Gather

It's bad enough that I'm dead

It's unfortunate that well-meaning health bloggers and personalities have joined grave robbers around the world in misusing mummies, particularly since there aren't a lot of them. It's clear they had some pretty tough lives and in death they are being paraded around to debunk various popular diets. If you think high-protein diets are bad, you have a tiny selection of Siberian, Aleut, and Eskimo mummies to defame. If you think grains are evil, you have a nice selection of Egyptian mummies with a few bog and ice mummies from various agrarian settlements thrown in. 

But if these diets are all so horrible, why do mummies from diverse places all seem to have atherosclerosis? And the other problems commonly represented in mummies, osteoporosis and cavities, don't seem to track with particular diets at all. For example, caries are present in Aleut mummies AND copper-age grain-eaters like Otzi. Osteoporosis is present in some Eskimo mummies, but also low-fat grain-eaters from South America. With sample sizes so low and the same problems present in all kinds of populations, I'd think nutrition geeks would be happy to leave mummies alone.

But tragically, mummy abuse is rampant in the nutritional community. I recently saw a anti-paleo vegan Youtube Series that used the poor Eskimo mummies to say "What we see here are effectively long-term studies of an animal-based Wise Traditions diet and the results are not pretty." (Credit to Cordain for first abusing these particular mummies). 

Yikes, that's one sad little study, but it's not just vegans who mistreat our poor mummy friends. Dr. Eades has written quite a bit on Egyptian mummies. While  I agree it's quite hilarious that their low-fat diet didn't do much for them, I'm not sure there are a reason to throw out the kamut just yet. 

You see, while mummies are great for understanding how people lived in the past, they aren't great tools for shooting down diets. There aren't very many of them and their health problems weren't all caused by their diets anyway. An excellent book if you are interested in mummies is Mummies, Disease, and Ancient Cultures, which includes an excellent survey of various mummies and what modern science can tell us about their health problems. Like the original scientists who studied the Eskimo mummies, this text concludes that their methods of heating and cooking were extremely detrimental to their health: "The winter houses were semisubterranean with a tunnel entrance and heated by small seal oil lamps. The hot air in the house would not sink into the tunnel when the door, in the floor of the house, was opened. This effect also trapped smoke in the house. In addition it was the duty of the women to trim the lamp at night; sleeping next to the lamp increased the exposure to smoke, resulting in severe anthracosis* at an early age and lung damage, including bronchiectasis and emphysema."

So their cooking and heating practices were the equivalent of working in a coal mine and definitely worse than smoking modern cigarettes (which almost always have a  filter). Needless to say, this is not good for your lungs, heart, or bones. Indoor air pollution from cooking and heating fires remains a major health problem in developing countries. If anything, these mummies are an excellent reason to me to be thankful for my gas stove and radiator heating during this cold December. And a reminder that things like lung and heart problems are not diseases of civilization. 

For the other mummies, in the age of modern dentistry and antibiotics, it's easy to underestimate the contribution of dental disease and infection to atherosclerosis. It's also easy to overestimate the certainty of paleopathology, which can be quite controversial:

The development of vascular calcification is related not only to atherosclerosis.4​ Other conditions may lead to the formation of such lesions, including aging, diabetes, disorders of calcium-phosphorus metabolism, chronic microinflammation, hyperhomocysteinemia, and chronic renal insufficiency.3 Moreover, given the poor state of preservation of the organic tissues, a differential diagnosis for the findings should include parasitic calcifications in lymphatic vessels (particularly from filariasis).
 

Conclusion on Mummies:

Relevance to your health: low

Chance of being haunted by vengeful undead: high

*= AKA "black lung" 

 Sometimes it seems like NYC government isn't sure what to do about food. There is a push towards a more paternalistic food policy, but it's rather laughable. For example, the "food desert" issue. Some time ago, food policy researchers started talking about "food deserts", places where it's almost impossible to get fresh fruits and vegetables without traveling a great distance. Some places in NYC were pegged as food deserts and the city had a few insipid initiatives to "help" the situation. One of them was fresh fruit and vegetable carts, called "green carts." They subsidized these carts, hoping to encourage them in these "food deserts." The problem was that savvy folks were more than happy to take the subsidy and set up in a gentrified area on the edge of a "food desert," such as Morningside Heights near Columbia University. They set up near upscale grocery stores, who were unhappy that the city was subsidizing their competition. In the meantime, I wonder how well those food policy experts who study food deserts looked into the grey market here. Get off a subway in East New York and you'll usually find several hawkers of fresh mango and other fruit. The problem is that these carts are illegal for some reason. So at the same time the city has been subsidizing Green Carts in areas where they weren't needed, they have been cracking down on some of these sidewalk vendors. The crackdown has unfortunately also happened in my neighborhood, which is economically mixed. The government says the produce might be unsafe because of car exhaust from the roads. I wonder if the government has ever heard of pesticides? The government has also been cracking down on people gathering wild berries, greens, and mushrooms from parks, a hobby of both immigrants and locavores. 

Either way, I think in urban areas like NYC, the idea that people are suffering from diabetes because they don't have fruit is delusional. Harlem is a diabetes hotspot and there is PLENTY of healthy fresh food in most of the same areas where diabetes, obesity, and heart disease is rampant. Every other store seems to have sidewalk displays of ample fresh produce, some very exotic

Display of fruits and vegetables in Hamilton Heights in Harlem, the restaurant next door is Dunkin Doughnuts

The problem here isn't lack of produce, the problem is that every other store that doesn't have produce seems to be a fried chicken joint or Dunkin doughnuts. People are so focused on the myth that produce is a magic bullet that they forget that plenty of unhealthy people eat fruits and vegetables. What's more important in making someone healthy? The inclusion of fresh produce or the exclusion of vegetable oil and sugar? Remember how much better the latter two taste anyway. In areas of the city with less of an immigrant population, efforts to get bodegas to sell fruits and vegetables have led to many bodegas having displays of rotting bananas and apples. If your store sells slurpies and apples, which one are the children going to pick? There is also the issue that in many immigrant communities vegetables might actually be a source of unhealthy eating, as they are frequently fried in the same way as in places like China, where produce consumption is connected with obesity. I find that in many immigrant communities there isn't much awareness about the health effects of using things like vegetable "ghee" or hydrogenated lard. Indeed, now that researchers are finally studying such immigrant communities, they are finding that access to produce doesn't have a connection with obesity. There have been some efforts in certain cities to limit the number of fast food restaurants, usually targeting chains, but a lot of restaurants serving fried sugary food are not chains, they are little mom and pops like the arepa stand in my neighborhood, where the well-meaning woman blissfully coats all her arepas with the cheapest margarine available. I have to wonder if she really knows that margarine isn't a good choice? The government certainly isn't about to tell her. 

 "Those shoes have no arch support!"

Yes, the tired refrain of someone wearing tank-like shoes with tons of sculpting for "support" when they see Vibrams or other totally flat thin-soled shoes. 

You'd think that from three years of such "unsupportive" shoes that my arches would have damn near collapsed. But quite the opposite has happened: they are taller and stronger than ever. In fact they are so well-developed that my shoe size has decreased quite dramatically. In high school I was a size 7. Last year I was buying size 6, but I thought maybe the brands I was buying were unusual. Much to my dismay, this year I'm more a 5.5 and now I know it's not some sort of weird sizing issue. My feet are not wider though, maybe they would be if I did more unshod barefoot running. 

It's very hard to find women's sandals that are totally flat and with a thin shoe. They either seem to be flat, but with an "Earth mama" "supportive" thick heel like these things...

