Meet Mark

Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

Tell Me More
Stay Connected
September 14 2009

Weighing the Evidence: Science and Anecdote in Nutrition Studies

By Mark Sisson

I was a science major (biology) in college, yet I have always been a little suspicious of the use of the “scientific method” when it comes to biological systems – especially humans. I guess it started when we were all taught in labs as far back as high school to strictly adhere to the scientific method, which generally goes as follows:

  1. Ask a question
  2. Formulate a hypothesis
  3. Perform an experiment
  4. Collect and organize data
  5. Draw a conclusion

But from those earliest lab experiences, I found it was pretty sketchy to draw conclusions based on what often appeared to be nothing more than some random set of data points. Weigh the excised thymus of irradiated rats and plot a line that shows the rate of atrophy, etc…I wanted black and white answers, solid trend lines and reliable conclusions but usually all I got was an ill-defined line that was different from what my lab peers got, sometimes by a little, sometimes by a lot. Yes or no, right or wrong was what I sought – but that’s not how science works. It works more like this: the prevailing science is deemed good or acceptable until something or someone proves that it’s not good any more. Hey, that sounds like Conventional Wisdom. (Remember how fats were good for a million years, then they were bad for a few decades, and now they are good again…all based on the latest science?)

My skepticism has only grown over the years as my own experience in sports drug-testing (I was the Anti-doping Commissioner for the sport of triathlon worldwide for over a decade) showed me first-hand how unreliable certain complex testing systems could often be, and how a few wavy lines on a graph indicating a difference of a few parts per billion in a test could sometimes needlessly end a promising career or allow someone else to skate by unethically. More recently, I have been disappointed at how bad many current medical diagnoses are, even using the latest high-tech, most expensive equipment. (I will relate in detail in a coming post how the “gold-standard” body fat testing equipment erroneously pegged my own body fat at 16.9% – twice what it likely is.) Finally, I am noticing an increase in the number of “retractions” in scientific journals, where peer-reviewed studies are found to have been falsified or erroneous (last month a major 2003 genetic study that had been cited as an authority in 140 subsequent papers was retracted). I suspect that with pressure to publish and the complexity of designing studies these days, a not-insignificant amount of work gets published that probably shouldn’t – like many drug trials, for instance.

Through all the hard science, you may have also noticed that for every study that says that X is likely true, there’s usually another one that says, no, X is likely not true. Even hard science has its biases. And don’t forget correlation is not causation.

Of course, this skepticism of science can become an issue when one puts forth the hypothesis – as I have here – that “Primal Blueprint eating and lifestyle adjustments will result in superior health outcomes for humans”. Obviously, many people want to see the hard science. They want to see data points, charts and graphs and conclusions before they embark on such an unproven adventure. They want double blind crossover studies done in bariatric (my spell-check just wanted me to correct that to “barbaric”) wards or room-sized calorimeters. But all of that is not likely to be done anytime soon. That is, 100% conclusive evidence isn’t immediately forthcoming. And meanwhile the world is going to hell in an obese hand basket. So I now propose to you that sometimes anecdotal “evidence” can be nearly as valid as the “hard science.”

Now don’t get me wrong. We have to start with some basis in arguable facts. And I believe the facts clearly point to a Primal lifestyle for health and longevity. There is strong, solid science in favor of the Primal Blueprint. I’ve presented it here (on MDA) and in my book and many others have done likewise with their books and websites. But what happens when new science is difficult to decipher? When the media sensationalizes and distorts the conclusions? When there is no clear message but only an endless series of murky, conflicting results? I often get these questions from readers trying to make sense of it all, and though I still point to the science I also understand that there are other ways to weigh the evidence.

You see, biological systems are – to say the least – non-linear, and humans are certainly among the most complex of any organisms subject to review. In human studies, confounding variables often make it extremely difficult (almost impossible) to truly isolate or identify the one variable that might provide a benefit (or at least a measurable effect). Of course, that makes it doubly ironic that much of today’s Conventional Wisdom is based on snapshot observations from short-term and only partially controlled studies. For example, as we have discussed here ad nauseum, most “meat is unhealthy for you” studies don’t account for amount and types of carbs, as well as antioxidant intake and exercise, as well as the composition of the meat, as well as (yes, I said it) the family genetic history, and so on ad infinitum. To do so – to isolate all these variables and account for their very real interactions – would be wickedly expensive, if not impossible.

