Central to my understanding of why VLCD appear to produce a unique and favorable metabolic state in humans when compared to diets high in carbohydrates (and consequently low in fat) is the idea that our digestive system, enzymes and hormones are developmentally adapted to a diet high in animal fat and protein, high in fiber and low in readily digested carbohydrate like sugars and cereal grains.

It is my contention that this specialization is also why rodent diet studies are of limited use when investigating the effects of different macronutrient combinations on humans. We are not rats but feeding a rat a diet at odds with its optimization is likely to have the same negative metabolic consequences as doing this to a human...the only difference is that those diets are not the same because rodents have developed their own dietary specialization in response to evolutionary pressures different from those acting on early humans.

What about apes and monkeys? Our primate cousins all subsist on a primarily vegetarian diet but we are also not apes or monkeys and several hundred thousand, perhaps millions of years of evolution separate us from them. So using contemporary non-human primates to inform the understanding of what our ancestors ate seems problematic at best. The question then becomes, is there any evidence to support the idea that the diet that formed the developmental blueprint for early humans, and for which we are consequentially optimized, is a diet high in protein, fat and fiber and low in readily digested carbohydrates?

It turns out there is, quite a bit actually...

Eur J Clin Nutr. 2002 Mar;56 Suppl 1:S42-52.
The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic.
Cordain L, Eaton SB, Miller JB, Mann N, Hill K.

Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado, USA. cordain@cahs.colostate.edu

OBJECTIVE: Field studies of twentieth century hunter-gathers (HG) showed them to be generally free of the signs and symptoms of cardiovascular disease (CVD). Consequently, the characterization of HG diets may have important implications in designing therapeutic diets that reduce the risk for CVD in Westernized societies. Based upon limited ethnographic data (n=58 HG societies) and a single quantitative dietary study, it has been commonly inferred that gathered plant foods provided the dominant energy source in HG diets. METHOD AND RESULTS: In this review we have analyzed the 13 known quantitative dietary studies of HG and demonstrate that animal food actually provided the dominant (65%) energy source, while gathered plant foods comprised the remainder (35%). This data is consistent with a more recent, comprehensive review of the entire ethnographic data (n=229 HG societies) that showed the mean subsistence dependence upon gathered plant foods was 32%, whereas it was 68% for animal foods. Other evidence, including isotopic analyses of Paleolithic hominid collagen tissue, reductions in hominid gut size, low activity levels of certain enzymes, and optimal foraging data all point toward a long history of meat-based diets in our species. Because increasing meat consumption in Western diets is frequently associated with increased risk for CVD mortality, it is seemingly paradoxical that HG societies, who consume the majority of their energy from animal food, have been shown to be relatively free of the signs and symptoms of CVD. CONCLUSION: The high reliance upon animal-based foods would not have necessarily elicited unfavorable blood lipid profiles because of the hypolipidemic effects of high dietary protein (19-35% energy) and the relatively low level of dietary carbohydrate (22-40% energy). Although fat intake (28-58% energy) would have been similar to or higher than that found in Western diets, it is likely that important qualitative differences in fat intake, including relatively high levels of MUFA and PUFA and a lower omega-6/omega-3 fatty acid ratio, would have served to inhibit the development of CVD. Other dietary characteristics including high intakes of antioxidants, fiber, vitamins and phytochemicals along with a low salt intake may have operated synergistically with lifestyle characteristics (more exercise, less stress and no smoking) to further deter the development of CVD.

PMID: 11965522
Am J Clin Nutr. 2000 Mar;71(3):682-92.
Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets.
Cordain L, Miller JB, Eaton SB, Mann N, Holt SH, Speth JD.

Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523, USA. cordain@cahs.colostate.edu

