The problem with the notion that tubers were a mainstay of the Palaeolithic Diet is that most need to be cooked etc. in order to be remotely absorbable by the human body( a good  example being cassava, which is a staple food in many African countries and contains cyanide-based compounds when raw). So, it is highly unlikely that tubers were a significant part of the diet before c.250,000 years ago, when cooking was invented. Also, from what I understand, most of the Australian megafauna was completely  wiped out c.40,000- 50,000 years ago, probably by the Aborigines themselves, so it would make sense if they then went in for tuber-/root-consumption as a substitute in the face of potential starvation re lack of meats.
 
Geoff> Date: Thu, 8 Jan 2009 21:20:40 -0700> From: [log in to unmask]> Subject: Re: A qustion for fans of Vilhjalmur Stefansson fans> To: [log in to unmask]> > william wrote:> > Keith Thomas wrote:> >> Here's a question for William and other Stefansson fans. The question> >> arises as an aquaintance of mine is shifting to palaeo eating but is> >> worried about becoming constipated.> >> .> >>> >> Do you know what Stefansson experienced by way of frequency and> >> ease of bowel movements? What the Inuit experience is in winter> >> and spring when there's virtually no roughage to be had?> >>> > I think that you have advised your friend well. Might add that animal > > fat is a lubricant, as well as nutrient and solvent.> > Roughage is not needed - it's the friendly bacteria that make us move.> >> > I don't remember Stefansson writing anything about bowel movements - > > in his time people were even more prudish than now about such things.> > The only knowledge I have of the Inuit in this regard is from 1960, > > when the snow melted around their tents the winter's turds were > > revealed. They were proper turds, well formed, but maybe not as > > splendid as mine have been recently. :D> >> > William> >> > A while ago when we were discussing roots and tubers, I posted some > portion of a very detailed study on paleo eating habits of Australian > aborigines before their diet become more "westernized". I highly > recommend reading the paper, but below you'll note that the estimated > fiber content was 40-80 grams/day along with total carbs of 101-202 > grams - high fiber content carbs. I expect this diet is more > representative of a paleo diet than that of the Inuit.> > Steve> > ---------> > If you pull up the following PDF file and scan to the section on "Roots > and tubers", there is an interesting discussion that applies to recent > posts on roots and tubers that has been ongoing. Farther down there is a > discussion under "Seeds" of cereal seeds and farther on some legumes. > All these were available without agriculture but some "technology" was > used.> > > Australian Aboriginal plant foods: a consideration of their nutritional > composition and health implications> http://www.google.com/url?sa=t&ct=res&cd=3&url=http%3A%2F%2Fjournals.cambridge.org%2Fproduction%2Faction%2FcjoGetFulltext%3Ffulltextid%3D593416&ei=658tSIOqH4WIpATJ99XFAQ&usg=AFQjCNFIYLNv15KQxNPyLuV4l_dij3whFw&sig2=lQPaqsz0Ls41vyPhtuc4NA > > http://journals.cambridge.org/download.php?file=%2FNRR%2FNRR11_01%2FS0954422498000043a.pdf&code=aa215b593ea11deda467b20ce538f628 > > > Abstract> > For at least 40-50000 years, plants played an important but > supplementary role in the animal-dominated diet of Australian Aboriginal > (AA) hunter-gatherers. New knowledge of the nutrient composition and the > special physiological effects of their foods provides another > perspective in the current debate on the composition of the prudent’ > diet and the diet on which humans evolved. In the present paper we have > calculated the average nutrient composition of over *800 Aboriginal > plant foods* (in total and by food group) and highlighted the > differences between these and modem cultivated foods. The data enable us > to calculate the absolute contribution of plant foods to total food and > nutrient intake of traditional living AA. If plants provided 20-40% of > the energy in the diet (the most likely range), then plants would have > contributed 22-44 g protein, 18-36 g fat, 101-202 g carbohydrate, 40-80 > g fibre and 90-180mg vitamin C in a 12500kJ (3000kcal) diet. Since all > the carbohydrate came from plant foods, the traditional AA diet would > have been relatively low in carbohydrate (especially starch) but high in > dietary fibre in comparison with current recommendations. Over half the > carbohydrate could have been in the form of sugars derived from fruit > and honey. The low glycaemic index of their carbohydrate foods, however, > would generate a relatively low demand for insulin secretion and this > characteristic may have protected AA from a genetic predisposition to > insulin resistance and its consequences (non-insulin-dependent diabetes > mellitus, coronary heart disease, obesity). The dietary pattern and > active lifestyle of recent hunter-gatherers such as AA may be a > reference standard for modem human nutrition and a model for defence > against diseases of affluence.> > <BIG SNIP>> > Roots and tubers> > Aboriginal people ate many kinds of roots, tubers and bulbs. The ones > that stand out are the Dioscorea species (yams), and Ipornoea costata > (wild potato), Cyperus species (native onion) the yam daisy, Microseris > scapigeris. Many of the roots contained a poison which was removed by > extensive leaching in running water. Some have a composition which is > similar to a potato with about 15-20% carbohydrate, but others are more > like a carrot with much less carbohydrate and less energy, but lots of > fibre. Many roots and tubers (for example Microseris scapigeris) > contained an unabsorbable carbohydrate called inulin which is thought to > promote a healthy intestinal flora (Incoll et al. 1989). In the Tables > we are unable to distinguish between> the roots that were high in inulin and those high in starch.> > In the Central Desert the tubers of Ipomoea costata and Vigna lanceolata > and the bulbs of Cyperus bulbosus were important staples available > during any season with suitable rainfall and thereafter they are > preserved underground indefinitely (O’Connell et al. 1983). Sweeney > (1947) writes of the desert yam as “the most remarkable of the native > foods that nature has developed in the desert providing a nutritious > food under hard conditions which can be harvested at any time of the > year”. Sweeney’s desert yam was probably Ipomoeu costata, not Dioscorea > sp. as was originally thought (Meggitt, 1957). The tubers found 50 to > lOOcm underground and are harvested by digging with yam sticks and using > wooden food vessels as shovels. Tubers of I. costata up to the size of a > human head were once obtained. They can be eaten raw or cooked and have > a slightly sweet taste.> > The average nutrient composition of all the AA roots (n = 65 ), tubers > (n = 86) and bulbs (n=30) is shown in Tables 1 and 2. Compared with 11 > cultivated rootstocks, AA roots and tubers are slightly lower in water > (76 v. 70 %) but fairly similar in protein (1.6 v. 2 %) and fat (0 v. > 0.5 %). The AA rootstocks are apparently similar in carbohydrate (17-22 > %) to cultivated varieties (19 %), but the figure for AA is a likely > overestimate. The fibre content of AA roots and tubers is at least 8% > (an underestimate) compared with only 2% in the cultivated bulbs such as > onions and leeks. AA bulbs (n = 30) are more desiccated (average > moisture 56 % v. 90 % in cultivated bulbs) and significantly higher in > carbohydrate compared with cultivated foods (3 v. 5 %). The vitamin C > content of AA roots and bulbs averages only 8-11 mg/lOOg, while the > tubers are a much better source with 46 mg/100 g, although the variation > is very high. The thiamin and riboflavin content of the wild and > cultivated varieties is similar.> > <CONTINUES>> > Writers often comment on the wide range of vegetable foods available to > hunter-gatherers which contrasts with the relatively narrow variety of > crops produced by agriculture. AA across Australia ate some 300 > different fruit species and 150 varieties of roots and tubers. However, > we do not know to what extent AA exploited all the species available or > limited themselves to an optimal foraging strategy based on relatively > few species. In the animal-dominated diets of AA, plants were > subsidiaries, not dietary mainstays that we recommend today.> > <CONTINUES>> > -- > > Steve
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