Kamis, 29 Mei 2008
Rabu, 28 Mei 2008
Vaccines
20.48
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I am a label reader. Whenever I'm thinking about buying food in a box, which is rare, I typically read the whole label to look for sinister ingredients. So when I got a booster vaccine for tetanus last week, naturally I asked for the product information.
Along with a nice dose of tetanus and diphtheria toxoids, my medial deltoid received 0.28 mg of aluminum, up to 0.3 micrograms of mercury, and up to 100 micrograms of "residual formaldehyde". I got the vaccine because I like being able to chew, but I wasn't able to lift my arm for several days. I don't know if that was due to an immune response to the tetanus and diphtheria (probably) or if it was caused by the aluminum, mercury and formaldehyde they injected into my arm.
We work with formaldehyde in my lab, and I can tell you it is not to be messed with. I had to take an entire training course just to use it, during which I learned that if there's enough of it to smell, it's toxic. 0.1 parts per million in the air is enough to cause a burning sensation in the mucous membranes. We always use it in the fume hood. Formaldehyde is a toxin, a carcinogen, and a teratogen (causes birth defects). So I'm sure you'll understand why I wasn't too happy about having 100 ug of it injected into my body.
I'm not criticizing the concept of vaccines, I just wish they'd make more of an effort to clean them up!
Along with a nice dose of tetanus and diphtheria toxoids, my medial deltoid received 0.28 mg of aluminum, up to 0.3 micrograms of mercury, and up to 100 micrograms of "residual formaldehyde". I got the vaccine because I like being able to chew, but I wasn't able to lift my arm for several days. I don't know if that was due to an immune response to the tetanus and diphtheria (probably) or if it was caused by the aluminum, mercury and formaldehyde they injected into my arm.
We work with formaldehyde in my lab, and I can tell you it is not to be messed with. I had to take an entire training course just to use it, during which I learned that if there's enough of it to smell, it's toxic. 0.1 parts per million in the air is enough to cause a burning sensation in the mucous membranes. We always use it in the fume hood. Formaldehyde is a toxin, a carcinogen, and a teratogen (causes birth defects). So I'm sure you'll understand why I wasn't too happy about having 100 ug of it injected into my body.
I'm not criticizing the concept of vaccines, I just wish they'd make more of an effort to clean them up!
Selasa, 27 Mei 2008
Exercise Didn't Keep Us From Getting Fat
One of the surprising things I noticed when I was poring over data from the NHANES survey (US CDC National Health and Nutrition Examination Survey) from 1975 to 2006 is that the number of inactive people has diminished in that same time period from 50% to 24%. This is shocking to most people. We have this romanticized idea that in the 1970s people were more active, as if everyone chopped wood and walked 15 miles to work in the morning. The reality is, there were office jobs, housewives and cars without the large numbers of runners and gym-goers we have today.
Granted, NHANES data are self-reported and should be taken with a grain of salt. However, Chris at Conditioning Research pointed me to a study looking at changes in energy expenditure from the 1980s to the present in North America and Europe. It doesn't suffer from the same biases because it's based on direct measurement rather than self-reporting. Here's the executive summary: we're expending slightly more energy than we used to, partly because we exercise more and partly because it takes more energy to move our heavier bodies around.
I'm certainly not blaming the obesity problem on an increase in physical activity, but I do think we can safely rule out inactivity as the reason we've gotten fatter. In my mind, this only leaves one major possible cause for the obesity epidemic: changes in diet. Don't get me wrong, I think exercise is good. It has numerous positive effects on physical and mental health. But it's not as powerful of a tool for fat loss and general health as diet.
Anecdotally, I do know several people who lose fat when they exercise regularly. I also know some who don't lose fat when they exercise. Exercise and a healthy diet converge on some of the same metabolic pathways, such as sensitivity to insulin. But diet changes are far more effective than exercise at correcting metabolic problems. The reason is simple: the problems a person corrects with a good diet are caused by a poor diet to begin with.
Granted, NHANES data are self-reported and should be taken with a grain of salt. However, Chris at Conditioning Research pointed me to a study looking at changes in energy expenditure from the 1980s to the present in North America and Europe. It doesn't suffer from the same biases because it's based on direct measurement rather than self-reporting. Here's the executive summary: we're expending slightly more energy than we used to, partly because we exercise more and partly because it takes more energy to move our heavier bodies around.
I'm certainly not blaming the obesity problem on an increase in physical activity, but I do think we can safely rule out inactivity as the reason we've gotten fatter. In my mind, this only leaves one major possible cause for the obesity epidemic: changes in diet. Don't get me wrong, I think exercise is good. It has numerous positive effects on physical and mental health. But it's not as powerful of a tool for fat loss and general health as diet.