So we are left in some cases with anecdotal reports. But if you have enough of them, I say you have what you need to make a legitimate informed decision regarding whether or not this lifestyle is for you. My friends Drs. Michael and Mary Dan Eades can point to thousands of patients over decades that they have put on low carb, primarily meat-based diets with great success. You could even call it one big experiment, albeit without a control group. (I guess the controls would be all the family and friends that didn’t embark on the diet). They didn’t necessarily set this up as a study, but they most certainly collected detailed data in monitoring their patients over the course of weeks, months or years. And they found that an overwhelming majority of these people lost weight in the form of body fat and experienced improvements in blood lipids. Thousands of them.

I was fascinated by some of the detailed reports from participants in our own latest 30-day Primal Challenge. We eventually heard from over 400 people, almost all of whom related an experience of increased well-being in one form or another: lost body fat, increased muscle strength, more energy, fewer colds, improvement in blood glucose or blood lipids, etc. Now most true scientists I know would take these results and throw them all out, saying that there was no real “control group” nor was this a “double blind” study (where neither the subjects nor the researchers would have known which program they were on? – yeah, right) and that this “proves” nothing. Who knows, maybe only the people reporting were those with positive results and all the rest were unsuccessful and didn’t feel like writing to us. But I would like to think that in this case, we have enough anecdotal evidence to corroborate the intuitive recognition (and supports the existing scientific literature) that when we eat and move and live as our genes evolved and expect us to, it will almost always result in an improvement in our condition.

For extra credit, read “Why I am Not a Scientist” by Jonathan Marks.

I’d love to hear your thoughts. How do you weigh the evidence (both scientific and anecdotal) when making personal health decisions? Hit me up with a comment. Thanks, everyone!

Subscribe to the Newsletter

If you'd like to add an avatar to all of your comments click here!

88 thoughts on “Weighing the Evidence: Science and Anecdote in Nutrition Studies”

Leave a Reply

Your email address will not be published. Required fields are marked *

  1. Funny was just mentioning being a systems engineer, this statement you made:

    “You see, biological systems are – to say the least – non-linear, and humans are certainly among the most complex of any organisms subject to review. In human studies, confounding variables often make it extremely difficult (almost impossible) to truly isolate or identify the one variable that might provide a benefit (or at least a measurable effect).”

    Made me think of a discussion a recent masters class, where the human dynamic is the most complex part of designing a system, people aren’t rational and don’t perform a “function” the same way, to many variable to account for, so why do engineers get it, yet the scientists don’t?

  2. “Now most true scientists I know would take all these results and throw them all out…”

    I would argue that such scientists were not “true”. A true scientist strives to be open-minded yet skeptical. Be critical of hypotheses (especially one’s own), but only so that supporting evidence can strengthen the case for (or against) it. I see a lot of bad science done these days, but I also see a lot of good science get rejected because the design or outcome wasn’t flawless. Always remember that science is a human endeavor, and humans err, have foibles, and strong biases–even the best of us do.

    Having said this, Mark, you raise a very important issue regarding what it means to be a scientist and what it means to do science. Too often scientists feel that double-blind controlled studies are the ONLY way to make progress. I think such restrictions, while probably based on good intentions, actually impede progress. On the other hand, many laypeople (and even, ahem, scientists) have undue faith in a single observation or news headline. The media, unfortunately, has been complicit in this–and it makes the scientists (if not Science itself) look undeservedly bad.

  3. A good friend of mine is a statistician. I was telling him about my new philosophies on eating. He’s asked to borrow the book so he can look up the referenced authors/studies to read the original sources and determine what the data that have been collected show. So, I will let him do that. It likely won’t change my decision to change my eating habits, but I do respect him as a scientist and someone who can read a journal article and really get it.

  4. I try to weigh both scientific and anecdotal info as much as possible to a certain degree when making health decisions. I’m definitely not one of those people that’ll look up every single medical reference journal an author sites to validate their point of view…and honestly, if it grasps my attention and I think it’ll bring me some benefit, and the risks don’t seem too bad,.. i kinda just use myself as a guinea pig… so yeah I hope this primal thing doesn’t have any negative effects on me in like 30 years down the road… heh heh.

  5. Actually, the scientific method (as outlined in the article) doesn’t much result in new ideas – it’s valid as a way to test new ideas, but most scientific discoveries are not heralded by “Eureka!” so much as by “That’s funny…”

    Never underestimate the value of a “thought experiment” – when you hear about a new idea in science, run through the process in your mind, see if it makes sense, and see what the logical outcomes are. For example, when you’re pitching the primal lifestyle to people, it’s generally useful to walk through what happens when you eat a load of refined carbs, so they can think it through for themselves and consider the consequences.

