I've been avoiding most gluten, particularly wheat, for over a year now. I never had obvious symptoms that I could clearly link to eating wheat, although I had my suspicions. I've made many changes to my diet over the last decade, and I feel much better than I did ten years ago, but it's hard to disentangle all the factors. I don't think I ever went an entire month without eating any gluten at all before this January. After posting Matt Lentzner's challenge to go gluten-free this January, I felt obligated to do it myself, so I signed up!
I succeeded in avoiding all gluten for the month of January, even though it was a pain at times. I felt good before January, and didn't start with any health or body weight problems, so there wasn't much to improve. I also felt good while strictly avoiding gluten this January, perhaps a little better than usual but it's hard to say.
At the end of the month, I did a blinded wheat challenge using the method I described in a previous post, which uses gluten-free bread as the placebo (1). I recorded my blood sugar at 30 minute intervals after eating the bread, and recorded how I felt physically and emotionally for three days after each challenge.
The result? I think the bread gave me gas, but that's about it. I'm not even positive that was due to the wheat. My energy level was good, and I didn't experience any digestive pain or changes in transit time. There was no significant difference in my blood glucose response between the bread and the gluten-free bread.
I decided that I didn't have any symptoms, so I celebrated by having a porter (1) with friends a few nights later. I slept poorly and woke up with mild digestive discomfort and gas. Then I ate wheat later in the week and slept poorly and got gas again. Hmmm...
Some people might say that the body adapts to any food, and wheat is no different. Go without it for a while, and the body has a tough time digesting it. But I can go for weeks without eating a potato, a chicken thigh or broccoli, and all will digest just fine when I eat them again.
I'm pretty sure I don't have a severe reaction to gluten. I think I'm going to stick with my mostly gluten-free habits, and eat it occasionally when I'm offered food in social situations.
Did anyone else do a blinded wheat challenge? Describe it in the comments!
Thursday, February 10, 2011
Wednesday, February 9, 2011
Gluten-Free January Raffle!
Hi, Gluten-Free January participants. Matt, Janine and I have collected about 200 survey responses at this point. So far, the results are very interesting! But we want to get as many responses as possible, because the more responses we get, the more informative the data will be for all of us. So please fill out the survey Matt sent you by e-mail, no matter what your results were, and no matter whether you stuck with the diet or not! The survey is strictly about your GFJ experience, not investment opportunities, timeshares, ShamWows or anything else. It will take you less than 5 minutes, and it's totally anonymous. The deadline is Feb 15th. Big thanks to everyone who has taken it so far.
To encourage participants to complete the survey, we're organizing a raffle. Matt and I have five Gluten-Free January T-shirts we're ready to give out for free. These shirts were designed by Matt and they're really cool. I have one myself, and the print and fabric quality are top notch. Here's what the logo looks like:
If you've completed the survey and want to be included in the raffle, please e-mail Matt to let him know you've completed it. Anyone who has already e-mailed Matt to let him know they completed the survey will automatically be entered, so no need for a second e-mail. So far, very few people have written Matt, so your probability of winning a shirt is high!
To encourage participants to complete the survey, we're organizing a raffle. Matt and I have five Gluten-Free January T-shirts we're ready to give out for free. These shirts were designed by Matt and they're really cool. I have one myself, and the print and fabric quality are top notch. Here's what the logo looks like:
If you've completed the survey and want to be included in the raffle, please e-mail Matt to let him know you've completed it. Anyone who has already e-mailed Matt to let him know they completed the survey will automatically be entered, so no need for a second e-mail. So far, very few people have written Matt, so your probability of winning a shirt is high!Saturday, February 5, 2011
Assorted Thoughts About the 2010 Dietary Guidelines
In the past week, I've been rooting through the USDA's 2010 Dietary Guidelines (1). Here are a few of my thoughts.
Positive
One of the things I've been enjoying recently is watching health authorities shift away from a nutrient-oriented philosophy in favor of a more food-oriented philosophy. For example, I recently read a nice editorial by Drs. Dariush Mozaffarian and David S. Ludwig (not associated with the USDA) that encapsulates this (2). Here's a quote:
Although the 2010 guidelines are too focused on nutrients for my taste, they do spend some time talking about food groups and eating patterns, for example, recommending an increase in the consumption of vegetables, fruit, whole grains and seafood. They also recommend Mediterranean and plant-focused eating patterns. Although I don't think their recommendations quite hit the mark, they do reflect a shift in thinking.
