Doctor's Note

My video Solving a Colon Cancer Mystery is a perfect example of the concept I presented above. If fiber was really the key, then sub-Saharan Africa would be rife with colorectal cancer these days.

For an extreme example, how about disease reversal with diet centered around white rice? See Kempner Rice Diet: Whipping Us Into Shape and Drugs and the Demise of the Rice Diet.

Wait a second, though, didn’t I just have a video saying you should specifically look for fiber? The Five to One Fiber Rule is just a way to identify less processed foods using fiber as a marker of whole foods.

For more intrigue in the world of fiber, check out Does Fiber Really Prevent Diverticulosis?

And if you’re thinking “Dr. Who?” then, for a historical perspective: Dr. Burkitt’s F-word Diet

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  • HaltheVegan

    Another great video! As a former system engineer (now retired), I can appreciate the “system-wide” approach to studying complex systems rather than the “reductionist” approach. Complex systems are almost impossible to study by taking a reductionist approach. We always used a mathematical simulation model run on powerful computer systems. I would think the human body and nutrition would be similar since they are infinitely more complex than any man-made system, I believe it is T. Colin Campbell who is another nutritionist who agrees with the “holistic” approach.

    • Yes, in fact Campbell is professor emeritus at Cornell, Dr of Biochemistry specializing in Nutrition with 27 yrs of NIH funded research and did much science on the mechanism whereby cancer growth is promoted (by animal protein). He speaks a lot about reductionism in his first book, The China Study – and then his second book, “Whole” is dedicated to the paradigm, not only as it relates to nutrition and the related processes in our bodies, but also how the reductionist attitude effects the actual nutritional science being done and which studies actually get funding.

    • largelytrue

      How are the mathematical simulations that you describe not reductionist? Don’t they depend on exhaustive computation based on detailed understanding of local effects? Aren’t they using the parts to understand the whole?

      • HaltheVegan

        It would be impractical to try to give a complete response to your question in the limited space of a comment here, so let me refer you to some sources for further reading. Here is an excerpt from a Wikipedia article at the link:

        As the the excerpt indicates, a key component of Systems Analysis as opposed to Reductionist Analysis is the existence of “Feedback Loops” in complex systems as opposed to a simple linear cause-effect relationship commonly found in most Reductionist approaches. Hope this helps.

        Begin excerpt:
        “Systems thinking has roots in the General Systems Theory that was advanced by Ludwig von Bertalanffy in the 1940s and furthered by Ross Ashby in the 1950s. The field was further developed by Jay Forrester and members of the Society for Organizational Learning at MIT which culminated in the popular book The Fifth Discipline by Peter Senge which defined Systems thinking as the capstone for true organizational learning.[2]

        Systems thinking has been defined as an approach to problem solving, by viewing “problems” as parts of an overall system, rather than reacting to specific parts, outcomes or events, and thereby potentially contributing to further development of unintended consequences. Systems thinking is not one thing but a set of habits or practices[3] within a framework that is based on the belief that the component parts of a system can best be understood in the context of relationships with each other and with other systems, rather than in isolation. Systems thinking focuses on cyclical rather than linear cause and effect.

        In systems science, it is argued that the only way to fully understand why a problem or element occurs and persists is to understand the parts in relation to the whole.[4]Standing in contrast to Descartes’s scientific reductionism and philosophical analysis, it proposes to view systems in a holistic manner. Consistent with systems philosophy, systems thinking concerns an understanding of a system by examining the linkages and interactions between the elements that compose the entirety of the system.

        Systems science thinking attempts to illustrate how small catalytic events that are separated by distance and time can be the cause of significant changes in complex systems. Acknowledging that an improvement in one area of a system can adversely affect another area of the system, it promotes organizational communication at all levels in order to avoid the silo effect. Systems thinking techniques may be used to study any kind of system — physical, biological, social, scientific, engineered,human, or conceptual.”

        • largelytrue

          Right, but my point is basically that emergent effects come about by the emanation of local interactions in the human body. What is ‘reductionist’ depends somewhat on the context. Proposing to simulate the entire human body at a low level is a reductionist strategy for studying human health. It proposes to reduce nutrition to mere chemistry, albeit “systems” chemistry with extremely complex feedback loops due to metabolism, hormones, and cognitive effects.

          The sort of holism that Campbell advocates, as far as I know, is grounded in population studies rather than biochemistry. There are a number of reasons that motivate the study of populations in nutrition research, but one of the most important is that it requires too much reductionist research and too much computational power to simulate all the effects of diet at a sufficiently low level.