    1. Very well put! I do medical research yet what I see being disseminated through the media has little to do with science and more to do with seizing the quotable and running with it. True scientists are more like kids finding an interesting “bit” and picking it apart/ finding out how it works or whatever but the curiosity is the same. I blame alot of the crap science on the system that says you need X publications for tenure or to retain your job etc. And don’t even get me started on funding! Before I even read a journal article I check who paid for the research. Look, I’m in the business and am lucky enough to have grants from places that don’t have (much of) an agenda but I feel for the usually decent people that are just trying to keep food on the table (primal or not) after 20 years of education in their chosen field. Sometimes you just gotta take the grant that keeps you in business even though you know you are selling your soul to Kellogg’s.

  6. The value of word-of-mouth isn’t nearly as high as it used to be. Now that science is accessible through the internet, people seem to take on a “prove it” mentality which sometimes hurts them more than it helps.

    1. This is so incredibly true. x__x It seems I can’t even have an opinion these days (Primal or not) without someone telling me I have to back it up. It’s exhausting.

      1. Haha, now when someone tells me to ‘prove it’, I tell them to prove THEIR views (aka CW). They quickly get off their high horse.

  7. There is also the practice of throwing out data sets that don’t match the trends since it must be “experimental error” or an anomoly.

    1. If it’s clearly an outlier, who cares? And if it’s being published, there should be some statistical analysis to justify throwing data away.

      Fudged data usually doesn’t hold against scrutiny.

  8. Sir Karl Popper made a great point of falsifiability, pointing out the logic behind that. He also like to relate how Einstein tried to look for experiments that could make-or-break his theories, really put them to the test.

    I can’t help wondering how many researchers in the field of nutrition deliberately try to disprove their own theories. It seems to me that some are setting up innocuous little tests that, with a little interpretation, can do little more than confirm what they’ve already decided.

  9. Science should be ‘a method of understanding and a means of establishing facts about the universe’. Scientists use this method.

    Unfortunately (sometimes) scientists are only human.

    Science is a bit like democracy: it’s not perfect, but do you know another way that is better?

  10. The key point missing from this article is self-experimentation. We can all serve as our own controls, and it doesn’t matter whether the results generalize to others. If going PB produces noticeable improvements, you can conduct your own ABAB experimental design by resuming your “normal” lifestyle and then returning to PB. It would help to take measurements at each phase, such as body fat composition, to document any changes. If PB works for you, that’s all you really need to care about!

  11. Thank you Mark for yet another excellent post. I feel like this post was written for me. My husband, a physician and a researcher, while seeing the benefits that Primal Living has brought about in me, was unconvinced about it due to the lack of “controlled/ double-blind” studies. But he is slowly switching sides. Scientific studies are subject to bias and errors but not evolution.

    Love the graph (grokph?)!

  12. I read too much on this topic. I wrote a blog post recently that revealed how obsessed I am with the topics of fitness and nutrition. The number of books I’ve read in the last couple years is amazing.

    So, what do I ultimately look for? I look for things that real people are using and seeing results. I look for plans that seem realistic. And, I’m willing to experiment. I spent a year as a vegetarian. During that year, I read the Paleo Diet for Athletes. I was having lunch one day in a Chinese restaurant when I read the statement about giving the book to someone who can use it if you are a vegetarian. I was somewhat offended, but I kept reading. At the end of 12 months, I reviewed my training and racing log. My weight had gone up, my body fat had gone up, I’d had more illnesses than usual, and I’d had a terrible racing season. So, what that meant *to me* was that *my* implementation of a vegetarian diet didn’t work.

    So, I started adding in animal protein again and have raced much better ever since.

    In 2004, I read the Fuhrman book Eat To Live. I lost a lot of weight initially following that book. I raced well for a while. And then, I found two things to be true. I was unhappy with my eating. It was truly unenjoyable. And, eventually, I started to get sick more often than normal. I think I wasn’t getting enough protein based on what I need, and while it worked for a while, it eventually caught up with me.

    A similar thing happened after 10 months of Pritikin in 1987. I hit my lowest adult weight, but I started to get sick and my training suffered.