Both anthropologists and nutritionists have long recognized that the diets of modern-day hunter-gatherers may represent a reference standard for modern human nutrition and a model for defense against certain diseases of affluence. Because the hunter-gatherer way of life is now probably extinct in its purely un-Westernized form, nutritionists and anthropologists must rely on indirect procedures to reconstruct the traditional diet of preagricultural humans. In this analysis, we incorporate the most recent ethnographic compilation of plant-to-animal economic subsistence patterns of hunter-gatherers to estimate likely dietary macronutrient intakes (% of energy) for environmentally diverse hunter-gatherer populations. Furthermore, we show how differences in the percentage of body fat in prey animals would alter protein intakes in hunter-gatherers and how a maximal protein ceiling influences the selection of other macronutrients. Our analysis showed that whenever and wherever it was ecologically possible, hunter-gatherers consumed high amounts (45-65% of energy) of animal food. Most (73%) of the worldwide hunter-gatherer societies derived >50% (> or =56-65% of energy) of their subsistence from animal foods, whereas only 14% of these societies derived >50% (> or =56-65% of energy) of their subsistence from gathered plant foods. This high reliance on animal-based foods coupled with the relatively low carbohydrate content of wild plant foods produces universally characteristic macronutrient consumption ratios in which protein is elevated (19-35% of energy) at the expense of carbohydrates (22-40% of energy).


PMID: 10702160


Eur J Nutr. 2000 Apr;39(2):71-9.
Dietary lean red meat and human evolution.
Mann N.

Department of Food Science, RMIT University, Melbourne, VIC, Australia. neil.mann@rmit.edu.au

Scientific evidence is accumulating that meat itself is not a risk factor for Western lifestyle diseases such as cardiovascular disease, but rather the risk stems from the excessive fat and particularly saturated fat associated with the meat of modern domesticated animals. In our own studies, we have shown evidence that diets high in lean red meat can actually lower plasma cholesterol, contribute significantly to tissue omega-3 fatty acid and provide a good source of iron, zinc and vitamin B12. A study of human and pre-human diet history shows that for a period of at least 2 million years the human ancestral line had been consuming increasing quantities of meat. During that time, evolutionary selection was in action, adapting our genetic make up and hence our physiological features to a diet high in lean meat. This meat was wild game meat, low in total and saturated fat and relatively rich in polyunsaturated fatty acids (PUFA). The evidence presented in this review looks at various lines of study which indicate the reliance on meat intake as a major energy source by pre-agricultural humans. The distinct fields briefly reviewed include: fossil isotope studies, human gut morphology, human encephalisation and energy requirements, optimal foraging theory, insulin resistance and studies on hunter-gatherer societies. In conclusion, lean meat is a healthy and beneficial component of any well-balanced diet as long as it is fat trimmed and consumed as part of a varied diet.

PMID: 10918988


Eur J Nutr. 2000 Apr;39(2):67-70.
Paleolithic vs. modern diets--selected pathophysiological implications.
Eaton SB, Eaton SB 3rd.

Dept Anthropology, Emory University, Atlanta, GA 30327, USA. sboydeaton@aol.com

The nutritional patterns of Paleolithic humans influenced genetic evolution during the time segment within which defining characteristics of contemporary humans were selected. Our genome can have changed little since the beginnings of agriculture, so, genetically, humans remain Stone Agers--adapted for a Paleolithic dietary regimen. Such diets were based chiefly on wild game, fish and uncultivated plant foods. They provided abundant protein; a fat profile much different from that of affluent Western nations; high fibre; carbohydrate from fruits and vegetables (and some honey) but not from cereals, refined sugars and dairy products; high levels of micronutrients and probably of phytochemicals as well. Differences between contemporary and ancestral diets have many pathophysiological implications. This review addresses phytochemicals and cancer; calcium, physical exertion, bone mineral density and bone structural geometry; dietary protein, potassium, renal acid secretion and urinary calcium loss; and finally sarcopenia, adiposity, insulin receptors and insulin resistance. While not, yet, a basis for formal recommendations, awareness of Paleolithic nutritional patterns should generate novel, testable hypotheses grounded in evolutionary theory and it should dispel complacency regarding currently accepted nutritional tenets.

PMID: 10918987

Mayo Clin Proc. 2004 Jan;79(1):101-8.
Cardiovascular disease resulting from a diet and lifestyle at odds with our Paleolithic genome: how to become a 21st-century hunter-gatherer.
O'Keefe JH Jr, Cordain L.

