There’s a chapter in Denise Minger’s book Death by Food Pyramid (full review coming soon) in which she explains one of the many reasons the grain-based Food Pyramid is such a disaster: there’s quite a lot of variability among humans in the ability to digest starch. Given the same load of starch, people who don’t digest it efficiently end up with far higher blood sugar (36 points higher on average in one study) than people who do digest it efficiently – and their blood sugar stays higher for hours.

The ability to efficiently digest starch is determined largely by genetics. As Minger explains:

In order to furnish the mouth with starch-digesting proteins, we all carry copies of a gene called AMY1, which encodes the salivary amylase enzyme. Indeed, amylase is a gem some plant-based diet advocates cite as evidence for a starchy diet being optimal for mankind. In his book The Starch Solution, McDougall discusses human amylase status as evidence that we are, as a species, genetic starchivores.

McDougall likes to point out that humans carry an average of six copies of the AMY1 gene, whereas our primate brethren carry an average of two. That would indicate that at some point after separating ourselves from chimps, we began eating more starch.

Fair enough. But then Minger writes this:

Just one problem. It’s not that simple. It turns out the number of AMY1 copies contained in our genes is not the same for everyone. And the amount of salivary amylase we produce is tightly correlated to the number of AMY1 copies we inherited. AMY1 copy number can range from one to fifteen, and amylase levels in saliva can range from barely detectable to 50 percent of the saliva’s total production. That’s a lot of variation.

Indeed it is.

Minger’s main point in the chapter is that people with fewer copies of the AMY1 gene are more likely to run into trouble with the high-carb, high-starch diet recommended by the USDA. They’re not genetically geared to handle it.  And in fact, a recent study demonstrated that people who carry fewer copies of the AMY1 gene are more likely to be obese.  Here are some quotes from an article about the study:

Researchers from Imperial College London, in collaboration with other international institutions, looked at the number of copies of the gene AMY1 present in the DNA of thousands of people from the UK, France, Sweden and Singapore. They found that people who carried a low number of copies of the salivary amylase gene were at greater risk of obesity.

The chance of being obese for people with less than four copies of the AMY1 gene was approximately eight times higher than in those with more than nine copies of this gene. The researchers estimated that with every additional copy of the salivary amylase gene there was approximately a 20 per cent decrease in the odds of becoming obese.

Given that modern diets are full of processed starch, it’s no surprise that people who don’t handle starch very well are more likely to become obese.  But I think we need to look at the number of AMY1 genes from the other direction as well.

If you’ve been following the comments on my posts about the Perfect Health Diet and safe starches, you know some people still insist that nobody – absolutely nobody – would need any starch in the diet to avoid the health problems the Jaminets say some people develop on a strict very-low-carb diet: slow thyroid, cold hands and feet, low energy, etc. If anyone needs a bit of starch to avoid those problems, then by gosh, it must mean they’re sick. Or there’s some other problem with their diets – a missing nutrient or a food allergy — because it can’t possibly be that their diets are too low in starch to fit their genetics. Very-low-carb is the best diet for everyone, so those people must be doing it wrong.

People who experience problems on a strict low-carb diet probably are, in fact, missing a nutrient. But the nutrient they’re missing is a bit of starch to avoid a glucose deficiency. I don’t believe everyone needs a Perfect Health Diet intake of starch, but I believe some people certainly do. I believe that partly because of what Minger wrote about the number of AMY1 copies we carry.

Under evolutionary pressure, the traits that don’t provide a benefit tend to fall away. That’s why the vegan argument that humans obviously aren’t intended to eat meat since we don’t have fangs and claws is, frankly, ridiculous. Humans learned to hunt with weapons hundreds of thousands of years ago. Hunting with a spear or a bow and arrow provides a definite evolutionary advantage over hunting with your hands and teeth: you’re less likely to get yourself killed while trying to kill your dinner. Since claws and fangs weren’t necessary anymore, they fell to the side of the evolutionary road.

By the same token, if humans carry three times as many copies (on average) of the AMY1 gene as other primates, there’s an evolutionary reason for that. If some humans carry fifteen copies – more than seven times the number of copies other primates carry – there’s an evolutionary reason for that too. The reason would be that in some Paleolithic human societies, tubers and other starches were part of the diet for a long, long time. That doesn’t mean starches dominated the diet, but they were clearly part of the diet – somewhere in the range of 15% to 40% of calories depending on the location, according to the Jaminets. There’s no other evolutionary reason to carry those extra AMY1 genes.