Or they are cute and feminine, but have a cheap standard sole with a small heel:

On a fluke last year I found some great gladiator sandals at Payless, but they literally fell apart recently and the new items at Payless all have hideous heels. So I splurged and got the Flex Collection by Cole Haan Women's Air Vernonia Gladiator Sandal  

It has a nice thin flexible Nike Free sole. Unfortunately the straps are quite uncomfortable and I'm still breaking them in a week later. I'll review them eventually, but if you know of a totally flat AND feminine sandal with a flexible sole, post it in the comments. 

 Another hypothesis is that lack of SCFAs is behind such diseases of civilization. A SCFA called butyrate provides some insight into this. Butyrate is the preferred fuel of the colonic epithelial cells and also plays a major role in the regulation of cell proliferation and differentiation (Wong, de Souza, Kendall, Emam, & D. J. a Jenkins, 2006). Lower than normal levels have been found in patients with several diseases, notably types of colitis and inflammatory bowel disorder. Studies show such diseases can be treated through application of butyrate in the colon. That and the fact that some studies show complete remission through bacteriotherapy transplants point to these diseases being caused by disturbed populations of gut bacteria. Interestingly, these diseases are common in captive populations of apes and unheard of in wild apes (McKenna et al., 2008).

Bacteria affect butyrate production, but so do dietary inputs. Certain fibers produce more butyrate than others in humans, whether or not this differs between primates would be an interesting avenue of research (Smith, Yokoyama, & German, 1998).

Figure 1: Butyrate production in response to fiber

Interestingly, one of the top producers is something known as “resistant starch.” Resistant starch represents the growing nuance in understanding of fiber, since it is a starch that acts like a fiber in terms of acting as a bacterial substrate. It first showed up on the scientific radar when scientists found that low rates of colon cancer were not just found in populations with high-fiber diets, but those with high-starch diets (O'Keefe, Kidd, Espitalier-Noel, & Owira, 1999)¹. Researchers found that a particular starch resisted digestion and ended up being fermented by colonic flora. They called this resistant starch and it is found mostly in cooked starches, some raw starches like green bananas, and some rough unprocessed grains and seeds. The former is termed type III and is a major part of the diets of many foraging populations who consume pounded and cooked starches like cassava, taro, true yam, and sago palm.

Whether or not humans are better adapted to certain types of resistant starch remains unexplored, but could account from some inconsistent results in studies that used type I resistant starch, mostly found in grains and seeds that would have probably been relatively uncommon in our ancestral diet. These studies have shown poor results and others with promising results are marred by high drop out rates due to unpleasant gastrointestinal side effects (Rinne et al., 2005; de Vrese & Marteau, 2007; Vuksan et al., 2007). Whether some populations would do better on this type of starch versus others would be an interesting investigation, but very few cultures consume large amounts of unmilled seeds and grains.

What type of starch we are best adapted to is interesting because the role of starch in human evolution is so controversial. Richard Wrangham has suggested that utilization of cooked starches was one of the dietary quality innovations that fed our rapidly expanding expensive brain tissue as it evolved towards hominid size (Wrangham, 2003). Recent analysis throws a wrench in that theory because it suggests habitual use of fire came after encephalization, about 300,000 years ago (Roebroeks & Villa, 2011). However, this does not mean that such cooked starches did not change humans, even if it reduces their significance in human evolution.

The burgeoning field of archeological starch grain analysis has transformed our view of hominids once thought to be mostly carnivorous. Microfossils on Neanderthal teeth from around 44,000 years ago show evidence of the consumption of many roots and tubers, some of which show evidence of cooking (Henry, Brooks, & Piperno, 2010). The full impact of the adoption of cooked starches on the human body has not been fully elucidated. One promising adaptation is the starch-digesting salivary amalyse gene, AMY 1 (Perry et al., 2007). Chimpanzees and bonobos have only two copies of this gene, humans have as many as 10 copies, though it varies quite heavily by population from 2 to 10 correlated with the importance of starch in the diet. Molecular genetic evidence places the origin of divergence on this gene at about 200,000 years, about the time when habitual fire use became common. Further genetic analysis shows that adaptations to root and tuber starch as a major source of calories may account for variation in human folic acid metabolism, since folic acid is usually low in starchy vegetables (Hancock et al., 2010).