Mid America Heart Institute, Cardiovascular Consultants, Kansas City, MO 64111, USA. jhokeefe@cc-pc.com

Our genetic make-up, shaped through millions of years of evolution, determines our nutritional and activity needs. Although the human genome has remained primarily unchanged since the agricultural revolution 10,000 years ago, our diet and lifestyle have become progressively more divergent from those of our ancient ancestors. Accumulating evidence suggests that this mismatch between our modern diet and lifestyle and our Paleolithic genome is playing a substantial role in the ongoing epidemics of obesity, hypertension, diabetes, and atherosclerotic cardiovascular disease. Until 500 generations ago, all humans consumed only wild and unprocessed food foraged and hunted from their environment. These circumstances provided a diet high in lean protein, polyunsaturated fats (especially omega-3 [omega-3] fatty acids), monounsaturated fats, fiber, vitamins, minerals, antioxidants, and other beneficial phytochemicals. Historical and anthropological studies show hunter-gatherers generally to be healthy, fit, and largely free of the degenerative cardiovascular diseases common in modern societies. This review outlines the essence of our hunter-gatherer genetic legacy and suggests practical steps to re-align our modern milieu with our ancient genome in an effort to improve cardiovascular health.

PMID: 14708953

westonaprice.org has some interesting commentary RE: Cordain's "politically correct Paleodiet" (i.e. no salt, low saturated fats/high omega-6 fats, and lean proteins).

The other thing I am getting from my research into this is that we have our sodium-potassium intake badly reversed...

hi heavy, but we need some sodium anyway.
2-3 gr is enough mostly.


Life Sci. 2008 Jan 26.

Perinatal salt restriction: A new pathway to programming adiposity indices in adult female Wistar rats.

Lopes KL, Furukawa LN, de Oliveira IB, Dolnikoff MS, Heimann JC.

Department of Internal Medicine, Laboratory of Experimental Hypertension of the University of São Paulo School of Medicine, 01246-903 São Paulo, Brazil.

Low birth weight has been associated with increased obesity in adulthood. It has been shown that dietary salt restriction during intrauterine life induces low birth weight and insulin resistance in adult Wistar rats. The present study had a two-fold objective: to evaluate the effects that low salt intake during pregnancy and lactation has on the amount and distribution of adipose tissue; and to determine whether the phenotypic changes in fat mass in this model are associated with alterations in the activity of the renin-angiotensin system. Maternal salt restriction was found to reduce birth weight in male and female offspring. In adulthood, the female offspring of dams fed the low-salt diet presented higher adiposity indices than those seen in the offspring of dams fed a normal-salt diet. This was attributed to the fact that adipose tissue mass (retroperitoneal but not gonadal, mesenteric or inguinal) was greater in those rats than in the offspring of dams fed a normal diet. The adult offspring of dams fed the low-salt diet, compared to those dams fed a normal-salt diet, presented the following: plasma leptin levels higher in males and lower in females; plasma renin activity higher in males but not in females; and no differences in body weight, mean arterial blood pressure or serum angiotensin-converting enzyme activity. Therefore, low salt intake during pregnancy might lead to the programming of obesity in adult female offspring.





--------------------------------
--------------------------------
"Even documenting an association of, for example, low-sodium diets with reduced incidence of heart attacks would only be the first step. Association is not the same as causation. Nevertheless, unless an association is established, we have no reason to think that a causal link is possible. Of the first fifteen “health outcomes” studies of sodium reduction, three have found an association in the general population between low-sodium diets and reduced incidence of cardiovascular events like stroke or heart attack (and two of those were in exceptionally high salt-consuming societies). Three others have identified health risks of low-salt diets. Here’s what scientists have found:

1. A ten-year study of nearly 8,000 Hawaiian Japanese men concluded: "No relation was found between salt intake and the incidence of stroke." (1985)

2. An eight-year study of a New York City hypertensive population stratified for sodium intake levels found those on low-salt diets had more than four times as many heart attacks as those on normal-sodium diets – the exact opposite of what the “salt hypothesis” would have predicted. (1995)

3. An analysis by NHLBI’s Dr. Cutler of the first six years’ data from the MRFIT database documented no health outcomes benefits of lower-sodium diets. (1997)

4. A ten-year follow-up study to the huge Scottish Heart Health Study found no improved health outcomes for those on low-salt diets. (1997)

5. An analysis of the health outcomes over twenty years from those in the massive US National Health and Nutrition Examination Survey (NHANES I) documented a 20% greater incidence of heart attacks among those on low-salt diets compared to normal-salt diets ( 1 2 ) (1998)

6. A health outcomes study in Finland, reported to the American Heart Association that no health benefits could be identified and concluded “…our results do not support the recommendations for entire populations to reduce dietary sodium intake to prevent coronary heart disease.” (1998)

