I think that no one is seriously suggesting complete elimination of
carbohydrates from diet, but from a theoretical point Westman's provocative
correspondence article
Westman EC.
Is dietary carbohydrate essential for human nutrition?
Am J Clin Nutr. 2002 May;75(5):951-3
http://www.ajcn.org/cgi/content/full/75/5/951-a
is highly interesting. Below some key points:
"The currently established human essential nutrients are water,
energy, amino acids (histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine, tryptophan, and valine),
essential fatty acids (linoleic and -linolenic acids), vitamin>
(ascorbic acid, vitamin A, vitamin D, vitamin E, vitamin K,
thiamine, riboflavin, niacin, vitamin B-6, pantothenic acid, folic
acid, biotin, and vitamin B-12), minerals (calcium, phosphorus,
magnesium, and iron), trace minerals (zinc, copper, manganese,
iodine, selenium, molybdenum, and chromium), electrolytes (sodium,
potassium, and chloride), and ultratrace minerals (4). (Note the
absence of specific carbohydrates from this list.)
[...]
Data in childhood are unavailable, but ketosis in adults can be
prevented by a daily CHO intake of about 50 g.
[...]
In the largest published series on carbohydrate-restricted diets,
ketosis was not typically symptomatic (7).
[...]
The most direct way to determine whether carbohydrate is an
essential nutrient is to eliminate it from the diet in controlled
laboratory studies. In studies involving rats and chicks, the
elimination of dietary carbohydrate caused no obvious problems
(8–12).
[...]
The usual way to discover the essentiality of nutrients is through
the identification of specific deficiency syndromes (4). I found no
evidence of a carbohydrate deficiency syndrome in humans. Protein
deprivation leads to kwashiorkor, and energy deprivation leads to
marasmus; however, there is no specific carbohydrate deficiency
syndrome. Few contemporary human cultures eat low-carbohydrate
diets, but the traditional Eskimo diet is very low (50 g/d) in
carbohydrate (2). It is possible that if more humans consumed diets
severely restricted in carbohydrate, a carbohydrate deficiency
syndrome might become apparent.
[...]
Although there is certainly no evidence from which to conclude that
extreme restriction of dietary carbohydrate is harmless, I was
surprised to find that there is similarly little evidence to
conclude that extreme restriction of carbohydrate is harmful. In
fact, the consequential breakdown of fat as a result of carbohydrate
restriction may be beneficial in the treatment of obesity (7).
Perhaps it is time to carefully examine the issue of whether
carbohydrate is an essential component of human nutrition."
--
Matti Narkia