Re: The Latest on Methionine

[Guest guest]

This sounds a little like having you cake and eating (most of it)...too.Is anyone doing proper MetR tests to see if it delivers life extension benefits like CR? A useful experiment to partner with that is CR without MetR. If the oxidative stress is predictive of LE benefits CR without MetR might be counter productive, so if anything we need to consider looking at how much we consume.I am always nervous about "less is always better" advice, but "too much is bad" is quite consistent with other findings.Perhaps we need to be sure that or moderation extend to moderating Methionine intake too. JROn Jun 28, 2008, at 8:08 PM, Rodney wrote:Hi folks:This dated June 2008:"........................    This suggests that the lowered intake of methionine is responsible for the decrease in oxidative stress observed in DR."Biogerontology. 2008 Jun;9(3):183-96."Forty percent and eighty percent methionine restriction decrease mitochondrial ROS generation and oxidative stress in rat liver."Caro P, Gómez J, López- M, Sánchez I, Naudí A, Jove M,Pamplona R, Barja G.Departamento de Fisiología Animal-II, Facultad de Ciencias Biológicas, Complutense University, c/ Novais-2, Madrid 28040, Spain."Dietary restriction (DR) lowers mitochondrial reactive oxygen species (ROS) generation and oxidative damage and increases maximum longevity in rodents. Protein restriction (PR) or methionine restriction (MetR), but not lipid or carbohydrate restriction, also cause those kinds of changes. However, previous experiments of MetR were performed only at 80% MetR, and substituting dietary methionine with glutamate in the diet. In order to clarify if MetR can be responsible for the lowered ROS production and oxidative stress induced by standard (40%) DR, Wistar rats were subjected to 40% or 80% MetR without changing other dietary components. It was found that both 40% and 80% MetR decrease mitochondrial ROS generation and percent free radical leak in rat liver mitochondria, similarly to what has been previously observed in 40% PR and 40% DR. The concentration of complexes I and III, apoptosis inducing factor, oxidative damage to mitochondrial DNA, five different markers of protein oxidation, glycoxidation or lipoxidation and fatty acid unsaturation were also lowered. The results show that 40% isocaloric MetR is enough to decrease ROS production and oxidative stress in rat liver. This suggests that the lowered intake of methionine is responsible for the decrease in oxidative stress observed in DR."PMID: 18283555Rodney.

[Guest guest]

JR,

We have discussed this topic before. These are the percentages of

methionine in various foods:

egg white 3.6

tuna 3.0

chicken 2.8

casein 2.7

beef 2.6

whey 1.9

yeast 1.5

soy 1.3

You can easily achieve over 25% reduction of methionine *without*

cutting any calories by just replacing eggs, fish, chicken, cheese and

beef with whey, yeast and soy.

Tony

Amino acid profiles of food proteins:

http://www.scientificpsychic.com/fitness/aminoacids1.html

>

> >

> > Hi folks:

> >

> > This dated June 2008:

> >

> > " ........................ This suggests that the lowered intake

> > of methionine is responsible for the decrease in oxidative stress

> > observed in DR. "

> >

> > Biogerontology. 2008 Jun;9(3):183-96.

> >

> > " Forty percent and eighty percent methionine restriction decrease

> > mitochondrial ROS generation and oxidative stress in rat liver. "

> >

> > Caro P, Gómez J, López- M, Sánchez I, Naudí A, Jove

> > M,Pamplona R, Barja G.

> >

> > Departamento de Fisiología Animal-II, Facultad de Ciencias

> > Biológicas, Complutense University, c/ Novais-2, Madrid

> > 28040, Spain.

> >

> > " Dietary restriction (DR) lowers mitochondrial reactive oxygen

> > species (ROS) generation and oxidative damage and increases maximum

> > longevity in rodents. Protein restriction (PR) or methionine

> > restriction (MetR), but not lipid or carbohydrate restriction, also

> > cause those kinds of changes. However, previous experiments of MetR

> > were performed only at 80% MetR, and substituting dietary

> > methionine with glutamate in the diet. In order to clarify if MetR

> > can be responsible for the lowered ROS production and oxidative

> > stress induced by standard (40%) DR, Wistar rats were subjected to

> > 40% or 80% MetR without changing other dietary components. It was

> > found that both 40% and 80% MetR decrease mitochondrial ROS

> > generation and percent free radical leak in rat liver mitochondria,

> > similarly to what has been previously observed in 40% PR and 40%

> > DR. The concentration of complexes I and III, apoptosis inducing

> > factor, oxidative damage to mitochondrial DNA, five different

> > markers of protein oxidation, glycoxidation or lipoxidation and

> > fatty acid unsaturation were also lowered. The results show that

> > 40% isocaloric MetR is enough to decrease ROS production and

> > oxidative stress in rat liver. This suggests that the lowered

> > intake of methionine is responsible for the decrease in oxidative

> > stress observed in DR. "

> >

> > PMID: 18283555

> >

> > Rodney.

> >

> >

> >

>

[Guest guest]

Hi folks:

Yes, we have! There are 246 posts in the archives that contain the

word " methionine " . And some of them are very long posts!

Rodney.

>

> JR,

>

> We have discussed this topic before.

[Guest guest]

I guess I need to search for studies that would be convincing to me. Sorry to bother.JROn Jun 30, 2008, at 5:40 AM, Rodney wrote:Hi folks:Yes, we have! There are 246 posts in the archives that contain the word "methionine". And some of them are very long posts!Rodney.>> JR,> > We have discussed this topic before.