7. A further analysis of the MRFIT database, this time using fourteen years’ data, confirmed no improved health benefit from low-sodium diets. Its author conceded that there is "no relationship observed between dietary sodium and mortality." (1999)

8. A study of Americans found that less sodium-dense diets did reduce the cardiovascular mortality of one population sub-set, overweight men – the article reporting the findings did not explain why this obese group actually consumed less sodium than normal-weight individuals in the study. (1999)

9. A Finnish study reported an increase in cardiovascular events for obese men (but not women or normal-weight individuals of either gender) – the article, however, failed to adjust for potassium intake levels which many researchers consider a key associated variable. (2001)

10. In September, 2002, the prestigous Cochrane Collaboration produced the latest and highest-quality meta-analysis of clinical trials. It was published in the British Medical Journal and confirmed earlier meta-analyses' conclusions that significant salt reduction would lead to very small blood pressure changes in sensitive populations and no health benefits. (2002)

11. In June 2003, Dutch researchers using a massive database in Rotterdam concluded that "variations in dietary soidum and potassium within the range commonly observed in Westernized societies have no material effect on the ocurrence of cardiovascular events and mortality at old age." (2003)

12. In July 2004, the first "outcomes" study identifying a population risk appeared in Stroke magazine. Researchers found that in a Japanese population, "low" sodium intakes (about 20% above Americans' average intake) had one-third the incidence of fatal strokes of those consuming twice as much sodium as Americans. (2004)

13. A March 2006 analysis of the federal NHANES II database in The American Journal of Medicine found a 37% higher cardiovascular mortality rate for low-sodium dieters (2006). See their university's news release. Hear a podcast.

14. A February 2007 reported in the International Journal of Epidemiology studied 40,547 Japanese over seven years and found "the Japanese dietary pattern was associated with a decreased risk of CVD mortality, despite its relation to sodium intake and hypertension." (2007)

15. An April 2007 article in the British Medical Journal found a 25% lower risk of CV events in a group which years earlier had achieved significant sodium reduction during two clinical trials (TOHP I and TOHP II). (2007)

16. An October 2007 analysis of a large Dutch database published in the European Journal of Epidemiology documented no benefit of low-salt diets in reducing stroke or heart attack incidence nor lowering death rates. The results, graphically. (2007)"





.

You missed something.
and
PS
32% is not VLCD
Furthermore, its an average across time.

Was in no way suggesting that sodium is unnecessary, nor that an imbalance between sodium and potassium is desirable. Rather, I meant to imply that Cordain's version of the Paleo diet is not consistent with what is know about ancient and present-day hunter-gatherer cultures.

http://www.unm.edu/~kimhill/papers/hill1989a.pdf

Time spent by two hunter-gather cultures to meet basic needs:

Our collected data-some 63 days’ worth of focal studies each on men and women and 1,055 person-days of subsistence studies-show that in the forest Ache men spend about 6.7 h/day in subsistence activities (searching, acquiring resources, and processing food) and another 0.6 hiday working on the tools used in subsistence activities. Men also spend about 4.5 h resting,
socializing, or in light activities each day (Hill et al. 1985). Women spend about 1.9 h in subsistence activities, 1.9 h moving camp, and about 8 h in light work or childcare (Hurtado et al. 1985). The contrast between the genders may not be surprising in light of the finding that men provide 87% of the energy supplied in the Ache diet and close to 100% of the protein and iipid consumed.

The Ache spend more than twice as much time in procuring, processing, and transporting food as !Kung men and women, who take 3.1 and 1.8 h/day, respectively, for such activities (Lee 1979).

Warrior Diet/IF:

On a foraging trip, camp members rise eariy, eat whatever is left over from the previous day, and set out
in search of food. ... Men generally eat very little during the day, but women and children sometimes collect and eat fruits and
insects while men hunt, and women often process palm trunks for their starchy fiber near the end of the dav. This
snacking usually’ accounts for less than 5% of of food consumed (Hill et al. 19&l).

They eat a ton of honey:

The data from short-term trips (with a range of 4 to 15 davs) suggest that as foragers the Ache eat an astounding
3,7OO calories per person per day (Hiil et al. 1984). (By contrast, active adult Americans consume about 2,700 calories per dav.) When the Ache are living in the forest, an average df 56% of their calories come from mammalian meat (ranging from 46% to 66%, depending on the season), with honey making up 18% (range 6-30s) and plants and insects providing an average of 26% (range 15-49%).