So doesn’t it make sense that some people would feel lousy on a diet that doesn’t (despite being called “paleo”) actually mimic the diet their paleo ancestors consumed? Or more to the point, doesn’t it make sense that some people whose paleo ancestors regularly consumed tubers and other starchy plants might actually become healthier after adding small servings of safe starches back into their diets? And isn’t it a little silly to insist that they’re sick or carb-addicted if they do?

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63 Responses to “Safe Starches And Human Variability”
  1. Azurean says:

    “If you’ve been following the comments on my posts about the Perfect Health Diet and safe starches, you know some people still insist that nobody – absolutely nobody – would need any starch in the diet to avoid the health problems the Jaminets say some people develop on a strict very-low-carb diet: slow thyroid, cold hands and feet, low energy, etc. If anyone needs a bit of starch to avoid those problems, then by gosh, it must mean they’re sick. Or there’s some other problem with their diets – a missing nutrient or a food allergy — because it can’t possibly be that their diets are too low in starch to fit their genetics. Very-low-carb is the best diet for everyone, so those people must be doing it wrong.”

    Insulin can be produced in sufficient quantities by the body, yet some people need regular shots of insulin. Would you call them “sick” ? Of course you would, it’s even called “type 1 diabetes”. When someone’s body doesn’t produce enough of a substance and needs to ingest some directly – insulin or glucose – then this person is “sick”, even if you think the word is pejorative while it isn’t. Cold hands are a good example too : the body constantly produces heat to keep the temperature at 37°C, yet for a healthy person it can do it all by itself, you don’t need to drink hot water to avoid hypothermia.

    I thought I would never use this phrase after elementary school, but “it’s the Jaminet who started” with their “VLC is dangerous” non-sense. I’m not saying these persons who do better with starch should stop eating it, nor would I say that diabetic should stop taking insulin. I’m merely saying that eating starch should be the exception for these particular people with thyroid dysfunctionment, and not the norm for a “perfect health diet”©.

    • Tom Naughton says:

      “When someone’s body doesn’t produce enough of a substance and needs to ingest some directly – insulin or glucose – then this person is “sick”, even if you think the word is pejorative while it isn’t.”

      So if my body doesn’t produce enough protein or fat and I need to ingest some to feel okay, that means I’m sick. Correct? After all, we know my liver can convert carbs to fat, so in theory I shouldn’t need to eat any fat at all and still be fine.

      Just applying your logic.

      • Azurean says:

        To my knowledge, there is no biological process in mammals that can create protein from something else. About eating zero fat and converting lots of carbs into fat, that’s pretty much what gorillas do : If I ever get motivated enough to multiply my colon size by 5 and introduce some gut flora unknown to human biome, I might give it a try.

        But in all seriousness, you’re not “applying my logic”, just strawmaning it in a snarky/passive-agressive way. When most (with extreme subjectivity on the definition of “most”) people still create enough glucose in a VLC diet, you can considerate it’s a “healthy” functionment(contrary to your “carbs into fat” analogy that we both know won’t be sustainable on long-term for “most” humans), and people who can’t fulfill it are “sick”. We could continue this debate on the definitions of “healthy” and “sick”, it kept doctors busy since Antiquity and will still keep them busy for a few millenaries.

        • Tom Naughton says:

          Correct, you can turn carbs into fat, but trying to provide all your body’s need for fat through that method would eventually fail because unlike a gorilla, you’re not genetically geared for it. And that’s my point. Some people may not be genetically geared to provide all their body’s need for glucose by converting protein. It doesn’t mean they’re sick. Almost no human cultures lived on diets that forced them to provide all their glucose through gluconeogenesis month after month after month — apparently not even the Inuits, given what Richard Nikoley dug up about the glycogen content of the raw meats and seafood they consumed. So there’s no evolutionary reason all humans should be genetically geared to provide all their glucose through gluconeogenesis all the time.

