onsdag 3 april 2013

Debunking the paleo-diet. The paleolithic diet, the 'meat myth'. Humans have no known anatomical, physiological, or genetic adaptations to meat consumption.

My notes as I was listening to a lecture about the real paleolithic diet.
Myth 1
Humans have evolved to eat meat and paleo-people consumed a lot of meat.

Quite the opposite is true.
Humans have no known anatomical, physiological, or genetic adaptations to meat consumption.
We have many adaptations to plant consumption.
Vitamin C is found in plants. We can’t make it ourselves such as carnivores.

Or digestive tract is longer than carnivores, so that our food can stay in the body longer so we can digest plant matter. We need more surface area and we need more microbes.

We have genera... We have bit molars there to shred fibers, plant tissue. We don’t have carnassials, the specialized teeth that carnivores have to shred meat. We do actually have some genetic mutations in some populations that are adapted to animal consumption, to milk not to meat. These arose in certain agricultural communities, primarily in Europe and Africa.

I call this the Meat myth. The idea behind is that we always have eaten meat. Anything that a paleolithic person would have eaten would probably have been lean, very small. And they wouldn’t really have eaten that much meat. Of course there is also bone marrow, organs, these would have been very important. We see evidence of harvesting a bone marrow in F.. .. We see characteristics in cutting of the bones for marrow extraction. Now sure people did eat meat, in special in the Arctic area with a long period with no plants available, they would have eaten a lot of meat. People in more temperate regions and tropical regions would have have had a very large portion of a plant-based-diet.

Where does the meat myth come from.
One is the inherent bias in Archeology record. Bone preserves much better than delicate plant remains.
The second is from bone bio chemistry study performed.
It is complicated but I am gonna break it down. You are what you eat. It is Nitrogen-14 and Nitrogen-15. With each step you go up of the trophic hierarchy the amount of the heavy isotope increases. If you measure the amount of heavy isotope in the bone you can infer where  that individual was on a food chain. This is an example of a generalized isotopic model: [Picture in the video]
However, one of the problems is that not all eco-systems conform to this model. ..
In East-africa we see some very strange patterns, how can a herbivore and a human be above a lion. It turns out that the food that you eat is not the only contributor to this values. Also irridity can have an impact. What we likely see is differences in water-access.

Ancient maya.
We know they were heavily relied upon corn. The model is wrong also here. It may depend on how they fertilized their crops.

What we think is happening. In very cold climates animals eat unusual things. Mammals are eating bark. Gives them very strange values.
If you don’t have a good control on the paleolithic eco-systems, you can come to very erroneous conclusions.

We have stone-tool evidence, 20000 years before the invention of agriculture, to grind up seeds and grains. We can measure fossilized dental plack. We can recover micro-fossils of plants and other remaints. My team is working on extract DNA and...
With the limited research we have we can see abundant remainders of  plant-based evidence. We can find legumes, grains and barley [e.g. inside Neanderthali].

Myth 3: Paleo-diet (the fad diet) foods are what our paleolithic ancestors ate.
Example bananans are the ultimate farmers food. Every banana is a genetic clone from every other banana. A farmers food.
A wild banana is so full of seeds.
Salads- we have radically changed it. In the wild it contains an indigestible component. Also to make it taste betters.
Tomatoes - in the wild it is toxic.
Oil - It requires rudimentary presses to remove it....
The blueberry-New England, avocado Mexico...Would have never appeared on paleolithic plate.
Wild avocado-a couple of millimeters of fruit, also wild olives.
Chickens-lays eggs every day.... Wild hens, small eggs, do not lay all year around.
Broccoli did not exist in the paleolithic period. Wild kale, wild Brussels sprouts-all the same species. We selectively bred it in different ways.
Broccoli -the flour of the plants. It is flours. Buy some broccoli, but it in a vase, and it will bloom.
Carrots, wild carrots-bitter in flavor, tastes bad...
Almond, closely related to prum. Bred out the cyanide, so that we can eat the seed.
Like carrots and broccoli- essentialy human invention.

Real paleo-diet
Many different paleo-diet. People ate local foods. When we speak about paleolithic diets- they are in plural.

Plenty of food on seasonal basis.
Wild plants: Prickly pear fruit, agave, various nuts, beeds and squashes..
They also ate rabbits, and other small animals.

Very much different from the Arctic regions and subtropic regions. People moved from resource-patch to resource-patch.
Food packets were generally small--collect a lot of broccoli. Generally collect tough, woody and fibrous food. They ate marrow and organs of animals.
Plant-foods with pytho-chemicals.
3 billion people can not eat like forgers.
Can we take lessons from them that we still can apply today?

3 main lessons to learn
1. Diversity is the key.
We lack the ability to synthesize many nutrients. So diversity is important.
Today it is almost only 3 species in everything we eat: soy, wheat and corn

In large urban societies you can’t eat everything fresh. Seeds and nuts preserve very well... We can preserve food from salting, drying, vinegar..
It all works by inhibiting bacterial growth. Our intestinal s are full of good bacteria that promote your immune system. Food with preservatives - we don’t know how it effects us and good bacteria in our stomach.

Your food.., Even the part you can’t digest are very important.
All sorts of function. Feeds the good bacteria.
Low-fiber diets....cause obesity and diabetes.
Unfortunate -- we are losing the whole foods.. We don’t get the benefits of the fiber and the pectin in the fruit juice, for example.
We can eat so many calories.. It shortcuts our abilities to no if we are full or not.
If you drink a full soda.. How much sugar cane would you have to eat. How many feet of sugar do you have to consume to reach that level. 8,5 feet of sugar cane in one soda.
We can override the mechanism that we have evolved to signal fullness. Dietary diversity is the key. We need to eat fresh foods when possible. We need to eat whole foods.

We still have a lot to learn from our paleolithic and our neolithic ancestors.


2 kommentarer:

  1. That is why starting on an early healthy diet is important. You should be avoiding unhealthy foods or at least keep it under moderation because those are the main culprits why people get fat or even build conditions. It's an adjustment that we have to make in order to be healthier and live longer. It's necessary to eat better because what we eat pretty much determine how we live our lives in the long term.

    Paleo diet is a good example of a good healthy diet. It focuses on basic food groups that we need that aren't causing us to be unhealthy. It's an adjustment we have to make.


  2. The "paleo diet" isn't healthy:


    So it should be avoided.

    A cow, or a horse, or a dog, or a cat -- is there any difference? They are all sentient beings, they all have feelings, they all want to live and they all love their family!!!!!
    We all agree that it is morally wrong to cause unnecessary suffering and death to animals -- and condemn people who for example enjoy and promote killing innocent dogs just because they got tired of them. However, we must also acknowledge that all animal products-eating is unnecessary and is done merely for "taste" and "enjoyment". So if we want to be moral we must also act upon what we acknowledge -that causing unnecessary suffering and death to animals is unnecessary. We always need to take the victims point of view!!!