I found an interesting discussion online about being in ketosis and how the body uses other acids that can be used in place of vitamin C. The "meat" of the conversation went a little something like this:
http://vitamincfoundation.org/forum/viewtopic.php?f=3&t=6086&p=19051
Quote:
Furthermore, a diet high in red meat actually decreases vitamin C requirement. Vitamin C is needed to hydroxylate the amino acids lysine and proline into hydroxylysine and hydroxyproline- connective tissue. That is why scurvy is characterized by a degeneration of connective tissue. However, unknown to most, red meat already contains hydroxylysine and hydroxyproline which is absorbed into the bloodstream when eaten...
[...]
Thus, less vitamin C is needed to hydroxylate proline and lysine, because they are already present in the blood in a hydroxylated state.
Vitamin C is also used to produce carnitine, if dietary supply is insufficient. But red meat, the staple of any carnivorist's diet, contains plenty of this nutrient, thus sparing vitamin C from usage in this pathway as well.
[...]
However, one might ask about the role vitamin C plays in antioxidant function. A purely carnivorous diet will prevent scurvy, but will it replace the other biochemical functions of vitamin C? While those who regularly consume liver and brains do not need to concern themselves too much here, what about those carnivores who consume primarily muscle meat and eggs? They may be free from scurvy, but are there some other unseen health effects, such as excessive free radical damage from lack of vitamin C?
First of all, a ketogenic metabolism produces less free radicals than a carbohydrate-burning metabolism. Secondly, there are numerous other substances, endogenous and dietary, that act as antioxidants present on a purely carnivorous diet. But is this insufficient?
The answer no. And the answer may lie in uric acid.
Uric acid is derived from purines in meat. They are the final metabolic end-product of purine compounds. This is because the genes encoding for the production of the enzyme uricase, needed to break down uric acid, have been absent from primate DNA for millions of years.
The thing that makes ascorbate as a molecule useful is the property of being a strong electron donor. Uric acid is also a strong electron donor (4). In fact, it may even be a better electron donor than vitamin C (5). Because of this, uric acid is a powerful antioxidant, similar to vitamin C. Thus, it follows that the loss of the enzyme uricase and the consequent increase in blood levels of uric acid in primates has probably provided a substitute for ascorbate in certain biochemical functions, including antioxidant activity.
Since meat is rich in purines, uric acid is inevitably abundant in the bloodstream of someone who consumes a large amount of muscle meat and organ products. Conclusion: Even if a human carnivore does not consume vitamin C-containing animal products, a purely carnivorous diet is still sufficient to produce the biochemical functions that vitamin C is normally responsible for.
No comments:
Post a Comment