The reason eggs are not supposed to supply too much cholesterol and create too much homocysteine, (and therefore not contribute to arterial plaque) is that they contain choline, lipase and B12 (a vitamin which is not destroyed by heat.) The plentiful amino acids in balance, within the egg, may have a hand in that process of methylation (one could say de-toxification) of the proteins as well.
stanford.edu
"All of this might sound very complicated, so let's review what we just learned. Folic acid helps to keep homocysteine levels low by aiding one of the two processing pathways. High homocysteine levels are associated with many health problems and may contribute to the progression of HD; consequently, it is important to keep homocystein levels low. In the first processing pathway, homocysteine becomes cysteine, which can become glutathione. The first pathway is important to people with HD because glutathione can help protect against oxidative damage. So, breaking down harmful homocysteine into helpful glutathione is a positive effect of the first pathway. In the second processing pathway, homocysteine becomes methionine, whose creation depends on an enzyme that needs folic acid. By having enough folic acid in the body, we can ensure that homocysteine levels will be kept low, so that the homocysteine does not have significant damaging effects.
Why is the re-methylation of homocysteine important?
The second pathway of homocysteine processing, the one influenced by folic acid, is called re-methylation. It is important for two reasons. The first reason is that it helps to lower total homocysteine levels. The second, perhaps more significant reason it is important is that the molecule formed by re-methylation is used to form another molecule called S-Adenosylmethionine (SAM). SAM is used to methylate (to methylate is to add a group of atoms called a methyl group) DNA, RNA, proteins, and other important molecules.
What does methylation do? Methylation of DNA is a major biological control of gene expression. While it is usually associated with gene silencing, methylation can also activate genes in some instances. In other words, methylation systems are absolutely essential for proper cell function because they are such important controls over how genes are used by cells. Also, methylation of proteins can change how the protein functions. (For more information on methylation, click here.) The re-methylation pathway of homocysteine processing is therefore also necessary because it results in products needed for regulation of gene expression and normal cell function.
To summarize, homocysteine metabolism is important for two general reasons:
1. It reduces the total amount of homocysteine available to cause problems like oxidative stress, inflammation, and increased sensitivity to excitotoxicity.
2. It results in products that cells need to control gene expression and function properly
Folic Acid and HD
By lowering total homocysteine levels, folic acid may also lower the oxidative damage that some forms of homocysteine can cause to nerve cells. Lowering homocysteine levels could also lower the risk for homocysteine-mediated apoptosis (programmed cell death) and for excitotoxic cell death (because homocysteine is a partial activator of NMDA receptors). In addition to these possible direct benefits, lowering homocysteine levels also has cardiovascular benefits that result from fewer negative protein interactions, less oxidative damage, and reduced inflammation throughout the body. Increasing cardiovascular health also increases blood flow to the brain, where it is important for the maintenance of nerve cell health and function. The cardiovascular benefits of lower homocysteine levels could be especially important for people with HD; cardiovascular disease, along with pneumonia, is a leading cause of death among people with HD. Although there is still a lack of definitive knowledge regarding the complete interactions of folic acid, homocysteine, and neuroprotection in the brain, research is ongoing. "
Amino balance of yolk and whites
fao.org
nutritive (vitamin, mineral) content of egg
nutritionandeggs.co.uk
The elements that appear in the table above that are particularly "heart or vascularly healthy" in an egg, are monounsaturated fat, magnesium, biotin, selenium, copper-zinc, potassium and the vitamin groups, particularly the folate-B vitamin group. Here the lecithin, lipase and choline are not listed, but it is known that these factors are not inconsiderable with respect to cholesterol de-peroxidation, an all important factor long known to be a key to controlling arterial plaque formation. |