          Instead (what I identify as the best form of) nutrition science uses a mixed approach. It tries to identify robust mechanisms of causation at a low level to better inform what data should be used to inform statistical models at a higher level, then builds predictive models from which recommendations are formed and the effects of behavior are estimated. At no point has an exhaustive simulation of all possibly relevant factors ever been done, at least not for the most important chronic diseases. I suspect that we’ll have utopia before we have the computational power and knowledge to simulate the entire human body in the way you seem to hope.

  • uma7

    So it’s well known that domestication of animals led to disaster, but what about the domestication of crops? More nutrient dense food allows us more leisure time and reduces the risk of famine, but fiber is lost. You can’t get 100g of fiber daily anymore like they did in the paleolithic period.

  • Lawrence

    reductionist thought
    makes it possible to be
    succinct: eat more plants.

    eating food as grown.
    nourishment from fertile soil
    makes people healthy.

    a vegan sat down
    before a chicken dinner
    and said, ‘no, thank you.’

    yes, we’re omnivores.
    but, some foods are better than
    others: eat more plants.

    • Well said along with HaltheVegan’s comment on complex aka adaptive systems. I would add the following comment for consideration.
      Animal biologic systems can be categorized as carnivore, omnivore or herbivore. Bears are an interesting example… Panda’s=herbivores, Polar=carnivores… most of the rest omnivores. We have the “systems” we have evolved to have but we can choose to eat contrary to the design of our “biologic” system. Melanie Joy has coined the term “carnism” to describe human’s choice to eat as an “omnivore” or in some cases as a “carnivore”. I would recommend her presentation, Carnism: The Psychology of Eating Meat”. Her 2012 presentation at the McDougall Advanced Study Weekend can be viewed at… Homo sapiens biologic system is as a “hind-gut fermenting herbivore”. Due to the structure of plant cell walls and presence of fiber compared to animal cell walls it is more difficult to extract energy from plant food. To address this herbivores have either modified “foreguts” such as multiple stomachs or “hind guts” such as colons to extract nutrients from bacterial breakdown of fiber. Fire helps in that cooking our foods allows us to further extract about 10-15% of the energy. We can choose to “violate” our design and eat as omnivores but that doesn’t change our biologic system. Every time we eat non plant food we increase our risk of a “systems” problem. The fact that it takes years for those problems to catch up with us or that some of us can live for years without a problem doesn’t change the current scientific paradigm or the risk involved. Happy Holidays.

      • Lawrence

        thanks for your reply,
        i stand corrected today,
        learning never stops.

      • HaltheVegan

        Excellent concise explanation, Don! And thanks for the link to the “Carnism” video … I haven’t seen that yet, but will watch it now.

      • Ray Tajoma

        I think it’s not just the fiber but being overweight that causes heart attacks. 69% of American people are overweight according to google! The reason they are overweight is not because they are rich and eat too much, but because they eat the wrong foods. meat, dairy, eggs (& processed foods like candy & coke) contain a lot of calories & very low volume. Here Dr. McDougall does a physical demonstration (starts at 1:22)

    • Panchito

      “yes, we’re omnivores.”

      A rabbit fed “cooked” meat could be labelled as omnivore too. Omnivores animals eat raw meat. But have you ever seen people eating raw meat? hmm Throw a raw pig heart to a baby and look for the omnivore smile.

      • Charzie

        LOL, I was thinking… put a cute fuzzy bunny in with a little baby, and watch baby rip it’s throat out and devour it! I know, not a pretty image, but exactly the kind of things I will toss out at people when they go militant with all the “we are carnivores because” nonsense, and how it gave us our big brains! My other favorite comeback when told we need to eat meat for protein or whatever is “gee, you should tell those puny vegan elephants and cows they need to start eating each other for protein so they can get a big brain like yours!” Nah, I’m not sarcastic.

        • Robert


        • Panchito

          Elephants are vegans and they have a bigger brain than humans.
          Lions eat more meat but they have a smaller brain than humans.

        • largelytrue

          I’d ask you and Panchito to think twice before using the baby comeback. I don’t think that you’ve thought it through carefully.

      • Israel Navas Duran

        Panchito: “But have you ever seen people eating raw meat?”
        — Yes, Eskimos (among other hunter-gatherer peoples). It’s also worth to mention that archaic humans cooked food (including meat) since they discovered the way to make fire, hundreds of thousands of years ago.