    Right now, I’m eating a combo of Primal, Precision Nutrition, and Paleo for Athletes, but it’s mostly Primal. I am still having some dairy, which is definitely not Paleo. I am having a little bit of grain, maybe one meal every other week or so, just so that I don’t feel like I’m permanently deprived. So, I’m not fully Primal. And, for the most part, I’m not eating 5-6 small meals every day, and not every single meal contains both protein and a veggie. So, I’m not quite following PN. But, the combo of the three is working for me. My measurements are moving in the right direction, my strength is moving in the right direction, and my eating feels sustainable. If I go through the winter, teaching skiing to kids, and I don’t get sick a lot, I’ll have some more data.

    So, I read a lot. I absorb what I read. I try things out. I use what works for me, and I discard things that don’t work. And bit by bit, I refine what I’m doing.

    I have my annual physical scheduled for January, so I have some new data coming then that I’ll add into how I interpret things. I just switched my vitamins to Mark’s vitamins from another brand of products I’ve been using for more than 5 years. I want to see what happens there.

    Without being stupid, find out what works for you and then use it. Don’t try lighting your body on fire because you heard somewhere that it’s a good weight loss technique. Yes, it might be, but IT’S STUPID.

    So, I try to avoid stupid, I try to educate myself, and I try things. I give them enough time to work or to fail. And, I try to stick with the things that work.

    It seems to me that to blindly follow anything without looking at how I individually react to it is stupid. But, I think most of the people here already know that CW isn’t working for them, and they are actively looking for what will.


  13. Ah, poor science. Politics and medicine (which is not scientific) tend to keep it bound and gagged.

    The scientific method is one of asking a question in such a way that the answer is most likely to be true. The experiment must be based on a falsifiable hypothesis. For instance, you can believe that unicorns exist, but that can never be falsified. You can just keep telling me that unicorns are where I am not looking. However, if I hold the belief that unicorns do NOT exist, this can be falsified: You can show me one. Or, if you can’t, I can keep holding on to my scientific belief of no unicorns.

    Science progresses when hypotheses FAIL, or when all tests FAIL TO REJECT the hypothesis.

    Does this level of rigor ever get applied to nutrition and health? I haven’t seen it. But let’s not throw out science. Let’s call scientists to task for being so sloppy on this particular subject.

    I think the sloppiness is forgiven because we all “know” that fat people eat too much out of gluttony , end of story. “Calories in/calories” out and anyone who says otherwise is lying. But this is a simple math error: Calories in – calories stored = calories burned. In other words you can only burn when you do not store. This statement is EQUIVALENT to the convention wisdom to calories in – calories burned == calories stored (it’s simple algebra) but no one wants to look at it seriously.

    The low-fat madness again is based on judging fat people as gluttons. Fat tastes good, therefor its bad for you. Fat people can’t control themselves.

    People from lower incomes have much higher obesity rates than other income brackets, and this has been true for centuries. I think much of the sloppy sciences is based on simple prejudice: THOSE people can’t control themselves, they are fat because they are gluttons, end of story. It’s only been recently that ALL social strata has been hit with obesity and its related diseases. It’s too bad that that’s what it takes to get science motivated to take the subject seriously, but I think its finally starting to happen.

  14. I think you missed one critical item on the scientific method list and that’s “get funding”. Unfortunately today’s science is so very closely linked to funding that it is sometimes difficult to find rigorous scientific studies. I was in research for 5 years and know this from personal experience as well as from my other classmates who ended up in research. If you don’t have funding, you have no money to do your research, and if you find results which are at odds with your main sponsor, do you publish? In most cases, unfortunately, the answer is no. I eventually left research, and this was part of the reason for it.

    1. One of my favorite movie lines is from “Ghostbusters”. When they get kicked out of the University, Bill Murray comments that they can get private sector jobs. Dan Akroyd replies “Oh, no…I worked in the private sector once; they expect results!”


  15. When I eat grains I feel horrible. When I eat primal, I feel great. I tend to do self-studies since it’s easier to put on a pair of slippers than to carpet the whole world.

  16. Science provides us with scenarios of different degrees of certainty. The extent to which these scenarios prove to be useful will depend on the quality if the methodology used to create them. Assessing this methodology usually requires an above-average knowledge about science, which is unfortunately not so common amongst the general population.

    So, at the end, the average Joe has no choice but to outsource the scientific stuff to scientists and take a leap of faith. But which is the best way to know who to trust?

    The best way to discriminate “good” from “bad” science is being able to tell good from bad sources of information.

    In short, when confronted with opposite versions of the same topic, trust over and you’ll probably be fine.

  17. I do research in neuroscience at the government-funded NIH. I majored in physics in college.

    Someone could write several books on the topic, but much of biology, health, and nutrition are being approached as “soft sciences” — epidimiology, observational studies, generalizations, assumptions, etc.