[Guest guest]

Hi folks:

Having now seen the full text of this one (thank you to our usual source!) I should perhaps add the following:

It is quite a technical paper, much of which is above my head. They seem to imply in the text that 80% MET restriction is no better than 40%. But most of the diagrams in the paper do seem to show better results for 80% restriction. What is clear though is that the lion's share of the benefit is obtained with 40% restriction, and diminishing returns are evident between 40% and 80%.

Keeping one's intake of MET to around one gram a day would seem to constitute considerably more than 40% restriction, and is perhaps around the RDA for it, all in very round numbers. So there is nothing to be gained, it seems to me, from going below one gram a day.

FWIW here is a list of symptoms of MET deficiency:

Fatty liver

Slow growth

Weakness

Edema

Skin lesions

In extreme cases, dementia

Rodney.

>> > Hi folks:> > This dated June 2008:> > "........................ This suggests that the lowered intake of> methionine is responsible for the decrease in oxidative stress observed> in DR."> > Biogerontology. 2008 Jun;9(3):183-96.> > "Forty percent and eighty percent methionine restriction decrease> mitochondrial ROS generation and oxidative stress in rat liver."

[Guest guest]

Hey..I have slow growth but I attributed that to being 59 yo.--------weakness,, check.. I get spanked by kids playing basketball all the time (like tonight).---------Edema.. thought that was from my varicose veins.----------Skin lesions.. bug bites?------------Dementia... that settles it, I need to increase my Methionine intake  :-)JRPS: the above is my weak attempt at humor but I am apprehensive of cutting back on my salmon and broccoli.. eggs I can live without. On Jul 3, 2008, at 9:26 PM, Rodney wrote:Hi folks:Having now seen the full text of this one (thank you to our usual source!) I should perhaps add the following:It is quite a technical paper, much of which is above my head.  They seem to imply in the text that 80% MET restriction is no better than 40%.  But most of the diagrams in the paper do seem to show better results for 80% restriction.  What is clear though is that the lion's share of the benefit is obtained with 40% restriction, and diminishing returns are evident between 40% and 80%.Keeping one's intake of MET to around one gram a day would seem to constitute considerably more than 40% restriction, and is perhaps around the RDA for it, all in very round numbers.  So there is nothing to be gained, it seems to me, from going below one gram a day.FWIW here is a list of symptoms of MET deficiency:Fatty liverSlow growthWeaknessEdemaSkin lesionsIn extreme cases, dementiaRodney.>> > Hi folks:> > This dated June 2008:> > "........................ This suggests that the lowered intake of> methionine is responsible for the decrease in oxidative stress observed> in DR."> > Biogerontology. 2008 Jun;9(3):183-96.> > "Forty percent and eighty percent methionine restriction decrease> mitochondrial ROS generation and oxidative stress in rat liver."

[Guest guest]

40 % of what?

I don't think I want to determine my best Meth level by waiting for a

symptom.

Regards

[ ] Re: The Latest on Methionine

Hi folks:

Having now seen the full text of this one (thank you to our usual source!) I

should perhaps add the following:

It is quite a technical paper, much of which is above my head. They seem to

imply in the text that 80% MET restriction is no better than 40%. But most

of the diagrams in the paper do seem to show better results for 80%

restriction. What is clear though is that the lion's share of the benefit

is obtained with 40% restriction, and diminishing returns are evident

between 40% and 80%.

Keeping one's intake of MET to around one gram a day would seem to

constitute considerably more than 40% restriction, and is perhaps around the

RDA for it, all in very round numbers. So there is nothing to be gained, it

seems to me, from going below one gram a day.

FWIW here is a list of symptoms of MET deficiency:

Fatty liver

Slow growth

Weakness

Edema

Skin lesions

In extreme cases, dementia

Rodney.

[Guest guest]

Hi JW:

Nor me.

One gram seems to me to be about the RDA. Compared with north american meat and egg eaters one gram is greater restriction than 40%.

I provided the deficiency symptoms simply in an attempt to be as thorough as possible about my coverage of the issue. I did not advocate reducing MET intake until symptoms emerge!

If anyone believes one gram of MET daily is dangerously low, please post. Fruitarians must be way below one gram a day. Do we know of evidence that fruitarians suffer MET deficiency?

Rodney.

>> 40 % of what?> I don't think I want to determine my best Meth level by waiting for a> symptom.> > Regards> > [ ] Re: The Latest on Methionine> > > Hi folks:> Having now seen the full text of this one (thank you to our usual source!) I> should perhaps add the following:> It is quite a technical paper, much of which is above my head. They seem to> imply in the text that 80% MET restriction is no better than 40%. But most> of the diagrams in the paper do seem to show better results for 80%> restriction. What is clear though is that the lion's share of the benefit> is obtained with 40% restriction, and diminishing returns are evident> between 40% and 80%.> Keeping one's intake of MET to around one gram a day would seem to> constitute considerably more than 40% restriction, and is perhaps around the> RDA for it, all in very round numbers. So there is nothing to be gained, it> seems to me, from going below one gram a day.> FWIW here is a list of symptoms of MET deficiency:> Fatty liver> Slow growth> Weakness> Edema> Skin lesions> In extreme cases, dementia> > Rodney.>