by Gelert » Wed Dec 08, 2010 11:11 am
[quote]Not convinced by this bit, can you elaborate please. I'm getting the contention that protein just doesn't make it if you take it in raw. I can't believe this because raw fooders would be somewhat dead. And there's some raw fooders who have a fair bit of muscle.
OK, fundamental mistake here. Allow me to explain in 13 different ways so we're absolutely clear!
Protein structure biochemistry 101: A protein assumes a 3D shape on the basis of the sequence of the amino acid chain it consists of. Each amino acid has a slightly different chemical behaviour, affinity or hatred of water molecules, for other amino acids, and ability to make bonds, and positive or negative charges which results in this mahoosive 3D structure. Like so:
A green fluorescent protein from jelly fish. The barrel like structure contains a chemical group somewhere inside which makes it fluoresce. Tweaking that barrel shape alters the shade of fluorescence.
Haemoglobin. The chains bind an iron-containing group which transports oxygen.
Etc. The bottom line, no-shitter is that a protein's shape determines its function. Some proteins are structural ones, such as the keratin in your hair. Others are catalytic, such as enzymes. Enzymes must have a particular structure to bind to their substrates to catalyze their reactions which converts the substrates into their products.
Now, as any GCSE Science student knows, proteins are not "alive", so we can't talk of them as living things, or of their death. Instead we refer to proteins folded into the right structure (and thus happy, functioning ones) as native, and those that are misfolded, in a tangled bloody heap on the floor as denatured. Now many things can cause a protein to become denatured. One example is temperature. To use a non-vegan but very visible example, this is what happens when people fry eggs and the albumen turns white (roughly around 65 *C). Another is the levels of acidity or alkalinity. If the environment is too acidic or too alkaline, the positive or negative charges on various bits of the protein are swamped out and the protein loses its structure and hence function.
One of the key contentions of raw foodism is that plants contain enzymes which would aid the digestion of plant food, and that cooking destroys these enzymes.
This is undoubtedly true, in particular for a few foods such as pineapples (which contain papain) or for food that is actively rotten (i.e. these enzymes are under control, otherwise the plant would self-destruct spontaneously).
Now where it all falls apart is the follow-on from this, that eating the food raw would enable humans to take advantage of these plant enzymes to aid our digestion in our own stomachs.
Recall that it's not just temperature that can fuck proteins. Extremes of pH can too. Now the problem is this: Our stomachs contain oxyntic cells which pump out hydrochloric acid to keep the stomach at roughly pH 1. Most plants have much more moderate pH levels, and thus their enzymes are adapted to work in those circumstances. So when they're put in the pH 1 stomach environment they get fucked.
And that's just one part of the process - the impact of an acidic environment on a plant protein mixture - and is what putting soya milk into vinegar and mixing it demonstrates
Now they also get fucked because we produce our own digestive enzymes (again, as GCSE science students will recall). For example pepsin, which digests other proteins - such as plant enzymes.
All of this is extraordinarily unfriendly to the proteins in our diet.
Why? It is firstly for the good of our health, so pathogens have a hard time of it in our gut.
But more importantly: to make proteins, we break down our food proteins into their amino acid components, and then export them to where they need to be used, to make new proteins.
Why?
1. Because human proteins are different from food proteins. Human protein X is evolved to work in human conditions, Plant protein X is evolved for sitting out in a field somewhere.
2. If we suddenly need protein X, and we're eating protein Y, we have to tear it apart to make X from Y. Most fundamentally, to make muscles, we need muscle proteins. Plants don't really have muscles. Likewise brains, antibodies etc.
3. Because proteins are big, fat massive things that can't really pass through cell membranes. Amino acids are tiny little things that can be let through turnstiles in the cell membrane.
3. Because the food proteins may be harmful to us in their native state.
4. For example, they may have been damaged during the plant's life, or the process of its harvest, etc.
Etc. Similar processes go on with everything else in our food, for example DNA, RNA, lipids and carbs. They all get broken down and recycled.
So yes, you can build muscle as a raw fooder, but only because
your own digestive enzymes break down the plant proteins into amino acids that the amazing biochemical recycling plant of you can rebuild them into new proteins, as and when they are required. A fundamental step in this is beasting them with pH and protein-digesting enzymes such as pepsin in your stomach. To paraphrase the title of a talk I once heard by a Nobel laureate on the subject -proteins - they "die" so that we can "live".
QED?