    The REAL scientific method works perfectly for physics and chemistry. But biology is too complex at the moment. Scientists make assumptions and simplifications. And with enough degrees of freedom, the bad science can be just as convincing as the good science.

    Add to this the fact that the source of funding can influence the results (e.g. the anti-drug government once “showed” that MDMA/Ecstasy causes parkinson’s by giving monkeys methamphetamine instead of the much safer MDMA).

    Then add to this the fact that scientists are motivated to get results and publish to advance in their career or put food on the table for their family (think tenure for an academic professor). This motivation can sometimes outweigh the motivation to do perfect science. And this is a motivation I can sympathize with, since I’ve been there myself.

    The problem isn’t with the scientific method. The problem is when scientists are motivated by results, and when they’re dealing a system that allows them to play with their results — that is, a non-linear system (biology) whose astronomical complexity allows for the bad science to look just as convincing as the good science.

  18. At some point, you just have to self-experiement: ‘n=1’ and listen to your body. All the great insights Mark provides are venture capital for self-experimenting and conducting your own personal ‘clinical trial’: it’s the statistics of individuals, and it benefits from agency.


    You should check out his blog, he is an experimental psychology prof who is very much into self experimentation, including diet. Interesting results, and also interesting thinking about how to get useful data on the cheap, somewhere between anecdote and a nice double blind study.

  20. Mark, have you heard of Dr James Chestnut?
    He is based in the primal idea, and has a sheetload of evidence to back it up. He has something called ‘the plant analogy’ which explains how randomized controlled trials do not work in biological systems… check it out in his book the innate diet.

    I think you will find a kindred spirit. And he wants to make it as big as you do – or bigger.

    I am studying his wellness certification atm

  21. I think there is a major problem with this self-experimentation and anecdotal evidence being compared to scientific study.

    The fact is if you go to any reasonable healthy eating pattern/diet plan website on the net (for example raw foods diet, or vegetarianism, etc) you will see thousands of people just like here at MDA saying how GOOD this diet is, how much it has CHANGED their life, how they noticeably feel better, how they have more energy, they have lost weight, etc.

    Without scientific evidence, all the people here at MDA or all the people at another paleo site are really just expressing an opinion, which can be blurred by a multitude of other aspects such as the placebo effect, and related to that the fact that often when people jump into a healthy lifestyle like this many factors are changed at once.

    I think the issue here is that not much rigorous scientific study has been done on the paleo lifestyle, and unfortunately-and i say this as a scientist-until it is we have to just hope that our ideas are correct. Evolutionary approaches to diet and nutrition to me are almost infallible in their logic but that doesn’t mean certain aspects of what we are following wont turn out to be wrong or modified in light of new evidence. Science throughout history has shown us that often logical and intuitive ideas we have about nature turn out to be wrong.

  22. Johnie, You’re correct that anecodotal stories are not the same as a scientific study. Yep. They’re not the same as a carefully planned and executed scientific study. But I would contend that the stories here are further confirmation of the multitude of papers that have been published for a low carb, high fat diet.

    There are numerous papers in peer reviewed journals by physicians and scientists that include stories (with data of course) similar to those in books by physicians and here on MDA. Stories of people (in experimental groups or individuals here) who lost weight, improved their blood panel, and/or improved sugar levels and went off their diabetes meds by going on a low-carbohydrate, high fat diet,

    And the stories started in the 1860s with William Banting. Seems like a pretty good body of evidence favoring the Primal lifestyle. Sure it seems that these stories start to add up to acceptable science. And then there are the carefully planned and organized scientific studies that tell the same thing.

    It’s difficult to ignore the huge number of peer-reviewed scientific studies reviewed by Gary Taubes in “Good Calories, Bad Calories.” In his analysis of this science, Conventional Wisdom has it all wrong.

    Again and again, the stories here confirm this evidence. The Primal Diet is basically no processed food and grains, no worrying about fat or red meat (except if it’s not grain fed), lots of good proteins and fats. It’s a low carbohydrate relatively high fat diet.

    As Mark says, CW supports poorly executed ‘studies’ “based on snapshot observations from short-term and only partially controlled studies”. I would add that CW is not based on any good scientific evidence. The initial Keys’ study omitted data which didn’t support his low fat hypothesis. CW spent years trying to find studies for a report supporting the Low-Fat diet, but finally abandoned the exercise. Nothing has been published since that supports the healthiness of low-fat.

    It’s not black and white, but seems pretty close!

