Benefits of 40% CR with 1% Restriction (????) Part 3. Implementation

[Guest guest]

Hi folks:

So, if it were deemed to be desirable to restrict Met (methionine),

how might it be done? The following may cause consternation in some

quarters! Pretty much anything that contains protein contains Met,

and we definitely do need to consume protein, and some Met. So, to

restrict Met we would have to shift our dietary habits away from the

protein sources with higher Met content to those with less.

White bread, for example, contains less Met than whole wheat bread.

White rice less than brown rice. Although the difference between

white and whole grain is not huge, this does raise an issue. No

doubt it can be argued that brown remains preferable because it

provides an appreciable increment of other beneficial nutrients which

more than compensates for some additional Met. Perhaps. Fat-free

cottage cheese is near the top of the list of foods ranked by Met

content. Although, strangely, sour cream seems not to be. Fish

contains substantial amounts of Met, especially the low fat fish

types. So it may turn out to be advisable to scrap the idea of

eating fish and take Met-free fish oil supplements instead? Needless

to say this would dramatically change the aisles I frequent on my

visits to grocery stores!

Some might ask: " How can this be true? The japanese in general, and

okinawans in particular, eat lots of fish and they seem to be doing

very well indeed. " The answer may be that the EPA and DHA in the

fish they eat is very helpful to them, especially for reducing their

incidence of heart disease, the principal cause of death in many

countries, but notably not so in Japan. But the excessive Met

content of this same fish may explain why, despite their supposedly

exemplary lifestyles, they live on average only a few years longer

than north americans, while most of the latter are sedentary and

eating the SAD diet. CR extends animal lifespans by ~40%, which for

humans means 30 or 40 years. So why are the okinawans not living at

least 30 more years than americans? Might it be excessive Met

consumption, especially from the fish they eat? Whether that is true

or not we do not know, but it is consistent with what the papers

posted earlier suggest. One can speculate that if the okinawans took

fish oil capsules instead of eating fish, and otherwise reduced their

Met intake, they might not only get the CVD benefits of the DHA and

EPA, but also the lifespan extension benefit of lower Met, and live

the 30% longer that animal experiments suggest they ought. For the

record, among the fish species whose data I have taken a look at,

mackerel appears to have the most acceptable (but still not great)

Met content - calculated, of course, on a per calorie basis.

Beef, pork and most other meats are also in the top half of the

list. Chicken breast contains more than double the amount of

mackerel, and a sizeably greater amount than beef eye of round or

pork tenderloin!

Protein supplements, favored in some quarters, would seem to be a

dreadful idea. Although gelatin appears to be by far the least

offensive protein source for Met content. The worst offending food

of those I have checked so far is EGG WHITES!!!! IIRC I read a

couple of years ago about one CRON enthusiast describing himself

as " swimming in egg whites " ! ***IF*** this information about Met is

confirmed then it is ironic that it seems likely that such a dietary

quirk may be doing a lot more to shorten his lifespan than all the

effort he is putting into his 40% CR is doing to lengthen it.

In round numbers, assuming four calories per gram of Met, measured in

percentage of calories contributed by Met, the amount in foods varies

from 0% (in those that contain no protein of any kind) to about 3% of

total calories. The zero qualifiers are things like sugar and

cooking oils. At the other end of the range, among the foods I have

checked so far, is egg white at 3·07%.

The following is a very brief list of a few items for which the Met

content exceeds (an entirely arbitrary) 1·5% of calories, assuming

four calories per gram of Met, in no particular order:

Egg whites; canned tuna; canned pink salmon; sole; cod; chicken

breast; beef eye of round; pork tenderloin; chicken breast; beef

liver; fat-free cottage cheese; bison meat ...............

The following is a very brief list of food items for which methionine

represents less than, an also arbitrary, 0·5% of calories:

Cashews; peanuts; almonds; walnuts; kale; (but spinach is just above

this threshold); romaine; bok choy; napa; chickpeas; kidney beans;

peas; Kelloggs All Bran; potato; sweet potato; pasta, rice and bread -

in all cases white has less methionine than brown, but both white

and brown qualify; wheat bran; rice bran; sweet potato; cocoa powder;

oats; full-fat sour cream (I have not found an amino acid breakdown

for fat-free sour cream); and most fruits.

The latter, fruits, is especially interesting. Many of the more

frequently consumed fruits contain quite a lot of calories in the

form of sugar, but rather few micronutrients apart from vitamin C (of

which anyone eating a sensible diet is never likely to be short, so

additional amounts are, imo, unlikely to confer much benefit) . But

it appears that the main benefit of these fruits may be not what is

in them, but rather what is not .......... that they contain only a

small quantity of Met!

It seems as if all this may explain some phenomena that had

previously appeared anomalous. It is interesting, for example, that

studies almost always find nuts to be healthy, despite their huge

fat/calorie content. Perhaps their low methionine is the reason? As

previously noted, perhaps the reason the older okinawans do not live

thirty years longer than we do is their excessive, fish-derived, Met

intake? Possibly Met restriction may also explain the surprising

longevity of the italians, since the Met content of pasta is just

0·16% of calories. Not many foods come in lower than that. (I know

Jeff will be smiling at this, lol.) In a similar vein, one study

posted a while back reported that populations where beans are eaten

seem to be unusually healthy - another food with low Met content.

(Pythagoras would have been upset about this!) This is all

speculation of course ........... just trying find a way to fit a

few more pieces of the puzzle.

More to come .....................

Rodney.