Difference between revisions of "Philosophy of Food Spring 2018 Class Notes"
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:*Carb chemistry/metabolism basics -- 120: also in our nutrition textbook chapters. Note unique types of saccharides in particular foods: read 121 and 126; insulin resistance. | :*Carb chemistry/metabolism basics -- 120: also in our nutrition textbook chapters. Note unique types of saccharides in particular foods: read 121 and 126; insulin resistance. | ||
− | :*Measuring MACs - the authors acronym for Macrobiotically Available Carbohydrates. - no standard measure of dietary fiber ( | + | :*Measuring MACs - the authors acronym for Macrobiotically Available Carbohydrates. - no standard measure of dietary fiber (note discrepancies from above.) |
:*RDAs: 29/38 grams. Actual 15 grams/day. | :*RDAs: 29/38 grams. Actual 15 grams/day. |
Revision as of 23:43, 1 February 2018
JAN 18: 1
- Course Content: A brief look at the major course research questions.
- Course mechanics:
- Websites in this course. alfino.org --> wiki and courses.alfino.org
- Roster information -- fill in google form
- Main Assignments and "Grading Schemes"
- To Do list:
- Send me a brief introduction through the "Tell Me" form on the wiki. (Soon, please.)
- Login to wiki for the first time and make a brief introduction on the practice page. (3 points if both are done by Friday.)
- After rosters are posted, login to courses.alfino and look around. Note "Links" for pdfs. Retrieve reading for Monday (and read it).
- Browse wiki pages, especially some of the old food news.
- Get the book. Pollan, In Defense of Food
- Start printing pdfs. Highly recommended.
- The Prep Cycle -- recommendations for success in the course!
- Read - Check out Advice on Reading. Look at last year's class notes for the reading, if available. Be ready for quizes.
- Make sure your in-class notes link class notes and problems and issues to readings. This is how you get a high level of information and detail to work with in your thought and expression.
- Class -- Our pattern is to consolidate our understanding of the reading and then engage in philosophy on the basis of it. Small group discussion is a training experience. Everything is a training experience.
- This is the basic pattern for our coursework. From this cycle we then develop short philosophical writing and position papers using by instructor and peer review.
JAN 23: 2
- show survey results; Spending on Food by country
JAN 25: 3
Gastrpod, "The End of the Calorie"
- Sanctorio Sanctorius - 30year practice for weighing inputs and outputs.
- Antoine Lavasier — Guinea pig in coffee urn - we “burn” food chemically. Change in temperature of water the pig is in. 1st “calorimeter”. Axed in French Rev.
- Later defined by a german scientists (Favre and Silbermann in 1852 or Mayer in 1848) as: Amount of heat energy to raise 1 gram of water by one degree centigrade from 14.5 to 15.5 at sea level.
- We still use calorimeters......museum of calorimeters also. Visit to contemporary calorimeter. Converted walk in cooler. Implication that the woman with the sewing machine “made a mess”?
- Bomb calorimeter. You burn the food. Segment on how it works.
- Wilbur Atwater. Atwater values. USDA scientist. “Father of nutrition science” (Nestle likes him.). 4,000 food values. Method...omg. Potental energy (bomb cal value) - excretion = value. 4 cal/gram of carb or protein. 9 calories per gram of fat. (7 alcohol).
- Recent evidence about variability of calorie values — researchers repeating Atwater research, but using additional measures. David Baer and Bill Rumpler both work at the Food Components and Health Laboratory at the USDA-ARS headquarters, in Beltsville, Maryland. Check out Baer and his colleagues' papers on the difference between the calories on the label and those our bodies can extract for almonds and walnuts.b. “The food is free, but you have carry ...”. 5-6% off on tree nuts, 30% on almonds, 21% walnuts,
- Richard Wrangham is the author of Catching Fire: How cooking made us human. Harvard medical anthropologist. —
- First to show that cooking changes food to allow earlier digestion (small intestine) and greater calorie recovery. 40% for starch. Also cooked meat, peanuts. All research on mice (and pythons). Still hard to say what the variation will be for us. Maybe 20-40%. What about heat extrusion, also called Food Extrusion? (Used in cereals.). Industrial food might raise calorie levels relative to atwater values. That's a good thing, right? Or is it?
- Digression on Food Extrusion (based on Sp'17 course):
- [1]
- So, if extrusion damages nutrition, what about pasta? Why doesn't it have a high glycemic index like breakfast cereals?