Anecdotally, I do know several people who lose fat when they exercise regularly. I also know some who don't lose fat when they exercise. Exercise and a healthy diet converge on some of the same metabolic pathways, such as sensitivity to insulin. But diet changes are far more effective than exercise at correcting metabolic problems. The reason is simple: the problems a person corrects with a good diet are caused by a poor diet to begin with.
Selasa, 20 Mei 2008
California "Raw" Almonds
19.26
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I bought about a pound of almonds yesterday for a backpacking trip I'll be doing this weekend. I like to soak raw almonds, then lightly toast them. It sweetens them and breaks down some of their anti-nutrients.
When I arrived at the grocery store, the only raw almonds they had were from California. I prefer to buy domestic products when I can, but in case you haven't heard, "raw" almonds from California are no longer raw. They are required to be sterilized using steam or antiseptic gases, despite their relative safety as a raw food.
The worst part is that they are not required to label them as pasteurized; they can still be labeled as raw. The Almond Board's argument is that there's no difference in quality and pasteurized almonds are safer. I find this highly offensive and deceptive. It flies in the face of common sense. If you walked up to someone in the street and asked them what the phrase "raw milk" means, would they say "oh yeah, that means pasteurized"? A raw seed can sprout. A pasteurized seed can't. Remember all those enzymes that break down anti-nutrients when you soak beans, grains and nuts? Denatured by heat.
I tried soaking them like I would regular raw almonds. I covered them in water overnight. In the morning, I noticed that the soaking water was milky and had an unpleasant smell. The outer layer of the almonds (the most cooked part) was falling apart into the water. They also didn't have the crisp texture of soaked raw almonds.
Tonight, I toasted them lightly. They definitely taste "off", and the texture isn't as good. There's no doubt about it, pasteurized California almonds are inferior. Despite my preference for domestic products, I'll be buying Spanish almonds the next time around. If enough of us do the same, we'll hit the Almond Board in the only place that counts: its wallet.
One of the most irritating things is that the new rule is designed to edge out small producers. I can't see any other reason for it. Raw almonds are a safe food. Far safer than lettuce. Should we pasteurize lettuce? Pasteurization requires specialized, expensive equipment that will be prohibitive for the little guys. I'm sure the bigger producers will generously offer to fill the production gap.
When I arrived at the grocery store, the only raw almonds they had were from California. I prefer to buy domestic products when I can, but in case you haven't heard, "raw" almonds from California are no longer raw. They are required to be sterilized using steam or antiseptic gases, despite their relative safety as a raw food.
The worst part is that they are not required to label them as pasteurized; they can still be labeled as raw. The Almond Board's argument is that there's no difference in quality and pasteurized almonds are safer. I find this highly offensive and deceptive. It flies in the face of common sense. If you walked up to someone in the street and asked them what the phrase "raw milk" means, would they say "oh yeah, that means pasteurized"? A raw seed can sprout. A pasteurized seed can't. Remember all those enzymes that break down anti-nutrients when you soak beans, grains and nuts? Denatured by heat.
I tried soaking them like I would regular raw almonds. I covered them in water overnight. In the morning, I noticed that the soaking water was milky and had an unpleasant smell. The outer layer of the almonds (the most cooked part) was falling apart into the water. They also didn't have the crisp texture of soaked raw almonds.
Tonight, I toasted them lightly. They definitely taste "off", and the texture isn't as good. There's no doubt about it, pasteurized California almonds are inferior. Despite my preference for domestic products, I'll be buying Spanish almonds the next time around. If enough of us do the same, we'll hit the Almond Board in the only place that counts: its wallet.
One of the most irritating things is that the new rule is designed to edge out small producers. I can't see any other reason for it. Raw almonds are a safe food. Far safer than lettuce. Should we pasteurize lettuce? Pasteurization requires specialized, expensive equipment that will be prohibitive for the little guys. I'm sure the bigger producers will generously offer to fill the production gap.
Senin, 19 Mei 2008
Real Food VII: Lentils
Lentils are a healthy food that comes with a few caveats. They have more protein and less carbohydrate than any other legume besides soybeans and peanuts, and they contain a remarkable array of vitamins and minerals, particularly B vitamins. One cup delivers 90% of your RDA of folate, so between lentils and liver there's no need for those sketchy prenatal vitamins.
Lentils must be properly prepared to be digestible and nutritious! I can't emphasize this enough. We did not evolve eating legumes, so we have to take certain steps to be able to digest them adequately. As with all beans and grains, proper soaking is essential to neutralize their naturally occurring toxins and anti-nutrients. Anti-nutrients are substances that interfere with the absorption of nutrients. Soaking activates enzymes in the seeds themselves that degrade these substances. It also cuts down substantially on cooking time and reduces flatulence.
