US Omega-6 and Omega-3 Fat Consumption over the Last Century

Omega-6 and omega-3 polyunsaturated fats (PUFA) are essential nutrients that play many important roles in the body. They are highly bioactive, and so any deviation from ancestral intake norms should probably be viewed with suspicion. I've expressed my opinion many times on this blog that omega-6 consumption is currently too high due to our high intake of refined seed oils (corn, soybean, sunflower, etc.) in industrial nations. Although it's clear that the quantity of omega-6 and omega-3 polyunsaturated fat have changed over the last century, no one had ever published a paper that attempted to systematically quantify it until last month (1).

Drs. Chris Ramsden and Joseph Hibbeln worked on this paper (the first author was Dr. Tanya Blasbalg and the senior author was Dr. Robert Rawlings)-- they were the first and second authors of a different review article I reviewed recently (2). Their new paper is a great reference that I'm sure I'll cite many times. I'm going to briefly review it and highlight a few key points.

1. The intake of omega-6 linoleic acid has increased quite a bit since 1909. It would have been roughly 2.3% of calories in 1909, while in 1999 it was 7.2%. That represents an increase of 213%. Linoleic acid is the form of omega-6 that predominates in seed oils.

2. The intake of omega-3 alpha-linolenic acid has also increased, for reasons that I'll explain below. It changed from 0.35% of calories to 0.72%, an increase of 109%.

3. The intake of long-chain omega-6 and omega-3 fats have decreased. These are the highly bioactive fats for which linoleic acid and alpha-linolenic acid are precursors. Arachidonic acid, DHA, DPA and EPA intakes have declined. This mostly has to do with changing husbandry practices and the replacement of animal fats with seed oils in the diet.

4. The ratio of omega-6 to omega-3 fats has increased. There is still quite a bit of debate over whether the ratios matter, or simply the absolute amount of each. I maintain that there is enough evidence from highly controlled animal studies and the basic biochemistry of PUFAs to tentatively conclude that the ratio is important. At a minimum, we know that excess linoleic acid inhibits omega-3 metabolism (3, 4, 5, 6). The omega-6:3 ratio increased from 5.4:1 to 9.6:1 between 1909 and 2009, a 78% increase.

5. The biggest factor in both linoleic acid and alpha-linolenic acid intake changes was the astonishing rise in soybean oil consumption. Soybean oil consumption increased from virtually nothing to 7.4% of total calories, eclipsing all sources of calories besides sugar, dairy and grains! That's because processed food is stuffed with it. It's essentially a byproduct of defatted soybean meal-- the second most important animal feed after corn. Check out this graph from the paper:

I think this paper is an important piece of the puzzle as we try to figure out what happened to nutrition and health in the US over the last century.

Fat-ten-u

I recently bought the book Food in the United States, 1820s-1890. I came across an ad for an interesting product that was sold in the late 1800s called Fat-ten-u. Check your calendars, it's not April fools day anymore; this is for real. Fat-ten-u was a dietary supplement guaranteed to "make the thin plump and rosy with honest fleshiness of form." I found several more ads for it online, and they feature drawings of despondent, lean women and drawings of happy overweight women accompanied by enthusiastic testimonials such as this:

"FAT-TEN-U FOODS increased my weight 39 pounds, gave me new womanly vigor and developed me finely. My two sisters also use FAT-TEN-U and because of our newly found vigor we have taken up Grecian dancing and have roles in all local productions."

I'm dying to know what was in this stuff, but I can't find the ingredients anywhere.

I find this rather extraordinary, for two reasons:

• Social norms have clearly changed since the late 1800s. Today, leanness is typically considered more attractive than plumpness.
• Women had to make an effort to become overweight in the late 1800s. In 2011, roughly two-thirds of US women are considered overweight or obese, despite the fact that most of them would rather be lean.

A rhetorical question: did everyone count calories in the 1800s, or did their diet and lifestyle naturally promote leanness? The existence of Fat-ten-u is consistent with the idea that our bodies naturally "defended" a lean body composition more effectively in the late 1800s, when our diets were less industrialized. This is supported by the only reliable data on obesity prevalence in the 1890s I'm aware of: body height and weight measurements from over 35,000 Union civil war veterans aged 40-69 years old (1). In that group of Caucasian men, obesity was about 10% of what it is today in the same age group. Whether or not you believe that this sample was representative of the population at large, I can't imagine any demographic in the modern US with an obesity prevalence of 3 percent (certainly not 60 year old war veterans).

