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As far as I understood, the controls from both models were fine and eating enough, which were referred to as well-nourished groups.
I remember that you mentioned some time ago that you eat a somewhat low-protein diet, have you experienced something in this regard?
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Thank you for changing the title, kind invisible entity.
Master, if it's confusing for you, it was clearly not well-written.Heh, I dunno at this point ... the article was not well written at all.
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I consistently test for low protein, and do not feel the need to eat more protein. This has been the pattern for almost 2 years now.
"Low protein" is here refers to something like 25-50g a day on average. All I do in terms of physical activity is a moderate amount of cycling (if you average it out over a week, I'd say 45 mins a day), then some almost-daily kettlebell work, and then daily mobility work. This is definitely nowhere close to athletic levels of activity (which I also have experience with in the past, at which time, I found recovery better with >2g/kg_bodyweight in protein).
Caloric sufficiency is likely attained -- probably about an average of 2600-2800kcal a day at 71kg.
No supplemental protein sources. Animal protein sources are mainly eggs. No dairy -- does not sit well with my body, no matter how many permutations of management strategies I try.
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Interesting, thanks.Just sharing in case someone's interested:
After a 2 days' fast the liver lost 20 % of its original protein content, while the losses from the heart, kidney and other organs amounted to only 4% of their original protein contents.
Probably the rats in the second study were growing animals, too.(1) in the first study, they used weanling rats -- ie: growing animals whose need for full-spectrum dietary amino acid consumption is different from a fully-grown animal. This logic applies to humans as well.
Ray Peat said:In some ways, rats never really mature, since they keep growing for nearly their whole lifespan. Their growth stops just a short time before they die, which is usually around the age of two or three years. (At this age, rats' cells still retain approximately the same high water content seen in the cells of a two year-old child.) They usually become infertile about half-way through their lifespan. If we try to draw conclusions about amino acid requirements from the rat studies, I think we would want to extrapolate the curve for the decreasing need for tryptophan, far beyond the point seen during the rat's short life.
hi amazoniac! so does this mean that i can mix gelatin with casein powder??? or does it mean that i can/should just mix gelatin with milk???Nutrition : Walter H Eddy : Free Download & Streaming : Internet Archive
"The experiment of de Vaux during the Paris Revolution in substituting gelatin for beef and its failure now becomes intelligible. If you will look at the table you will see why the experiment failed; we cannot make body protein without tryptophane and gelatin contains no tryptophane."
"It was Osborne and Mendel for example who showed by rat-feeding experiments that these animals would live and grow when milk casein was their sole source of protein, that they would live but fail to grow when wheat gliadin was substituted for casein, and that gelatin or corn zein would allow them neither to grow nor live. Further, they showed that for both maintenance and growth lysine and tryptophane are necessary and that while lysine was not essential to maintenance it was necessary to growth. They confirmed these views by the following experiments: They restored rats of suspended growth on a ration of wheat gliadin either by adding pure lysine to the ration or by adding gelatin or some other protein which contained lysine. On the other hand they showed that the addition of gelatin to rats on corn zein as a source of protein failed to prolong life, for while the gelatin supplied the lysine which the zein lacked neither zein nor gelatin contains any tryptophane."
A bit unrelated but interesting:
"Recently, however, Downey and his co-workers at the Mellon Institute have found that a small amount of gelatin added to milk may actually increase our ability to use the milk protein. This improvement cannot be due to any amino acids added by the gelatin, for milk contains all that are in gelatin. Downey believes the improvement to be due to another function of the gelatin. Mothers know that barley water is often added to baby milk formulae as a diluent to make it more digestible, that is, to prevent the formation of large milk curds in the baby's stomach. Downey finds that gelatin, like the barley water, has this property of preventing the formation of large milk curds. By reducing their size it allows the digestive juices to act more quickly and completely and thus more casein is digested and absorbed."
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Tryptophan Nutrition and Metabolism: An Overview - Springer
"Tryptophan's role in maintaining normal physiologic function goes beyond its role as a substrate for tissue protein synthesis. Tryptophan has been suggested to play a unique role in regulating protein synthesis in the liver, and has been shown to affect protein synthesis in other tissues in a fashion that appears unrelated to its function as a precursor amino acid. Tryptophan gives rise to a wide array of metabolites involved in a variety of aspects of normal nutrition and metabolism. For example, picolinic acid, a product of TRP's oxidative metabolism, is involved in normal intestinal absorption of zinc. Another TRP metabolite, quinolinic acid, is involved in the regulation of gluconeogenesis. Tryptophan can also contribute to the body's pool of the nicotinamide nucleotides through its metabolic conversion to niacin. Finally, TRP is the precursor of several neuroactive compounds including serotonin (5-hydroxytryptamine, 5-HT) , which functions as a neurochemical substrate for a variety of normal behavioral and neuroendocrine functions. In light of the neurotransmitter precursor function of TRP it is not surprising that many of the effects of treatments or conditions which severely alter TRP nutrition and metabolism are expressed as behavioral effects reflecting altered central nervous system function."
"It has long been recognized that protein synthesis in the whole animal is sensitive to nutritional factors, including the supply of energy and the amount and pattern of amino acids provided in relation to amino acid requirements. Over the past 30 years, a variety of studies have yielded information suggesting a unique role for TRP in the regulation of protein synthesis in a number of tissues including liver (Sidransky et al., 1984), muscle (Lin et al., 1988) and brain (Blazek and Shaw, 1978). Much of the work focusing on the role of TRP has come from studies of protein synthesis in the liver and suggests that TRP may act at several different points in the overall process."