Phytic acid is an anti-nutrient that's abundant in beans, grains and nuts. It can dramatically reduce the absorption of important minerals such as iron, calcium, magnesium and zinc, leading to deficiencies over time. It may be one of the main reasons human stature decreased after the adoption of agriculture, and it probably continues to contribute to short stature and health problems around the world.
Lentils and other seeds also contain trypsin inhibitors. Trypsin is one of the digestive system's main protein-digesting enzymes, and seeds probably inhibit it as a defense against predators. Another class of toxins are the lectins. Certain lectins are able to bind to and damage the digestive tract, and even pass into the circulation and possibly wreak havoc. This is a short list of a few of the toxins found in beans and grains. Fortunately, all of these toxins can be reduced or eliminated by proper soaking. I like to soak all legumes for a full 24 hours, adding warm water halfway through. This increases the activity of the toxin-degrading enzymes.
Here's a method for preparing lentils that I've found to be effective. You will actually save time by doing it this way rather than cooking them without soaking, because they cook so much more quickly:
many thanks to *clarity* for the CC photo
Lentils must be properly prepared to be digestible and nutritious! I can't emphasize this enough. We did not evolve eating legumes, so we have to take certain steps to be able to digest them adequately. As with all beans and grains, proper soaking is essential to neutralize their naturally occurring toxins and anti-nutrients. Anti-nutrients are substances that interfere with the absorption of nutrients. Soaking activates enzymes in the seeds themselves that degrade these substances. It also cuts down substantially on cooking time and reduces flatulence.
Phytic acid is an anti-nutrient that's abundant in beans, grains and nuts. It can dramatically reduce the absorption of important minerals such as iron, calcium, magnesium and zinc, leading to deficiencies over time. It may be one of the main reasons human stature decreased after the adoption of agriculture, and it probably continues to contribute to short stature and health problems around the world.
Lentils and other seeds also contain trypsin inhibitors. Trypsin is one of the digestive system's main protein-digesting enzymes, and seeds probably inhibit it as a defense against predators. Another class of toxins are the lectins. Certain lectins are able to bind to and damage the digestive tract, and even pass into the circulation and possibly wreak havoc. This is a short list of a few of the toxins found in beans and grains. Fortunately, all of these toxins can be reduced or eliminated by proper soaking. I like to soak all legumes for a full 24 hours, adding warm water halfway through. This increases the activity of the toxin-degrading enzymes.
Here's a method for preparing lentils that I've found to be effective. You will actually save time by doing it this way rather than cooking them without soaking, because they cook so much more quickly:
- 24 hours before cooking, place dry lentils in a large bowl and cover with 2" of water or more.
- After 12 hours or so, drain and cover the lentils with very warm water (not hot tap water).
- Drain and rinse before cooking.
- To cook, simply cover the soaked lentils with fresh water and boil until tender. I like to add a 2-inch piece of the seaweed kombu to increase mineral content and digestibility.
many thanks to *clarity* for the CC photo
Sabtu, 17 Mei 2008
US Fructose Consumption Trends
As you may have noticed, I suspect fructose is involved in overweight and other health problems. It seems to have adverse effects on fat deposition in the liver and insulin sensitivity that could be related to its association with weight gain. I looked through USDA estimated per capita consumption of different sweeteners to get an idea of how fructose consumption has changed in the US in the time since adult obesity rates have doubled.
In 1970, we ate an estimated 72.5 lb/year of cane and beet sugar (sucrose) per person, which is 50% fructose and 50% glucose. We also ate 0.4 lb/year of corn syrup, which is most commonly 55% fructose, 45% glucose. Consumption of other unspecified sweeteners was 12.0 lb/year, for a total intake of 84.9 lb/year of added sweeteners.
In 2007, we ate an estimated 44.2 lb/year of sucrose, 40.1 lb/year of corn syrup, and 12.9 lb/year of other unspecified sweeteners, for a total added sweetener intake of 97.2 lb/year. Doing the math, and generously assuming that the "other" sweeteners are 100% honey (~50% fructose), here are the results:
- 1970: 42.5 lb/year of added fructose.
- 2007: 50.6 lb/year of added fructose.
What has caused the dramatic expansion of American waistlines in the last 30 years? No one knows for sure, but I think it's probably related to diet since the percentage of people who exercise has actually increased in the same time period. My money is on the wheat and sugar, with possible contributions from hydrogenated oil, polyunsaturated vegetable oils and chemical pollutants. The reason is that wheat and sugar seem to have devastating metabolic effects on populations throughout the world, such as the Pima.
Kamis, 15 Mei 2008
Lessons From the Pima Indians
At 38% and climbing in 2006, the Pima indians (Akimel O'odham) of Arizona have the highest rate of diabetes of any population in the world. They also have staggering rates of obesity (~70%) and hypertension.
Things were very different for them before 1539, when the Spanish first made contact. They lived on an agricultural diet of beans, corn and squash, with wild fish, game meat and plants. As with most native people, they were thin and healthy while on their traditional diet.