Another thing I enjoyed about the Guidelines is the table on page 12 of chapter 2, which shows just how messed up the average American diet is. The number one source of calories in all age groups is "grain-based desserts". The next five in adults are yeast breads, chicken dishes, soda/sports drinks, alcohol and pizza. To see typical American food habits presented like this just blows me away. They call this the "obesogenic environment"; the idea that we're surrounded by tasty but unhealthy food and situations that favor the consumption of it. I agree.
The Guidelines also contain a surprisingly accurate one-sentence review of the glycemic index literature:
The first problem is the creation of the category "solid fats and added sugars", abbreviated SoFAS. With the creation of this term, they lump pastured butter together with Crisco and Red Hots. If they've been hiding the evidence that pastured butter, virgin coconut oil or red palm oil contribute to heart disease, I'd like to see it so I can stop eating them!
Another problem is their list of recommendations to curb the obesity epidemic. They say:
Jokes aside, I do think energy balance is a huge issue, perhaps even the central issue in chronic disease risk in affluent nations. The basic problem is that Americans are eating more calories than is optimal, and they have a very hard time stopping. It's not because they have less willpower than their stoic ancestors, it's because their bodies have decided that overweight/obesity is the new lean, and they defend that higher level of fat mass against changes. Simply telling an overweight person to eat fewer calories, without changing the dietary context, is not very effective in the long term, due to compensatory mechanisms including hunger and increased metabolic efficiency (fewer calories burned for the same muscular exertion).
What does the USDA recommend to lose fat or maintain leanness?
At one point, they talk about changes in the US diet that have corresponded with the obesity epidemic:
Conclusion
Although the 2010 USDA Dietary Guidelines show some promising trends, and contain some good information, I hope you can find a better source than the USDA for your nutrition advice.
Positive
One of the things I've been enjoying recently is watching health authorities shift away from a nutrient-oriented philosophy in favor of a more food-oriented philosophy. For example, I recently read a nice editorial by Drs. Dariush Mozaffarian and David S. Ludwig (not associated with the USDA) that encapsulates this (2). Here's a quote:
Nutritional science has advanced rapidly, and the evidence now demonstrates the major limitations of nutrient-based metrics for prevention of chronic disease. The proportion of total energy from fat appears largely unrelated to risk of cardiovascular disease, cancer, diabetes, or obesity. Saturated fat—targeted by nearly all nutrition-related professional organizations and governmental agencies—has little relation to heart disease within most prevailing dietary patterns. Typical recommendations to consume at least half of total energy as carbohydrate, a nutrient for which humans have no absolute requirement, conflate foods with widely divergent physiologic effects (eg, brown rice, white bread, apples). Foods are grouped based on protein content (chicken, fish, beans, nuts) despite demonstrably different health effects. With few exceptions (eg, omega-3 fats, trans fat, salt), individual compounds in isolation have small effects on chronic diseases. Thus, little of the information found on food labels’ “nutrition facts” panels provides useful guidance for selecting healthier foods to prevent chronic disease.Tell it! Although he doesn't use the word nutritionism, that's basically what he's arguing against. Dr. Mozaffarian seems to represent the less reductionist school of nutrition, which is a more informed version of what nutrition pioneers such as Sir Edward Mellanby, Dr. May Mellanby, Dr. Weston Price and Sir Robert McCarrison advocated.
In contrast with discrete nutrients, specific foods and dietary patterns substantially affect chronic disease risk, as shown by controlled trials of risk factors and prospective cohorts of disease end points
Although this approach may seem radical, it actually represents a return to more traditional, time-tested ways of eating. Healthier food-based dietary patterns have existed for generations among some populations.
Although the 2010 guidelines are too focused on nutrients for my taste, they do spend some time talking about food groups and eating patterns, for example, recommending an increase in the consumption of vegetables, fruit, whole grains and seafood. They also recommend Mediterranean and plant-focused eating patterns. Although I don't think their recommendations quite hit the mark, they do reflect a shift in thinking.