          So what you’re arguing is that if you can’t thrive on a diet that none of your ancestors actually consumed, and in fact almost no humans anywhere consumed, you’re sick. I don’t buy that any more than I buy the vegan argument that if you can’t live without meat, you’re sick.

        • Gabe says:

          It seems obvious that comparing insulin, a hormone secreted by the human endocrine system, to an energy substrate such as glucose, which can be produced by conversion in the liver and/or sourced exogenously, isn’t an apples-to-apples comparison.

          What about subbing cholesterol for insulin? Every cell in our body is capable of producing cholesterol, yet a severely restricted intake of it can have profound adverse effects on our health. It’s generally accepted that cholesterol intake requirements vary greatly at an individual level, with folks at either end of the U-curve suffering great consequences. Perhaps it is so with glucose? Seems reasonable to at least consider the possibility.

          • Tom Naughton says:

            Like you’re reading my mind. I thought of that same analogy.

          • Azurean says:

            Good point.

          • Laura from France says:

            Great point. We could apply it to a lot of “non-essential” nutrients:

            - It is necessary to consume preformed vitamin A to fulfill our needs, because the conversion rate from beta-carotene is low and variable.
            - Vegan answer: Well no, if you can’t fulfill your requirement of vitamin A from beta-carotene in vegetables, it just means you’re sick.

            - Long-chain omega 3s are essential for neurodevelopment, that’s why we should eat fatty fish.
            - Vegan answer: Yeah well, you can make them from alpha-linolenic acid in flax seed oil… And if not, there’s something wrong with you.

            - You should eat bone broth, which is rich in glycine, which is an essential component of the extracellular matrix. It’s good for bone and joint health.
            - Vegan answer: Come on, glycine is not even an essential amino acid. If you can’t synthesize enough of it, you’re just metabolically damaged.

            (Repeat with taurine, coenzyme Q10, etc.)

  2. Ash Simmonds says:

    Yep, I called it – in 2015 all the rage in Paleosphere will be about “Amylase Reset Protocols” and “Bumping Your Amylase Copies” and “Amylase This, Amylase That”, followed by starch-avenging weight-loss products and supplements like “Raspberry Amylases”, “Amylase Force”, etc etc.

    Mock my words.

  3. Stephen says:

    This makes so much sense.

    Doesn’t stop me wishing i had fangs and claws though!

  4. Janet says:

    I can’t thank you enough for having done this series and introducing me to the idea of resistant starch. I have been on a very low-cab diet for a number of years now because I am on full thyroid replacement and have trouble losing weight. I have lost track of the number of times I have been told that if I can’t lose weight, clearly I am still eating too many carbs.

    I have added resistant starches back into my diet, and besides making me feel better overall–because I feel like I am finally feeding my body what it needs–the weight is actually starting to go down; not dramatically, but enough to be very encouraging. It has also made meal planning in my house considerably easier. I look forward to what you and the rest of these nutritional pioneers have to share with us. Thank you!

    • Tom Naughton says:

      I hope the weight loss continues.

    • Bret says:

      I second Janet’s thanks. I feel more energized now that I have added more (mostly resistant) starch to my daily routine–while of course preserving the basic structure of a whole foods only, grain-free, low-carbohydrate (100 g/day ish) lifestyle.

  5. Nice post Tom.

    It makes me think about V. Stefansson and his men when they lived with the Inuit and ate their fare for quite a long period of time. A year or more I believe. Apparently they not only did not suffer without starches, but thrived.

    I think that just because you have the genes that allow for more starch intake than another, I’m not convinced this means you SHOULD eat more of it.

    Is anyone looking for the “meat gene?”

    I’ll miss you on the cruise! I was looking forward to us walking around the ship with our bottles of Pinot, talking about…well I forget now…

    Best, Fred

    • Tom Naughton says:

      That’s why I was quite interested in Richard Nikoley’s posts about the glycogen content of the raw meats and fish the Inuits consumed. Turns out their diet might have been up to 20% glycogen by calories.

      Either way, I think for individuals, it comes down to a simple equation: if you end up feeling lousy on any diet over time, you need to make an adjustment.

      I don’t remember what we talked about while walking around with those bottles of Pinot either. Must have been good Pinot.

      • Tom Welsh says:

        “…if you end up feeling lousy on any diet over time, you need to make an adjustment”.