In 1859, the Pima were restricted to a small fraction of their original land along the Gila river, the Pima Reservation. In 1866, settlers began arriving in the region and diverting the Gila river upstream of the reservation for their own agriculture. In 1869, the river went dry for the first time. 1886 was the last year any water flowed to the Pima Reservation in the Gila river.
The Pima had no way to obtain water, and no way to grow crops. Their once productive subsistence economy ground to a halt. Famine ensued for 40 desperate years. The Pima cut down their extensive mesquite forests to sell for food and water. Eventually, after public outcry, uncle Sam stepped in.
The government provided the Pima with subsidized "food": white flour, sugar, partially hydrogenated lard, and canned goods. They promptly became diabetic and overweight, and have remained that way ever since.
The Pima are poster children for mainstream nutrition researchers in the US for several reasons. First of all, their pre-contact diet was probably fairly low in fat, and researchers love to point out that they now eat more fat (comparable to the average American diet). Another reason is that there's another group of Pima in Mexico who still live on a relatively traditional diet and are much healthier. They are genetically very similar, supporting the idea that it's the lifestyle of the American Pima that's causing their problems. The third reason is that the Mexican Pima exercise more than the Arizona Pima and eat a bit less.
I of course agree with the conclusion that their lifestyle is behind their problems; that's pretty obvious. I think most Pima know it too. If they got their water back, maybe things would be different for them.
However, the focus on macronutrients sometimes obscures the fact that the modern Pima diet is pure crap. It's mostly processed food with a low nutrient density. It also contains the two biggest destroyers of indigenous health: white flour and sugar. There are numerous examples of cultures going from a high-fat diet to a lower-fat "reservation food" diet and suffering the same fate: the Inuit of Alaska, the Maasai and Samburu of Kenya, tribes in the Pacific Northwestern US and Canada, certain Aboriginal groups, and more. What do they all have in common? White flour, sugar and other processed food.
The exercise thing is somewhat questionable as well. True, Mexican Pima exercise 2.5 times more than Arizona Pima, but the Arizona Pima still exercise much more than the average American! Women clock in at 3.1 hours a week, while men come in at a whopping 12.1 hours a week! I am a bike commuter and weight lifter, and even I don't exercise that much. So forgive me if I'm a little skeptical of the idea that they aren't exercising enough to keep the weight off.
The history of the Pima is a heart-wrenching story that has been repeated hundreds, perhaps thousands of times all over the world. Europeans bring in white flour, sugar and other processed food, it destroys a native populations' health, and then researchers either act like they don't understand why it happened, or give unsatisfying explanations for it.
The Pima are canaries in the coal mine, and we can learn a lot from them. Their health problems resemble those of other poor Americans (and wealthier ones also, to a lesser extent). This is because they are both eating similar types of things. The problem is creeping into society at large, however, as we rely more and more on processed wheat, corn, soy and sugar, and less on wholesome food. Obesity in the US has doubled in the past 30 years, and childhood obesity has tripled. Diabetes is following suit. Life expectancy has begun to diminish in some (poor) parts of the country. Meanwhile, our diet is looking increasingly like Pima reservation food. It's time to learn a lesson from their tragedy.
Things were very different for them before 1539, when the Spanish first made contact. They lived on an agricultural diet of beans, corn and squash, with wild fish, game meat and plants. As with most native people, they were thin and healthy while on their traditional diet.
In 1859, the Pima were restricted to a small fraction of their original land along the Gila river, the Pima Reservation. In 1866, settlers began arriving in the region and diverting the Gila river upstream of the reservation for their own agriculture. In 1869, the river went dry for the first time. 1886 was the last year any water flowed to the Pima Reservation in the Gila river.
The Pima had no way to obtain water, and no way to grow crops. Their once productive subsistence economy ground to a halt. Famine ensued for 40 desperate years. The Pima cut down their extensive mesquite forests to sell for food and water. Eventually, after public outcry, uncle Sam stepped in.
The government provided the Pima with subsidized "food": white flour, sugar, partially hydrogenated lard, and canned goods. They promptly became diabetic and overweight, and have remained that way ever since.
The Pima are poster children for mainstream nutrition researchers in the US for several reasons. First of all, their pre-contact diet was probably fairly low in fat, and researchers love to point out that they now eat more fat (comparable to the average American diet). Another reason is that there's another group of Pima in Mexico who still live on a relatively traditional diet and are much healthier. They are genetically very similar, supporting the idea that it's the lifestyle of the American Pima that's causing their problems. The third reason is that the Mexican Pima exercise more than the Arizona Pima and eat a bit less.
I of course agree with the conclusion that their lifestyle is behind their problems; that's pretty obvious. I think most Pima know it too. If they got their water back, maybe things would be different for them.