Another thing I enjoyed about the Guidelines is the table on page 12 of chapter 2, which shows just how messed up the average American diet is. The number one source of calories in all age groups is "grain-based desserts". The next five in adults are yeast breads, chicken dishes, soda/sports drinks, alcohol and pizza. To see typical American food habits presented like this just blows me away. They call this the "obesogenic environment"; the idea that we're surrounded by tasty but unhealthy food and situations that favor the consumption of it. I agree.
The Guidelines also contain a surprisingly accurate one-sentence review of the glycemic index literature:
Strong evidence shows that glycemic index and/or glycemic load are not associated with body weight; thus, it is not necessary to consider these measures when selecting carbohydrate foods and beverages for weight management.Negative
The first problem is the creation of the category "solid fats and added sugars", abbreviated SoFAS. With the creation of this term, they lump pastured butter together with Crisco and Red Hots. If they've been hiding the evidence that pastured butter, virgin coconut oil or red palm oil contribute to heart disease, I'd like to see it so I can stop eating them!
Another problem is their list of recommendations to curb the obesity epidemic. They say:
The current high rates of overweight and obesity among virtually all subgroups of the population in the United States demonstrate that many Americans are in calorie imbalance—that is, they consume more calories than they expend. To curb the obesity epidemic and improve their health, Americans need to make significant efforts to decrease the total number of calories they consume from foods and beverages and increase calorie expenditure through physical activity.Looks like we have Sherlock Holmes on the case. Now that we have this information, all we have to do is tell overweight people to eat less and they'll be lean again! What's that, they already know and it's not working?? Someone should tell the USDA.
Jokes aside, I do think energy balance is a huge issue, perhaps even the central issue in chronic disease risk in affluent nations. The basic problem is that Americans are eating more calories than is optimal, and they have a very hard time stopping. It's not because they have less willpower than their stoic ancestors, it's because their bodies have decided that overweight/obesity is the new lean, and they defend that higher level of fat mass against changes. Simply telling an overweight person to eat fewer calories, without changing the dietary context, is not very effective in the long term, due to compensatory mechanisms including hunger and increased metabolic efficiency (fewer calories burned for the same muscular exertion).
What does the USDA recommend to lose fat or maintain leanness?
- Count calories. Doesn't work for most people, although I acknowledge that it is physically possible to lose fat (and lean mass) by restricting calories.
- Reduce sweetened beverages. Thumbs up.
- Serve smaller portions. As far as I know, this rests exclusively on very short-term studies that showed that food consumed at a single meal or three is reduced if portion size is smaller. I guess it can't hurt to try it, but I'm not convinced it will have any effect on long-term body fatness. I think restaurant portion sizes have probably increased because people eat more, rather than the other way around, although both could be true.
- Eat foods that are less calorie dense. I think vegetables are healthy, but is it because they're less calorie-dense? Why is dietary fat intake generally not associated with obesity if it's the most calorie-dense substance? Why do many people lose body fat eating energy-dense low-carbohydrate diets? Not convinced, but I'm feeling open minded about this one.
- Exercise more and watch less TV. Exercise is good. But don't let it make you hungry, because then you'll eat more!
At one point, they talk about changes in the US diet that have corresponded with the obesity epidemic:
Average daily calories available per person in the marketplace increased approximately 600 calories, with the greatest increases in the availability of added fats and oils, grains, milk and milk products, and caloric sweeteners.Let me edit that so it's more complete:
Average daily calories available per person in the marketplace increased approximately 600 calories per day, 250 calories of which were actually consumed (USDA and NHANES). Added fats increased, due to a large increase in seed oil intake, but total fat intake remained approximately the same because of a roughly equal decrease in fatty meat and whole milk consumption (USDA and NHANES). Grain intake, predominantly wheat, increased, as did the consumption of refined sweeteners, predominantly high-fructose corn syrup (USDA).It reads a bit differently once you have a little more information, doesn't it? Animal fat intake declined considerably, and was replaced by seed oils, in parallel with the obesity and diabetes epidemics. Maybe it contributed, maybe it didn't, but why not just be forthright about it? People appreciate honesty.