- "In pasta products, gluten forms a viscoelastic network that surrounds the starch granules, which restricts swelling and leaching during boiling. Pasta extrusion is known to result in products where the starch is slowly digested and absorbed (59,60). Available data on spaghetti also suggest that this product group is a comparatively rich source of resistant starch (61). The slow-release features of starch in pasta probably relates to the continuous glutenous phase. This not only restricts swelling, but possibly also results in a more gradual release of the starch substrate for enzymatic digestion. Pasta is now generally acknowledged as a low glycemic index food suitable in the diabetic diet. However, it should be noted that canning of pasta importantly increases the enzymic availability of starch, and hence the glycemic response (62).[2]
- Sarah Haley — scientist claiming counting calories didn’t work.
- CALORIES AND THE GUT MICROBIOME
- Peter Turnbaugh's lab at the University of California, San Francisco, promises "better living through gut microbes." In our conversation with him, we discussed this study on the effects that transplanting gut microbes from lean and obese twins had on the weight of mice. Further examples of the impact of microbes on energy balance can be found in this paper on one woman's weight gain following a fecal transplant, and this paper on how risperidone is associated with altered gut microbiota and weight gain.
- microbiota creates variation in calorie capture.
- 36:45. Sarah Hailey comment.
- CALORIE REPLACEMENTS?
- Susan B. Roberts is the creator of the satiety-based "iDiet." She has also done extensive research into the accuracy of calorie counts on menu labels. David Ludwig's book, Always Hungry?, also proposes measuring foods based on their satiety score. Adam Drenowksi's Nutrient-Rich Food Index is explained here.
- They acknowledge that we don’t have a better standard, but other methods might tell us more.
- DAVID WISHART AND METABOLOMICSDavid Wishart's research group is based at the University of Alberta. You can check out the Human Metabolome Project Database online here. And the Israeli study on personalized nutrition based on individual glycemic responses is available online here.
- WHY THE CALORIE IS BROKEN
- We wrote a feature article for Mosaic, the online publication of the Wellcome Trust, to accompany this episode. You can read it online here.
- THE CHEMICAL DEFINITION OF THE CALORIE
- In the episode, we say that a calorie is the amount of heat energy needed to raise the temperature of one gram of water by one degree centigrade, from 14.5º to 15.5º, at one unit of atmospheric pressure. This is accurate, but it is misleading, because throughout the rest of the episode, we are discussing a different kind of calorie—the kilocalorie, which is the amount of heat energy needed to raise the temperature of one kilogram of water by one degree centigrade. The kilocalorie is the number we see on our food labels and recommended daily allowances, but no one other than chemists actually calls it the kilocalorie. Instead, it has been shortened to "calorie" on labels and in everyday usage. Throughout our episode, we follow common practice by calling a kilocalorie a calorie, but then we mistakenly gave the definition of a true calorie without noting the difference. We apologize for any confusion!
- The University of Alberta's David Wishart offers us a glimpse of the future, in which truly personalized nutrition advice will evolve from the emerging science of how the chemicals in our bodies interact with all the different chemicals in the food we eat. And Susan Roberts, director of the energy metabolism laboratory at the Tufts USDA nutrition center, suggests an alternative unit as a replacement for the traditional calorie.
-
Groopman, Jerome, "Is Fat Killing You, Or is Sugar?"
- the author, a medical doctor, start with 1960's cholesterol culture in US and his own experience with diet and statins to change his levels.
- Fat is back -- oils and nuts are good again, Atkins and paleo diets (ketosis diets) make health claims. But looking at a study underlying one of these claims for the med diet, one finds the significance of the science overstated.
- The article uses a review of two books to make some points about the connection between nutrition science and dietary advice.
- Sylvia Taylor, Secret Life of Fat
- Gary Taubes, The Case Against Sugar
- Digest of Taylor's case: You need fat in your body to metabolize many vitamins, to signal regulatory mechanisms for appetite (leptin). Every neuron in your brain is sheathed in a lipid. She also espouses an inflammation theory of obesity. Groopman is critical of the quality research here. There is no easy dietary advice that follows from understanding lipids. (But note that it could still be helpful in training our intuitions against simplistic dietary advice!)
- cites historical models for "moral diets" like Brillat-Savarin, Graham, Fletcher....(We will read more about these characters.)