However, the focus on macronutrients sometimes obscures the fact that the modern Pima diet is pure crap. It's mostly processed food with a low nutrient density. It also contains the two biggest destroyers of indigenous health: white flour and sugar. There are numerous examples of cultures going from a high-fat diet to a lower-fat "reservation food" diet and suffering the same fate: the Inuit of Alaska, the Maasai and Samburu of Kenya, tribes in the Pacific Northwestern US and Canada, certain Aboriginal groups, and more. What do they all have in common? White flour, sugar and other processed food.
The exercise thing is somewhat questionable as well. True, Mexican Pima exercise 2.5 times more than Arizona Pima, but the Arizona Pima still exercise much more than the average American! Women clock in at 3.1 hours a week, while men come in at a whopping 12.1 hours a week! I am a bike commuter and weight lifter, and even I don't exercise that much. So forgive me if I'm a little skeptical of the idea that they aren't exercising enough to keep the weight off.
The history of the Pima is a heart-wrenching story that has been repeated hundreds, perhaps thousands of times all over the world. Europeans bring in white flour, sugar and other processed food, it destroys a native populations' health, and then researchers either act like they don't understand why it happened, or give unsatisfying explanations for it.
The Pima are canaries in the coal mine, and we can learn a lot from them. Their health problems resemble those of other poor Americans (and wealthier ones also, to a lesser extent). This is because they are both eating similar types of things. The problem is creeping into society at large, however, as we rely more and more on processed wheat, corn, soy and sugar, and less on wholesome food. Obesity in the US has doubled in the past 30 years, and childhood obesity has tripled. Diabetes is following suit. Life expectancy has begun to diminish in some (poor) parts of the country. Meanwhile, our diet is looking increasingly like Pima reservation food. It's time to learn a lesson from their tragedy.
Selasa, 13 Mei 2008
Your Gut Talks to Your Brain
21.34
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I've been reading through some papers on a gut-brain connection that regulates food intake and blood nutrient balance. I've learned some interesting things.
First of all, when fat hits your small intestine (especially long-chain fatty acids), it sends a message to the brainstem via the vagus nerve. This rapidly inhibits eating behavior.
The hypothalamus can also inhibit glucose production by the liver in response to fat in the bloodstream, by sending it signals via the vagus nerve.
A recent paper that got me interested in all this showed that when you put fatty acids on the upper small intestine, it sends a signal to the brain, which then sends a signal to the liver, increasing insulin sensitivity and decreasing glucose production.
The upper small intestine is not just a passive nutrient sponge. It's a very active player in the body's response to food, coordinating changes in food intake and nutrient disposal.
First of all, when fat hits your small intestine (especially long-chain fatty acids), it sends a message to the brainstem via the vagus nerve. This rapidly inhibits eating behavior.
The hypothalamus can also inhibit glucose production by the liver in response to fat in the bloodstream, by sending it signals via the vagus nerve.
A recent paper that got me interested in all this showed that when you put fatty acids on the upper small intestine, it sends a signal to the brain, which then sends a signal to the liver, increasing insulin sensitivity and decreasing glucose production.
The upper small intestine is not just a passive nutrient sponge. It's a very active player in the body's response to food, coordinating changes in food intake and nutrient disposal.
Minggu, 11 Mei 2008
Diabetes and Your Small Intestine
In the last post, I introduced you to the remarkable antidiabetic effect of gastric bypass surgery. It rapidly reverses diabetes in 83% of patients, and it seems to be due to bypassing the upper small intestine specifically, rather than caloric restriction. This points to a special role of the upper small intestine in regulating food metabolism. I told you I was going to look into the mechanism of why this effect happens, and here's the short answer:
It's complicated and no one understands it completely.
Now for the long answer. Nutrient homeostasis is very important and we have sophisticated ways of coordinating it among different tissues. Part of the small intestine's job is telling the body that nutrients are on their way into the bloodstream. Two ways it conveys this signal are by secreting hormones into the bloodstream, and by sending signals to the brain and liver via parasympathetic nerves.
The small intestine secretes dozens of hormones, one category of which is called the incretins. Incretins by definition increase the secretion of insulin by the pancreas, among other things. They were discovered when researchers realized that oral glucose elicits more of an insulin response than intravenous glucose. The reason is that cells in the upper small intestine secrete incretins when they detect glucose.
There are two known major incretin hormones that are secreted by the small intestine, GIP and GLP-1. There was a recent study by the lab of Blanca Olivan which looked into the levels of incretins in patients who had undergone Roux-en-Y gastric bypass, a common type in which 95% of the stomach and part of the upper small intestine is bypassed.
