer.

    Being someone who does not take patent medicines, I would take cassia cinnamon as it has been compared directly to Warfarin. That is why most natural food sites recommend Ceylon cinnamon unless keeping the blood thin is the objective.

    The link is here:

    http://www.newsmax.com/Health/Health-News/blood-thinner-warfarin-prevent/2017/11/07/id/824555/?ns_mail_uid=100354791&ns_mail_job=1762228_11072017&s=al&dkt_nbr=010502zh2f4x




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    1. I heard on the TV machine that 81 mg aspirin also helps reduce many forms of Cancer.. If I was of that ilk i’d rather take aspirin than warfarin. Less complications I bet.. Aspirin cost less too. Interesting that they are both blood thinners.. I’m curious if it’s the blood thinning effect and not the drugs. I still think a hi fiber WFPBD trumps (sri) the drugs…
      https://www.cancer.gov/about-cancer/causes-prevention/research/aspirin-cancer-risk
      mitch




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      1. Yeah, I think aspirin and NSAIDs in general may reduce inflammation which may lead to a reduction in cancer risk.

        But for me (and I take it daily) White Willow Bark is a much preferred choice over aspirin as it does the same thing but with fewer dangerous side effects than aspirin.




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          1. I know! Ain’t nature grand!

            And the White Willow Bark won’t eat away the lining of your stomach like aspirin. And I THINK, but am not sure enough to recommend it, that White Willow Bark MAY NOT cause Reye’s Syndrome in children as aspirin does for some.




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      1. equayona, thanks for pointing that out.

        Yes, in large amounts (don’t play the cinnamon eating game) cinnamon, just like warfarin (and especially if you are already on blood thinners) is ill advised as stated on Web MD.

        Cinnamon contains coumarin, a compound in warfarin, which is a drug taken to prevent blood clotting, so seek medical advice about cinnamon supplements if you are already prescribed blood thinners.

        https://www.webmd.boots.com/healthy-eating/guide/cinnamon

        But just like grapefruit is not recommended when taking some drugs, grapefruit itself is a beneficial citrus. I take it in some form or another every day the same as I do cinnamon, either cassia or ceylon.




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        1. Thought I should follow up from my own experience… I work outside and often when trimming a tree or bush or riding the mower too close to low limbs, I puncture the skin or my arms.

          The blood is nice and thin but is easy to staunch the flow. I don’t know where in my diet that clotting ability comes from but I’m wondering if it’s not because I have a high Vitamin C intake. In fact I have dusted Vit C powder on a wound and that has caused the blood to clot back when it wasn’t so easy to stop the flow.

          I got this idea when a neighbor’s unfriendly dog took up residence at my home while she was away at rehab. The dog was bitten by a rattlesnake on the loose flesh around the neck.

          The dog wouldn’t let me near it to administer electricity from a stun gun to disrupt the venom protein, so it was left to nature to decide if the dog lived or died. I watched for days as the dog licked where it could and saw the flesh just melt away from the skin on the neck.

          The dog healed and actually got a neck job that made it look better, after the skin closed back.

          Knowing that animals make their own Vitamin C, elevating to the levels required, I concluded Vitamin C could be a topical healer.

          Oh, and the dog was a blue heeler.




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  3. Hi talking about free radical have you seen the research on Glutathione. Please investigate on our behalf. It is being proclaimed as the new cure for all ILLS. If the research is positive would it be advisable to have a test for depleted levels and what is the best way to top up. Interested in other opinions too.




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  4. https://en.wikipedia.org/wiki/Bile#Function

    “Bile tends to be alkali on average. The pH of common duct bile (7.50 to 8.05) is higher than that of the corresponding gallbladder bile (6.80 to 7.65). Bile in the gallbladder becomes more acidic the longer a person goes without eating, though resting slows this fall in pH.[5] As an alkali, it also has the function of neutralizing excess stomach acid before it enters the duodenum, the first section of the small intestine. Bile salts also act as bactericides, destroying many of the microbes that may be present in the food.”




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    1. One of Dr Greger’s video clips on colon health (sorry, I don’t remember the name of it) said that we want “pink poo” (ie, an acidic colon) and “blue pee” (an alkali kidney). This article ties right into that.




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      1. Related to the latest high cholesterol video: https://nutritionfacts.org/video/the-best-food-for-high-cholesterol/

        http://www.vivo.colostate.edu/hbooks/pathphys/digestion/liver/bile.html

        “Secretion into bile is a major route for eliminating cholesterol.

        Hepatic synthesis of bile acids accounts for the majority of cholesterol breakdown in the body. In humans, roughly 500 mg of cholesterol are converted to bile acids and eliminated in bile every day.

        Interestingly, it has recently been demonstrated that bile acids participate in cholesterol metabolism by functioning as hormones that alter the transcription of the rate-limiting enzyme in cholesterol biosynthesis. “




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  5. So how low fat do we have to eat? If fat causes this then should we not even eat any flax or nuts or avocados? I know you suggest us eating flax and nuts and recently you said avocados are a green light food so this is confusing. I was super low fat for years eating no nuts no seeds and on rare occasion a half an avocado. Ran into health problems and now I eat a lot of plant fats. I eat 1/2 cup of flax or chia a day and on top of that I eat nuts and avocados and sometimes up to 1/2 cup or more of hempseeds. So lots of fat.




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    1. Christina,

      It’s about balance and I’m thrilled to hear that you found what works for you. There is a minimum of oils intake that allows our bodies to produce adequate hormones to function, as one example. Brain “fats” is another consideration along with maintenance of good flexible cell membranes and the list goes on….

      With both a bit of lab work and good observation anyone can find their balance point. Very low fat diets have been consistently found to be deleterious. The conundrum is what constitutes low fat and for whom.