Another relatively unexplored avenue of research would be whether butyrate in the diet itself has led to decreased reliance on butyrate for colonic fermentation in some cultures that consume large amounts of dietary butyrate. The major source of butyrate in food is from the milk fats of grazing animals (Smith et al., 1998).

It is most common in the modern diet in butter at 3%. It is possible that pastoral cultures consume substantial amounts of exogenous butyrate. Currently there have been few studies on oral consumption of butyrate in humans. Animal studies have been inconclusive, with some showing positive effects and some showing negative effects, which is complicated by the fact that if ingested orally it is also present in the small intestine, where it may play different roles (Sengupta, Muir, & Gibson, 2006; Wächtershäuser & Stein, 2000). A small study found orally-administered butyrate had a positive effect on symptoms of Crohn’s disease, but the method of administration was through pills rather than food (Di Sabatino et al., 2005).

Another potential source of butyrate is fermented foods. Some fermented foods like ogi, a pounded fermented starch, contain measurable levels (Hesseltine, 1979). Fermented foods are worth examining evolutionarily because they represent another human dietary innovation in improving food quality. Fermentation increases the bioavailability of nutrients, breaks down starches, and reduces levels of anti-nutritional factors and toxins (Mugula, 2003). It is unknown how long humans have been purposefully fermenting food. Fermentation naturally occurs in the wild and many wild animals are known to indulge in such foods to the point of drunkenness (Dudley, 2002). Spontaneous fermentation and consumption of such foods by wild primates is unfortunately not well studied. However, fermentation is practiced by almost every known culture to some extent, with the largest diversity in fermented foods among African farmers (Dirar, 1993) It is estimated that fermented foods make up 1/3 of the diet of humans worldwide (van Hylckama Vlieg, Veiga, Zhang, Derrien, & Zhao, 2011). Exogenous fermentation may substitute for the reduced fermentative ability of the human gut.
 

1. The researchers concluded that colon cancer risk was increased with meat consumption. I will remain skeptical until they do studies on other cultures that eat relatively low-fiber and high-meat diets like the Masai and Siberian cultures for example.

Di Sabatino, A., Morera, R., Ciccocioppo, R., Cazzola, P., Gotti, S., Tinozzi, F. P., et al. (2005). Oral butyrate for mildly to moderately active Crohnʼs disease. Alimentary pharmacology & therapeutics, 22(9), 789-94. doi: 10.1111/j.1365-2036.2005.02639.x.

Dirar, H. A. (1993). The indigenous fermented foods of the Sudan: a study in African food and ... (p. 552). CAB International. Retrieved May 9, 2011, from http://books.google.com/books?id=J-ogAQAAIAAJ&pgis=1.

Dudley, R. (2002). Fermenting fruit and the historical ecology of ethanol ingestion: is alcoholism in modern humans an evolutionary hangover? Addiction (Abingdon, England), 97(4), 381-8. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11964055.

Hancock, A. M., Witonsky, D. B., Ehler, E., Alkorta-Aranburu, G., Beall, C., Gebremedhin, A., et al. (2010). In Light of Evolution IV: The Human Conditions Sackler Colloquium: Human adaptations to diet, subsistence, and ecoregion are due to subtle shifts in allele frequency. Proceedings of the National Academy of Sciences of the United States of America, 107(Supplement_2), 8924-8930. doi: 10.1073/pnas.0914625107.

Henry, A. G., Brooks, A. S., & Piperno, D. R. (2010). Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium). Proceedings of the National Academy of Sciences of the United States of America, 1-6. doi: 10.1073/pnas.1016868108.
Hesseltine, C. W. (1979). Some important fermented foods of Mid-Asia, the Middle East, and Africa. Journal of the American Oil Chemists’ Society, 56(3), 367-374. Springer Berlin / Heidelberg. doi: 10.1007/BF02671501.