Here are two more ads for Fat-ten-u and "Corpula foods" for your viewing pleasure:

Dr. Kevin Patterson on Western Diets and Health

A few readers have pointed me to an interesting NPR interview with the Canadian physician Kevin Patterson (link). He describes his medical work in Afghanistan and the Canadian arctic treating cultures with various degrees of industrialization. He discusses the "epidemiological transition", the idea that cultures experience predictable changes in their health as they go from hunter-gatherer, to agricultural, to industrial. I think he has an uncommonly good perspective on the effects of industrialization on human health, which tends to be true of people who have witnessed the effects of the industrial diet and lifestyle on diverse cultures.

A central concept behind my thinking is that it's possible to benefit simultaneously from both:

• The sanitation, medical technology, safety technology, law enforcement and lower warfare-related mortality that have increased our life expectancy dramatically relative to our distant ancestors.


• The very low incidence of obesity, diabetes, coronary heart disease and other non-infectious chronic diseases afforded by a diet and lifestyle roughly consistent with our non-industrial heritage.

But it requires discipline, because going with the flow means becoming unhealthy.

Spiced Lentils with Mushrooms and Greens

I'm always on the lookout for a way to incorporate lentils into my diet as well as more greens. So this recipe for Spiced Lentils with Mushrooms and Greens from the February, 2011 issue of Food and Wine magazine is perfect, especially since I think nothing with mushrooms can ever be bad. And there is nothing I love better than when foods that seem somewhat boring on their own (i.e. dry lentils and Swiss chard) get tossed together with some spices and end up super tasty as a result! And this is exactly what I got with this one. In fact, it was so good I didn't eat it as a side-dish as suggested in the recipe, I ate it stand alone as a light meal.

Spiced Lentils with Mushrooms and Greens 4 side-dish servings 1/2 cup brown or green lentils 3 Tbsp extra-virgin olive oil 1/2 pound shiitake mushrooms, stems discarded and caps sliced 1/4-inch thick Salt 1 garlic clove, minced 1/4 tsp ground cumin 1/4 tsp ground coriander 1/4 tsp freshly ground black pepper 1/8 tsp turmeric 1/2 pound Swiss chard or other tender greens, large stems discarded and leaves coarsely chopped 1 Tbsp chopped parsley

In a small saucepan, cover the lentils with 2 1/2 cups of water and bring to a boil. Cover and cook over low heat until the lentils are tender, about 30 minutes.

Meanwhile, in a medium saucepan, heat 2 tablespoons of the olive oil. Add the shiitake and season with salt. Cover and cook over moderate heat, stiffing, until the mushrooms are tender and starting to brown, 5 minutes. Add the remaining 1 tablespoon of olive oil along with the garlic, cumin, coriander, pepper and turmeric and cook, stirring, until fragrant, 1 minute. Add the greens and cook, stirring, until wilted, 2 minutes.

Add the lentils and their cooking liquid to the mushrooms and simmer for 3 minutes. Add up to 1/4 cup water if the lentils are too dry. Season with salt. Ladle the lentils into bowls, garnish with parsley and serve.

My Legume Love Affair (MLLA) was originally started by Susan of The Well-Seasoned Cook. This month's MLLA #33 is being hosted by Ammalus Kitchen

Scarlet Barley with Mushroom & Cannellini Paprikas

I admit that the main reason I made this recipe is so that I could shred a beet. I have had a thing with beets this past fall but so far I have only tackled roasting them. I found the concept of peeling the raw beet and then shredding it and using it as an ingredient intriguing. And when I learned this month's Monthly Mingle theme is "Think Pink" I decided this recipe for Scarlet Barley from Isa Chandra Moskowitz's "Appetite for Reduction" would be a fun contribution.

The Scarlet Barley along with the Mushroom & Cannelini Paprikas came together in about an hour. Shredding the beet for the Scarlet Barley was harder than I thought. I used the shredder on my mandolin and since the beet is naturally hard it was a bit difficult to get a good position for the shredder to shred it. And of course my hands turned all red. But once that was done the rest was simple. And it wasn't too difficult that I wouldn't do it again to use for other recipes if the ingredient is called for.

I prepared this dish prior to an evening appointment and let it sit on the stove for at least two hours before I ate it. Unfortunately I think it lost some flavor. The end result was somewhat bland to me. I think if I would have tried the barley after letting the fresh lemon sit for about 10 minutes it would have been much better.

The next day I sauteed some Swiss chard with green onions and garlic (like the way it is done for the Miso Udon Stir-fry with Greens and Beans recipe) and then threw the leftovers into the pan to reheat. I mixed it all together and after it was plated I squirted on a bit of sriracha. It was a really great combo to be eaten this way!

