Take Home Messages from AHS 2012 | Chris Kresser

Take Home Messages from AHS 2012


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This past weekend, I attended the Ancestral Health Symposium at Harvard University, where some of the biggest contributors to the ancestral health movement gathered to discuss their research findings and theories on health and nutrition. One of the highlights of the conference for me was meeting people I’ve been in contact with for years, but hadn’t yet had the chance to meet in person: Mat LaLonde, Stephan Guyenet, Chris Masterjohn and many more.

There were several great presentations, but unfortunately I was only able to attend a few of them. I’m looking forward to watching the presentations online once the Ancestral Health Society posts them to their website. They’ll be available for free, and I think the videos will be an incredible resource for anyone looking to educate themselves further on topics of health and nutrition, as well as food policy and healthcare reform.

I did manage to see a few excellent presentations that had some important take-home points that could be incorporated into a paleo or primal lifestyle. While we’re waiting for the videos to be posted, I’ll share a few great ideas and practical tips that were discussed at the conference that you may use to improve your health.

Dan Lieberman, Ph.D.

Dan opened the conference with his talk entitled “What are Humans Adapted For?” Dan’s main point was that we’re mismatched with our current environment in several important ways, and that mismatch is the cause of modern disease. One of the most crucial ideas he emphasized was that the body is a “palimpsest” of complex adaptations and non-adaptations that evolved over millions of years in multiple contexts. He suggested that answering the question “what humans are actually adapted for” is tricky because the concept of adaptation is itself very complex, especially when viewed in light of what we know about what happened in human evolution. Although many modern illness are mismatch conditions caused by living in ways in which we are clearly not adapted, there is no one optimal way to promote health. For that reason, there is no one “paleo” diet, and there are likely many different diets that can promote optimal health; it’s important to remember this when determining the appropriate diet for you. You can learn more about Dan’s research on his website.

Mat Lalonde, Ph.D

“The Kraken” presented his work on a new model of nutrient density that, though imperfect, could be used as an argument against the many other nutrient density measurements on the market today, such as ANDI scores and Joel Fuhrman’s Nutrient Density Line. Based on Mat’s analysis, animal products, especially organ meats, are the most nutrient dense foods when analyzed using his scientifically supported guidelines. Animal foods were highly ranked even though raw and cooked meat were not segregated and essential fatty acids, essential amino acids, vitamin B7, some essential minerals, and bioavailability were not taken into account.

Mat made the important observation that much of the high value placed on foods like grains and legumes in other databases are based on analyses performed in the uncooked state. As grains and legumes are inedible unless cooked, it makes more sense to look at their nutrient density in the cooked state, where they are far less impressive. Another interesting point Mat made was that, based on his calculations, white potatoes were significantly more nutrient dense than sweet potatoes largely due to their higher mineral content, which shocked a few in the audience.

While Mat did an incredible job analyzing the data available to him, there were a few flaws in the analysis due to lack of data on particular nutrients in the USDA database. For example, the USDA database doesn’t distinguish between the various forms of certain nutrients, such as preformed vitamin A as compared to beta carotene, or vitamin K1 versus vitamin K2. If possible, it would be useful in the future for us to consider these differences in bioavailability when ranking foods on their nutritional quality. That said, Mat did an incredible job analyzing the available data, and his analysis provides good evidence to support the benefits of a diet containing animal foods. Hopefully his list of the most nutrient-dense foods will be available for widespread use in the future.

Peter Attia, M.D.

Peter gave a fantastic presentation entitled “The Straight Dope on Cholesterol,” which described the biological importance of cholesterol in human physiology, and the way in which this molecule can cause damage if produced pathogenically. He explained that the cholesterol we eat has little to do with the cholesterol we measure in our bloodstream, and that the cholesterol in our bloodstream has little to do with the cholesterol in our artery walls. In addition, high LDL particles (LDL-P), not LDL cholesterol content (LDL-C), is what drives sterols into artery walls. Peter explained that LDL particle number is a far more significant marker for heart disease than LDL-C, and that LDL particle size is not significant after adjusting for particle number. Peter covers much of this information on his website, The Eating Academy.

In short, standard total and LDL cholesterol numbers don’t really tell us that much about a person’s health, and there are better ways to assess cardiovascular health and risk of heart disease.

I will go into much more detail on this topic in my High Cholesterol Action Plan, which I’ll be publishing in early September. Keep an eye on the blog for details.