Hylckama Vlieg, J. E. van, Veiga, P., Zhang, C., Derrien, M., & Zhao, L. (2011). Impact of microbial transformation of food on health-from fermented foods to fermentation in the gastro-intestinal tract. Current opinion in biotechnology, 22(2), 219-211. doi: 10.1016/j.copbio.2010.12.004.

McKenna, P., Hoffmann, C., Minkah, N., Aye, P. P., Lackner, A., Liu, Z., et al. (2008). The macaque gut microbiome in health, lentiviral infection, and chronic enterocolitis. PLoS pathogens, 4(2), e20. doi: 10.1371/journal.ppat.0040020.

Mugula, J. (2003). Microbiological and fermentation characteristics of togwa, a Tanzanian fermented food. International Journal of Food Microbiology, 80(3), 187-199. doi: 10.1016/S0168-1605(02)00141-1.

OʼKeefe, S. J., Kidd, M., Espitalier-Noel, G., & Owira, P. (1999). Rarity of colon cancer in Africans is associated with low animal product consumption, not fiber. The American journal of gastroenterology, 94(5), 1373-80. doi: 10.1111/j.1572-0241.1999.01089.x.

Perry, G. H., Dominy, N. J., Claw, K. G., Lee, A. S., Fiegler, H., Redon, R., et al. (2007). Diet and the evolution of human amylase gene copy number variation. Nature genetics, 39(10), 1256-60. doi: 10.1038/ng2123.

Rinne, M. M., Gueimonde, M., Kalliomäki, M., Hoppu, U., Salminen, S. J., & Isolauri, E. (2005). Similar bifidogenic effects of prebiotic-supplemented partially hydrolyzed infant formula and breastfeeding on infant gut microbiota. FEMS immunology and medical microbiology, 43(1), 59-65. doi: 10.1016/j.femsim.2004.07.005.

Roebroeks, W., & Villa, P. (2011). On the earliest evidence for habitual use of fire in Europe. Proceedings of the National Academy of Sciences of the United States of America, 1018116108-. doi: 10.1073/pnas.1018116108.

Sengupta, S., Muir, J. G., & Gibson, P. R. (2006). Does butyrate protect from colorectal cancer? Journal of gastroenterology and hepatology, 21(1 Pt 2), 209-18. doi: 10.1111/j.1440-1746.2006.04213.x.

Smith, J., Yokoyama, W., & German, J. B. (1998). Butyric Acid from the Diet: Actions at the Level of Gene Expression. Critical Reviews in Food Science and Nutrition, 38(4), 259-297. doi: 10.1080/10408699891274200.

Vrese, M. de, & Marteau, P. R. (2007). Probiotics and Prebiotics: Effects on Diarrhea. J. Nutr., 137(3), 803S-811. Retrieved May 9, 2011, from http://jn.nutrition.org/cgi/content/abstract/137/3/803S.

Vuksan, V., Whitham, D., Sievenpiper, J. L., Jenkins, A. L., Rogovik, A. L., Bazinet, R. P., et al. (2007). Supplementation of conventional therapy with the novel grain Salba (Salvia hispanica L.) improves major and emerging cardiovascular risk factors in type 2 diabetes: results of a randomized controlled trial. Diabetes care, 30(11), 2804-10. doi: 10.2337/dc07-1144.

Wong, J. M. W., Souza, R. de, Kendall, C. W. C., Emam, A., & Jenkins, D. J. a. (2006). Colonic health: fermentation and short chain fatty acids. Journal of clinical gastroenterology, 40(3), 235-43. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/16633129.

Wrangham, R. (2003). “Cooking as a biological trait.” Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology, 136(1), 35-46. doi: 10.1016/S1095-6433(03)00020-5.

Wächtershäuser, a, & Stein, J. (2000). Rationale for the luminal provision of butyrate in intestinal diseases. European journal of nutrition, 39(4), 164-71. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11079736.
 

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