Scarlet Barley Serves 6 1 tsp olive oil 2 cloves garlic, minced Freshly ground black pepper 1 bay leaf 1 cup pearl barley, rinsed 2 1/2 cups vegetable broth 1/4 tsp salt 1 beet (about 3/4 pound), grated Juice of 1/2 lemon Fresh dill, for garnish (optional)

Preheat a 2-quart pot over medium heat. Saute the garlic in the olive oil for about 30 seconds. Add several pinches of pepper and the bay leaf. Add the barley, broth, and salt; cover and bring to a boil. Once boiling stir and lower the heat to low. Cover and cook for about 20 minutes, stirring occasionally.

When most of the water has absorbed, mix in the grated beet. Cook for about 20 more minutes, stirring occasionally. Turn off the heat, mix in the lemon juice, and taste for salt. Cover and let sit for about 10 mire minutes. Remove bay leaf and serve topped with fresh dill.


Mushroom & Cannellini Paprikas
Serves 4

1 1/2 tsp olive oil
4 cloves garlic, minced
1 pound cremini mushrooms, sliced
Several pinches of freshly ground black pepper
1/4 tsp salt
1/2 cup dry red cooking wine
1/4 cup vegetable broth
2 tsp smoked paprika
2 Tbsp fresh chopped thyme
1 (16-ounce) can cannellini beans, drained and rinsed
1/4 cup chopped fresh dill
1 recipe Scarlet Barley

Preheat a 4-quart pot over medium-high heat. Saute the onions in the oil until lightly browned, about 7 minutes. Add the garlic and saute for about 30 seconds. Add the mushrooms, pepper, and salt; cook until lots of the moisture has been released, stirring occasionally, for about 5 minutes.

Add the wine, broth, smoked paprika, and thyme. Turn up the heat and bring the mixture to a low boil. Boil for about 3 minutes. Lower the heat and add the beans. Cook to heat through, about 4 more minutes. Use a strong fork to lightly mash some of the beans, to thicken the sauce. Just mash a few against the side of the post and then mix 'em back in. Taste for salt and serve.

Serve over Scarlet Barley with plenty of fresh dill.

This month's Monthly Mingle theme is Think Pink and is being hosted by Sarah at Maison Cupcake.

Randy Tobler Show: Welcome

This morning, I had a conversation with Dr. Randy Tobler on his radio show "Vital Signs", on 97.1 FM News Talk in St Louis. Dr. Tobler is an obstetrician-gynecologist with an interest in nutrition, fitness and reproductive endocrinology from a holistic perspective. He asked me to appear on his show after he discovered my blog and found that we have some things in common, including an interest in evolutionary/ancestral health. We talked about the history of the American diet, the health of non-industrial cultures, what fats are healthiest, and the difference between pastured and conventional meat/dairy-- we took a few questions from listeners-- it was fun.

The show is available as a podcast here (3/26 show), although as far as I can tell, you need iTunes to listen to it. My section of the show starts around 8:20.

To everyone who arrived here after hearing me on the air this morning: welcome! Here are a few posts to give you a feel for what I do here at Whole Health Source:

The Coronary Heart Disease Epidemic
US Weight, Lifestyle and Diet Trends, 1970-2007
Butter vs. Margarine Showdown
Preventing and Reversing Tooth Decay
The Kitavans: Wisdom from the Pacific Islands
Potatoes and Human Health, Part I, Part II and Part III
Traditional Preparation Methods Improve Grains' Nutritional Value
Real Food XI: Sourdough Buckwheat Crepes
Glucose Tolerance in Non-industrial Cultures
Tropical Plant Fats: Palm Oil
It's Time to Let Go of the Glycemic Index

Safflower Oil Study

A few people have sent me a new study claiming to demonstrate that half a tablespoon of safflower oil a day improves insulin sensitivity, increases HDL and decreases inflammation in diabetics (1). Let me explain why this study does not show what it claims.

It all comes down to a little thing called a control group, which is the basis for comparison that you use to determine if your intervention had an effect. This study didn't have one for the safflower group. What it had was two intervention groups, one given 6.4g conjugated linoleic acid (CLA; 50% c9t11 and 50% t10c12-CLA) per day, and one given 8g safflower oil. I have to guess that this study was originally designed to test the effects of the CLA, with the safflower oil group as the control group, and that the interpretation of the data changed after the results came in. Otherwise, I don't understand why they would conduct a study like this without a control group.

