Hi. Here’s a rather technical nutrition question. I’d appreciate everyone’s thoughts on this, but especially @JamesCollier, of course. Basically, it’s been knows for a long time that restricting calories leads to longer life in most animals, most likely including humans. For some time it’s been clear that a large part of the reason for this is due to restricting proteins. Thus the protein cycling diet (https://proteincyclingdiet.wordpress.com). Now there’s mounting evidence that most of the benefits from restricting protein intake might come from restricting just one amino acid: methionine. Methionine is essential and consuming none of it is, besides very difficult, fatal. But restricting oneself to the minimal amounts of it has been shown to have a host of health benefits and significantly increases life span in mice. Google “methionine restriction” for details and studies. Plats proteins are generally lower in methionine than animal proteins, and this has been suggested as a large part of the reason for the health benefits of a vegan diet.
Now, Huel is vegan, with its protein coming from peas and rice. That’s good, since both of these sources contain relatively little methionine. However, Huel has a lot of protein, which means we still get 269% of the minimum recommended dose on 2000 kcal of Huel. That’s too bad.
There’s hope, though. Here’s a long and complicated thread on the Longecity forums talking about supplementing glycine: http://www.longecity.org/forum/topic/78902-glycine-should-we-be-taking-it/. Basically, it seems glycine can play a role in getting rid of excess methionine, thus perhaps mimicking a methionine restriction diet without the need to severely restrict methionine (and thus protein).
So, I’m thinking of starting to add some glycine to my Huel. Huel already contains plenty of it, but there’s quite a bit of methionine, too. In the Longecity thread, there’s no clear consensus of how much glycine compared to one’s excess methionine one should consume to “counter” it, but on the other hand, it’s also clear that glycine is a common amino acid and it’s considered safe even in relatively large doses (though don’t go nuts). It’s also very cheap, much due to high demand from body builders. I haven’t yet settled on a daily dose and I might want to do some more research before I do, but I think this’ll be interesting to try.
What are your thoughts? Is it worth it to increase the glycine content? If so, by how much?
I have come across the methione things before, but it’s not well researched enough for any conclusions. Indeed, is it merely a marker for something else going on?
How does supplementing glycine ‘get rid’ of the excess methionine and where does this methionine go?
Maybe. I’m just an interested spectator to all this research, but the way I’ve understood it, methionine, containing sulphur (as does cysteine), is more readily oxidized in proteins than other amino acids are. But even though the mechanism might not be entirely known, I think the increased lifespan from a methionine-restricted diet has pretty robust backing, in mice if not in humans.
According to Darryl in the LongeCity thread linked above: [quote=“Darryl”]And perhaps of most interest on this board, glycine supplementation appears to mimic methionine restriction, with clearance of excess methionine via glycine N-methyltransferase.[/quote]
There are a lot of links to studies in his post: http://www.longecity.org/forum/topic/78902-glycine-should-we-be-taking-it/#entry733879 but I don’t have access to a lot of them. I think I read that glycine supplementation increased methionine levels in urine? It’s all pretty early for all of this, so it’s certainly true that these are not robust findings readily transferable to personal nutrition. I find it interesting, though, as I’m very interested in lifespan extension.
Thanks, Ari. Gotta be honest; I’m a skeptic! But I will have a peruse of some of those links in more depth. The glycine thing, I hadn’t come across before.
Understandably. I’m a skeptic, too, trying to be aware of my own wishful thinking. But the folks at LongeCity are impressively well-read and educated, and uncompromisingly scientific, so I like to follow their debates from time to time, even though I’m not really qualified to weigh in myself.
HI @rikefrejut - i’ve had a look. There are some studies on the methione issue, but the evidence is far from strong. Indeed, there is evidence out there that both protein restriction and higher protein intakes can ‘help’ the aging process.
Glycine is more interesting and there does seem to be evidence that it may have a positive role. However, the amounts needed for ‘benefits’ are easily met on a ‘trypical’ protein intake in a Western diet and Huel contains more than this (based on a 2,000 calorie inate).
Therefore, I see no reason to supplement with glycine nor worry about either amino acid.