        • Panchito

          Sure. There were cannibals in remote islands where there was nothing else to eat. Does that mean that humans are cannibals? If you want a good laugh, give a self called omnivores a chunk of bloody raw meat with veins as snack, and look at their face.

          • Israel Navas Duran

            Are you aware that chimps (one of the closest human relatives) also hunt and consume raw meat regularly?

          • Julot

            more like insects and some eggs even more rarely…

  • Julie

    I completely agree–fiber is just a marker for reduced disease rates. When you take the standard American diet and add Metamucil, it still doesn’t look anything like the traditional African diet of tubers, grains and vegetables.

  • Acreech

    Had Brukitt focused on foods for fiber rather than just fiber, he’d likely been written off as a quack.

    • Alan

      Sad but most likely true.

  • HemoDynamic, MD – NF Volunteer

    Another great eduvideo! Eat even more plants!

    Interestingly all my patients that have taken metamucil or any other psyllium husk fiber supplement have all said it makes them feel bloated. Rarely do I get any patients saying that whole plant foods make them feel bloated. But there are two: cabbage and beans.

    Also within the bean/legume family the two that seem to cause the most flatulence and hence bloating are Green/Brown lentils and Pinto Beans.

    This resource, however, may help with the reduction of the ‘breaking wind’ syndrome:Does adding baking soda to soaking beans reduce gas?

    • balconesfalk

      Would it be considered “bloating” to simply be gaining weight? “Breaking wind” often is just a signal that one has to defecate.

    • Charzie

      I was very disconcerted to hear a failing diabetic friend tell me his doctor never mentions a word about diet, just told him to take metamucil, in response to my emphatic pleas to change his horrid diet! I wish there was a way for me to let her and other doctors know how much influence they could have on the health of their patients if only they would at least make the effort to stress the importance of diet, and be specific. I get that most don’t listen, but that is no excuse for not trying! All I was ever told in regards to diet was “you need to lose weight… ” but no useful direction!

    • Alan

      I have never noticed a problem with Lentils, but pinto’s, yes !!

    • vegank

      Is it also possible that people who grow up eating legumes and whole vegetables (60-70% of the meal) can handle them better even when they’ve had a period of going away from the whole food diet and then return to their original diet/tradition ?
      Do you think there might be a window of time / age your ability to digest Whole food efficiently before it’s set?
      (compared to children who grow up on mostly processed food and without vegetables /Legume/Fruit etc)
      I’m wondering because I don’t have any problem with so called “roughage” .

    • Paul

      I think you just need to eat more beans, no matter how you cook them. (baking soda, sans baking soda) I don’t even soak beans anymore before cooking them. My favorite way to cook them is in the oven slow-cooked, but I’ve also pressure cooked and cooked them on the stovetop. Whatever works! But definitely soak old beans you find in the back of the pantry or they will never cook!

  • Carol Brown

    T. Colin Campbell not only agrees with this, he wrote a whole book on this, called ‘ Whole ‘ on the whole system approach as opposed to the reductionist approach — boiling things down to one thing, a ‘ silver bullet ‘. Its better to get our nutrients from a whole food plant based diet than singling out the main nutrient and putting it in a pill.
    I just read the book from the library.

    • Joseph Gonzales R.D.

      I have heard “Whole” is a wonderful book! His son helped co-author it and I had the pleasure of attending his lecture at the Plant-Based Prevention of Disease Conference.

      • Rebecca Cody

        Joseph, We are all going to miss you so much! You shed a lot of light on our many questions. I made my donation, but alas, I cannot afford to pay your salary! Wish I could.

        • Joseph Gonzales R.D.

          You are too kind :-) Thank you. All is well and for the best. I just look forward to NutritionFacts growing and continuing to spread a message of good health.

          • Rebecca Cody

            I hope you’ll still comment as a reader like the rest of us.

          • valnaples

            nooooooo! you cannot leave…you and Dr. G are a great match!!!! You’ve been SO awesome helping answer questions, & being so positive…!

          • Joseph Gonzales R.D.

            :-) I’ll still be around and check in. Thanks again for your nice remarks. I still love Dr. G and I know this site will continue to grow and remain one of the best places on the web to find real Nutrition Facts!

        • valnaples

          WHAT???!!! what are you TALKING about? Joseph is LEAVING??? but but but…WHY???? sorry to hear this….

          • Rebecca Cody

            The story is in the donation request.