      Dr. Alan Kadish moderator for Dr. Greger http://www.CenterofHealth.com




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  6. A friend just passed this week from colon cancer. I cannot comprehend why because she was a very conscientious WFPB eater for 35 years, and this turn of her health devastated her emotionally. I also eat a WFPB diet for health, assuming it is my best form of “health insurance”. This was a wake-up call that sometimes even our dedicated efforts towards optimum health cannot beat “all the odds” that we are facing as mortals at this time and place on our planet (ie, environmental degradation, toxicity, etc). I whole-heartedly believe that this lifestyle and way of eating is the best option we have for the health of the planet, our burgeoning population, and individually for our bodies and spirits! So, I will continue on, and I encourage all NutritionFacts followers to do the same for the sake of health and well-being — for we, indeed, are mortal and destined to die of something!




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    1. I am sorry you lost a friend in such a dreadful way. My uncle died of colon cancer in his fifties and it isn’t a pretty way to go. But you are right, we will all die of something. I don’t expect immortality from WFPB eating, just striving for health as long as it is available.




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  7. Hello,

    I see Dr. Greger will be in Winnipeg on Feb 9th but the link does not provide any details about the talk/conference. Is this open to the public? If so, where could I register?

    Thanks in advance!

    Susan




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  8. Is the nutritionfacts.org comments section actually part of an ongoing study into online interaction between opposing views and beliefs?

    It seems the so called “Moderators” of this comments section have little to no understanding of how to moderate comments.

    I have been and currently still am a moderator/admin on a forum for over 12 years with over 100,000 members, and the way this comments section has been allowed to “flow” is a disgrace.

    Regardless of your beliefs, this is a website primarily run by Dr Greger to share scientific evidence supporting the notion that a whole food plant based (WFPB) diet is the healthiest one.

    Incessant and let’s be honest trolling posts to the contrary of this WFPB way are not only unhelpful and disruptive, but down right rude.

    To Dr G and the “Moderators”:I think the time has come to take some positive action.




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    1. Indeed there is a group dynamic happening here… and it is resulting in an “explosion!” of ideas and information!

      Moderation is going on… it’s just being done quietly. (I can vouch that part of an exchange between myself and a fellow forum member was removed… no big deal)

      IMO, NF is healthy and well-suited for our community goal of more knowledge.

      I think church would be where you would find the kind of interaction you seek.




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    2. I agree with your view Scott. I have adminned for large groups in a face-paced debate setting for many years. The comment section here at NF is disappointing at best considering all the effort to seek greater professionalism in how the site displays.

      If I can add another point about the moderators. .. some are terrific and I really appreciate the time people take to answer questions, including my own. I have tried to help out a bit by answering the easy uncomplicated questions regarding resources at NF, or where a simple link will do. I have noticed that many days moderator(s) will answer the same questions I did, and even use the same links I posted…. And then ignore the other questions on the forum. What the heck! This is not impressive. If I did that same maneuver on the job, I’d be fired.




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      1. oh yes Susan, the moderators are great here with regards to answering some questions and providing great info. No issues there at all and apologies for not making that area of their support clearer. The issue is the actual moderation of the comments section, which has to all intents and purposes become a forum.

        Over the many years (8+) visiting here I’ve found some great info shared by commenters here. The removal of the Disqus commenting platform caused many issues with many long standing commenters leaving (or at least no longer commenting). Now we have people here that constantly go against Dr Greger’s informational sharing and the spirit of the site. I’m not saying everyone needs to be 100% in agreement with everything, but the main facts seem irrefutable in my opinion; a whole food plant based diet is healthiest and one that contains animal produce is not as healthy, indeed positively disease causing. Simple.

        Yet there are a few here that like to go against the science… constantly. I do not know what their end-game is.




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    1. Scott B,

      I think I have the solution for you and others like you who seek a “pure vegan” NF comment section. It will however require some equipment change by the website.

      That is, for those of you who cannot self-censor… that is, skip over the comments of those you dislike… if there were an ignore option for an individual to assign to each commentor they don’t like, then you wouldn’t be able to see the posts from that individual.

      Rather than make it a blanket ban, make it a personal ban that you control. This way, some of the people you agree with but may get banned in a blanket action, are still available… while those you personally don’t like can be excluded from your narrow world.

      Problem solved… your welcome.




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  9. If I’m the Jerry you are referring to. Well I’m 82, ate hamburgers for lunch, two eggs and a strip of thick bacon for decades. There weren’t any widespread books on plant eating so I was using the then current American Heart Association Cookbook. Wasn’t working, hungry 5 times a day and slowly gaining weight.
    First read the Zone diet books from Barry Spears (if I have that right) then The China Study when it came out. By then I was 70 and who knows, my colon cancer may have been started by decades of “wrong foods”. Radiation, chemo, surgery, worked as intended, but subsequent “maximum dose of chemo 5-Fu” gravely ill. It’s poison.
    Now back to 1 12 hours fitness 6 days a week including cardio, weights, yoga, stretching, feeling good.
    Now if Nutrition Facts were available in 1960 I could well have avoided colon cancer…..




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    1. I’d like to see the role of bitters addressed as well since I add Angostura Bitters to so many things… ice cream or yogurt when I eat that, cocoa powder + other things when I mix that up, almond milk, tea, just about anything.




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  10. I have read from this site that foods rich in high fat and low fiber significantly increase the risk of getting cancer of the colon. Anyway aside from eating fatty foods or animal products there are still other risks or factors in getting colon cancer that people must consider and be aware of.




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  11. Absolutely…smoking and alcohol intake are two. But eating a WFPB diet reduces the risk as compared to a high fat low fiber diet.

    Dr. Ben




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