  23. Mark, what’s wrong with people wanting conclusive evidence? I know that biological systems are complex and one could say everyone is different, but on the whole, humans are very similar. You’re a scientist, why don’t you start the movement, initiate the research, and get that “hard evidence”. And to say anecdotal “evidence” is nearly as valid as “hard evidence” can be very misleading, because it’s natural for human beings to seek and find patterns. This can make it easy to believe anecdotal evidence is true and also makes it easy to get carried away with it.

  24. When I hear “Reset your genes” I tend to think b.s. The assumption, bandied about here, is that due the modern methods of eating, our “primal genes” have somehow become dormant and only through primal eating will they be reactivated. This idea is plastered all over this website and patently absurd.

    At the same time, it is also promulgated, to substantiate the above claim, that our genome as it pertains to physiology, hasn´t evolved that much since the neanderthal. So that only a switch in substrate (food) will alleviate the ills for which many people seem to have that populate this website.

    Science, the good, the bad and the ugly, is responsible for this site and to claim a high road of any sort is less than honest.

    1. Dr. Pierre Debs, I respectfully ask what kind of doctor you are? If you are a medical doctor, then I find it alarming that you would suggest that it’s BS to “reset” our genes. (Note that I use the term “reprogram” – not reset). I’m not suggesting we can change our DNA – we can’t, and I have never suggested we could. Nevertheless, our genes are being turned on or off in response to signals we provide every second of every day. The increase or decrease in hormone production, receptor sites, muscle mass, bone mass and immune function are but a few examples of the thousands of changes influenced by gene expression every minute. Our bodies today represent the manifestation of those “on/off” switches over the years. Reprogramming is a metaphor I use for selectively turning those switches on or off based on foods, activity, sleep, stressors, environmental air, etc etc. The idea of manipulating gene expression to achieve good health is not only NOT “patently absurd” but represents the ONLY way out for most people who have become obese, diabetic, arthritic, asthmatic, atherosclerotic, etc, or even cancer-ridden. Unfortunately, modern medicine would rather you take a pill to circumvent normal recovery pathways, easing the symptoms today but prolonging the problem, rather than addressing it at the only level it makes any sense – the level of genetic expression.

      On another note, the Neanderthal was a different hominid species (or subspecies) now extinct, so to suggest our genes haven’t evolved much from them is quite irrelevant. Unless you meant “since modern humans outwitted, outplayed and outlasted Neanderthals” 😉

      Finally, this post was not to argue against science, but rather to poke holes in the standard “scientific method” which drives many scientific studies. Believe me, I want to be able to back up my own hypotheses as much as possible using good solid science. It’s just that solid science is getting harder and harder to come by.

      1. Hi Mark,

        I am a molecular biologist and I am currently working on somatic cell reprogramming. Maybe I should not have said “BS” and I realize you are not arguing against science. I was more or less playing devils advocate.

        As far as resetting, awakening or reviving dormant genes……my point is that I do not believe, a priori, that the genes products which metabolize food and which MAY be very similar to those neanderthal genes are somehow dormant. I say “a priori” because I have not found a study which compares the two and thus I have nothing too support or deny this proposition. I also do not know if these genes are the same. IF our genome has not evolved that much, then the genes may very well be similar. It cannot be wholly explained by epigenetics, which we should not forget, alters the expression of and not the sequence of a gene.

        On the other hand, last year there was a paper in PloS which showed by gene expression profiling that resistance exercise results in an increase in “youthful” and regenerative mitochondrial gene expression.

        A large part of your promulgations can be verified by a few experiments which measure the expression profile of metabolic related genes in cells which are “feed”, a modern energy source vs. a PB energy source. (I just gave away a science paper)

        Solid science is out there, it is just getting harder to find it.

        I don´t think there is a problem with the Standard scientific method; it is the interpretation of the results which is at fault. As many have already noted, the interpretation is being driven for various commercial motivations.

        Sorry my response is a bit all over the place, I am writing a review and 1000 ideas are coursing threw my head and I have to get to the gym to do my 30 minutes of power cleans!

  25. So, the world is complex and science doesn’t give immediate, satisfying answers. So what. No one promises that all investigations are stand alone processes that reveal the TRUTH all wrapped up in a neat little box, tied with a ribbon. Science over time converges to the truth, despite all the petty politics, biases, and dead ends that get in the way.

    If one disparages “correlation is not causation” then stay away from incredibly complex fields like endocrinology, where many parallel processes occur, which at best, are often weakly linked.