Can you hypothesize as to overall caloric intake? If calories were extremely restricted (maybe over the course of winter), this could be a fairly low number.

do the Grass-Fed vs. Corn fed and breeding for fattier meat issues go here?

"These circumstances provided a diet high in lean protein, polyunsaturated fats (especially omega-3 [omega-3] fatty acids), monounsaturated fats, fiber, vitamins, minerals, antioxidants, and other beneficial phytochemicals."

Which is the focus of this thread. Did they sit on their ass all the time and watch HDTV? No. Is this important to the low incidence of degenerative disease? Most likely.



Depends on your perspective. Current American dietary guidelines call for almost twice this amount of carbs. The main point is that there is good evidence that our ancestral diet, the one that we are optimized for, was high in animal protein and fat and low in carbs, essentially devoid of cereal grains and sugars.

All of Cordain's publishings are here: http://thepaleodiet.com/published_research/

What happened to the adaptive specialization created by the thousands of intervening years of agricultural societies? It strikes me that these arguments are probably both genomically and genetically relevant for many present-day aboriginal societies, but are ignoring a lot of very relevant evolutionary history for the majority of pastorally-descended societies. Neolithic diets, FTW!

What?

A lot of shit happened between the paleolithic and the current day that involved fields and stuff.

Wait second ... are you trying to tell us that the holy grail was really mary magdalen pregnant with jesus's baby??

Pretty much, yeah.

It was a joke, actually...I'm just so used to not knowing what the heck you say that I figured I may as well run with it!

But, yes, your second response makes much more sense to me.

And, of course, much more shit happend before our ancestors practiced "paleolithic diet" (if it ever was actually practiced) ...

http://www.nytimes.com/2007/09/10/science/...&oref=login

Its a good question. Cultivation of cereal grains started ~10,000 years ago in the Fertile Crescent. Is that enough time to change the optimization developed by 50-250,000 years of living mainly on animal meat and whatever fruit, berries, nuts and tubers one could find? Hard to know how fast the selective pressures would push us towards into a condition better suited to live on these. Dairy got into our diet at about the same time and would further complicate things.

There's an abstract floating around here detailing the spread of the lactase (?) gene through European populations...

Poliquin has suggested that those who gained agriculture first (Mediterraneans and Asians) are those who handle it best. I don't find this disagreeable but more research is needed. The inverse is that Asians traditionally don't handle dairy well, as they received it much later...hell, 75% of the planet is lactose intolerant. I don't see why it's a stretch to deem someone carb intolerant.

I'm sure these have been seen before, but worth the review:
http://www.johnberardi.com/articles/nutrition/built1.htm

http://www.johnberardi.com/articles/nutrition/built2.htm

Diabetes. 2008 Feb 19 [Epub ahead of print]
Asian Indians Have Enhanced Skeletal Muscle Mitochondrial Capacity to Produce ATP in Association with Severe Insulin-Resistance.
Nair KS, Bigelow ML, Asmann YW, Chow LS, Coenen-Schimke JM, Klaus KA, Guo ZK, Sreekumar R, Irving BA.

Division of Endocrinology, Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, MN.

Objective: Type 2 diabetes has become a global epidemic; and Asian Indians have a higher susceptibility to diabetes than Europeans. We investigated whether Indians had any metabolic differences compared to Northern European (NE) Americans that may render them more susceptible to diabetes. Research Design and Methods: We studied thirteen diabetic Indians, thirteen non-diabetic Indians, and thirteen non-diabetic NE Americans who were matched for age, body mass index, and sex. The primary comparisons were insulin sensitivity by hyperinsulinemic-euglycemic clamp and skeletal muscle mitochondrial capacity for oxidative phosphorylation (OXPHOS) by measuring mitochondrial DNA copy number (mtDNA), OXPHOS gene transcripts, citrate synthase activity and maximal mitochondrial ATP production rate (MAPR). Other factors that may cause insulin-resistance were also measured. Results: The glucose infusion rates required to maintain identical glucose levels during the similar insulin infusion rates were substantially lower in diabetic Indians than in the non-diabetic participants (p<0.001); and were lower in non-diabetic Indians than in non-diabetic NE Americans (p<0.002). mtDNA (P<0.02), OXPHOS gene transcripts (P<0.01), citrate synthase and MAPR (P<0.03) were higher in Indians irrespective of their diabetic status. Intramuscular triglyceride, C-reactive protein, IL-6 and TNF-alpha concentrations were higher, whereas, adiponectin concentrations were lower in diabetic Indians. Conclusion: Despite being more insulin-resistant diabetic Indians had similar muscle OXPHOS capacity as non-diabetic Indians, demonstrating that diabetes per se does not cause mitochondrial dysfunction. Indians irrespective of their diabetic status had higher OXPHOS capacity than NE Americans, although Indians were substantially more insulin-resistant, indicating a dissociation between mitochondrial dysfunction and insulin-resistance.