        True enough. But one might have hoped that, after 150 years of scientific and medical research into the matter, we might by now have slightly more specific recommendations for a healthy diet.

        Making an adjustment sounds easy enough, but when you contemplate all the myriad adjustments you might try – and bear in mind that it could take up to a year or more for the effects to become apparent – it’s not so simple.

        • Tom Naughton says:

          It’s definitely an ongoing journey.

        • Bret says:

          One might have hoped for more specific recommendations indeed, but that possibility went out the window when politics began to dominate the discussion, thanks mostly (or at least originally) to that jackass, the late Sen McGovern, may he RIP.

          Politics aside even, the issue of optimal nutrition is extraordinarily complex, as you mentioned, T.W., mainly because the human body is equally complex. I suspect that even 500 years from now, humans still will not know everything there is to know about healthy diet & lifestyle. Frightfully, our intervening descendants might unlearn the lessons we have learned–the same way our parents unlearned the work of Banting and of the pre-WW2 German biochemists–and repeat the same painful mistakes all over again.

  6. Boundless says:

    hmmm …. AMY1, ApoE2/E4, MTHFR ….

    Well, the FDA won’t let the genetic testing company 23andme.com provide medical risk analysis with your data, but perhaps ’23 could get into giving out genotype-specific diet advice (assuming they can figure out what advice to give).

    Somebody will. Coming to a future near you, nanny state permitting, of course.

    • Tom Naughton says:

      My suspicious side says the government doesn’t want us knowing much about our own genetics because we’d realize how much of their advice sucks.

      • Boundless says:

        > … government doesn’t want us knowing much about our own
        > genetics because we’d realize how much of their advice sucks.

        I suspect it’s more a case of: they don’t want private insurance to get, or even casually ask about that data on you, because it has direct bearing on your health risks.

        If health insurance premiums were based on actual risk factors, that would be “unfair” in some alternate egalitarian universe where equal outcomes are all that matters, even if it means punishing the cautious, responsible and lucky to simulate that equality.

        The reality we could have, once human nutrition is understood, is that armed with your genetic data, you could choose a diet and lifestyle that dials your need for expensive healthcare to nearly zero for chronic non-infectious diseases, and to 19th century out-of-pocket levels for everything else.

        Instead, we have healthcare expenditures rising faster than GNP, and Unaffordable Care Acts that force people choosing health to subsidize those choosing ailments (or just falling victim to suicidal government health and diet advice).

        • NancyM says:

          There is already legal framework in place to stop health insurance companies from discriminating against people because of their genes. However, life insurance companies still can.

          • Bret says:

            Heh. More laws to fix problems that were created by too many laws in the first place (as well as other forms of government intervention, mainly federal spending).

            The more we regulate these insurers, the more costs will rise on all of us. We can keep deficit-financing it…for a while. That will grind to a halt eventually.

            I only hope brother Jerry’s prediction of the corporate funded health insurance apocalypse happens sooner rather than later. That is the one potential occurrence on the horizon that stands a real chance at driving costs down–I find it even more likely than Rand Paul being elected and successfully inspiring the congress to cut spending. If it does not happen soon, I may just boycott health insurance until our national bankruptcy resets all of this widespread cronyist incest that is keeping costs high and outcomes crappy.

      • Pierson says:

        Allegedly, it’s also quite unreliable. Ultimately though, that’s neither here-nor-there. If we’re going to get unreliable tests *cough-standardbloodpanels-cough*, it’d be better if we could get them on our own dime

  7. A while back I read a paper on cats. They were described as extreme carnivores, but their livers still could create glucose, and their endocrine system is very similar to humans. The biggest dissimilarity (in the paper) was that cats have no AMY1 genes. I’d love to get my DNA tested. Unfortunately, it’s not something 23andme reports (even before the government shut down that part of the business). I have a feeling this particular gene is going to be instrumental in the future to tailor diets assuming the evidence can back it up.

    The only caveat I’d make to increasing starch is that a lot of people interpret the possible initial “Atkins flu” symptoms for “this diet isn’t working, so I’d better add some starches back.” If they’re straddling the edge of ketosis, it’s possible they’re perpetually going through the transition phase over and over. I’d suggest people who aren’t feeling okay at least first try a salty beef broth. Also, I’ve heard that Morton’s Lite Salt contains potassium, which should help during the transition, too.