Their results are very interesting! Compared to controls losing an equivalent amount of weight on a low-calorie diet, the bypass patients saw a HUGE increase in their oral glucose tolerance test (OGTT) GLP-1 secretion (9.8 vs 112.5 pmol/L), a large increase in GIP secretion, and a corresponding increase in insulin secretion (575 vs 769 pmol/L). Two-hour OGTT blood glucose levels went from borderline diabetic to "normal", by American Diabetes Association standards. Fasting glucose and insulin dropped substantially. The bypass group gained considerable glucose control, better than the matched controls on a low-calorie diet.
It looks like part of the mechanism involves whipping the pancreas to produce more insulin in response to glucose. It also affected fasting insulin, although that could simply be due to calorie restriction because it went down in both groups. Interestingly, non-diabetic patients who get a Roux-en-Y bypass often get reactive hypoglycemia, where their pancreas overproduces insulin after a meal and they get dangerously low blood sugar. Dr Mary-Elizabeth Patti calls it "diabetes reversal in people who don't have diabetes". So the effect doesn't seem to be specific to people with diabetes.
There is some suggestion that the effect on incretins is due to bypassing the duodenum, which is part of the upper small intestine. Here's how the (very sophisticated) reasoning goes: when the duodenum doesn't get glucose dumped on it, that somehow increases release of incretins by the small intestine further along the line.
There's actually an antidiabetic drug that mimics GLP-1; it's called Byetta. There's another that inhibits the breakdown of GLP-1 called Januvia. A second effect of GLP-1 is to delay stomach emptying, which both drugs do. They have been effective for some diabetics.
Well this turned into a long post, so I'll follow up on the parasympathetic (nerve) signaling of the small intestine next time.
It's complicated and no one understands it completely.
Now for the long answer. Nutrient homeostasis is very important and we have sophisticated ways of coordinating it among different tissues. Part of the small intestine's job is telling the body that nutrients are on their way into the bloodstream. Two ways it conveys this signal are by secreting hormones into the bloodstream, and by sending signals to the brain and liver via parasympathetic nerves.
The small intestine secretes dozens of hormones, one category of which is called the incretins. Incretins by definition increase the secretion of insulin by the pancreas, among other things. They were discovered when researchers realized that oral glucose elicits more of an insulin response than intravenous glucose. The reason is that cells in the upper small intestine secrete incretins when they detect glucose.
There are two known major incretin hormones that are secreted by the small intestine, GIP and GLP-1. There was a recent study by the lab of Blanca Olivan which looked into the levels of incretins in patients who had undergone Roux-en-Y gastric bypass, a common type in which 95% of the stomach and part of the upper small intestine is bypassed.
Their results are very interesting! Compared to controls losing an equivalent amount of weight on a low-calorie diet, the bypass patients saw a HUGE increase in their oral glucose tolerance test (OGTT) GLP-1 secretion (9.8 vs 112.5 pmol/L), a large increase in GIP secretion, and a corresponding increase in insulin secretion (575 vs 769 pmol/L). Two-hour OGTT blood glucose levels went from borderline diabetic to "normal", by American Diabetes Association standards. Fasting glucose and insulin dropped substantially. The bypass group gained considerable glucose control, better than the matched controls on a low-calorie diet.
It looks like part of the mechanism involves whipping the pancreas to produce more insulin in response to glucose. It also affected fasting insulin, although that could simply be due to calorie restriction because it went down in both groups. Interestingly, non-diabetic patients who get a Roux-en-Y bypass often get reactive hypoglycemia, where their pancreas overproduces insulin after a meal and they get dangerously low blood sugar. Dr Mary-Elizabeth Patti calls it "diabetes reversal in people who don't have diabetes". So the effect doesn't seem to be specific to people with diabetes.
There is some suggestion that the effect on incretins is due to bypassing the duodenum, which is part of the upper small intestine. Here's how the (very sophisticated) reasoning goes: when the duodenum doesn't get glucose dumped on it, that somehow increases release of incretins by the small intestine further along the line.
There's actually an antidiabetic drug that mimics GLP-1; it's called Byetta. There's another that inhibits the breakdown of GLP-1 called Januvia. A second effect of GLP-1 is to delay stomach emptying, which both drugs do. They have been effective for some diabetics.
Well this turned into a long post, so I'll follow up on the parasympathetic (nerve) signaling of the small intestine next time.
Kamis, 08 Mei 2008
The Miracle Diabetes Cure You Don't Know About
What would you say if I told you there's a cure for type II diabetes that's effective in 83% of people, extremely rapid, and requires no lifestyle changes? Would you think I was crazy? Well maybe I am, but the cure exists nevertheless.
All it requires is a little intestinal mutilation. It's called gastric bypass surgery. It's an anti-obesity surgery where the digestive tract is re-routed, bypassing 95% of the stomach as well as the duodenum and jejunum, which are parts of the upper small intestine.