The inverse of early agricultural development is lactose intolerance?

If the dietary adaptation and plasticity we have seen in other species are reasonably analogous (notably in foraging strategy), the answer would be yes. Given what we know about power laws in complex food web structures and dynamics, I would assert that this is a viable comparison.

I see how that would be implied, but my point was that there's a genetic disposition to said intolerance, likely due to the low occurrence of industrialized and commercial dairy use is low. Japan seems to be becoming less intolerant, but only marginally so:
http://www.ncbi.nlm.nih.gov/pubmed/1234085

It is curious that, according to the map on wikipedia, that the Mediterranean and Asian regions of the world are the most intolerant while also being the first places that agriculture developed.

I suppose it gets even more difficult to asses given that some humans had cereal grains as long as 10k years ago but the widespread consumption of processed flour by a majority of the human population is more recent, probably only 5k years or so and for some populations, its much shorter than even that.

LOL...I was just being intentionally literal minded.

Plus miscegenation, plus neutral drift, plus...

http://hmg.oxfordjournals.org/cgi/content/full/16/R2/R134

Check out the Figure 1 - too funny.

Dietary adaptation
The diversity of environments occupied by hunter–gatherer humans after the early migrations are mirrored by a diversity of diets. Early heterogeneity of resources may still have an impact today: for example, as judged by modern Y chromosome diversity (36), population expansions occurred earlier in the northern part of East Asia, probably because of the abundant megafauna of the ‘Mammoth Steppe’, but later in the south, due to poorer resources.

In terms of influence on diet, the most important development in human prehistory was agriculture, beginning ~10 KYA in the Near East, with distinct varieties emerging later in China, the Americas and West Africa (Fig. 1B). Increased population densities, reduced dietary diversity, sedentary lifestyle and exposure to animal pathogens together represented a major set of challenges. A common view is that post-Neolithic humans are adapted, through a ‘thrifty genotype’ (37,38) to a hunter–gatherer lifestyle of feast and famine (39), and that the arrival of agriculture signalled the start of an era of dietary maladaptation, leading to high incidences of type 2 diabetes. Later colonization events, like those of the Pacific islands (Fig. 1C), may have involved particularly strong selection for thrifty genotypes (40) – possibly causing subsequent extreme levels of diabetes. These views have not gone unopposed, however (41,42), and recent studies of diabetes susceptibility loci suggest that reality is not so simple.

A variant in the transcription factor 7-like 2 gene (TCF7L2) is responsible for 17–28% of the risk of type 2 diabetes in Europeans (43), but, contrary to expectations of the thrifty genotype hypothesis, is associated with reduced body mass index (BMI) in diabetics (44). In the HapMap samples, the frequency of another variant of the same gene, associated with increased BMI, has been driven by selection to near fixation (95%) in East Asians, with lower frequencies elsewhere. The ages of the variant in the different populations correspond approximately to the times of origin of agriculture, suggesting that it conferred some advantage in the post-agricultural environment. However, the nature of this advantage is unclear.

A clear example of genetic adaptation to cultural innovation is the selection of alleles of LCT permitting persistence of lactase expression into adulthood. This allows the drinking of milk without adverse effects, and the distribution of the phenotype correlates well with that of populations with a history of cattle domestication and milk drinking (45). In the HapMap samples (16), LCT in Europeans shows the strongest signal of positive selection, reflecting a powerful advantage that may have been more related to milk as a source of uninfected water than as a source of nutrition.

