Methionine restriction for life extension
Taka
responsible for the CR lifespan extending effects:
The following article suggests that soy protein is very low in
methionine:
QUOTE: When breaking down the specific amino acids, soy is rich in
branched chain amino acids, lysine and arginine while being low in
methionine and cysteine. To this end, soy protein is still "complete"
in terms of the full amino acid profile. However, due to the lower
methionine and cysteine content, it's marginal in this regard. Indeed,
some experts consider soy a touch inferior to animal-based proteins.
UNQUOTE.
SOURCE: http://www.precisionnutrition.com/members/showthread.php?t=10896
I think that another protein low in methionine is in gelatin. Perhaps
restricting meat and dairy and supplying dietary protein from soy and
gelatin could bring the same effects as the starving CR regimes.
Taka
ironjustice
Or is it the .. iron.
Eur J Clin Nutr. 2007 Feb 14; [Epub ahead of print]Iron-dependent
formation of homocysteine from methionine and other thioethers.
Baggott JE, Tamura T.
1Department of Nutrition Sciences, University of Alabama at
Birmingham, Birmingham, AL, USA.
Objective:We tested whether homocysteine is formed from methionine
and
other thioethers in vitro and in vivo, because methionine can be
chemically demethylated to homocysteine.Design:In in vitro studies,
chemical conversions of thioethers (methionine, S-
adenosylhomocysteine
and cystathionine) into homocysteine were measured under various
aerobic conditions. In humans, oral methionine (0.17 mmol/kg body
weight) loading tests with and without an oral iron dose (ferrous
sulfate, 13 mumol/kg) were performed.Setting:A university setting in
Birmingham, AL, USA.Subjects:A total of five healthy adult subjects
volunteered.Results:The in vitro incubation of methionine, S-
adenosylhomocysteine or cystathionine with chelated iron resulted in
the formation of homocysteine. These conversions were iron- and pH-
dependent (pH optima between 5.0 and 6.0) and it was also chelator-
dependent. In humans, oral methionine loading tests resulted in a 45%
increase in the area-under-the-curve for plasma total homocysteine
concentrations, when iron was given together with
methionine.Conclusion:Our data suggest that iron-dependent chemical
formation of homocysteine can occur in vivo, and contribute to the
plasma total homocysteine pool, since this formation can occur
ceaselessly. We hypothesize that plasma total homocysteine
concentrations reflect, in part, non-protein-bound iron in the
body.European Journal of Clinical Nutrition advance online
publication, 14 February 2007; doi:10.1038/sj.ejcn.1602665.
PMID: 17299471 [PubMed - as supplied by publisher
Who loves ya.
Tom
Jesus Was A Vegetarian!
http://jesuswasavegetarian.7h.com
Man Is A Herbivore!
http://tinyurl.com/a3cc3
DEAD PEOPLE WALKING
http://tinyurl.com/zk9fk
Lou Pagnucco
There are several special diets commercially available for people
suffering from hypermethioninemia (inability to properly metabolize
methionine.)
You can find them by doing an advanced Google search with
the terms "Hypermethioninemia methionine-free diet".
I am sure that formulating a proper diet would require
medical supervision/monitoring. Otherwise, it could be
dangerous. Perhaps, an every-other-day regimen would be
safe.
Until the issue of the safety of soy is settled, I would not
consider it. See "Too much tofu induces 'brain aging,'
study shows" at URL:
http://starbulletin.com/1999/11/19/news/story4.html
Lou Pagnucco
Marshall Price
I take it "CR" stands for "caloric restriction"?
It's not true that soy protein is very low in methionine. In general,
"legumes are long in leucine and lycine," while seeds (grains and nuts)
are better sources of tryptophan and methionine. But soybeans actually
have more methionine than other legumes.
However, if you really want loads of methionine, you should consider
eggs. (If you want to avoid it, that should be easy.)
--
Marshall Price of Miami
Known to Yahoo as d021317c