I try to remain within the ranges that Dr. Peat mentions in Gelatin, stress, longevity (2009)
Gelatin (the cooked form of collagen) makes up about 50% of the protein in an animal, but a much smaller percentage in the more active tissues, such as brain, muscle, and liver. 35% of the amino acids in gelatin are glycine, 11% alanine, and 21% proline and hydroxyproline.
The 1936 Cyclopedia of Medicine (G.M. Piersol, editor, volume 6) mentions the use of gelatin solution to quickly control nosebleeds, excessive menstrual bleeding, bleeding ulcers (using three doses of 18 grams as a 10% solution during one day), and bleeding from hemorrhoids and the lower bowel, and hemorrhage from the bladder. But since Selye's work relating the thrombohemorrhagic syndromes to stress wasn't known at that time, gelatin was thought of as a useful drug, rather than as having potentially far-reaching physiological effects, antagonizing some of the agents of stress-induced tissue damage.
Although I pointed out a long time ago the antithyroid effects of excessive cysteine and tryptophan from eating only the muscle meats, and have been recommending gelatinous broth at bedtime to stop nocturnal stress, it took me many years to begin to experiment with large amounts of gelatin in my diet. Focusing on the various toxic effects of tryptophan and cysteine, I decided that using commercial gelatin, instead of broth, would be helpful for the experiment. For years I hadn't slept through a whole night without waking, and I was in the habit of having some juice or a little thyroid to help me go back to sleep. The first time I had several grams of gelatin just before bedtime, I slept without interruption for about 9 hours. I mentioned this effect to some friends, and later they told me that friends and relatives of theirs had recovered from long-standing pain problems (arthritic and rheumatic and possibly neurological) in just a few days after taking 10 or 15 grams of gelatin each day.
In some of the older studies, therapeutic results improved when the daily gelatin was increased. Since 30 grams of glycine was commonly used for treating muscular dystrophy and myasthenia gravis, a daily intake of 100 grams of gelatin wouldn't seem unreasonable, and some people find that quantities in that range help to decrease fatigue. For a growing child, though, such a large amount of refined gelatin would tend to displace other important foods. The National Academy of Sciences recently reviewed the requirements for working adults (male and female soldiers, in particular), and suggested that 100 grams of balanced protein was needed for efficient work. For adults, a large part of that could be in the form of gelatin.
If a person eats a large serving of meat, it's probably helpful to have 5 or 10 grams of gelatin at approximately the same time, so that the amino acids enter the blood stream in balance.