The effect was first reported in 1995 by Dr. Walter Pories. Initially, researchers thought the cure was simply from caloric restriction due to a smaller stomach volume, but since then the story has become much more interesting. The key finding was published in 2004 by Dr. Francesco Rubino, who showed that bypassing the duodenum and jejunum but not the stomach of type II diabetic rats was enough to cure their diabetes. The effect wasn't due to caloric restriction, since both groups ate the same amount of food.
What this suggests is that there's some kind of feedback coming from the upper small intestine that affects glucose control and insulin sensitivity. What could be causing it? It just so happens there are some pretty good candidates: hormones called GLP-1 and ghrelin.
I'm going to dive into this and see if I can figure out what's going on.
Sorry for the cheesy post title, I'm practicing for my best-seller. Maybe I should add the word "secret"? How about this: "101 Secret Diabetes Cures THEY Don't Want You to Know About".
All it requires is a little intestinal mutilation. It's called gastric bypass surgery. It's an anti-obesity surgery where the digestive tract is re-routed, bypassing 95% of the stomach as well as the duodenum and jejunum, which are parts of the upper small intestine.
The effect was first reported in 1995 by Dr. Walter Pories. Initially, researchers thought the cure was simply from caloric restriction due to a smaller stomach volume, but since then the story has become much more interesting. The key finding was published in 2004 by Dr. Francesco Rubino, who showed that bypassing the duodenum and jejunum but not the stomach of type II diabetic rats was enough to cure their diabetes. The effect wasn't due to caloric restriction, since both groups ate the same amount of food.
What this suggests is that there's some kind of feedback coming from the upper small intestine that affects glucose control and insulin sensitivity. What could be causing it? It just so happens there are some pretty good candidates: hormones called GLP-1 and ghrelin.
I'm going to dive into this and see if I can figure out what's going on.
Sorry for the cheesy post title, I'm practicing for my best-seller. Maybe I should add the word "secret"? How about this: "101 Secret Diabetes Cures THEY Don't Want You to Know About".
Selasa, 06 Mei 2008
Cob
I've been thinking a lot about natural building lately. Here in the US, we are practically forced into occupying homes that are expensive and destructive to the environment. I met a woman last weekend who lives in a yurt and has an outdoor composting toilet. She paid $3,000 for the yurt, making it a dignified way to live on a low income. She's worried because what she's doing on her own property is illegal. She's living in a safe, efficient, inexpensive structure that is extremely light on the land, an it's illegal under her county building codes.
A conventional home that costs $200,000 may end up costing $400,000- $600,000 including interest paid to the bank and all fees. If you can save money and cut out the bank, you might be able to build your own code-compliant house for $100,000 or less, including the land. It isn't difficult to see the financial advantage of building yourself.
Conventional homes are also highly destructive to the environment, partly due to materials and partly due to inefficiency of the completed structure. As usual, I'm looking for alternatives.
One possibility that has caught my imagination is a material called cob. It's made of sand, clay and straw that's mixed together and allowed to harden into a durable monolithic structure. It's a traditional form of construction throughout the world, but the word comes from the UK, where thousands of cob buildings are still standing after up to 500 years. It's similar to adobe, except bricks are not used.
Cob uses inexpensive materials that can typically be gathered on-site or nearby, and have a low embodied energy. The straw is an agricultural waste product and is very inexpensive. Building with cob doesn't require much skill or strength. It can produce highly efficient structures in appropriate climates due to its high thermal mass. It's also extremely durable if cared for properly. Cob has all the attributes of an effective vernacular building technique.
It's also not code-compliant in most places in the US, but that may change as it becomes more familiar. That's also a reason why I'm considering alternatives like strawbale and timberframe construction. It's possible to build code-compliant cob houses in the UK.
Last weekend I went to a "Basics of Cob" workshop at the Ancient Earth school of natural building on Whidbey island. We learned how to mix cob and then we built a bench out of it. The bench will eventually be coated in a smooth earthen or lime plaster. Cob is an amazing material. It's sculptable when wet, but becomes very hard when it dries. It's compatible with a number of other natural building techniques like strawbale and light straw-clay. It really is at the intersection of construction and sculpting. When you build with cob, you aren't limited to straight lines and right angles, so you can create spaces that are highly functional and aesthetic, while also being space-efficient. Here are some photos from the workshop:
A conventional home that costs $200,000 may end up costing $400,000- $600,000 including interest paid to the bank and all fees. If you can save money and cut out the bank, you might be able to build your own code-compliant house for $100,000 or less, including the land. It isn't difficult to see the financial advantage of building yourself.
Conventional homes are also highly destructive to the environment, partly due to materials and partly due to inefficiency of the completed structure. As usual, I'm looking for alternatives.
One possibility that has caught my imagination is a material called cob. It's made of sand, clay and straw that's mixed together and allowed to harden into a durable monolithic structure. It's a traditional form of construction throughout the world, but the word comes from the UK, where thousands of cob buildings are still standing after up to 500 years. It's similar to adobe, except bricks are not used.
