Ed,
I am proposing that organ meats can increase the hepatic capacity for urea
formation- by the provision of vitamin and mineral co-factors for the
production of urea. (This is analogous to the situation of the metabolism of
carbohydrates- it is sometimes mentioned that fruits contain sufficient
thiamine to enable to metabolism of their carbohydrate, whereas pure sucrose
does not). It should be possible to test this proposition with simple
feeding trials. It really depends on which vitamins and minerals are
required in which quantities to metabolise protein. One then can look at
their dietary sources. Liver, for example plays a major metabolic role as a
store for vitamins and minerals and so provides large quantities.
Perhaps they could increase ammonia excretion by providing co-factors for
that process too.
I have demonstrated some critical differences below with USDA figures
http://www.nal.usda.gov/fnic/foodcomp/ for lamb liver and lamb leg- You will
observe that liver has significantly higher levels of Iron Phosphorus
Copper, Manganese, Selenium, Vitamin C, total ascorbic acid Thiamin
Riboflavin Niacin Pantothenic acid Vitamin B-6 Folate, B12 and Vitamin A.
Liver is often mentioned as a source of other nutrients such as biotin,
alpha lipoic acid, glutathione, and Co-Q10 (though I do not know their
bioavailablity).
I propose that some or all of these vitamins are required to metabolise
dietary protein. This in turn explains much of the reason why carnivores
require organ meats in their diets. High protein diets of dogs and lions are
high in organ meats and thus would be high in the above vitamins.
Traditional hunter gatherer diets may be similarly high in organ
meats(comments?)(NB organ meats were significant in ref 1).
I do not know if the PRAL (potential renal acid load) of organ meats differs
from that of muscle meats. The PRAL is determined by the metabolic fate of
the food.
The other factors I mentioned (alkaline load from fruit vegetables and
natural waters, essential fatty acids, other vitamins not required for
protein metabolism) would also contribute to the healthfulness of the diet.
Ben Balzer
> Are you proposing that there might be a mechanism for:
>-increased hepatic capacity for urea formation?
>-decreased ammonia toxicity (due to body compartment channeling or improved
ammonia metabolism/excretion)?
>-increased anabolism (increased protein accretion at the tissue/enzyme
level)?
DATA lamb liver and lamb leg- Note that this data does not specify whether
it was grain fed or pasture fed (nor did beef liver, which I would presume
was grain fed in the USA). I am not aware of US lamb feeding practices.
References:
1. Cordain L, Brand Miller J, Boyd Eaton S, Mann N, Holt SHA, and Speth JD
Plant-animal subsistence ratios and macronutrient energy estimations in
worldwide hunter-gatherer diets Am J Clin Nutr 2000;71:682–92.
USDA:
Lamb, variety meats and by-products, liver, raw rawNDB
No: 17199 Nutrient Units Value per100 grams ofedible portion
SampleCount Std.Error
Proximates
Water g 71.37 17 0.201
Energy kcal 139 0
Energy kj 582 0
Protein g 20.38 1
Total lipid (fat) g 5.02 1
Ash g 1.44 1
Carbohydrate, by difference g 1.78 0
Fiber, total dietary g 0.0 0
Minerals
Calcium, Ca mg 7 1
Iron, Fe mg 7.37 1
