Longevity: Calorie Restriction or Protein (Methionine) Restriction?

[hailtotheking]

One of the ongoing debates among life-extensionists is what components of caloric restriction are actually responsible for lifespan increases.

Further research over the last decade or so seems to point the finger at protein content of diet, although nearly all of it is in animal and insect studies.

Even further digging seems to point the finger at specific amino acids, esp. methionine. Its believed that high intake throughout life may raise homocysteine levels, ageing, and increased risk of tumour formation. Methionine is mainly found in meat, lean fish, egg whites, and grains. The only significant source of lean protein i can find that is low in methionine is most legumes.

Some are even going as far to say that you would not need to restrict calories if you restricted methionine.

Although the links below are from 'holistic' sites, they do explain the idea reasonably well and reference proper peer-reviewed mainstream studies, highlighting some of the comments made by reseachers on the idea.

Methionine Restriction and Longevity

Methionine Restriction Differs From Calorie Restriction

Methionine Restriction as the Cause of Calorie Restriction Benefits

Prescribing Yoga: The Low-Methionine Theory

Please try and ignore the vegan bias nonsense in thise links, as the broccoli-heads fail to realise grains, some nuts, and some legumes are also very high in methionine I linked them merely to illustrate the theory and some of the research.



Some bloggers have picked up on this, and have suggested that an over-relaince on high methionine foods such as muscle meats, without balancing them with foods predominant in other amino acids (e.g. glycine from connective tissue and bones) and nutrients like folic acid (in veggies) and choline (e.g. egg yolks and liver) that are used to metabolise methionine correctly.

The Daily Lipid: Anyone Doing Paleo Without Liver, Bones, Skin, and Greens?

Gelatin, stress, longevity Peat also beleives excess cysteine and tryptohpan could cause health issues in the long run



John Berardi has even suggested that just getting a full array of amino acids and nutrients from a varied diet should offset the any potential methionine-related issues, esp dietary serine and cysteine, and folic acid. (just search the page for 'methionine'_

John Berardi - The Protein Debate - Do Athletes Need More Protein



Don Matesz does quite an amusing disection of some of the studies (mostly animal) used to support the concerns, highlighting soem of the serious issues that have occured with enforced low methionine diets in animals. However, he seems to have swung from one extreme (concerns about high methionine) to another (scaremongering about low methionine intake dangers). What about just consuming adequate methionine ..?

Primal Wisdom: Protein Restriction and Longevity: My Initial Impressions




And for more amusement, heres Lyle's opinion on the whole thing. However, funnies aside, some of the posts here do illustrate the fact that the high protein intakes being recommended by guys like Lyle and Martin Berkhan seem instictively fairly unnatural to try and consume, and the guys trying to eat that amount of protein typically really struggle.

Eat Less, Live Longer Article - Protein? - BodyRecomposition Support Forums


Anyway, this whole this post was more about just posting some of the random stuff i have found on the web about this issue, and might springboard some debate about it.

It seems to me that a low methionine diet would be very impractical due to the fact that methionine is abundant in most foods barring veg and fruit, and also potentially dangerous if the kind of side effects seen in the animal studies occured in humans.

Personally i'm inclined to go with Chris Masterjohn and Ray Peat on this, and balance my moderate lean muscle meat, eggs, and fish intake with stuff like bone broths, some gelatin, legumes or pea protein, and dairy for the rest of my protein. And never have egg whites without the egg yolks!

Investigating this from my pescetarian angle, it seems that most seafood low down on the food chain like crustaceans and molluscs are lower in methionine than lean white fish.

[munch]

Makes you wonder if air and the food we eat are designed by God to slowly kill us. Natures way of moving us on.

Dan

[NU_nutrition_TS]

Quote

It seems to me that a low methionine diet would be very impractical due to the fact that methionine is abundant in most foods barring veg and fruit, and also potentially dangerous if the kind of side effects seen in the animal studies occured in humans.

Personally i'm inclined to go with Chris Masterjohn and Ray Peat on this, and balance my moderate lean muscle meat, eggs, and fish intake with stuff like bone broths, some gelatin, legumes or pea protein, and dairy for the rest of my protein. And never have egg whites without the egg yolks!

Without yet reading any of the information at the links you posted - I tend to naturally concur with your assessment above.

It seems at odds with evolutionary theory that something that is naturally abundant in our diet would be that deleterious to health.

I also share your concern that a lot of this is coming from the vegetarian/vegan camp and that fruit and veg, being the least concentrated sources of this particular amino acid, seems like yet another 'convenient peg' to hang your 'meat in the diet is an unnatural and unhealthy thing so go vegetarian' hat on!

I also agree with your summation of the advice from Chris Masterjohn and Ray Peat - that squares with the observation of both carnivorous animals and extant hunting humans: they rarely, if ever, eat only the lean muscle meat but preferentially eat organs, connective tissue, fat, skin and bone (certainly the marrow from the bone).

[hailtotheking]

Like i said in the OP, its funny that the vegans use this as one of their arguments for their diet, because grains, which vegans typically consume in large amounts, are are also high in methionine, as are a number of legumes and nuts. Just noticed sesame seeds are the second highest methionine-containing known food on the planet (egg whites are top)!

One of my up and coming experiments is to keep my moderate protein intake where it is (from dairy, seafood from the lower end of the food chain, whole eggs, hemp protein, legumes / legume protein), and then add to this a fairly large amount of protein purely from hydrolysed gelatin (i have sourced it cheap from ebay, and checked my source is free of additives and fit for human consumption), to see if some of Peat's theory pans out about normalising thyroid (and thus metabolism), adrenal, and sex hormones, and producing an anti-inflammatory effect. Gelatin is also pretty good for the digestion when taken with other foods, probably due to its hydrophillic effect encouraging more HCL and enzyme activity upon food digestion (see Pottenger's Hydrophilic Colloid Diet back in the 1930's), and poor digestion is something tha'ts also bothered me on and off over the last 5 years.

[hailtotheking]

Just been looking at methionine content of different cuts of meat. It seems that organ meat and meat 'on the bone' (e.g. ribs) is significantly lower in methionine than muscle meat. Lamb meat also seems lower in methionine than beef.