Cob uses inexpensive materials that can typically be gathered on-site or nearby, and have a low embodied energy. The straw is an agricultural waste product and is very inexpensive. Building with cob doesn't require much skill or strength. It can produce highly efficient structures in appropriate climates due to its high thermal mass. It's also extremely durable if cared for properly. Cob has all the attributes of an effective vernacular building technique.
It's also not code-compliant in most places in the US, but that may change as it becomes more familiar. That's also a reason why I'm considering alternatives like strawbale and timberframe construction. It's possible to build code-compliant cob houses in the UK.
Last weekend I went to a "Basics of Cob" workshop at the Ancient Earth school of natural building on Whidbey island. We learned how to mix cob and then we built a bench out of it. The bench will eventually be coated in a smooth earthen or lime plaster. Cob is an amazing material. It's sculptable when wet, but becomes very hard when it dries. It's compatible with a number of other natural building techniques like strawbale and light straw-clay. It really is at the intersection of construction and sculpting. When you build with cob, you aren't limited to straight lines and right angles, so you can create spaces that are highly functional and aesthetic, while also being space-efficient. Here are some photos from the workshop:
Jumat, 02 Mei 2008
Real Food VI: Liver
Liver was a highly regarded food among many hunter-gatherer and traditional agricultural societies. It's not surprising once you realize it's quite literally the most nutritious food in the world. It's because the liver is a storage depot, into which important nutrients are deposited in case of later need. A modest 4-oz serving of calf's liver contains 690% of your RDA of B12, 610% of preformed vitamin A, 215% of folate, 129% of B2, 24.5 g protein, and the list goes on. The nutrients found in liver are particularly important for development, but are also helpful for continued health in adulthood.
Preformed vitamin A is one of the nutrients Weston Price suggested was responsible for the glowing health of the cultures he studied in his book Nutrition and Physical Degeneration. It's an essential nutrient, but it's different from most vitamins (except D) because it acts like a hormone, entering cells and altering gene transcription. Thus, it has its hand in many important bodily processes.
"Vitamin A" from plant sources such as carrots is actually a group of vitamin A precursors called carotenes, which the body inefficiently converts to actual vitamin A. The efficiency of conversion varies around 10%, depending on the carotene and how much fat is ingested along with it. Nutrition labels in the US do not reflect this. When a nutrition label on a plant-based product says "30% vitamin A", you can assume you will get about 3% of your RDA from it. This doesn't apply to eggs, dairy and liver, which contain preformed vitamin A.
I'm not sure how this happened, but somewhere along the line we decided in the US that muscle is the only proper animal tissue to eat. We are missing out on the most nutritious parts of the animal, and our health is suffering.
I recommend purchasing organic calf's liver, 100% grass-fed if possible. Chicken livers are also nutritious but ruminant livers are the most concentrated in vitamins by far.
Here is a recipe for a liver pate. I recognize that many people don't like the taste of liver, which is why I chose this recipe because it is very mild.
Ingredients
Preformed vitamin A is one of the nutrients Weston Price suggested was responsible for the glowing health of the cultures he studied in his book Nutrition and Physical Degeneration. It's an essential nutrient, but it's different from most vitamins (except D) because it acts like a hormone, entering cells and altering gene transcription. Thus, it has its hand in many important bodily processes.
"Vitamin A" from plant sources such as carrots is actually a group of vitamin A precursors called carotenes, which the body inefficiently converts to actual vitamin A. The efficiency of conversion varies around 10%, depending on the carotene and how much fat is ingested along with it. Nutrition labels in the US do not reflect this. When a nutrition label on a plant-based product says "30% vitamin A", you can assume you will get about 3% of your RDA from it. This doesn't apply to eggs, dairy and liver, which contain preformed vitamin A.
I'm not sure how this happened, but somewhere along the line we decided in the US that muscle is the only proper animal tissue to eat. We are missing out on the most nutritious parts of the animal, and our health is suffering.
I recommend purchasing organic calf's liver, 100% grass-fed if possible. Chicken livers are also nutritious but ruminant livers are the most concentrated in vitamins by far.
Here is a recipe for a liver pate. I recognize that many people don't like the taste of liver, which is why I chose this recipe because it is very mild.
Ingredients
- 1/2 to 1 lb calf's liver, chopped into 1-in strips
- 3 eggs
- 1/2 stick butter
- 1/2 onion
- 1-2 carrots (optional)
- Sage and/or rosemary (optional)
- Salt to taste
- Saute the onions and carrots in 1 tbsp butter until they're soft.
- Add liver and herbs and cook until the liver is just done.
- Crack the eggs right into the pan and stir them until they're cooked.
- Turn off the heat, add the remaining butter.
- Blend until smooth.
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