The Ancestral Health Debate
The Ancestral Health Debate
Nick Hiebert and I debate the value of ancestral health as a heuristic, covering arguments around antagonistic pleiotropy and past failures in the development of artificial diets.
Here is the debate I had with Nick Hiebert about the value of ancestral health. In the second half, Avi Bitterman takes over for Nick, and Saar Wilf makes a brief appearance.
This originally was held on Twitter Spaces and has no video. You can listen to the audio using YouTube above, Spotify below, or find it in your favorite podcast app under “Mastering Nutrition.”
Below is my summary and reflections, the time stamps, relevant links, and transcript.
In this post:
Summary and Reflections
Nick took the position that an ancestral diet is superior to a standard Western diet and lifestyle, but that there are a subset of unnatural diets that are superior to the range of ancestral diets. Thus, the best diet we can eat would likely contain artificial manipulation.
I took a more elaborate position as follows.
We can separate ancestral health frameworks into those centered around ancestral constraints, and those centered around ancestral knowledge and wisdom.
Ancestral constraints are unchangeable things that characterized our ancestral environment, such as lack of artificial lighting or refined foods. These serve as a goldmine of hypotheses that will generate plenty of wrong ideas, but be better much better than a random idea generator.
The body of ancestral knowledge and wisdom is valuable both as a hypothesis generator and to use as a default in the face of scientific uncertainty. This body of knowledge is not determined genetically and is therefore not subject to natural selection. Whereas natural selection is biased towards promoting health early in life during the window of fertility, our ancestors may have compensated for this by selecting knowledge and wisdom that promotes longevity late in life.
I also took the position that there is no such thing as an optimal diet for everyone. Each person has an optimal diet for a particular point in their life that may change dynamically. If you take the sum total of optimal diets for all people at all times in their lives, the range of optimal diets will almost completely overlap with the range of ancestral diets. Most deviations from ancestral diets will incorporate artificial enhancements of certain ancestral components, such as the addition of a vitamin at a dose higher than can be obtained from food.
Finally, I took the position that, in principle, we should be able to make a superior artificial diet once our knowledge about nutrition is sufficiently complete, but we are likely so far away from this level of completeness that we will do far more harm than good for far too long when trying, and this is supported by our past experience trying to make artificial diets at great cost to those consuming them. The key examples are total parenteral (intravenous) nutrition (TPN), infant formula, and purified diets for laboratory rodents.
Nick’s argument centers around a concept known as antagonistic pleiotropy. This is the principle that a gene can often have multiple functions (that is, can be pleiotropic), and often at least one of them may promote health early in life during the window of fertility, and at least one of them may hurt health late in life after the window of fertility. Since these two properties are antagonistic to one another with respect to health, the principle is known as antagonistic pleiotropy.
Nick took the position that antagonistic pleiotropy is so ubiquitous that it describes the majority or even most genetic adaptations. During the debate, I accepted this for the sake of discussion, but stated explicitly that I did not know it to be true. After the debate, I read through Nick’s arguments on his web site as well as some related papers, and I wrote a much more extensive argument disputing this.
During the debate, however, we focused on what this would mean for the health value of ancestral foods if it were true.
Nick argued that if antagonistic pleiotropy describes the majority of genetic adaptations to food, then it must also describe the majority of ancestral foods. Therefore, the majority of ancestral foods must hurt longevity in the post-reproductive window.
I argued that Nick was conflating genetic adaptations with foods, and that the proportion of antagonistic pleiotropy among genetic adaptations tells us nothing at all about its proportion among foods.
Nick and I never came to any agreement on this.
Nick agreed with me that there will be many hurdles on the way toward developing artificial foods that are superior to ancestral foods, but considered this irrelevant to his inference, which was simply that there exist some artificial foods to pursue that will be superior to the best ancestral foods.
In the second half, Avi Bitterman came on and reframed the argument around antagonistic pleiotropy. Saar Wilf also jumped in to make some comments in defense of natural selection promoting health in old age.