Conclusion
Although the 2010 USDA Dietary Guidelines show some promising trends, and contain some good information, I hope you can find a better source than the USDA for your nutrition advice.
Monday, January 31, 2011
Gluten-free January Participants: Take the Survey!
Matt Lentzner, Janine Jagger and I have designed a survey for participants of Gluten-free January, using the online application StatCrunch. Janine is an epidemiologist who studies healthcare worker safety at the University of Virginia; she has experience designing surveys for data collection so we're glad to have her on board. The survey will allow us to systematically gather and analyze data on the results of Gluten-free January. It will be 100 percent anonymous-- none of your answers will be connected to your identity in any way.
This survey has the potential to be really informative, but it will only work if you respond! The more people who take the survey, the more informative it will be, even if you didn't avoid gluten for a single day. If not very many people respond, it will be highly susceptible to "selection bias", where perhaps the only people who responded are people who improved the most, skewing the results.
Matt will be sending the survey out to everyone on his mailing list. Please complete it, even if you didn't end up avoiding gluten at all! There's no shame in it. The survey has responses built in for people who didn't avoid gluten. Your survey will still be useful!
We have potential data from over 500 people. After we crunch the numbers, I'll share them on the blog.
This survey has the potential to be really informative, but it will only work if you respond! The more people who take the survey, the more informative it will be, even if you didn't avoid gluten for a single day. If not very many people respond, it will be highly susceptible to "selection bias", where perhaps the only people who responded are people who improved the most, skewing the results.
Matt will be sending the survey out to everyone on his mailing list. Please complete it, even if you didn't end up avoiding gluten at all! There's no shame in it. The survey has responses built in for people who didn't avoid gluten. Your survey will still be useful!
We have potential data from over 500 people. After we crunch the numbers, I'll share them on the blog.
Thursday, January 27, 2011
The Diabetes Epidemic
The CDC just released its latest estimate of diabetes prevalence in the US (1):
These data are self-reported, and do not correct for differences in diagnosis methods, so they should be viewed with caution-- but they still serve to illustrate the trend. There was an increase in diabetes incidence that began in the early 1990s. More than 90 percent of cases are type 2 diabetics. Disturbingly, the trend does not show any signs of slowing.
The diabetes epidemic has followed on the heels of the obesity epidemic with 10-20 years of lag time. Excess body fat is the number one risk factor for diabetes*. As far as I can tell, type 2 diabetes is caused by insulin resistance, which is probably due to energy intake exceeding energy needs (overnutrition), causing a state of cellular insulin resistance as a defense mechanism to protect against the damaging effects of too much glucose and fatty acids (3). In addition, type 2 diabetes requires a predisposition that prevents the pancreatic beta cells from keeping up with the greatly increased insulin needs of an insulin resistant person**. Both factors are required, and not all insulin resistant people will develop diabetes as some people's beta cells are able to compensate by hypersecreting insulin.
Why does energy intake exceed energy needs in modern America and in most affluent countries? Why has the typical person's calorie intake increased by 250 calories per day since 1970 (4)? I believe it's because the fat mass "setpoint" has been increased, typically but not always by industrial food. I've been developing some new thoughts on this lately, and potentially new solutions, which I'll reveal when they're ready.
* In other words, it's the best predictor of future diabetes risk.
** Most of the common gene variants (of known function) linked with type 2 diabetes are thought to impact beta cell function (5).
Diabetes affects 8.3 percent of Americans of all ages, and 11.3 percent of adults aged 20 and older, according to the National Diabetes Fact Sheet for 2011. About 27 percent of those with diabetes—7 million Americans—do not know they have the disease. Prediabetes affects 35 percent of adults aged 20 and older.Wow-- this is a massive problem. The prevalence of diabetes has been increasing over time, due to more people developing the disorder, improvements in diabetes care leading to longer survival time, and changes in the way diabetes is diagnosed. Here's a graph I put together based on CDC data, showing the trend of diabetes prevalence (percent) from 1980 to 2008 in different age categories (2):
These data are self-reported, and do not correct for differences in diagnosis methods, so they should be viewed with caution-- but they still serve to illustrate the trend. There was an increase in diabetes incidence that began in the early 1990s. More than 90 percent of cases are type 2 diabetics. Disturbingly, the trend does not show any signs of slowing.
