Health Benefits of Eating Vegan

[nautica]

Man, all of this talk about not eating meat is making me hungry. Where's the beef? Rare, please.

Nautica

 

[Adrian]

lol nautica... Nothing beats a pound of rare, sizzlin' beef...

 

[wasteofo2]

Is there any difference between the uses of animal and plant proteins, other than you need more of some than you do of others?

 

[Adrian]

No. All dietary protein is broken down into amino acids.
Their primary use is as a building material for your own polypeptides, e.g. structural polypeptides (muscle tissue, hair, ...), enzymes, hormones, ...
When the body is starving AND/OR the amino acid pool in the bloodstream is full, amino acids can be converted to glucose through gluconeogenesis in the liver for energy.

EDIT Some of the 20 amino acids can be derived from others, but 8 of them (tryptophan, lysine, methionine, phenylalanin, threonine, valine, leucine & isoleucine) are essential: they cannot be produced by the human body and need to ingested with food. Human polypeptides and proteins typically contain them in a certain ratio. The least available essential amino acid in relation to the ratio is a limiting factor for the production of your protein.

Animals have amino acid ratios similar to ours; the amino acid breakdown of their protein pretty much meets our demands. Plants' aa makeup differs more, and some plants lack one or two aa's almost completely. That's why vegeatarians need to balance their diet carefully and should eat / drink plenty of dairy and eggs.

 

[wasteofo2]

What are the specific amino acids which plants lack/are deficient in responsible for and what would be the consequences of not getting them? Are these amino acids found in seafood as well as things like poultry/beef/pork?

 

[Adrian]

Animal protein (which includes all kinds of meat, seafood, dairy, and eggs) is also called "complete" protein because it contains sufficient amounts of all AAs we need.

Different plants may lack different AAs. Go to http://www.quackwatch.org/03HealthPromotion/vegetarian.html and scroll down to Table 4. Protein Complementation for a few examples.

Vegans can complement the protein in the differents plant they eat though. If plant A lacks amino acid X but has all others, and plant B lacks AA Y but is otherwise complete, you can combine them to get all AAs you need. But in the combined protein mix you'd still have only 50% of the AAs X and Y in this case, so that amount will be the limiting factor for your own protein synthesis. It's still much better than nothing, of course.

It's highly unlikely that anyone will miss out on one particular AA completely, unless his metabolism is affected by some kind of genetic disorder. But not getting enough of any of the 8 essential AAs OR not getting enough protein in general will lead to loss of muscle mass and strength, fatigue and decreased energy, stretch marks, can mess up the endocrinal system, will stun growth and mental development during childhood and adolescence, will stun the baby's development during pregnancy, anemia --- basically it will mess up everything in your body that requires proteins as enzymes or as building material. Extreme deprivation od protein over prolonged periods of time will result in death, but before that happens, the body will "cannibalize" its own tissue, such as muscles. That's how people can go without any food for over 3 weeks (e.g. soldiers behind enemy lines).

 

[Galatea]

Originally posted by Adrian
The figure for physically inactive people is closer to 80g a day, depending on size (make it roughly half a gram per pound of bodyweight).

From http://www.afpafitness.com/articles/ProteinRequie.htm

"The WHO protein figures translate into 56g of protein a day for a (75kg) man, and 48g for a (64kg) woman. The recommendations of the UK Department of Health and Social Security (DHSS) are slightly higher, at about 68g a day for sedentary or moderately active men, and 54g a day for women (2). Both these official recommendations suggest that eating 10% of our daily energy as protein will provide an adequate amount."

Actually most Westerners do not get enough protein in their diets, although they could if they wanted to.

I find this hard to believe considering how much meat the average Westerner eats. Reference?

One more thing: Plant protein is lower-quality
Therefore, I personally believe eating vegan is not very smart from a nutritional point of view. You can debate about red meat as much as you want, but even vegetarians often say they can eat the way they do because of eggs and dairy. I don't see any rational reasons not to eat dairy (a cup of cottage cheese before bed will do wonders). It is very high-quality protein, too.

What vegetarians are these? I sure haven't met them. I know a few people whose nutrional requirements require them to consume animal products every now and then but I also know many vegans who do not need them as long as they supplement with B12 occasionally.

I, personally, am quite lactose intolerant. Dairy is out of the question for me despite my moral qualms with consuming it. I get plenty of protein from my (varied) day to day diet.