Chris Masterjohn, Ph.D.

Chris had a superb presentation of his doctoral research on carbohydrate metabolism, oxidative stress, and insulin resistance. He explained that humans have several more copies of salivary amylase genes than non-human primates, which suggests that we are all adapted to starch digestion, but the capacity to digest starch varies from population to population. Some people are far more capable of starch digestion and metabolism than others, but when any individual begins to express more amylase gene, their pancreas produces more insulin before the glucose has even entered the bloodstream, reducing the overall blood glucose response as well as the total insulin release when carbohydrate is ingested. This is probably a good reason to chew your food well, particularly when you’re eating carbohydrate, to allow for adequate amylase activity and insulin response.

Also, although low carb proponents typically vilify starch because of concerns that glucose “spikes” will lead to AGE formation, Chris showed that glucose is not a significant contributor to AGE formation compared to dicarbonyls like methylglyoxal; and, ironically, insulin protects against methylglyoxal-induced AGE formation in several ways. In general, excess energy intake leads to oxidative stress if cells allow too much energy into the mitochondria, so insulin resistance could actually be protective against this oxidative damage. Therefore, in order to keep a healthy metabolic response to carbohydrates, it is important to keep your caloric intake appropriate to your personal level of physical activity. You can check out Chris’s work on his blog, The Daily Lipid.

My Presentation: Iron Behaving Badly

My presentation was on iron overload and how even mild iron accumulation can cause significant metabolic problems, including insulin deficiency, insulin resistance, and hepatic disfunction. Elevated ferritin levels are associated with increased incidence of diabetes, and reducing iron stores improves and can even reverse the metabolic abnormalities associated with excess iron. After explaining the various ways that genetics can put a person at risk for excess iron, I gave the audience a few clinical treatment options for this condition. My first recommendation is phlebotomy, or blood donation, on a frequent enough basis to reduce iron to a safe level. If you are unable to donate blood, a natural iron chelator called apolactoferrin can be used. Other options include avoiding high iron foods such as red meat, and avoiding high doses of vitamin C. (For more information about iron overload, you can access my references and some of my slides by clicking here.)

Denise Minger

In her talk entitled “Meet your Meat”, Denise also brought up the issue of iron overload as a potential reason to limit red meat in the diet; iron overload is a significant concern for a big portion of the population, so be sure your iron status is healthy if you are eating a lot of red meat. Denise also recommended including other parts of the animal such as tendons, skin, and cartilage, which are high in glycine and can balance out the high levels of methionine found in muscle meats.

High levels of methionine raise homocysteine in the blood, which is a risk factor for heart disease. Therefore, Denise stressed the importance of nose-to-tail eating for more than just ethical or environmental reasons.

Her blog is Raw Food SOS.

Stephan Guyenet, Ph.D.

Stephan had a fantastic presentation on digestive health, inflammation, and the metabolic syndrome. Stephan presented a wide variety of evidence suggesting that metabolic dysfunction is linked to poor diet, low-grade inflammation, blood lipid abnormalities, gut dysbiosis, and digestive disorders. Stephan reviewed the various dietary and lifestyle factors that could be causing these disorders in our population, and explained a few ways to improve metabolic function and prevent the development of metabolic syndrome in future generations. I appreciated that Stephan had a strong focus on gut health as being a key factor in the development of obesity and metabolic syndrome. While it is unclear whether or not metabolic syndrome can be fully cured, optimizing gut flora and digestive health can be one of the most important factors in regaining healthy metabolic function. You can read more about Stephan’s work on his blog, Whole Health Source.

Well, there you have it! The Ancestral Health Symposium was a fantastic experience all around, and I’m really looking forward to seeing more of the talks once they’re available online. I hope you found this recap to be informative, and I recommend watching the lectures for yourself once they’ve been posted.

Did you attend AHS 2012? What was your favorite part of the event?

  1. The link to references for your talk is broken, namely /ahs12. I’d like to see those references.

  2. Chris, what are your thoughts on when it is safe to add coconut milk? My daughter is almost 9 months old, she has been breastfed exclusively, with solid foods being introduced around 6 months. I know it is recommended that cow’s milk should not be introduced until 12 months but I dont plan on giving her dairy. I was also wondering if purchasing the Health Baby Code made sense since she is 9 months. Thank you. I thoroughly enjoy reading and learning from your insight.

    Sorry I am adding this post here but i cannot log onto Facebook at work to comment on the appropriate article.

