New paleo study.  Abstract and link below.  If anyone has access to the full
article, may I have a read, please?

Theola
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American Journal of Clinical Nutrition, Vol. 76, No. 6, 1308-1316, December
2002


Estimation of the net acid load of the diet of ancestral preagricultural
Homo sapiens and their hominid ancestors1,2,3
Anthony Sebastian, Lynda A Frassetto, Deborah E Sellmeyer, Renée L Merriam
and R Curtis Morris, Jr
1 From the Department of Medicine and the General Clinical Research Center,
University of California, San Francisco.


Background: Natural selection has had < 1% of hominid evolutionary time to
eliminate the inevitable maladaptations consequent to the profound
transformation of the human diet resulting from the inventions of
agriculture and animal husbandry.

Objective: The objective was to estimate the net systemic load of acid (net
endogenous acid production; NEAP) from retrojected ancestral preagricultural
diets and to compare it with that of contemporary diets, which are
characterized by an imbalance of nutrient precursors of hydrogen and
bicarbonate ions that induces a lifelong, low-grade, pathogenically
significant systemic metabolic acidosis.

Design: Using established computational methods, we computed NEAP for a
large number of retrojected ancestral preagricultural diets and compared
them with computed and measured values for typical American diets.

Results: The mean (± SD) NEAP for 159 retrojected preagricultural diets
was -88 ± 82 mEq/d; 87% were net base-producing. The computational model
predicted NEAP for the average American diet (as recorded in the third
National Health and Nutrition Examination Survey) as 48 mEq/d, within a few
percentage points of published measured values for free-living Americans;
the model, therefore, was not biased toward generating negative NEAP values.
The historical shift from negative to positive NEAP was accounted for by the
displacement of high-bicarbonate-yielding plant foods in the ancestral diet
by cereal grains and energy-dense, nutrient-poor foods in the contemporary
diet-neither of which are net base-producing.

Conclusions: The findings suggest that diet-induced metabolic acidosis and
its sequelae in humans eating contemporary diets reflect a mismatch between
the nutrient composition of the diet and genetically determined nutritional
requirements for optimal systemic acid-base status. Am J Clin Nutr
2002;76:-16

http://www.ajcn.org/cgi/content/abstract/76/6/1308

For index to all articles:
http://www.ajcn.org/content/vol76/issue6/index.shtml