Who am I?

Copenhagen, Denmark
I'm a 21 year old student of the Copenhagen Metropolitan University College's Global Bachelor in Nutrition and Health, Copenhagen, Denmark. The purpose of this blog is to record my experiences with different diet approaches and health techniques, which I try out for 30 days at a time, thus the name.

mandag den 19. april 2010

Paleo diet for athletes + Part 1 of arguments against the Paleo diet

So Wednesday I completed my original 30 day Paleo challenge. So far I have found the results to be hard to evaluate. So I'm giving it one more chance, to succeed or fail, 30 days more.

However this time I have changed the regimen a slight bit (explanation will follow). Last Sunday last i participated in a half marathon race, I finished, but at about 20 km through, I suddenly had no more energy, and just couldn't seem to move my legs as fast as I wanted (and had). My time was just under 1 hour and 48 minutes, which I think is acceptable, but not what I wanted. So Thursday I started the second 30 days, and this time I am following the Paleo diet for athletes. This is of course mainly the same diet, however with some modifications before, during and after exercise/race, in order to provide enough, and easily absorb able enough, nutrition for the special circumstances endurance elites have. The main differences are that fruit juice, potatoes, sweet potatoes and yams, as well as salt, glucose and non paleo protein powders are allowed in conjunction with exercise/races.

My result so far is positive. Yesterday (this Sunday) I ran another half marathon, this time having eaten potatoes and more fruit before, as well as having a mix of fruit and vegetable juice along with me. My this time i finished my 21,1 km in under 1 hour and 45 minutes, and where a week before I had been almost unable to move my legs after I was done, this time I ran 25 km :D

So hopefully this will keep working, and I will be able to run the Copenhagen Marathon in 34 days.

And now to first part of my promised post on arguments against the Paleo diet:

There are several arguments against 'the paleo diet' being the optimal diet for human beings. Some of them are directed at foundations of the theory of the paleo diet, while others are biochemical or statistical arguments that point in another direction, than the diet promoted by Loren Cordain.

I will try to make a (hopefully) easily understandble walkthrough of the ones I have come across, as well as possible counter arguments, and my own evaluation of their significance.

Saturated fat is not bad.

One of the first arguments against the eating regimen promoted by Loren Cordain, is an argument promoted by many other paleo/primal diet advocates as well as Dr. Mercola and the Western A. Price Foundation – In his book 'the Paleo diet' Loren Cordain adheres, at least in part, to the so called lipid hypothesis which claims that a high intake of dietary cholesterol and saturated fat increases the amounts of these nutrients in the blood and promotes athereosclerosis. Loren Cordain actually downtones the significance of cholesterol intake somewhat, but still puts a limit on egg (which is high in cholesterol) intake, at 6 a week. However he goes along with the idea that a high intake of saturated fats, cause, or at least promote, plague building up in the arteries.  

The counter argument is of course that this is not the case, and that saturated fats have lots of healthfull properties to them, in fact both cholesterol and saturated fats are both very important for different bodily functions. For instance it is described in the classsic 'Nutrition and Physical degeneration' by Western A. Price, how he found that idegenous people who had a high intake of fat soluble vitamins (which are often found in animal products with a high cholesterol and saturated fatty acid content) were much healthier than their counterparts, that had adopted a western diet.

It is also argued that the statistics that show a correlation between a high intake of saturated fatty acids and heart disease, do so, because they count the extremly unhealthy mostly artificial trans fatty acids together with saturated fatty acids.

Proponents of paleo/primal diets that are more heavily based on saturated fatty acids for calories also argue that our early ancestors had very high intake of these, from all the animal fat they consumed.

Loren Cordain's counter argument is that when you take into account the fatty acid composition of the entire animals, not just the fat situated around and inside the muscles (our ancestors ate almost the entire animal, not just the muscle meat), as well as their intake of nuts and seeds, the picture is one of an intake based more on mono and poly unsaturated fatty acids.

