Paleo Diet & Fitness


If you haven’t seen the new TED talk featuring anthropologist Christina Warinner where she “debunks” the Paleo diet, it’s worth watching.

I think the “debunking” rhetoric here is somewhat oversold and that the introduction to the talk in particular attacks a number of straw men. Many in the Paleo community have long recognized that it would be impossible, and perhaps not very enjoyable, to eat an authentically paleo diet. There was no one paleo diet in history, just as there are variants of modern approaches to diet and fitness that come under the umbrella of paleo or ancestral health.

To me, it’s never been about re-enactment, but asking how evolution and anthropology can better inform approaches to diet, health, and lifestyle in the modern world. For some, “paleo” is just shorthand for this kind of thinking and experimentation. For others, I suppose it’s a catchy label used to package and sell stuff.

All of that said, the takeaway from Christina Warinner’s talk is eminently sensible, and the journey she takes to get there is interesting as well. In the end, the more anthropologists, nutritionists, doctors, etc, that get involved in asking how evolution and anthropology can better inform approaches to diet, health, and lifestyle in the modern world, the better. So no need to get your panties in a bunch, just watch and enjoy!

Back in the late 80s and early 90s when I was in high school and college, my understanding of genetics was a pretty simple and mechanistic one. Maybe this is not so surprising–I’m a layperson, and sometimes a bit of a simpleton. But heck, even for my wife, a Harvard-trained physician, what they learned about genetics 10 years ago is already somewhat dated. Anyway, when I first started to read about “gene expression” several years ago, it was enough of a paradigm shift in thinking about genes that I had a hard time getting my head around it.

A new study on sleep by researchers at the University of Surrey helps to illustrate just how dynamic genes are, responding in incredibly complex ways to our diet and lifestyle:

Researchers at the University of Surrey analysed the blood of 26 people after they had had plenty of sleep, up to 10 hours each night for a week, and compared the results with samples after a week of fewer than six hours a night. More than 700 genes were altered by the shift. Each contains the instructions for building a protein, so those that became more active produced more proteins – changing the chemistry of the body.

As noted by the study authors, “The affected genes are involved in chromatin remodeling, regulation of gene expression, and immune and stress responses.” In case Mark Sisson and others haven’t convinced you, try to get some sleep! That means powering down electronic devices a couple of hours before bedtime so that melatonin production isn’t suppressed.

BBC write up here. Study here.

It all sure adds an interesting twist to the ancient nature v. nurture debate.

There’s a very provocative rebuttal of Gary Taubes’ carbohydrate-obesity thesis over on Stephan Guyenet’s excellent Whole Health Source blog. In a nutshell, Guyenet argues that fat regulation in the body is far more complicated than Taubes has suggested, and that even if low-carb dieting appears to produce good results for some, the reasons for this are not as simple as Taubes suggests. Furthermore, Taubes thesis cannot account for healthy populations across the world who have thrived on high-carb diets.

Personally, I feel like I have learned a lot from reading both Guyenet and Taubes, and don’t have the scientific background to enter the fray at any level of detail.

What I come back to in terms of paleo eating is what I have pointed out previously:

  • There is no one Paleo diet. There is a wide range of diets that have kept traditional populations healthy, from high to low carb and everything in between.
  • What those diets do have in common, however, is that they are generally simple, real-food diets with little processing that avoid modern, industrial food product.
  • Demonization of any one macronutrient, be it carbs, protein, or fat, is simply not that helpful to understanding health.
  • Using evolution as a filter to help think about diet and fitness can be a helpful tool, but it involves a lot of guesswork and there is still a lot of learning and debate going on.
  • Amply footnoted tomes by well respected authors are no substitute for using your head and engaging in rigorous self-experimentation.

Not sure what it is, but I can’t seem to get enough broiled veggies these days. Olive oil, salt, 10 minutes, and you have summer time perfection.

Here they are prepped and ready to go into the oven:

summer grill

And here’s the full meal. Veggies, and a little chicken seasoned with mango chutney:

grill 2

(The corn isn’t kosher paleo, I’ll admit, but as an occasional cheat drenched in butter, I’ll take my chances.)