The diabetes epidemic has followed on the heels of the obesity epidemic with 10-20 years of lag time. Excess body fat is the number one risk factor for diabetes*. As far as I can tell, type 2 diabetes is caused by insulin resistance, which is probably due to energy intake exceeding energy needs (overnutrition), causing a state of cellular insulin resistance as a defense mechanism to protect against the damaging effects of too much glucose and fatty acids (3). In addition, type 2 diabetes requires a predisposition that prevents the pancreatic beta cells from keeping up with the greatly increased insulin needs of an insulin resistant person**. Both factors are required, and not all insulin resistant people will develop diabetes as some people's beta cells are able to compensate by hypersecreting insulin.
Why does energy intake exceed energy needs in modern America and in most affluent countries? Why has the typical person's calorie intake increased by 250 calories per day since 1970 (4)? I believe it's because the fat mass "setpoint" has been increased, typically but not always by industrial food. I've been developing some new thoughts on this lately, and potentially new solutions, which I'll reveal when they're ready.
* In other words, it's the best predictor of future diabetes risk.
** Most of the common gene variants (of known function) linked with type 2 diabetes are thought to impact beta cell function (5).
Two Wheat Challenge Ideas from Commenters
Some people have remarked that the blinded challenge method I posted is cumbersome.
Reader "Me" suggested:
Reader "Me" suggested:
You can buy wheat gluten in a grocery store. Why not simply have your friend add some wheat gluten to your normal protein shake.Reader David suggested:
They sell empty gelatin capsules with carob content to opacify them. Why not fill a few capsules with whole wheat flour, and then a whole bunch with rice starch or other placebo. For two weeks take a set of, say, three capsules every day, with the set of wheat capsules in line to be taken on a random day selected by your friend. This would further reduce the chances that you would see through the blind, and it prevent the risk of not being able to choke the "smoothie" down. It would also keep it to wheat and nothing but wheat (except for the placebo starch).The reason I chose the method in the last post is that it directly tests wheat in a form that a person would be likely to eat: bread. The limitation of the gluten shake method is that it would miss a sensitivity to components in wheat other than gluten. The limitation of the pill method is that raw flour is difficult to digest, so it would be difficult to extrapolate a sensitivity to cooked flour foods. You might be able to get around that by filling the pills with powdered bread crumbs. Those are two alternative ideas to consider if the one I posted seems too involved.
Monday, January 24, 2011
Blinded Wheat Challenge
Self-experimentation can be an effective way to improve one's health*. One of the problems with diet self-experimentation is that it's difficult to know which changes are the direct result of eating a food, and which are the result of preconceived ideas about a food. For example, are you more likely to notice the fact that you're grumpy after drinking milk if you think milk makes people grumpy? Maybe you're grumpy every other day regardless of diet? Placebo effects and conscious/unconscious bias can lead us to erroneous conclusions.
The beauty of the scientific method is that it offers us effective tools to minimize this kind of bias. This is probably its main advantage over more subjective forms of inquiry**. One of the most effective tools in the scientific method's toolbox is a control. This is a measurement that's used to establish a baseline for comparison with the intervention, which is what you're interested in. Without a control measurement, the intervention measurement is typically meaningless. For example, if we give 100 people pills that cure belly button lint, we have to give a different group placebo (sugar) pills. Only the comparison between drug and placebo groups can tell us if the drug worked, because maybe the changing seasons, regular doctor's visits, or having your belly button examined once a week affects the likelihood of lint.
Another tool is called blinding. This is where the patient, and often the doctor and investigators, don't know which pills are placebo and which are drug. This minimizes bias on the part of the patient, and sometimes the doctor and investigators. If the patient knew he were receiving drug rather than placebo, that could influence the outcome. Likewise, investigators who aren't blinded while they're collecting data can unconsciously (or consciously) influence it.