Furthermore he says that intake of saturated fatty acids increases LDL cholesterol, and LDL cholesterol is related to athereosclerosis. There are several counter arguments to this – First of all there is some confusion as to the exact realation between LDL cholesterol and athereosclerosis, however that is a discussion for another day. Secondly only some saturated fatty acids cause LDL levels to go up. And thirdly some saturated fatty acids cause HDL levels to go up, which is ascociated with protection from heart disease.

2. Grains and legumes are not (nescesarilly) bad

There are several sidses to this argument, the first being that grains and legumes have a lot of beneficial properties including water solluble fiber and long chain polysaccrides, thus giving a slow steady realease of energy, and at the same time nourishing the colon and preventing reuptake of cholesterol from bile in the small intestine.

The second part of the argument is that: yes they do contain antinutrients, things that are supposedly part of the plants immune system, but all plant foods do.

And thirdly the amount of these antinutrients can be severely disminished by sprouting and/or fermenting them, as well as heating them, something that 'traditional' cultures have long been doing. Asian cultures for instance fermented the soybeans they ate.

3. There is no good source of calcium in 'the paleo diet'.

This is set forth by people advocating the consumption of dairy products, such as the Western A. Price foundation. It is however, in my opinon, not a very good one, as it is easily refuted- Loren Cordain argues that because of the high intake of vegtables and fruits (which acording to him push the body in an alkaline direction), as well as an increased uptake of calcium caused by the high protein content of the diet, the need for calcium on this diet is less, than on a more acid producing diet, such as the standard american diet.

On top of that, there are several good sources of calcium in allowed in the paleo diet – most green leafy vegetables have a high calcium content, an most (not spinach for instance) also are more easily assimilated than calcium from dairy. Also sessame seeds have a high calcium content.

4. Our closest contemporary non-human relatives; the great apes (especially chimpanzees and bonobos) eat very small amounts of meat, therefore we should this way as well.

This argument asumes several things:

  • that because the great apes are so closely realted to us, the chimpanzees and bononbos share 98% of our genes, we have the same nutritional requirements as they do.

  • that great apes living in the wild are consuming their optimal diet, this part of the argument goes something like this: because the great apes don't have any culture (something that not everybody agrees upon) they don't have any rules or taboos about eating (which it is argued is the reason the human diet has gone astray), and thus eat whatever feels natural to them (again this builds upon the assumption that what feels best for them also is best).

    There are several counter arguments to this -

  • There are several key differences between humans and apes, for instance our digestive system is more like that of an omnivore (who eats more meat than apes) than that of the apes (frugivores – they live of a diet of fruit, green leaves, nuts, seeds and small amounts of meat), and thus we can handle less fiber, but more meat, than the great apes. On the other hand we have smaller canines than our close relatives do, just take a look at a gorillas teeth, and they actually seem better equiped to rip meat.

  • Brain started evovling after animal consumption arose -

    There is some evidence that early humans brain started to grow (beyond the size of for example the brain of a chimpanzee) at the same time that our intake of animal foods began to increase. This off course beggs the question of what came first, and wheter or not the two were related – the theory (of those that asume that the increased animal intake caused this brain growth) is that increased animal intake led to increased calorie consumption, which allowed the development of a bigger brain (brains use a lot of calories). Also nutrients found mostly in animals, such as EPA and DHA omege 3 oils, are essentiel for brain development, so an increased availability of these may have lead, at least in part, to bigger brains.

  • Another counter argument to this is that if we consumed so little meat (excluding the option of eggs or dairy as well) we would not get optimal amounts fo protein, especially not atheltes. This however is hard to belive, if you take a look at our hairy relatives – a large silverback gorilla is both way larger and stronger than any bodybuilding athlete, however they consume a diet largely made up of green leaves, fruit nuts, and seeds, in other words a diet low in animal 'products' and protein.

1 kommentar:

  1. When eating paleo you don’t need to consume as much calcium, as your body loses much less when following a paleo lifestyle. Listed here are the various ways calcium is lost: http://paleodiet.com/losspts.txt.