- Wibur Atwater -- still a census: Calories matter.
- Post WW2 AMA declares obsesity a major health problem. Ancel Keys -- Promoted low fat, low unsaturated fat diet, such as Med. Diet.
- traces Taubes early food journalism, "What is Its all a Big Fat Lie?" 2007: Good Calories, Bad Calories. Taubs 1. makes strong claims for sugar as the "culprit" in the Western Diet and 2. tells the Big Sugar political story, e.g. "the food industry has systematically tried to obstruct scientific research that exposes the dangers of sugar, just as tobacco companies tried to hide the risks of smoking." (note that Groopman agrees with the latter claim.)
- traces history of sugar industry effort to refute the claim that is is an "empty calorie" (makes a food calorie dense)
- research funding history, research funding wars.
- Groopman claims that Taubes overstates the evidence for sugar as a single cause. Follows his somewhat unscientific reasoning. He lumps lots of very different diseases together. The analogy between tobacco and sugar doesn't carry over to the molecular level. (Note: This does not mean that glycemic response is not an important area of recent research, just that it can't be recruited in this fashion.)
- Note his closing critique of diet books: oversimplification, overreliance on macronutrient theories, or behavioral tricks. Meta-research on diets undermines their efficacy.
- (To the extent that diet books are effective, it's because their advice overlaps to some degree with mainstream advice. The "trick" in the diet isn't what's effective.)
JAN 30: 4
Microbiome Movie Notes
Montgomery, David and anne Bilke, "What Your Microbiome Wants for Dinner"
- Digestion Basics
- good introduction to digestion.
- inverse relation between complexity of the food molecule and how far it continues to contribute to digestion as it moves through the tube.
- note distinct environments of the tract and their respective "ecologies" - 7 quarts of fluids through small intestine.
- genomic "division of labor" -- our genes code for 20 enzymes to break down complex carbs but our bacterial guests code for 260 enzymes for that purpose.
- Microbiota (M) like a pharmacy.
- Grain Wreck
- Chemistry of Typical cereal crop seed --
- Note that you lose the fats in the grain to stabilize it for production purposes. Fats go rancid. Also, white bread is sweet to the taste. Because it's already breaking down into sugars (simpler carbs) even in your mouth.
- historical point: total carb consumption stable over 20th c US, but types of carbs changed. Whole grains and rate of sugar absorbtion (tracked by "glycemic index")
- Meat
- Protein Putrefication (Does this happen alot?) - compounds produced by undigested meat in large intestine interferes with butyrate production -- important for general colonic health. Thinning of bacterial density leaves openning for pathogens and physical damage.
- High fat diets can lead to higher rates of bile in the large intestine, which it doesn't handle well. secondary bile acids.
- Needn't be a general health argument against meat, but he acknowledges some legitimate health advantages to a vegetarian diet. Point is that cereal fermentation might be part of the process that helps us tolerate the protein putrefication and excess bile of meat and fat.
- espouses what I'm calling the "consensus healthy diet" - movement away from industrial processed food.
Sonnenbergs, C 1, "What is the Microbiota and Why Should I Care?"
- How the world looks to a microbiologist! "Without microbes humans wouldn't exist, but if we all disappeared, few of them would notice." 10
- Introduction to the Tube and digestion
- Microbiota Case against the Western Diet
- Sets the history of human diet in context. Agriculture already a big change, but then industrial ag / industrial foods
- Adaptability of M remarkable. Makes us omnivores.
- Baseline M - cant' be health Western Diet eaters. studies of groups like Hadza -- far more diverse.
- 19 - Evolved Symbiotic relationship between us and bacteria --
- types of symbiotic relationship - parasitic, commensal (one party benefits, little or no effect on the other), mutualism.
- The heart warming story of Tremblaya princeps and Moranella endobia. (21) -- why we should be happy mutualists. Delegation and division of labor might create resiliance.
- 22-30 - Cultural History and History of Science on Bacteria
- The Great Stink 1858 London, Miasma theory disproved, Cholera bacterium, not isolated until near end of century. Dr. Robert Koch.
- 60-70's: Abaigail Salyers: early pioneer, 2008: Human Microbiome Project
- Contemporary research: gnotobiotic mice. early fecal transplant studies of [Dr. Jeffrey Gordon].