    • Panchito

      T. Colin Campbell did not created a new idea. He applied ideas from other fields to nutrition. The idea (holism) came from “Systems Thinking”

      look for Holism in the link above

  • Joe Caner

    Oh man! I was hoping that my double helping of Metamucil after my steak dinner what going to do the trick. ;-)

  • ks391262

    I was expecting Dr. Greger to then highlight a study (randomized, double-blind, placebo controlled perhaps?) pitting two groups with equal fiber intake but one from whole plant foods and the other from fiber supplements to see which had more rates of these diseases. But I’m assuming one does not yet exist or he would have found it! Looking forward to a future video that says “It didn’t exist…until now!”

  • Brux

    When it comes to sugar isn’t the consensus that fiber sort of buffers the sugar from entering your system so that your body and your organs do not get a big shock from an artificially high “dose” of what could almost be called a drug.

    The way our good industry processes food, the delivery system is like a drug. Could it be that fiber slows down the absorption of nutrients to something that body can handle routinely over a lifetime compared to a shot and shock of refined nutrients blasting into the system?

    And then also fiber gives something for the intestines to grab onto and push through the system as it digests, so maybe digestion can be more autonomic and effective?

  • Wade Patton

    Yes, and thanks again. Good vid to share.

  • walterbyrd

    Did the people eating wheat bread, and taking fiber supplements, have any improvement in their health?

    • Joe Caner

      I have a two words that should answer your question, “Whole Foods.”

      • Israel Navas Duran

        That’s a non-answer.

  • Thea

    I LOVE this video for many reasons. One reason is that it answers the criticisms/questions that so many people have when the subject of looking at populations comes up. For example: Do we see this result simply because the people don’t live as long? Etc. This is a very comprehensive video in a short package. Great work!

  • Lawrence

    Those drug store fiber shelves are almost impossible get my vegan head around. (Yes, I wasn’t always vegan and I get it completely).
    I am not a professional, but if you or a loved one is taking fiber supplements, at least consider using something like this instead. I mean, honestly, how could one go wrong with flaxseed meal? No, it’s not orange-flavored, but…

  • Aleks

    Thank you Dr. Greger! Have you considered signing up as a charity under Amazon Smile? That way many of us can support this incredible resource with 5% of our purchases being donated to this website/non-profit.

    • valnaples

      Aleks, yes you CAN already help Nutritionfacts already with Amazon Smile…when I bought “How Not to Die” the new book by Dr. Greger, I bought it through Amazon SMILE…and I buy my organic Ceylon cinnamon that way too…in fact, whenever I buy anything on Amazon I do it through Amazon SMILE to help the website!

  • san
    • Tom Goff

      I’d be very careful about taking such studies at face value. They seem to be incompatible with the fact that people have lived on high fibre, high carb diets for millennia. Not to mention the fact that primates as a whole seem to specialise in high fibre diets. None of these groups is noted for constipation problems.

      I suspect the reason for such results is that the people in these studies were advised to increase the fibre content of their diets but apparently weren’t advised to increase their water/liquids consumption. That’s definitely a recipe for trouble. You might want to read this …..

    • Guest

      both those links are from questionable quacks. The first is a low carb dr whos unhealthy diet advice is the same psudo science we see all the time from the low carbers. the second link is just a computer programmer who has no medical background and a hobbiest website. i would not listen to those 2 quacks. they dont base anything on science.

      • san

        Those were science studies done you freaking idiot. People got better on a low fiber diet, especially those with IBS. Moron.

  • BigChief

    Table 2 (minute 1.33) shows that Negroes in South-Africa who reached 50 have better chances of reaching 70 than Negroes in USA. BUT, Caucasians in South Africa, who reached 50, had LOWER chances of reaching 70 compared to Caucasians in USA… Could this be because Caucasians in South Africa eat an even sadder diet than the SAD?

    • Fred

      Carnivores tend to want to dominate their own and other species?

    • Panchito

      Sedentary lifestyle? The life purpose of some people is to seat all day after reaching 50 while having papers and tricks to collect money. In other words, other people do the work.

  • Martin

    Interesting. About 3 or 4 years ago, I abandoned Walter Willets, a reductionist although highly intelligent and well-informed researcher, in favor of T. Colin Campbell, a researcher with the same qualities primarily because Dr. Campbell’s arguments against reductionist diet design made so much sense to me. This video certainly supports his position, and, thus, reinforces my own thinking. Very well done, very professionally done presentation. This is my first visit to this site, but I think I will bookmark it for future reference.