  3. Chris, you say: “..when any individual begins to express more amylase gene, their pancreas produces more insulin..”.

    Later on for that reason:
    “..chew your food well.. to allow for adequate amylase activity and insulin response.”

    Is not it a contradiction, or I do not get the point?

    • People with more copies of amylase gene experience a smaller blood glucose response to starch consumption. The mechanism for this is not certain, but the pattern of insulin release is the best guess we have at this time.

      High-amylase people experience a “pre-absorptive” insulin release phase in the first few minutes of consuming starch, whereas low-amylase people do not. Total insulin secretion in response to the meal does not differ much between high and low amylase individuals, so the initial phase might be the key factor in keeping glucose levels more stable.


  4. Chris, is there any clinical evidence that high-dose ascorbate causes siderosis?
    I’ve never seen so much as a case study.
    my understanding is that ascorbate merely reverses the iron-chelating effect of polyphenols if these are present in a meal. This ought not to result in the body absorbing more iron than it needs.
    Siderosis can deplete ascorbate:


  5. Chris,
    FYI, Joel Fuhrman’s Nutrient Density score is the ANDI score, that is the same thing. Thanks for the write-up, I couldn’t go this year even though it was in my backyard as we have a new little boy. Appreciate all of the time you put into this.

  6. “Therefore, in order to keep a healthy metabolic response to carbohydrates, it is important to keep your caloric intake appropriate to your personal level of physical activity. You can check out Chris’s work on his blog, The Daily Lipid.”

    This is of course the conventional wisdom, which says a disordered carbohydrate handling ability is largely due to calorie excess, rather than carbohydrate excess per-se. And that may very well be the case. However, the real-world evidence of Asians who become diabetic while still fairly LEAN, seems to argue against this idea to at least some extent.

    They appear to to become diabetic when eating too much white rice and sugar…even though they still are not apparently exceeding their daily calorie need by much, as evidence by their lack of obesity when becoming diabetic.

    In fact, white rice (The “safe starch”) has been so strongly linked with T2 diabetes (Despite it’s nil fructose content) that even that semi-crazy vegan doctor dude…Joel Furhman…says the “plant based” food known as white rice really increases T2 risk.


    • The lean diabetic is an interesting case. It might be more common in Asia, but here in the West it seems like calorie excess is the more dominant factor. Perhaps it is partially explained by genetics?

      White rice has been linked with type 2 diabetes primarily in observational studies. In short term controlled trials, the results are conflicting. See this paper for one example (note that it was conducted on CHINESE subjects!):

      Another vegan doctor, John McDougall, does not think white rice is a big deal (even though he agrees that brown rice is preferable).

  7. Regarding iron-excess…The idea someone following a meat-rich diet would have to artificially have excess iron pumped out of their system via blood-donating has always seemed to be an argument AGAINST a paleo/LC diet. I mean if a diet is correct in terms of human evolution, it should NOT put things into us – such as excess iron – that we have to artificially removed, right?

    This iron overload idea has really, really bothered me, and caused me mucho cognitive dissonance over the idea of paleo/lc diets.

    But I have recently come across some work by Dr. Wolfgang Lutz of “Life Without Bread” fame that hints at the notion that “excess iron” may be a total non-issue within the context of a low carb diet. But that it is only an issue when eating a fair amount of carbohydrates along with the iron.

    Here’s what he wrote on this issue…

    “Too Much Iron in the Blood (Hyper-siderosis)

    The same diet also has a beneficial effect on abnormally high iron levels (*62). Fig. 18 includes 38 cases in which an elevated iron level responded to restriction of carbohydrate intake. Cases of siderosis (too much iron in the blood) are even more common than sideropenia (too little iron) and are important since they may lead to deposition of iron in the tissue and thus to severe metabolic disturbances (haemochromatosis).

    The Bantus use only iron vessels for cooking and their diet therefore contains adequate quantities of iron. Anyone, like the Bantus, eating food from iron pots, accompanied by large amounts of carbohydrate, may suffer from siderosis.

    The Bantus could probably change this, either by giving up their iron pots or their carbohydrates.

    Joking apart, the fact that one and the same measure, in this case a low-carbohydrate diet, can restore abnormal to normal from both directions strongly suggests a common causal effect. It appears that carbohydrates are cause of both disorders and, in a manner as yet unknown to us, rob us of our ability to keep our iron balance in order.”


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