|MadSci Network: Biochemistry|
What an interesting question. My first reaction was "How could drinking urine be beneficial?" but once I started doing a little research, I began to question if it was harmful or not.
The process of starving to death is rather complex. Your body uses glucose as its primary source of energy; glucose is the only molecule your brain can use for energy. First your body uses its supply of blood- glucose, and then all the glucose stored as glycogen in your liver. Then your fat is mobilized and turned to glucose, and as a last resort your muscle tissue (protein made of amino acids) is degraded into glucose. According to Dr. A.H. Free (Urinalysis in Clinical Laboratory Practice, but my source was from http:// www.all-natural.com/urine.html) these compounds are found in urine: Alanine* (38 mg/day); Arginine* (32 mg/day); Ascorbic acid (30 mg/day); Allantoin (12 mg/day); Amino acids* (2.1 g/day) Bicarbonate (140 mg/day); Biotin (35 mg/day); Calcium (23 mg/day) Creatinine (1.4 mg/day); Cystine* (120 mg/day); Dopamine (0.40 mg/day) Epinephrine (0.01 mg/day); Folic acid (4 mg/day); Glucose (100 mg/day) Glutamic acid* (308 mg/day); Glycine* (455 mg/day); Inositol (14 mg/day) Iodine (0.25 mg/day); Iron (0.5 mg/day); Lysine* (56 mg/day); Magnesium (100 mg/day); Manganese (0.5 mg/day); Methionine* (10 mg/day); Nitrogen (15 g/day); Ornithine (10 mg/day); Pantothenic acid (3 mg/day); Phenylalanine (21 mg/day); Phosphorus, organic (9 mg/day); Potassium (2.5 mg/day; Riboflavin (0.9 mg/day); Tryptophan* (28 mg/day); Tyrosine* (50 mg/day); Urea (24.5 mg/day); Vitamin B6 (100 mg/day); Vitamin B12 (0.03 mg/day); Zinc (1.4 mg/day).
All of those amino acids (I marked them with an *) can be turned into glucose. Of couse, the glucose itself can be used for energy. Urine is mostly water which is critical for life, just as an energy source is. As far as I know, the only substance in that great list that your body is excreting because it actually *needs* to get rid of it, is urea. Urea is your way of getting rid of excess nitrogen; which you obtain from amino acid degradation. A lot of those compounds are just excess molecules your body can't store, such as vitamins and some organic elements.
I suppose if you were starving to death in a desert, stuck in the rubble of an earthquake or some sort of other dire situation, drinking your own urine would be an okay idea (if you think drinking urine is "okay" that is.) As a last resort, when you have no other source of glucose, amino acids, a few organic molecules, vitamins, and water, urine-drinking would probably be able to extend your life for a little while.
Hope that helps you out with your discussion with your friend.
MolecBio&Biochem Undergrad, McMaster University.
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