    • Thea

      Martin: Welcome to the site! In case you didn’t notice, I wanted to let you know that there are some helpful buttons to the right of each video, including ‘Sources Cited’ and ‘transcript’. New videos are published Mon, Wed, and Fri. Blog posts, which do a great job of summarizing topics and sometimes sneaking in new information are published Tue, Thr.
      Also, the daily videos are typically very short. But once a year, Dr. Greger does an annual summary that is about an hour long. These talks are *GREAT*. If you want to treat yourself

      • Thea

        Ooops. I got cut off. I meant to conclude with: If you want to treat yourself to them, go to the bottom of the hope page and you will see the section for ‘Nutrition Year In Review’.
        Hope to ‘see’ you around these parts.

  • Great video thanks for the clarity.

  • Tom Goff

    Earlier this month, the American Journal of Clinical Nutrition published a paper on this subject based on data from the (Spanish) PREDIMED study. Apparently, the jury is still out on whether it is the fibre itself or whole plantfood which is responsible for the bulk (apologies for the pun) of the benefits (the accompanying editorial additionally provides a fascinating commentary and summary of the current state of the science on this topic). In brief, the research paper concluded:
    “When the updated dietary information was considered,participants with fruit consumption .210 g/d had 41% lower risk of all-cause mortality (HR: 0.59; 95% CI: 0.44, 0.78). Associations were strongest for CVD mortality than other causes of death.
    Conclusion: Fiber and fruit intakes are associated with a reduction in total mortality.”

    A 41% lower risk of all-cause mortality sounds like a pretty good reason for eating fruit every day! Apples seem to have been the main fruit consumed. Perhaps disappointingly, neither vegetable nor wholegrain consumption seem to have been significantly associated with lower mortality risk in this population (although, strictly speaking, fruits and grains are vegetables and other studies have found differently eg

    The links to the research paper and the editorial are below:

  • Wade Patton

    Could somebody please direct me to the video where the waste removal function of the brain (during sleep) is explained. I’ve searched “sleep”, “insomnia”, “brain”, and more to no avail. Thank you very much.

    • Thea

      Wade: I tried to look for you, but didn’t find anything. Then again, I don’t remember that video, so I wasn’t sure what I was looking for. I just wanted you to know that I tried.

      • Wade Patton

        Thanks Thea, and others who may have looked. I’m almost (was) certain that it was a Dr. G production.

        OH WAIT!!! It was from TED, Jeff Iliff. One well-worded search found it on Youtube.

        SORRY I FOR MY confusion, and YES I’m well-rested. ;-P

        Here’s the vid:

  • It is worth repeating: There is no magic bullet. There is no easy way out.
    Kylneth teaches that you need to focus on the idea that “They” are deliberately trying to kill you!
    (Not just make a buck or billion….)
    Life is all about focus, really.
    Here are three easily observable things from my own personal last almost 4 generations of observation and experience:
    1. I once lived for some time with the last of the primitive-style Aborigines in Australia.
    I asked why the bothered to go to all the trouble of finding material to light a fire when they never really properly cooked the animals they caught, anyway.
    ANSWER: The fire singed off the fur/hair and the bug infestations . Oh, and the burnt/charred bits smelt and tasted better. AND the ash never went to waste e.g. cosmetics, paint….

    2. What did they aim to eat?
    Anything. They were/are opportunists. Primitive people are programmed to keep moving – like the rest of the wildlife. They liked meat, but there wasn’t a lot around that was easy to catch – you can burn a lot of energy chasing animals and it is dangerous, too.

    3. CONVENIENCE: If it is white, in a packet, has no smell, has long shelf life, can be prepared and eaten in minutes, it is already dead and you too-soon will be too.
    ( There is no such thing as gluten intolerance – it is the frankenwheat itself. Just try some stone-ground “health-nut” flour bread made from real grains.
    Oh, but you would have to grind it yourself and make dough and bake it?
    Your little microwave oven doesn’t have a setting over 3 minutes??
    And who has time, anyway…..

    Merry Solstice to you all and whatever you do, don’t drink the water (Fluoride is more deadly than cheap booze!)

    Great info video, too, thanks!

  • Nancy Nowak

    I donated $200 over the week-end. Do I automatically receive the DVD mentioned earlier? Thank you

  • Cristina

    what about this study…I can’t understand more than what it concludes. That fiber would be harmful for the intestines, specially the colon. Doesn’t make sense.

  • Ricky Gladney

    I just discovered these videos and they have already changed my life. Thank you for everything you do.

    • Thea

      Ricky Gladney: Welcome aboard! I’m so glad you found us. If you get a chance to watch the yearly summary videos, I think you will be equally blown away. You can find them at the bottom of the NutritionFacts home page. Enjoy.