Methionine Restriction Extends Lifespan: Roles For SCFAs And FGF21, But Not Calorie Restriction

[Mike Lustgarten]

 

[drewab]

The effect of methionine restriction appears to be dramatic to say the least. It appears that one (or at least a mouse) has to be pretty low in methionine to qualify as LM - 0.17% seems very low! Is it correct to assume that 0.17% is the percent of total protein intake? I did some quick math on my methionine intake yesterday just out of curiosity and it was 1.0g out of 69.8g protein total or about 1.4%. I also eat 99.9% whole food plant based and practically speaking it seems to come out to a normal intake... or perhaps low compared to the rest of the Western world at least, but I do wonder the extent to which methionine can be restricted in humans.

 

[Mike Lustgarten]

That's a big point-we'd all have to be close to vegan to be around 0.15% methionine. But, is that the optimal level? I'd like to see a dose response for MR on lifespan-would 0.3% be better, the same, or worse for longevity? There's no data for that, yet

[Saul]

Hi Mike and ALL!

Michael Rae discussed this subject.  His conclusion was:  You can either do Calorie Restriction OR Methionine restriction, but not both.  His decision (with which I agree):  He practices CRON, with methionine MODERATION -- that is, eating foods that are not high in methionine.

For example, Michael used to eat egg whites -- but stopped, when he discovered that egg white is high in methionine.

(IMO, that's no surprise:  High methionine is good for embrios and babies -- which need to grow, not perform calorie restrriction. Whole grains are also high in methionine (in comparison with most other plant products) -- but still lower in methionine than animal protein (pig, cow, fowl, dairy, fish).

  --  Saul

[mccoy]

One more aspect not often commented (never commented AFAIK): in chronically vegan diets, the hepatic FGF21 signal may induce lineages of gut bacteria to upgrade carbon and nitrogen to synthetize essential amino acids (among which methionine). As it happens in the ruminants, as discussed in the post below linked.

If the above happens, the practice of dietary methionine restriction may become futile.