Wednesday, November 21, 2012

Paleolithic Diet

First, let’s annoy the Creationists. Human beings evolved over time and we have been in our current form for about 200,000 years. We began in the Rift Valley in Kenya, spread north into Europe and east into Asia, then through to Australia (about 40,000 years ago) and north America (about 12,000 years ago). For most of that time we gathered and hunted for food. About 10,000 years ago we began to settle down and try agriculture as a means of growing our own food.

Let’s not get caught up in the actual dates, and focus on simple concepts. That is, trace your ancestors back far enough and they would be African. For most of human history we ate mainly animal foods, root vegetables, seeds, nuts, berries, fruits and eggs. Only fairly recently have we consumed dairy food, grains, alcohol, coffee and legumes.

The Pro side 
The argument for the Paleo Diet is that our digestive system has not evolved to handle the more recent foods we have added to the diet, such as grains and dairy. That is, we should be eating foods that were around through most of our evolution. As the diet comprises of minimally processed food and has a high protein content, it is quite filling, therefore it is unlikely that you will over-consume and start packing on the kilos/pounds.

A wide variety of nutrients are present if you include the full range of foods and, equally important, it is low in the components that we know can cause harm, such as excess salt, alcohol and saturated fat. All biscuits, cakes, pastries, confectionery, french fries and Krispy Kremes have gone, so the nutrient density will improve..

The Glycemic Index of the diet is low, probably a bit lower than regular healthy eating. When people move from standard fare to a Paleo diet their insulin sensitivity improves, blood pressure drops and body weight improves. To be frank, you could scoop up 100 people in any shopping mall, get them to cut out all treats, alcohol and takeaways and they too would all lose weight and feel better.

The Con side
There is accumulating evidence that the domestication of cattle, camels and goats provided a survival advantage when we started consuming their milk and, subsequently, yogurt and cheese. Domesticated animals became a guaranteed source of nutrient-rich food, with the earliest evidence being 7000 years ago in sub-Saharan Africa.

There is evidence that peoples in Europe were consuming grains 30,000 years ago, although it probably was gathered rather than cultivated.

With an emphasis on meat and seafood, the diet may be a bit more pricey than plain healthy eating, although you will save money once that nice bottle of red, your favourite chocolate and the gourmet ice cream has been deleted. It will be difficult to follow the diet to the letter because all meat was wild, so unless you shoot your own kangaroo, elk, moose, rabbit then you will be dining on domesticated animal flesh.

As far as we can tell Paleolithic man had an average lifespan of 35 years, with only 10-20% clocking up six decades. That doesn’t stack up well against the 80+ years we expect from non-smokers who eat their vegetables, walk the dog, give to charity, catch up with friends and laugh when they confuse the travel toothpaste tube for the tinea cream (which, believe me, doesn’t have a minty flavour).

Want to know more?
Should you follow a Paleo Diet? First note, that it will be tricky because you will be preparing virtually all your own meals, unless you are happy to relax the rules once a week or so. You can also do some reading of your own to determine your viewpoint. A free publishedreview article for those with a science background is a good place to start. It seems that humans turning to meat had a significant role in our evolution. If you prefer a more gentle read, then get hold of Loren Cordain’s book. He is a researcher from Colorado State University with a special interest in the Paleo Diet.

What does it all mean?
The argument for the Paleo Diet can be quite compelling, however we don’t know of a long-lived group of humans that have existed solely on the Paleo Diet. That’s not to say they wouldn’t live a long life. Naturally it won’t suit vegetarians, Meatless Mondayers, Mediterranean and Asian cultures with a lower reliance on animal flesh.

Of course, there is no single Paleolithic Diet. If we plonked you in the Tardis and set the dial for 10,000 years ago, your diet in north America, central Australia, France, and Viet Nam would all be different.

Anyway, it’s not for me. I enjoy a plant-based diet, which includes the tea leaf, the grape in the form of wine, and a little animal food because life is so much less without camembert. You, on the other hand, are your own boss.