Tag Archives: Richard Wrangham

Segmented Sleep: Our Ancestral Pattern?

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Richard Wrangham estimates hominins tamed fire and started cooking with it 1.8 million years ago

I heard about segmented sleep a couple years ago. The idea is that you sleep for maybe three hours, then get up and putter around for two or three hours, then go back to sleep for another three or four hours.

The easy availability of light after sunset has changed our sleeping patterns only recently, on an evolutionary scale. Before we had electric lights, candles, oil and gas lamps, our only sources of artificial light after sundown were campfires and short-lived torches.

Karen Emslie has an article on segmented sleep at Aeon. A snippet:

Before electric lighting, night was associated with crime and fear – people stayed inside and went early to bed. The time of their first sleep varied with season and social class, but usually commenced a couple of hours after dusk and lasted for three or four hours until, in the middle of the night, people naturally woke up. Prior to electric lighting, wealthier households often had other forms of artificial light – for instance, gas lamps – and in turn went to bed later. Interestingly, Ekirch found less reference to segmented sleep in personal papers from such households.

For those who indulged, however, night-waking was used for activities such as reading, praying and writing, untangling dreams, talking to sleeping partners or making love. As Ekirch points out, after a hard day of labouring, people were often too tired for amorous activities at ‘first’ bedtime (which might strike a chord with many busy people today) but, when they woke in the night, our ancestors were refreshed and ready for action. After various nocturnal activities, people became drowsy again and slipped into their second sleep cycle (also for three or four hours) before rising to a new day. We too can imagine, for example, going to bed at 9pm on a winter night, waking at midnight, reading and chatting until around 2am, then sleeping again until 6am.

Think about this if you have insomnia that wakes you in the middle of the night and you can’t get back to sleep. It may not be a detrimental condition that requires medication or other intervention. Can you really win a fight with a million years of evolution?

RTWT.

Steve Parker, M.D.

Dr. Guyenet Makes a Case for Beans in the Paleo Diet

As an introduction, he writes…

The canonical Paleolithic diet approach excludes legumes because they were supposedly not part of our ancestral dietary pattern.  I’m going to argue here that there is good evidence of widespread legume consumption by hunter-gatherers and archaic humans, and that beans and lentils are therefore an “ancestral” food that falls within the Paleo diet rubric.  Many species of edible legumes are common around the globe, including in Africa, and the high calorie and protein content of legume seeds would have made them prime targets for exploitation by ancestral humans after the development of cooking.

Richard Wrangham thinks hominins started cooking with fire as long as 1.8 million years ago. There’s no expert consensus yet.

Read the rest.

What Exactly Is the Paleo Diet?

Pure paleo

Let’s be realistic: There’s no way to eat a Stone Age diet these days unless you live off the land, hunting, fishing, and gathering from what’s naturally available in the wild.  Few can do that, although it’s not impossible.  I’m going to specify my version of the paleo diet because I’m starting a paleo diet trial soon—a first for me.

How long has man had fire?  Biological anthropologist Richard Wrangham estimates hominins tamed fire and started cooking with it 1.8 million years ago.  So I’m cooking my paleo foods if I wish.

As with my beloved Mediterranean diet, definitions of the paleo diet vary.  The following guidelines are influenced by my review of blogs or websites by Loren Cordain, Julianne Taylor, Robb Wolf, and Kurt Harris.  The first three are closely affiliated with each other, so expect lots of overlap.  It’s simplest to define paleo by what’s not allowed.

What’s NOT Paleo?

Industrial vegetable oils (e.g., soybean, corn,safflower), legumes, dairy, refined sugars, grains, alcohol, and high salt consumption.

What Is Paleo? 

The focus is on minimally processed, in-season, locally available foods.  Many favor pastured, grass-fed beef, free-range chickens, “organic,” and the like.  I guess that’s fine if you can afford it; I choose to spend my money elsewhere.

Proteins

Meat, fish/seafood, eggs, poultry, and wild game.  Most paleo proponents favor lean meats over fatty ones; it’s debatable. Undoubtedly, our domesticated feedlot animals are fattier than wild game, generally.  Processed meats such as bacon would not be pure paleo, but many paleo advocates allow it.

Nuts and Seeds

Favor those with the best omega-6/omega-3 ratio (2 or 3:1), such as walnuts, almonds, macadamia, and cashews.  Modern humans eat way more omega-6 fatty acids compared to ancient hunter-gatherers.

Fruits and Vegetables

It’s probably best to favor those with lower glycemic index.  Examples are berries, melons, cauliflower, tomatoes, onions, and broccoli.  Most modern fruits and veggies  have been bred for large size and good looks.  Ancient fruits and veggies were smaller and had much more fiber per serving.

Tubers, Roots, Bulbs

These are OK per Cordain, and I agree.  Examples include potatoes, cassava, taro root, onions.  Some paleo proponents exclude potatoes.

Oils

Cordain favors oils such as canola, flax, olive. Others mention avocado oil.  Aim for a good omega-6/omega-3 ratio.  Lard is probably OK although obviously processed.

Herbs and Spices

Many of our favorites should be OK.  Wolf says balsamic vinegar is allowed, although processed, like all vinegars.  Vinegar is “natural,” as you might have noticed if you ever walked through an apple orchard with rotting fruit on the ground; you can smell the vinegar.

Condiments

Undecided.  Note that you can make mayonnaise from olive oil and egg yolk.

Miscellaneous

Olives?  They’re processed, but I’m inclined to keep them in the mix.  Coffee?  Not paleo, but I ain’t givin’ it up.  Consider limiting nuts to one ounce daily since most of them are high in omega-6 fatty acids.  Fresh foods are more purely paleo than canned or frozen, but I’ll not exclude canned and frozen.  Limit fruit?  Probably: in most environments, they’re available only seasonally.  Diet sodas?  Clearly not paleo, but I enjoy one now and then and don’t see any drawbacks to low consumption.

Steve Parker, M.D.

Update October 8, 2012

I learned today that my version of paleo, by coincidence, is similar to the Hartwigs’s Whole30 plan.  But they allow clarified butter or ghee, green beans, and snow peas.  I include potatoes, but Whole30 doesn’t.