Back to diet. I want to know if I react to wheat. I've been gluten-free for about a month. But if I eat a slice of bread, how can I be sure I'm not experiencing symptoms because I think I should? How about blinding and a non-gluten control?
Procedure for a Blinded Wheat Challenge
1. Find a friend who can help you.
2. Buy a loaf of wheat bread and a loaf of gluten-free bread.
3. Have your friend choose one of the loaves without telling you which he/she chose.
4. Have your friend take 1-3 slices, blend them with water in a blender until smooth. This is to eliminate differences in consistency that could allow you to determine what you're eating. Don't watch your friend do this-- you might recognize the loaf.
5. Pinch your nose and drink the "bread smoothie" (yum!). This is so that you can't identify the bread by taste. Rinse your mouth with water before releasing your nose. Record how you feel in the next few hours and days.
6. Wait a week. This is called a "washout period". Repeat the experiment with the second loaf, attempting to keep everything else about the experiment as similar as possible.
7. Compare how you felt each time. Have your friend "unblind" you by telling you which bread you ate on each day. If you experienced symptoms during the wheat challenge but not the control challenge, you may be sensitive to wheat.
If you want to take this to the next level of scientific rigor, repeat the procedure several times to see if the result is consistent. The larger the effect, the fewer times you need to repeat it to be confident in the result.
* Although it can also be disastrous. People who get into the most trouble are "extreme thinkers" who have a tendency to take an idea too far, e.g., avoid all animal foods, avoid all carbohydrate, avoid all fat, run two marathons a week, etc.
** More subjective forms of inquiry have their own advantages.
The beauty of the scientific method is that it offers us effective tools to minimize this kind of bias. This is probably its main advantage over more subjective forms of inquiry**. One of the most effective tools in the scientific method's toolbox is a control. This is a measurement that's used to establish a baseline for comparison with the intervention, which is what you're interested in. Without a control measurement, the intervention measurement is typically meaningless. For example, if we give 100 people pills that cure belly button lint, we have to give a different group placebo (sugar) pills. Only the comparison between drug and placebo groups can tell us if the drug worked, because maybe the changing seasons, regular doctor's visits, or having your belly button examined once a week affects the likelihood of lint.
Another tool is called blinding. This is where the patient, and often the doctor and investigators, don't know which pills are placebo and which are drug. This minimizes bias on the part of the patient, and sometimes the doctor and investigators. If the patient knew he were receiving drug rather than placebo, that could influence the outcome. Likewise, investigators who aren't blinded while they're collecting data can unconsciously (or consciously) influence it.
Back to diet. I want to know if I react to wheat. I've been gluten-free for about a month. But if I eat a slice of bread, how can I be sure I'm not experiencing symptoms because I think I should? How about blinding and a non-gluten control?
Procedure for a Blinded Wheat Challenge
1. Find a friend who can help you.
2. Buy a loaf of wheat bread and a loaf of gluten-free bread.
3. Have your friend choose one of the loaves without telling you which he/she chose.
4. Have your friend take 1-3 slices, blend them with water in a blender until smooth. This is to eliminate differences in consistency that could allow you to determine what you're eating. Don't watch your friend do this-- you might recognize the loaf.
5. Pinch your nose and drink the "bread smoothie" (yum!). This is so that you can't identify the bread by taste. Rinse your mouth with water before releasing your nose. Record how you feel in the next few hours and days.
6. Wait a week. This is called a "washout period". Repeat the experiment with the second loaf, attempting to keep everything else about the experiment as similar as possible.
7. Compare how you felt each time. Have your friend "unblind" you by telling you which bread you ate on each day. If you experienced symptoms during the wheat challenge but not the control challenge, you may be sensitive to wheat.
If you want to take this to the next level of scientific rigor, repeat the procedure several times to see if the result is consistent. The larger the effect, the fewer times you need to repeat it to be confident in the result.
* Although it can also be disastrous. People who get into the most trouble are "extreme thinkers" who have a tendency to take an idea too far, e.g., avoid all animal foods, avoid all carbohydrate, avoid all fat, run two marathons a week, etc.
** More subjective forms of inquiry have their own advantages.
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