    • Tom Naughton says:

      Good point. People feel lousy when they give up refined sugar, but that’s withdrawal. I’d give any dietary change sufficient time for an adjustment period. The people who end up feeling lousy on very-low-carb often have the opposite experience: they felt great for months or even a couple of years before the problems arose.

      • Lori Miller says:

        If these symptoms take months or years to appear, though, doesn’t that suggest it’s not glucose deficiency? It doesn’t take that long to burn through your glucose.

        I’m hypoglycemic and I don’t need anything close to the amount of carbohydrate the Jaminets recommend.

        • Tom Naughton says:

          I suspect it’s more of a case of burnout; i.e., gluconeogenesis is a survival mechanism that some people aren’t meant to rely on month in and month out, so eventually their bodies tire of the effort. Sort of like how our bodies can tire from the effort of producing big blasts of insulin three times per day to handle a high-carb diet. The negative effects can take awhile, perhaps even years, to manifest.

          • Bret says:

            I think gluconeogenesis burnout is a strong hypothesis that I would love to see tested.

            Anecdotally, I can attest to having more energy after going VLC for nearly a year before developing the fogginess of focus and the drop in energy, both of which exacerbated a bit more over the following year. Both of those issues have more or less disappeared now that I am no longer shunning starch completely as though it were rat poison.

            • Tom Naughton says:

              Exactly the point Jaminet makes in the PHD book. We adopt a new diet, which provides nutrients that had become depleted, and we feel great. Then that diet depletes some other nutrient over time, and we don’t feel so great anymore. The goal he set for PHD was to design a diet that doesn’t deplete us of any nutrients, including glucose.

    • Boundless says:

      > … AMY1 genes. I’d love to get my DNA tested.
      > Unfortunately, it’s not something 23andme reports …

      AMY1 is not in the ’23 raw data? Or is it just a case of: they don’t analyze the data anymore (there are other sites that will).

      I was just about to order one of the ’23 kits, to find out AMY1 (along with ApoE & MTHFR), but not if they don’t even have the raw data.

      • NancyM says:

        I just checked my raw data and put AMY1 in the gene search and it came back with nothing. I’m going to check the Promethease report I have.

    • Lori Miller says:

      Phinney & Volek describe something similar in The Art and Science of Low Carbohydrate Living: eating too much carbohydrate to run on ketones, but not enough to run on glucose. Result: you bonk. A lot of less informed people say they’re eating no carbs, but if you ask them what they eat, they’re eating quite a bit of carbohydrate. Just look up “no carb recipes” on Pinterest–there’s fruit popsicles, hummus, beans, tomatoes, coconut milk, etc. (My best friend said she didn’t think of orange juice as having carbohydrates.)

      • Walter says:

        (My best friend said she didn’t think of orange juice as having carbohydrates.)

        Ouch! Not only carbohydrates, but that devil of devils fructose.

        There are people who lie awake at night trying to figure out how to get more sugar into the food supply.

  8. Sabine says:

    There is probably more involved than just the amylase gene.

    However, according to anthropological studies, you are right in pointing out, that there were some variations in starch consumption and tolerance among hunter gatherers.

    Those of Sub-Saharan Africa, and those of Australia, seem to be able to tolerate and also ate more starches, as did some of the ancient inhabitants of tropical South America.

    So, if you have tropical and African/Australian ancestors, you would be eating a traditional diet by including some starches (Not modern rice and potatoes of course).

    For those of us, who are blessed with Northern (European/Asian/American) genes, starches may not be such a good idea.

    • Tom Naughton says:

      That’s what I used to assume as well, but it turns out roots and tubers were part of the diet all over creation. There’s even a tuber known as the “Eskimo potato” that grows waaaay up north. So while there was variation in how much roots and tubers figured into the diet, they seem to have been included almost everywhere.