    Yes, Science is slow, inefficient and dissatisfying to a society that craves immediate grtification. Tough. Science is the ONLY way to establish truth, a truth that eludes personal experience and anecdote.

  26. We all love to measure things. Total calories, % body fat, total carbs, BMI.
    I think a lot of these scientists are missing the point. I am by no means the quintessential PB’er but by cutting way down on grain and upping my consumption of meat and vegetables and performing daily workouts, I feel alot better, look alot better, more alert, more energy, and for some odd reason alot more flexible. I have no idea what I weigh, my lipid panel numbers, BMI or any of that nonsense. I feel “Healthy” and alot of my previous aches and pains are gone. That is the only measurement that counts. How does one measure “Healthy”? There are just too many variables. Feeling and performing your best, albeit subjective measurements, are the only ones that matter. No sense having all your CW health markers in line and feeling like ****. What good is that??
    Poor Grok… the lad was lucky if he could count to 3, but was a health SPECIMEN.

    1. 1. how do yo know you weight lose or your increased energy is not solely due to exercise? All of your changes can be a result of exercise and increased energy expenditure.

      2. Until now, Grok and his health is absolute, pure conjecture.

      3. If we are not able to measure healthy, then all science and medicine fails. They don´t and it is entirely possible to measure the health status of the human body and declare said body to be healthy or not-healthy. I assure you, many people fell fine and are deathly ill. If we relied soley on subjective feelings as pertains to health, we would be in a lot of trouble. A blood test can tell you more about your health status than any subjective expression.

  27. Mark is right on about reprogramming our genes for healthy gene expression. The PB is the correct way of living a healthy life just the way God intended. The problem is that you have all of this “Science” that constantly steers people away from the simple truth about what the body needs. There are textbooks that are still being printed with information that is false as far as the “Science” of the human body goes. When you go to school to become a doctor, half of what you learn is correct at the time, and half of that half will be proven incorrect within a couple of years. Keep it simple stupid! Who are we to change what has worked for thousands of years. Modern medicine and the modern world has sickened the human race.


    I am giving up on spreading the word. No one is listening to me, and articles like this are used against me.

    I feel like when I was in HighSchool; electric blue hair, riding my skateboard and getting beat up by foot ball players who now have kids that watch pro skateboarding and think its “extreme.”

    Did Grok cry? Because I am.

  29. When it comes to training, scientific research is at least 5 years behind the times. Trainers/strength coaches that have a brain in their heads are constantly tweaking and making changes to training programs in order to maximize their clients’ performance.

    We take what science tells us, test it, throw out what doesn’t work and keep what does.

    We also do that with nutrition.

    It’s sad when ‘experts” hide behind studies instead of providing real world results.

    Bottom line…we are our own lab experiments. If you are fat, do a little online research, find a plan (primal) that you think might work for you, and then give it a try. If it works, great. If it doesn’t, go back to the drawing board.

    It ain’t rocket science

    Mark – FitnessFail had a similar post that you might find interesting –

  30. “Mark is right on about reprogramming our genes for healthy gene expression.”

    This statement is wholly hogwash and challenge you to show any proof. Can you even explain healthy gene expression?

  31. I think before we measure healthy, you need to define healthy. Is it BMI, Cholesterol, %Body fat,or other health factors , or is it really a combination of physical and phsycological factors that allow one to live a full and happy pain free life and do the thing he/she wants to do or has to do without reservation ,restriction or stress?

    I like to look at things from a quality of life perspective. I am 50 years old. I am on no medication nor do i take any except if in dire need. None in at least 5-6 years. My only medical expenses have been qtly chiropractic tune ups. I haven’t had a cold, flu or any illness for a number of years. My last trip to a doctor was for a broken ankle running at 5:30 AM when I tripped on an unseen stone 5 1/2 years ago. Physically I can keep up with people 1/2 my age without tiring. As far as I know there is no activity that I would hesitate in doing even though I do not specifically train for any specific sport. I have run a 5K, a 10K, and sparred 15×3 minute rounds in Martial Arts classes in the last month. My exercise includes Bodyweight circuits,and HIIT, about 30 minutes a day. I enjoy snickers bars and ice cream and eat them occasionally without guilt. If I die of a heart attack when I am 51 I can go with a full heart knowing I lived my life to its fullest without being restricted by physical or mental inability. Is it exersize? diet? or genetics that allow me to be this way? I don’t know nor care.

    I would gladly take that life than being artificially kept alive as some CW success stories ie Cancer survivors who are ravaged by chemo and radiation therapy and puking every time i ate a freezie pop.