Philosophical Implications of the Microbiome
- The Microbiome research we are reading seems to have implications for the following course research questions:
- 1. What is food?
- 5. What are the challenges of nutrition science as a field of knowledge and what is the state of knowledge about nutrition, broadly?
- 6. What is a nutritious diet?
- 10. How should I critically assess my own food practices in light of my understanding of the nature of food and food culture?
- Here are some possible theoretical claims for you to evaluate in terms of their plausibility and their own implications:
- Your food doesn't just feed you.
- Your food doesn't just nourish you, it also supplies a pharmacy in your gut. These effects cut across the health spectrum and life span.
- You exist as a distinct organism, but you cannot survive outside of the symbiotic relationships you have with bacteria and other organisms that call you home.
- Mental health is influenced by the health of our M.
- We have co-evolved with our Microbiome.
- The interic nervous system is an ecology.
- Some of the requirements of industrial food production are at odds with the requirements of a health Microbiome.
- In small group discussion, consider how information about the Microbiome might change your approach to questions like "What is Food?" Then look over the proposed philosophical implications above. Are they too strong? Warranted? Do you have sceptical doubts about using this research to alter your view of these research questions?
FEB 1: 5
- Data on glycemic index and a puzzle....
- Isolated Fiber in industrial food
Sonnenbergs, C 5, "Trillions of Mouths to Feed"
- Microbiota extinction -- not just from change in foods, less fermented foods, more sterile food and sterile environments. pets help with our microbiota.
- Microbiota mechanisms:
- direct response to diet, "recyclers",
- life is hard for our M germs: no oxygen down there and transit time is fast. So they make SCFAs that can metabolize in the blood stream where there is oxygen.
- Why feed the gut? Isn't that just more calories? (116) - No. people with high scfa diets lose weight, decrease inflammation, Western diet diseases.
- History of research -- field doctors: Thomas Cleave, 70s "The Saccharine Disease" "Bran Man"; Denis Burkitt studies comparing Western and Africans on fiber, stool quality, and health.
- Carb chemistry/metabolism basics -- 120: also in our nutrition textbook chapters. Note unique types of saccharides in particular foods: read 121 and 126; insulin resistance.
- Measuring MACs - the authors acronym for Macrobiotically Available Carbohydrates. - no standard measure of dietary fiber (note discrepancies from above.)
- RDAs: 29/38 grams. Actual 15 grams/day.
- research discovering enzyme in nori, a seaweed based sushi wrapper: found in Japanese guts. Helps digest fish. Note: Terrior. Local adaptation of the M.
- research on rich and poor. richness of M better predictor of disease than obesity.
- Gordon's famous FMT mouse research: need M and M-supporting diet.
- what's wrong with refined cereal seeds (130) (like Montgomery's account). Wheat bread vs. Wheat berries. The form of the food matters to the fiber count.
- What about the Inuit?
- What about excess gas?
Sonnenbergs, C 7, "Eat Sh*t and Live"
- This chapter is more focused on diseases that have been treatable with new knowledge about the M, and the limits of that research currently.
- Gastroenteritis, infectious diarrhea, -- culprits like Giardia, Salmonella, and norovirus.
- Immunological effects of the M: "colonization resistance" - mechanisms (165) - crowding out, bacteriocidal chemicals. Problematic nature of antibiotics in the M.
- C. difficile (Cdiff) -- associated disease CDAD. why antibiotics don't always help. spores.
- 2013 Dutch FMT therapy for CDAD - 94% cure rate (note earlier researcher in 50s who tried this.)
- Antibiotics -- Interesting that Americans not only eat the Western Diet, but take high levels of antibiotics. Effects of Cipro on M. -- decrease in volume (-10-100x) and diversity of bacteria (25-50% of species). Test subject had diverse responses. Some recovered M in several weeks. Some sustained damage. 2nd round of Cipro hurt everyone's M.
- IBS and IBD - 177:
- Difficulties with FMT as a therapy: dangers in introducing new bacteria into someone's gut. Might be hard to remove. (Like issue of releasing GMOs in environment.)
- Limited results from FMT in humans for obesity treatment. or inflammatory bowel disease.
Some implications of Microbiome research
- The form of the food you eat partly determines the kinds of nutrition you can get from it.
- Nutritional information about the food is incomplete for assessing potential nutrition from the food.
- Which part of you eats the food affects what kind of nutrition (and other benefits) you receive from it.