    • Pierson says:

      Not necessarily. According to my Ghanaian mother, eggs, fish, goat milk, boiled peanuts, small amounts of chicken, and coconut oil were her only sources of protein and fat in an otherwise starch and fruit-heavy diet. The folks there were all healthy and lean too, despite eating mostly sorghum, corn meal, rice, potatoes, and lots of oranges and mangoes

  9. Firebird7478 says:

    I’ve been three weeks into adding RS to my diet. While I haven’t seen any weight gain, I haven’t noticed any weight loss either. I do get the graphic dreams, though. My training at the gym seems to have improved, too, regarding recovery. I notice that I don’t get a carb surge/crash like I would when I ate pastas or oatmeal.

  10. Laura S. says:

    The potato starch really jacked up my fasting blood sugar, but when I added cold potatoes instead via potato salad, no problems at all. I am sleeping more soundly and waking up before the alarm each day feeling refreshed. No vivid dreams, though, plus a definite improvement in my digestion. I also added the pre & pro biotics every day.

    Going low carb did not adversely affect my thyroid, but Atkins induction caused me terrible muscle cramps in my thighs, calves and feet. I tried everything they recommend and the only thing that stopped them was coming out of induction.

    Thanks for investigating this, Tom, and sharing it with everyone.

  11. Marla Umhoefer says:

    I have seen a study or two where T3, the active form of thyroid hormone, dropped or was not able to be utilized by the body’s cells while the subjects were on a low carb diet. I certainly feel horrible on a VLC diet.

    • Tom Naughton says:

      In the same book by Denise Minger that I quoted from, she has a sidebar explaining that people who lived in Arctic regions would feast on the thyroid glands of the moose they killed, apparently to keep their thyroid function up. This was, according to Weston A. Price, considered essential among women who wanted to get pregnant.

      • Laura S. says:

        Maybe I didn’t have issues because I have been on synthroid for the last 30 years due to already having hypothyroidism? My regular yearly tests didn’t show any degradation from being low carb.

        Interesting about needing to eat the thyroid glands. That makes sense.

        • Tom Naughton says:

          I didn’t develop any thyroid issues either, according to the lab tests I had taken when I turned 55. Then again, I’ve been eating a sweet potato here and there for the past few years and eating a high-carb Mexican meal most Saturday nights, so I don’t know what would have happened if I’d been strictly ketogenic for three or four years.

  12. Martin Levac says:

    But what about the liver, the duct that goes to the gallbladder, the gallbladder, the duct that goes to the stomach, the stomach, and bile, and then chylomicrons that transport fat to the liver for processing and to fat tissue for storage? All of this is dedicated to the digestion and processing of fat. Compared to AMY1, which basically eliminates the need for a stomach/liver/gallbladder/fat tissue to digest and process starch, cuz it’s all done in the mouth via saliva then goes straight to the bloodstream, we get a whole lot more stuff dedicated to the digestion of fat, than to the digestion of starch. Yeah, it’s an absurd and extreme example of fallacious logic, but then so is the argument about AMY1 and genetic starchyvorenumnuts.

    It’s all good and well to hypothesize about what individual organs and cells can do. The real test is what the entire organism can do. This means taking two groups of 100 people, feeding starch to one group for a while, feeding fat to the other group for a while, then switch diet/group, testing a wide array of markers like BG and mental performance for example, comparing the results, and drawing conclusions on those results. Until we do this, we’re all armchair experts and don’t we all feel smug about that.

    • Tom Naughton says:

      It’s not an either/or situation, however. The choice isn’t between fat (which the Perfect Health Diet book declares to be our primary source of energy) and glucose. The PDH recommendation is to use fat as fuel for pretty much everything except the obligate glucose consumers.

  13. Roy GA says:

    Dr. Eades wrote a blog post over 6 years ago on resistant starch. You may want to take a look. http://www.proteinpower.com/drmike/metabolism/resistant-starch/

    • Tom Naughton says:

      I did.

    • Bret says:

      Roy, that Eades post reads more like a snide mockery of the RD’s comments about RS, rather than an honest (and certainly not thorough) critique of the topic of RS itself. I’m not sure if Dr. Mike realized this, because his post was patently dismissive of the whole idea of RS. Now, as he pointed out, the RD’s presentation was not exactly rock solid, so perhaps she deserved such criticism. But all the same, attacking the speaker is not the same as refuting what she said.