Magnesium, Mg mg 19 1
Phosphorus, P mg 364 1
Potassium, K mg 313 1
Sodium, Na mg 70 1
Zinc, Zn mg 4.66 8 0.375
Copper, Cu mg 6.979 520 0.228
Manganese, Mn mg 0.184 13 0.028
Selenium, Se mcg 82.4 13 7.680
Vitamins
Vitamin C, total ascorbic acid mg 4.0 1
Thiamin mg 0.340 1
Riboflavin mg 3.630 1
Niacin mg 16.110 1
Pantothenic acid mg 6.130 1
Vitamin B-6 mg 0.900 1
Folate, total mcg 230 4 19.068
Folic acid mcg 0 0
Folate, food mcg 230 4 19.068
Folate, DFE mcg_DFE 230 0
Vitamin B-12 mcg 90.05 19 5.464
Vitamin A, IU IU 24612 2
Retinol mcg 7391 2
Vitamin A, RAE mcg_RAE 7391 2
Lipids
Fatty acids, total saturated g 1.940 0
14:0 g 0.050 21
16:0 g 0.680 21
18:0 g 1.120 21
Fatty acids, total monounsaturated g 1.050 0
16:1 undifferentiated g 0.130 21
18:1 undifferentiated g 0.920 21
Fatty acids, total polyunsaturated g 0.750 0
18:2 undifferentiated g 0.320 21
18:3 undifferentiated g 0.070 21
20:4 undifferentiated g 0.360 21
Cholesterol mg 371 4 43.495
Amino acids
Tryptophan g 0.236 6
Threonine g 0.882 6
Isoleucine g 0.878 6
Leucine g 1.665 6
Lysine g 1.102 6
Methionine g 0.442 6
Cystine g 0.214 6
Phenylalanine g 0.910 6
Tyrosine g 0.727 6
Valine g 1.122 6
Arginine g 1.143 6
Histidine g 0.479 6
Alanine g 1.022 6
Aspartic acid g 1.758 6
Glutamic acid g 2.198 6
Glycine g 0.985 6
Proline g 0.974 6
Serine g 0.878 6
Lamb, domestic, leg, sirloin half, separable lean only, trimmed to 1/4"
fat, choice, rawNDB No: 17021 Nutrient Units Value per100 grams
ofedible portion SampleCount Std.Error
Proximates
Water g 73.57 32 0.470
Energy kcal 134 0
Energy kj 561 0
Protein g 20.55 32 0.328
Total lipid (fat) g 5.08 32 0.221
Ash g 1.07 32 0.011
Carbohydrate, by difference g 0.00 0
Fiber, total dietary g 0.0 0
Minerals
Calcium, Ca mg 7 32 0.465
Iron, Fe mg 1.83 32 0.094
Magnesium, Mg mg 27 32 1.196
Phosphorus, P mg 189 16 4.452
Potassium, K mg 284 32 14.399
Sodium, Na mg 64 32 2.551
Zinc, Zn mg 3.77 32 0.173
Copper, Cu mg 0.132 32 0.006
Manganese, Mn mg 0.024 0
Selenium, Se mcg 23.4 0
Vitamins
Vitamin C, total ascorbic acid mg 0.0 0
Thiamin mg 0.140 16 0.007
Riboflavin mg 0.250 16 0.015
Niacin mg 6.330 16 0.303
Pantothenic acid mg 0.740 16 0.017
Vitamin B-6 mg 0.170 0
Folate, total mcg 24 16 1.354
Folic acid mcg 0 0
Folate, food mcg 24 16 1.354
Folate, DFE mcg_DFE 24 0
Vitamin B-12 mcg 2.76 16 0.149
Vitamin A, IU IU 0 0
Retinol mcg 0 0
Vitamin A, RAE mcg_RAE 0 0
Vitamin E mg_ATE 0.240 0
Tocopherol, alpha mg 0.24 0
Lipids
Fatty acids, total saturated g 1.820 0
10:0 g 0.010 373
12:0 g 0.010 373
14:0 g 0.130 373
16:0 g 0.990 373
18:0 g 0.600 373
Fatty acids, total monounsaturated g 2.040 0
16:1 undifferentiated g 0.150 373
18:1 undifferentiated g 1.850 373
Fatty acids, total polyunsaturated g 0.460 0
18:2 undifferentiated g 0.350 373
18:3 undifferentiated g 0.070 373
20:4 undifferentiated g 0.050 373
Cholesterol mg 66 16 1.602
Amino acids
Tryptophan g 0.240 0
Threonine g 0.880 0
Isoleucine g 0.991 0
Leucine g 1.598 0
Lysine g 1.815 0
Methionine g 0.527 0
Cystine g 0.245 0
Phenylalanine g 0.837 0
Tyrosine g 0.691 0
Valine g 1.109 0
Arginine g 1.221 0
Histidine g 0.651 0
Alanine g 1.236 0
Aspartic acid g 1.809 0
Glutamic acid g 2.982 0
Glycine g 1.004 0
Proline g 0.862 0
Serine g 0.764 0
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