Tag Archives: paleo cooking

Embracing Your Inner Paleo Chef | The Paleo Diet
It’s often said that meat made us human. Meat allowed for larger brains and greater intelligence, not to mention more time for pursuits other than chewing. So how did a species that ate relatively little meat 2.6 million years ago evolve into one that depended on meat and was radically transformed by its consumption?

Do we owe this success to fire and our learned ability to cook? Or does a more rudimental form of “cooking” deserve the credit? As every chef knows, you don’t just toss whole vegetables and large slabs of meat into the casserole. You have to slice and dice before turning on the fire. This sequence of processing food with tools before applying fire, which happens every time we cook, epitomizes the entire evolution of cooking.

Today’s chefs use knives, blenders, and other modern “processing tools,” but the “old-old school” chefs, to whom the entire human enterprise owes its existence, used crude stone tools to process meat, making it easier to chew and digest. This was and still is the beginning of cooking.

 

Chef Erectus

Around 1.8 million years ago, Homo erectus emerged on the Paleolithic scene. Homo erectus differed in many ways from earlier hominins, including his larger brain, shorter digestive tract, smaller jaws and teeth, reduced chewing muscles, and weaker bite force.

Between 2 and 3 million years ago, Africa was undergoing a dramatic drying trend, which resulted in new grassland habitats. Consequently, Homo erectus had larger foraging areas than his jungle-dwelling arboreal predecessors. In the words of University of Colorado paleoanthropologist Thomas Wynn, “Erectus has gone completely terrestrial — not climbing trees very much at all.”1

Homo erectus needed calories and plenty of them. Bigger brains require more calories as do the demands of travelling long distances searching for food. The modern human brain consumes 20 percent of the body’s at-rest energy, more than twice that of other primates.2 Less evolved primates, on the other hand, expend the bulk of their energy digesting low-calorie plant food. “You can’t have a large brain and big guts at the same time,” explains Leslie Aiello, an anthropologist and director of the Wenner-Gren Foundation in New York City.3

Homo erectus evolved because he ate meat, but what made this possible? Have you ever tried chewing raw meat? It’s extremely tedious and wholly unlike chewing cooked meat. Had Homo erectus already mastered the use of fire for cooking? Or was this technology still more than a million years from being discovered? If the latter, how was Homo erectus able to chew raw meat with such decidedly disadvantaged teeth?

The Homo Erectus School of Cooking

In his 2009 book, Catching Fire: How Cooking Made Us Human, Harvard anthropologist Richard Wrangham hypothesized that Homo erectus was already cooking with fire by 1.8 million years ago. Convincing evidence notwithstanding, most archaeologists, paleontologists and anthropologists think Wrangham was wrong. A more reasonable estimate for the beginning of fire-based cooking is 400,000 years ago.4

One thing is certain though. Before man learned to cook with fire, he learned to process meat with tools. On the difficulty of chewing raw meat, even Wrangham acknowledges, “It probably wouldn’t take [early man] long to realize you could pound the meat. To pound the meat they would have gotten more energy out of it.”5

But just how much energy did such tool processing save? This question was put to the test for a study recently published in Nature6. Harvard scientists Daniel Lieberman and Katherine Zink attached electrodes to volunteers’ faces to measure muscle activity while using force transducers between their molars to measure chewing force. They tested meat and root vegetables, including cooked samples, unprocessed samples, and sliced/pounded samples.

They found that slicing and pounding meat and vegetables results in 17% less chewing, equating to 2.5 million less chews per year. Lieberman and Zink concluded that tool processing, which is an early form of “cooking,” enabled Homo erectus to reap the benefits of meat. “If you are using less force and using fewer chews, you are, of course spending less time eating,” Zink explained. “And if you no longer need to maintain the big jaws and big teeth, it allows natural selection to choose for other performance benefits that improve fitness and survival.”7

We can say that Wrangham, Lieberman, and Zink are all correct. Cooking made us human because cooking enabled us to eat meat. And although Homo erectus probably didn’t cook with fire, he certainly used stone tools to slice and pound meat, making it easier to chew and digest. This is how the technology of cooking began, just as every cooked meal today begins with chopping, slicing, and dicing. So go ahead and embrace your inner Paleo chef. For if cooking truly made us human, then at our cores we are all chefs.

References

[1]  Choi, CQ. (November 11, 2009). Human Evolution: The Origin of Tool Use. LiveScience. Retrieved from //www.livescience.com/7968-human-evolution-origin-tool.html

[2] Raichle, ME, et al. (August 6, 2002). Appraising the brain’s energy budget. Proceedings of the National Academies of Sciences, 99(16). Retrieved from //www.pnas.org/content/99/16/10237.full

[3] Joyce, C. (August 2, 2010). Food For Thought: Meat-Based Diet Made Us Smarter. NPR. Retrieved from //www.npr.org/2010/08/02/128849908/food-for-thought-meat-based-diet-made-us-smarter

[4] Roebroeks, W., et al. (2011). On the earliest evidence for habitual use of fire in Europe. Proceedings of the National Academy of Sciences, 108(13). Retrieved from //www.pnas.org/content/108/13/5209.full

[5] Gorman, RM. (2007). Evolving Bigger Brains through Cooking: A Q&A with Richard Wrangham. Scientific American. Retrieved from //www.scientificamerican.com/article/evolving-bigger-brains-th/

[6] Zink, KD and Lieberman, DE. (2016). Impact of meat and Lower Palaeolithic food processing techniques on chewing in humans. Nature. Retrieved from //www.nature.com/nature/journal/vaop/ncurrent/full/nature16990.html

[7] Netburn, D. (March 9, 2016). How raw meat — and our ancestors’ inability to chew it — changed the course of human evolution. LA Times. Retrieved from //www.latimes.com/science/sciencenow/la-sci-sn-raw-meat-stone-tools-evolution-20160309-story.html

 

Ghee | Paleo Diet

Released from The Insider Vault: What’s the Skinny on Ghee?