      As Tom pointed out in some of his recent posts, many of us LC folk have been similarly guilty of giving in to our biases and thus rejecting new information before we have given it the time of day–simply because it contradicts our existing beliefs. That is a natural human reaction, but it is one we ought to fight. Otherwise, our beliefs are in reality rooted in dogma, not science. At that point, we are no longer willing to learn, and then we are really in trouble.

  14. T. says:

    I hate to break it to you, but your understanding of how evolution works is flawed. It’s really not your fault though, because about 90% of people don’t understand it. Evolution is not Lamarkian. Genes do not “fall away”. Genes only go away if they are actively selected against, i.e. that only happens before reproductive age. In other words you don’t live to reproduce. Evolution is not benign, all knowing, or omniscient. It is random due to the conditions at the time. If you do not already possess the genes to live in your changing environment, you die out. You do not produce genes in response to an environment. You have to already have them.

    While Lamarkianism may be a beautiful and elegant theory, it’s wrong.

    • Tom Naughton says:

      So when humans migrated from Africa to Northern Europe, are you saying they already had the genes for fair skin, blonde hair and blue eyes? Or were those mutations that proved beneficial? And why did most Europeans lose the gene for sickle-cell anemia, which protects against malaria, while Africans retained it? That’s not a gene falling by the wayside because it wasn’t beneficial to them anymore? Or would you say it was more a case of being actively selected against in Europe because the disadvantages outweighed the advantages in Northern Europe? Serious questions … not being sarcastic here.

      Anyway, to your point (which is well taken), it would be more accurate in that case to say that a mutation that allowed for humans to consume starchy plants proved beneficial because starchy plants were an obtainable food source and thus became part of the diet after the mutation. Similar to the mutation that made most Europeans lactose tolerant. (And claws and fangs went away because hands and teeth provided the competitive advantages of hunting with weapons and chewing those now-digestible tubers.) So coming at it from that angle, I’d still end up at the same place: Some humans carry more copies of the AMY1 gene because it provided a competitive advantage in sourcing food in their part of the world, which is essentially the same as saying a low number of copies of the AMY1 gene was selected against — which would mean humans carry those extra copies because starches were an important food source.

    • Firebird7478 says:

      It looks to me like you rather enjoyed breaking it to him.

  15. Norm says:

    Hi Tom,

    1. “They found that people who carried a low number of copies of the salivary amylase gene were at greater risk of obesity.” “The researchers estimated that with every additional copy of the salivary amylase gene there was approximately a 20 per cent decrease in the odds of becoming obese.”

    How are above conclusions different than saying people eating saturated fat are at a higher risk of heart disease? People with Apo E3/3, E2/3 have high levels of chelesterol which is associated with E4/4. When it comes to staurated fat and cholesterol etc we demonise poor science but when it comes to the ideas we like (safe starches, VLC) we don’t mind it and love to draw vague and speculative conclusions.

    2. How do we explain the genetic aspect of sudden rise in obesity that is closely related to the rise in higher consumption of glucose/sugar? Did people suddenly start to lose copies of AMY1?

    Thanks

    • Tom Naughton says:

      It is an association and therefore not proof, but the hypothesis is also supported by the clinical study Minger cited in her book, the one in which low-amylase people averaged BG readings 36 points higher given the same load of starch.

      No, people didn’t lose copies of AMY1. People unable to efficiently process starch began eating more of the stuff — as they were told to do by all those experts. That’s one of the main points of her book: many, many people don’t handle a high-starch diet well because of genetics, yet the USDA declared a high-starch diet ideal for everyone.

  16. Harold says:

    My son has come up with a new diet. It’s the “Have Skinny People Spit on Your Starches Before Fat People Eat it Diet.” It should be available from Amazon soon. Hey I started eating liver and heart and dandelions why not a little spit.

    • Tom Naughton says:

      Give it time, we’ll find out there’s something called “other people’s spit probiotics” that are good for gut health.

  17. Curtis says:

    “And isn’t it a little silly to insist that they’re sick or carb-addicted if they do?”

    Yes it is. A few years ago I went on a “raw foods diet” and in the forum I was a part of if folks were having trouble this is all they talked about trying to figure out what they were doing wrong since the author of the book we read was doing great years after she started. Well that is what she said to the public anyway.

    As a side note eating a raw foods diet left me with very little energy to exercise let alone get up in the morning.:) When I added meat back my energy lvls came back.

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