    Yes, as a scientist myself, I realize that measuring cause and effect is the only true way to understand the mechanisms of things. However, give a kid a lollipop (sorry Mark–just an example)and watch the smile. Is it the flavor, the color, the fact you gave them something or the expression of love that made the child smile? Does it matter?

    Its time we start looking at life and health holistically rather than hanging are hats on some number derived in a lab.

  32. I really hope we don’t have any PB-ers showing up on other folks’ blogs and picking fights because they disagree. To those of you who find the PB to be “wholly hogwash,” fine. There’s the door.

  33. Sorry if I’m out of line, Mark (it’s not my house), but jeez.

  34. Beth, no problem. I do encourage discussion here (with a special emphasis on witty reparte). The good Dr has commented before, so I know he checks in once in a while. There must be something that attracts him to the site. I certainly don’t want this to be a “believers-only” club. How else we gonna change the world?

  35. Wo nelly- I do follow a more or less PB lifestyle, but I scrutinize everything and I am a researcher working on somatic cell reprogramming, amongst other topics. I have a rather intimate relationship with “Genetic Reprogramming”….Not picking fights

    1. The whole emerging field of epigenetics is predicated on the role of environment on gene expression. That is phenotype is not a static endpoint of genetic expression but a dynamically coactive (with environment) one. There’s an excellent article in the Observer (a publication of the Association for Psychological Science) on this topic and I believe it is freely available here: It is a must read for anyone interested in nutrition, lifestyle, and health.

    2. Calling someone’s beliefs “wholly hogwash” or “bs” is picking fights. It offers nothing of value.

  36. Scientifically, my blood tests show a tremendous improvement in my health. the only change I have made that could account for this improvement is diet and exercise over time. Yes, this is anecdotal, but it is MY anecdote. when I read something that makes sense to me, I try it. If it works, I keep it – if it doesn’t, I lose it. I am my own lab rat and I am, by every medical number you can have tested a healthier person.

    1. Bravo David,

      I have gotten into this debate before with people who are unwilling to consider any health/fitness concept that hasn’t been given a Mainstream Science Seal of Approval.

      So sad.

      Way to go fellow lab rat

  37. I think the bigger problem is economics, and that powerful interests want to maintain status quo.

    The same problem is in the Physics community. They have very firm indication that Relativity (as defined currently) is not working beyond our solar system. It does not work well when accelaration due to gravity drops below a limit. We are getting a lot of artifacts like Dark Matter and Dark Energy. But the problem is economic, rather than scientific. There is no theory to take the place of relativity. Even though we know that it is wrong no one will admit to it. Because if they do what are they going to do. There is no money in trying to work finding a new theory, at least not for the majority. They need the grants which only come when you can show them what you can do in the given time frame.

    Economics trumps the Scientific method everytime.

  38. Interesting thoughts. I’m a scientist and care deeply about food and health, and I agree that many of your points are valid. At the same time, however, well done science can tell us a lot.

    Anecdotal evidence certainly has its value as well, but the problem with it is all it represents is an observation, not a real test. It is the first part of the scientific method only–telling us what, but not why.

    Personally I think we have to be skeptical of all data, anecdotal or peer-reviewed, because as you say, biology can be very non-linear. I let the science inform my decisions, but always try to remember that even if the data is 100% unambiguous (sometimes it is) there can still be more than meets the eye.

    For my own health I make my best guess on the science (which is arguably better than most people’s) then do what feels the best for me. I think we all need to do this since we each start at a different baseline.

    Thanks for making me think harder today 🙂

  39. i’m a chemist. i like to think of the scientific method this way: you’re stuck in a dark room and you’re trying to find out what the other objects are in the room by throwing little pebbles at everything. it’s long, it’s laborious, but really really exciting when one of your little pebbles hits a light switch and part of the room is illuminated. it’s fun and effective. also, i think being a scientist is part of human nature!

    science itself isn’t at fault for all of the issues related to poor scientific research. there are a lot of politics and special interests that go into what gets funded. everything is motivated by money/power. this is more of a cultural issue than a problem with science.

  40. Late to the party but found the conversation here interesting. I think we can look to history and see where both conventional wisdom and science have been extremely foolish. My motto is no matter who is selling, caveat emptor.

  41. I don’t need scientific proof to know that hydrogenated soybean oil, HFCS and bran is BAD.

    It’s obvious there is something seriously wrong with our food system if great masses end up with the same diseases…all in the same place.