I’m often asked is ghee Paleo? If you are not familiar with ghee, it comes from the Sanskrit word ghrita, meaning bright, and is clarified butter fat in which most of the water has been boiled off and the nonfat solids removed by continued heating, filtration, or decanting the remaining oil mixture.1 Traditional societies in India and elsewhere have produced and consumed ghee since at least 1500 BC.1

HOW IS IT MANUFACTURED?1

  1. Milk butter or desi method
  2. Direct cream method
  3. Cream butter method
  4. Pre-stratification method

All four commercial procedures to produce ghee rely upon heating at temperatures from 105° to 118° C to remove the water.1

Ghee typically contains milk fat (99 to 95%), water (< 0.5%) and protein (0.1%). The butter fat remaining in ghee after boiling and removal of nonfat solids contains saturated fatty acids (53.9 to 66.8%), polyunsaturated and monounsaturated fatty acids (22.8 to 38%), free fatty acids bound to albumin (1-3%), and cholesterol (0.15 to 0.30%).1, 2

In 1987, Jacobson first pointed out that ghee contained high concentrations (12.3%) of oxidized cholesterol, otherwise known as oxysterols.3 He suggested that consumption of ghee, with its high levels of oxidized cholesterol, by Indian immigrant population living in the UK likely represented an important dietary risk factor for atherosclerosis and heart disease.3 In subsequent years, it has been conclusively demonstrated in human, animal and epidemiological studies that dietary intake of oxidized cholesterol accelerates the rate of atherosclerosis or the hardening of the arteries, as well as increasing the size of the arterial plaque.4, 5, 6 Hence because of their atherogenic, cytotoxic and pro-inflammatory effects, oxidized cholesterol food products are almost universally recommended to be reduced or minimized in our diets.7, 8, 9

The final aspect of the ghee story that requires further scrutiny is the high concentration (12.3%) of oxidized cholesterol that Jacobson initially reported in
1987.3 This value has been questioned because of the analytical procedures that were used to measure the oxidized cholesterol.9 More recent studies suggest this
high value may have been incorrect.9, 10, 11

Fresh butter and cream samples contain barely detectable concentrations of oxidized cholesterol, whereas ghee manufactured at temperatures below 120°C contained 1.3% oxidized cholesterol.10, 11

Whether or not regular consumption of oxidized cholesterol at this lower concentration can still induce atherosclerosis in humans is currently unknown. However, part of the problem with ghee is that it is frequently used to fry food or is re-used many times in cooking foods. Both of these procedures are known to increase oxidized cholesterol to levels known to cause atherosclerosis in animal models.4 Foods fried in ghee may contain 7.1% oxidized cholesterol, whereas intermittently heated ghee contains 8.1 to 9.2% oxidized cholesterol.10

My advice is to skip ghee altogether and replace it with virgin olive oil for Paleo cooking and in salads.

 

References

1. Sserunjogi ML, Abrahamsen RK, Narvhus J. A review paper: Current knowledge of ghee and related products. Int Dairy J. 1998;8:677–88.

2. Sarojini JK, Ubhayasekera SJ, Kochhar SP, Dutta PC. Lipids and lipid oxidation with emphasis on cholesterol oxides in some Indian sweets available in London. Int J Food Sci Nutr. 2006 Nov-Dec;57(7-8):451-8.

3. Jacobson MS. Cholesterol oxides in Indian ghee: possible cause of unexplained high risk of atherosclerosis in Indian immigrant populations. Lancet. 1987 Sep 19;2(8560):656-8.

4. Soto-Rodríguez I, Campillo-Velázquez PJ, Alexander-Aguilera A, Rodríguez-Estrada MT, Lercker G, Garcia HS. Biochemical and histopathological effects of dietary oxidized cholesterol in rats. J Appl Toxicol. 2009 Nov;29(8):715-23

5. Staprans I, Pan XM, Rapp JH, Feingold KR. The role of dietary oxidized cholesterol and oxidized fatty acids in the development of atherosclerosis. Mol Nutr Food Res. 2005 Nov;49(11):1075-82.

6. Staprans I, Pan XM, Rapp JH, Moser AH, Feingold KR. Ezetimibe inhibits the incorporation of dietary oxidized cholesterol into lipoproteins. J Lipid Res. 2006 Nov;47(11):2575-80.

7. Otaegui-Arrazola A, Menéndez-Carreño M, Ansorena D, Astiasarán I.Oxysterols: A world to explore.Food Chem Toxicol. 2010 Dec;48(12):3289-303.

8. Hur SJ, Park, GB, Joo ST. Formation of cholesterol oxidation products (COPs) in animal products. Food Control 2007;18:939-947.

9. Sieber R. Oxidised cholesterol in milk and dairy products. Int Dairy J 2005;15:191-206.

10. Kumar, N. and Singhal, O. P. (1992), Effect of processing conditions on the oxidation of cholesterol in ghee. J. Sci. Food Agric., 58: 267–273.

11. Kumar MV, Sambaiah K, Lokesh BR. Effect of dietary ghee–the anhydrous milk fat, on blood and liver lipids in rats. J Nutr Biochem. 1999 Feb;10(2):96-104.

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