All three of us agreed that natural selection will have some effect in old age. Avi was very insistent that at some point, however, antagonistic pleiotropy would win out over pro-longevity adaptations, such that ultimately our adaptations would be in net bad for longevity after some age.
I remained agnostic on this point, even though I pointed out — and we all agreed — that longevity always loses to death in the end. I emphasized, however — and we all agreed — that the relative proportions of antagonistically pleiotropic adaptations may ultimately be irrelevant since it might be very few genes that have outsized importance on all the major killers. Avi agreed, but pointed out that probability still favors large-magnitude adaptations being in net antagonistically pleiotropic after some age.
As during my discussion with Nick, I granted the predominance of antagonistic pleiotropy after some age with Avi for the sake of the discussion, although I remained agnostic. For reasons I described in my Ancestral Health Vs Ancestral Pleiotropy? followup, I now strongly question whether this is true.
One thing that Avi and I agreed on that seemed distinct from Nick’s position is that our adaptations to food will influence our genetically encoded food-seeking behaviors, but not the composition of foods available to us. And while Avi did defend the hypothetical superior artificial food, he also acknowledged that his argument about novel diets could simply apply to mixes of ancestral foods in different proportions than we are genetically driven to seek them.
This is important, because it does not support Nick’s arguments that the ancestral foods themselves must be majority antagonistic to longevity, and thus does not support Nick’s argument that artificial foods that are healthful early in life are probabilistically more likely to be beneficial than ancestral foods late in life.
Like Nick, Avi agreed with me on the principle that there would be empirical hurdles toward developing a superior non-ancestral diet, but Avi also added that he believes I’m exaggerating how poor our current state of knowledge is and that this would likely involve much less difficulty than I am suggesting.
Ultimately, the point where I formed the most agreement was with Avi, that it is possible for our genetically encoded food-seeking behaviors to be antagonistically pleiotropic after some age. In other words, in order to live as long and as healthfully as we possibly can, after some age, we may need to seek ancestral foods in different proportions than our genes drive us to seek them.
I find this rather trivial, because even our ancestors had knowledge and wisdom in which they advocated using strength of character and discipline to procure foods or engage in certain ways of life. That is, ancestral knowledge and wisdom includes methods of overriding our most base instincts to pursue the healthiest options.
Overall I found this debate interesting, but it didn’t change my belief about the value of the ancestral health framework.
Time Stamps
Part 1: I debate Nick Hiebert
02:24 Nick’s opening position.
03:48 My opening position.
13:38 Nick lays out his case about antagonistic pleiotropy in detail.
20:45 Red meat and ApoB-containing lipoproteins as an example of antagonistic pleiotropy. Interaction with infectious diseases.
34:09 Iron, anemia, and hemochromatosis as a counter-example.
35:14 We debate whether novel foods would escape ancestral adaptations.
47:25 We return to iron, anemia, and hemochromatosis, and then revisit red meat, ApoB, and infectious and cardiovascular diseases.
53:14 Nick closes his primary argument.
55:54 I lay out my primary argument about ancestral restrains, ancestral health and wisdom, and the history of trying to create artificial foods — emphasizing rodent diets, total parenteral nutrition (TPN) and infant formula — in detail.
01:10:54 Nick makes his closing statement.
01:12:12 I make my closing statement.
Part 2: I debate Avi Bitterman; Saar Wilf joins in
01:19:21 Avi reframes the antagonistic pleiotropy argument.
01:41:03 Saar Wilf joins in to make points about selection for post-fertility longevity.
02:06:55 I make my ultimate closing comment.
02:10:32 Avi makes his ultimate closing comment.
02:13:07 Nick makes his ultimate closing comment.
Relevant Links
Nick’s article, “Should Modern Humans Eat Like Hunter-Gatherers?”
My article, Ancestral Health vs. Antagonistic Pleiotropy?
Please Show This Post Some Love
Let me know what you think in the comments! And please like the post if you found it valuable, and share the post with others if you believe they too would find it valuable.
Read the Transcript or Leave a Comment
Masterpass members have access to the transcript below.
Masterpass members can also read and leave comments below. Non-members can read and leave comments on the general podcast page.
Learn more about the Masterpass here.