Studies in European populations identified a causative regulatory variant ~14 kb upstream of the LCT gene (46), with an estimated age of 2000–20 000 years (47). However, lactase-persistent populations elsewhere, including Africa, do not carry this variant. Studies of Tanzanians, Kenyans and Sudanese (48,49) reveal three further nearby variants causing lactase persistence. Examination of surrounding haplotypes show that the three African variants arose independently of each other and of the European variant (a further example of convergent evolution), within the last ~7000 years. The known variants still do not account for all of lactase persistence; so further examples are likely to exist.

Further dietary adaptations remain to be discovered, and signals of selection around genes involved in the metabolism of other carbohydrates, fat and alcohol (18) are interesting.

http://www.canada.com/theprovince/news/sto...k=53770&p=1

"The 57-year-old immediately cut carbs so as not to exacerbate his already soaring blood-sugar level. It was not meant to be a treatment for his diabetes, which typically requires drug therapy, so much as a stalling tactic.

But then a curious thing happened: His blood sugar normalized, his energy returned, he lost weight and even the nighttime urination and constant thirst ceased. Wortman's wife pointed out that he was actually on the Atkins diet.

But to Wortman, it reminded him of the cuisine of his childhood in Northern Alberta, when dried moose meat was an ubiquitous snack and wild game and plants low in sugar formed the bulk of meals."

Amen.

Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors 1,2,3
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.

Interesting, had not even considered the acid-base aspects of the equation...

J Hum Evol. 2008 Mar 25 [Epub ahead of print]
Related Articles
Click here to read
Eland, buffalo, and wild pigs: were Middle Stone Age humans ineffective hunters?

Faith JT.

Hominid Paleobiology Doctoral Program, CASHP, Department of Anthropology, George Washington University, 2110 G St NW, Washington, DC 20052, USA.

Patterns of faunal exploitation play a central role in debates concerning the behavioral modernity of Middle Stone Age (MSA) peoples. MSA foragers have been portrayed as less effective hunters than their Later Stone Age (LSA) successors on the basis of relative species abundances from ungulate assemblages in southern Africa. Specifically, MSA hunters are said to focus on docile eland while avoiding more aggressive prey, particularly buffalo and wild pigs. To evaluate these arguments and compare subsistence behavior, I present a quantitative examination of 51 MSA and 98 LSA ungulate assemblages from southern Africa to show that: (1) with respect to ungulate exploitation, MSA diet breadth may have exceeded LSA diet breadth, (2) ungulate assemblage evenness is equivalent in the MSA and LSA, (3) eland, buffalo, and wild pig are equally abundant in the MSA and LSA, and (4) large ungulate prey are more common in the MSA than in the LSA. With few exceptions, the broad patterns, which sample a range of geographic and environmental contexts, are supported by an environmentally controlled comparison of Middle and Later Stone Age faunas that accumulated under interglacial conditions along the southern African coastline. When interpreted within a foraging theory framework, these differences suggest that MSA hunters enjoyed increased meat yields due to elevated encounter rates with large prey. These results need not imply cognitive differences, but are consistent with an increase in human populations from the Middle to Later Stone Age, which resulted in diminished abundances of large ungulates.

Agrarian diet and diseases of affluence – Do evolutionary novel dietary lectins cause leptin resistance?

free full text: http://www.biomedcentral.com/1472-6823/5/10

All I know is. I have been experimenting with low carb, finally, after all these years. But I've just been replacing a meal here and there. I'm now to where I replace all but one meal with low carb fare. I'm about to kick that last one. What have I discovered? Same thing everyone else has - better mood, much improved blood sugar, appetite actually reduced and I find a meal that is solely meat and green veggies and some nuts to be an absolutely satisfying thing.

I had at some point drilled into my head "Carbs Are For Energy KIDSS!!!" It was like some demented schoolhouse rock thing from when I was just a lil squirt. Loafs of bread doing the watusie in my mind and singing some song about how I need them if I want to be able to run and laugh and play.

Well that meme is being replaced. Now when I sit down to eat I imagine being a caveman and sitting down to my freshly hunted game and yes a salad the wife made because she wants to look good in her leopard print at the quarry this summer.

But I used to think, Oh my god Deprivation!!! Now I think about eating steak until my stomach is bloated and I feel great.

Best thing is too I feel good during the workouts. I ate an apple and some peanut butter (I know, I know, it's carbs run for the hills!) and a few bites of some cottage cheese before a workout. I never felt better. Every time I've gone in to the gym after a heavy starch breakfast or something I usually suffered in my workouts. It was just uncanny really.

Should we be eating our meat raw now too?