"..However, the observation that TRP is normally the least abundant amino acid in the liver free amino acid pool when animals are fed nutritionally adequate diets, and the finding that the TRPtRNA content of liver falls more rapidly during food deprivation than do the t-RNAs of other indispensable amino acids (Rogers, 1976), suggests that TRP may be an important effector of hepatic protein synthesis under many physiological circumstances."
"In studies in which rats or mice were given solutions containing single amino acids, Sidransky and coworkers (1971) found that administering TRP alone stimulated ribosome aggregation and protein synthesis in liver while giving isoleucine, methionine or threonine alone did not. A somewhat lesser response was observed with certain TRP metabolites including 5-HT, 5-hydroxytryptophan (5-HTP), indole and 3-hydroxyanthranilic acid. This effect was still intact in adrenalectomized animals and thus could not be attributed to an effect of adrenal corticosteroid secretion. Protein synthesis was stimulated both in fed and fasted animals when TRP was given, and thus was apparently not due simply to increasing tissue TRP content."
"Sidransky and associates have investigated the mechanism of this response to TRP and have found that TRP administration affects a number of aspects of hepatic RNA metabolism, including DNA-dependent RNA polymerase activity, polyribosomal RNA and nuclear RNA synthesis, cytoplasmic po1y(A) and poly(A)-mRNA concentrations, nucleocytoplasmic translocation of po1y(A)-mRNA and levels of nucleoside triphosphatase activity in the nuclear envelope (Sidransky et a1., 1984). These workers have hypothesized that TRP can stimulate hepatic protein synthesis by at least two mechanisms: 1) increasing the synthesis of mRNA, and 2) increasing nucleocytoplasmic translocation of mRNA, which would increase the supply of message to locations in the cell where translation occurs. Recent evidence from this group indicates that TRP's effect involves its specific binding to a nuclear membrane glycoprotein (Sidransky et a1., 1984)."
I only quoted parts that concern the thread, but it's worth reading the entire thing, it has interesting information like this:
"The oxidation of TRP via the kynurenine pathway is quantitatively the most significant route of TRP disposal in the body, accounting for 95% or more of daily TRP metabolism. Tryptophan catabolism via this route leads to a number of end products including the nicotinamide nucleotides and acetyl-CoA which can be further oxidized to CO2 to yield energy."
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http://www.sciencedirect.com/science/article/pii/S0166432803002870
Casein isn't too low in tryptophan:hi amazoniac! so does this mean that i can mix gelatin with casein powder??? or does it mean that i can/should just mix gelatin with milk???
thank you. i usually mix it with apple sauce & drink coffee with skim milk. would it be better to just use cream with my coffee? should gelatin maybe just be eaten away from all other proteins? i sometimes add lysine &taurine to my gelatin, is that bad? people on here seem to be over gelatin.Casein isn't too low in tryptophan:
Whey protein, as exclusively nitrogen source, controls food intake and promotes glutathione antioxidant protection in Sprague-Dawley rats (the cysteine difference is more impacting, worth reading)
View attachment 11341
Greater amounts of gelatin will inevitably deplete it and extra niacin will be required:
The effect of gelatin on the transformation of tryptophan to niacin in rats on low casein diets
"The data in Table I and Fig. 1 show the growth-depressing effect of 6 per cent gelatin added to the 10 per cent casein diet. They also demonstrate that the addition of either 5 mg. per cent niacin or 50 mg. per cent of tryptophan at the beginning of the experiment is equally effective in abolishing this inhibitory action of gelatin. It is worth noting that the addition of the niacin or of the tryptophan to the gelatin-containing diet (Groups 5 and 6) results in better growth than on the basal diet alone without gelatin (Group I). Thus, the growth-depressing effect of gelatin appears to be due almost entirely to a lack of niacin, and not to any otherwise toxic effect of the large amount of gelatin in the diet."
"[Our] data indicate clearly that the presence of an excess of gelatin in the 10 per cent casein diet results in an impairment of the metabolic pathway from tryptophan to niacin. This defect, if permitted to develop for several weeks, cannot be remedied by the addition of a small amount of tryptophan (50 mg. per cent) but can be abolished either by adding a small amount of niacin or by relatively very large amounts of tryptophan (25 to 100 mg. daily)."
"Schweigert. and Pearson (7) recently reported that the addition of 12 per cent gelatin to a 12 per cent casein-sucrose diet depressed the growth of rats and that the addition of 1 mg. per cent of niacin or the feeding of 100 mg. doses of nL-tryptophan daily restored the growth. It is to be noted that this restoration was obtained with relatively huge doses of tryptophan."
Acute tryptophan depletion in humans: a review of theoretical, practical and ethical aspects
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Kellogg argued that it can be challenging for the body to adjust the optimal amount of stomach acid needed for milk protein when there are various other foods in the meal, especially other proteids. There are people who tolerate milk with gelatin fine, but I suspect that combining it coagulated casein is safer because there's less risk of forming an indigestible coagulate from too much acid. If the two options are problematic, it's better to it away from dairy meals.
The advantage of combining it with milch is that it can help to prevent the absorption of contaminants like lead in commercial gelatin. Mixing with too much fat might facilitate the early absorption of microbial toxins from it. If you eat meats, I would favor its consumption with them. I can't think of any problem in adding lysin and taurin to it.thank you. i usually mix it with apple sauce & drink coffee with skim milk. would it be better to just use cream with my coffee? should gelatin maybe just be eaten away from all other proteins? i sometimes add lysine &taurine to my gelatin, is that bad? people on here seem to be over gelatin.