The premise is simple enough. Like any animal, we are healthiest when we eat within the range of diets consistent with our body’s natural evolution, and that evolution has largely been as hunter-gatherers. If we look to ancestral hunter-gatherer diets for inspiration we can lower the chances of suffering from the various “diseases of civilization”: diabetes, cancer, heart disease, etc.  On that, many in the “Paleo community” agree.

The tricky thing for those who want to follow a list of rules, the halal and haaram of Paleo eating, is that there is a wide range of diets that have kept traditional populations healthy:

  • There were healthy hunter-gatherer populations that lived off of tubers, fish, and coconut (high carb diet), and maintained excellent health.
  • There were hunter gatherer populations that ate something closer to a low-carb diet, and yet also maintained excellent health.
  • Some pre-agricultural populations ate lots of fruit, and collected good quantities of wild grains.

Add to this the general lack of empirical data about what many pre-agricultural populations actually ate, and you get a recipe for confusion and myth-making. My own approach is to tailor carb intake to my activity levels, adding in more starch during weeks when I am doing more physical activity, less when I am more sedentary. Depending on your goals and health conditions, a lower-carb variant might work better for you.

There is a lot of learning going on, a lot more learning that needs to be done,  and there is no “one” paleo diet.  You have to use your head: THINK, experiment, see what works for you. Gandhi’s autobiography is called “The Story of My Experiments with Truth.” At this stage of our knowledge of evolution and nutrition, all diets, including the Paleo diet in all its variants, are just that:  experiments in truth (or health).

As the Paleo diet goes more mainstream, I see a creeping dogmatism reminiscent of veganism, or anyone who thinks they have found “the Truth.” It’s gotten to the point where some who got into Paleo eating years ago don’t even want to use the label anymore. I think perhaps the label “ancestral health” might be a better one as it dispenses with the irksome caveman metaphor (apologies to Mark Sisson’s Grok). Unfortunately, “Ancestral Velo” doesn’t have quite the same ring to it!

In any event, I think we need to remind ourselves that it’s about sensible principles, not inflexible rules:  Just eat real food (JERF), cut down the sugar, stay active, get out into nature and sunlight, take time to relax, etc.

Maybe it would be hard to write a book or popularize such a non-fussy, keep-it-simple approach to it all, but that’s my take.

More dangerous food from this newfangled, faddish diet:

photo

Don’t forget that grass-fed meat and organic vegetables could destroy your health. Just ask the “experts” at US News!

Not a very attractive description, is it?

This, from a recent article about changes in average human height and brain size that came along with the advent of agriculture.

Abstract

The population explosion that followed the Neolithic revolution was initially explained by improved health experiences for agriculturalists. However, empirical studies of societies shifting subsistence from foraging to primary food production have found evidence for deteriorating health from an increase in infectious and dental disease and a rise in nutritional deficiencies. In Paleopathology at the Origins of Agriculture (Cohen and Armelagos, 1984), this trend towards declining health was observed for 19 of 21 societies undergoing the agricultural transformation. The counterintuitive increase in nutritional diseases resulted from seasonal hunger, reliance on single crops deficient in essential nutrients, crop blights, social inequalities, and trade. In this study, we examined the evidence of stature reduction in studies since 1984 to evaluate if the trend towards decreased health after agricultural transitions remains. The trend towards a decrease in adult height and a general reduction of overall health during times of subsistence change remains valid, with the majority of studies finding stature to decline as the reliance on agriculture increased. The impact of agriculture, accompanied by increasing population density and a rise in infectious disease, was observed to decrease stature in populations from across the entire globe and regardless of the temporal period during which agriculture was adopted, including Europe, Africa, the Middle East, Asia, South America, and North America.

Stature and robusticity during the agricultural transition: Evidence from the bioarchaeological record, Amanda Mummert, Emily Esche, Joshua Robinson, George J. Armelagos, Economics and Human Biology 9 (2011) 284–301.

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