Anyway, they found that the safflower oil group did better than the CLA group over 16 weeks, showing a higher insulin sensitivity, higher HDL, lower HbA1c (a marker of average blood glucose levels) and lower CRP (a marker of inflammation). But they also found that the safflower group improved slightly compared to baseline, therefore they decided to attribute the difference to a beneficial effect of safflower oil. The problem is that without a control (placebo) group for comparison, there's no way to know if the improvement would have occurred regardless of treatment, due to the season changing, more regular check-ups at the doctor's office due to participating in a study, or countless other unforeseen factors. A control group is essential for the accurate interpretation of results, which is why drug studies always have placebo groups.

What we can say is that the safflower oil group fared better than the CLA group, because there was a difference between the two. However, what I think really happened is that the CLA supplement was harmful and the small dose of safflower oil had no effect. Why? Because the t10c12 isomer of CLA, which was half their pill, has already been shown by previous well-controlled studies to reduce insulin sensitivity, decrease HDL and increase inflammatory markers at a similar dose and for a similar duration (2, 3). The safflower oil group only looked good by comparison. We can add this study to the "research bloopers" file.

It's worth noting that naturally occurring CLA mixtures, similar to those found in pastured dairy and ruminant fat, have not been shown to cause metabolic problems such as those caused by isolated t10c12 CLA.

Miso Udon Stir-fry with Greens & Beans

Wow! This dish tastes about 10 times better than it looks. With a little Sriracha and salt on top, it's creamy and salty and spicy... perfect!

I bought a few kinds of different kinds of beans the other week just to have on hand. One of those was a bean I hadn't heard of before: azuki beans. So when I was flipping through my new cookbook, Appetite for Reduction, I flagged this recipe as the first one to make because of it's use of this fun new ingredient.

I couldn't find brown rice udon noodles as suggested in the recipe so I bought some brown rice spaghetti. But I had some regular pre-cooked udon packages in my refrigerator so when it came time to put this together I decided to use those.

I realize now that I forgot to add the sesame seeds. Oh well, I do bet they would have been great on this but it was really tasty all the same.

Miso Udon Stir-fry with Greens and Beans Serves 4 1 pound broccoli, stems sliced thinly, tops cut into florets 8 ounces brown rice udon noodles 1 teaspoon olive oil 6 cloves of garlic, minced 1 bunch Swiss chard (about ½ pound), coarse stems removed, chopped roughly 1 cup thinly sliced green onions, plus extra for garnish 1/2 teaspoon salt 1 (16-ounce) can azuki beans, drained and rinsed 1/3 cup miso 1/2 cup hot water 4 teaspoons toasted sesame seeds Sriracha hot sauce, to serve

Prepare a pot of salted water for cooking the noodles.

Preheat a large skillet over medium-high heat. First saute the broccoli with a bit of nonstick cooking spray and a pinch of salt for about 5 minutes. Cover the pan and flip once or twice. The broccoli should be browned in some spots. Add a splash of water at the end, then cover for another minute. The pan should be steaming. Remove broccoli from the pan and set aside.

At this point, the water should be boiling. Use a mug to remove ½ cup of water; you can use that to mix into your miso in a few steps. Then cook the noodles according to the package directions. Drain when ready.

Now we'll put everything together. Preheat the large pan again, over medium heat. Saute the garlic in the oil for about a minute, until fragrant. Add the chard, green onion, and salt, and saute for about 5 minutes, until wilted. Add the beans and let heat through.

In the meantime, in a mug or measuring cup, mix together the miso and warm pasta water until relatively smooth.

Add the drained noodles to the pan, along with the miso mixture and broccoli. Saute for about 2 minutes, using a pasta spoon, making sure everythin is nice and coated. Taste for salt. To serve, to with sesame seeds and green onions and keep the Sriracha close at hand.

No Croutons Required March bogging event theme is "aduki beans or mung beans" and it is being hosted by Lisa's Kitchen. View the roundup here.

New Ancestral Diet Review Paper

Pedro Carrera-Bastos and his colleagues Maelan Fontes-Villalba, James H. O'Keefe, Staffan Lindeberg and Loren Cordain have published an excellent new review article titled "The Western Diet and Lifestyle and Diseases of Civilization" (1). The paper reviews the health consequences of transitioning from a traditional to a modern Western diet and lifestyle. Pedro is a knowledgeable and tireless advocate of ancestral, primarily paleolithic-style nutrition, and it has been my privilege to correspond with him regularly. His new paper is the best review of the underlying causes of the "diseases of civilization" that I've encountered. Here's the abstract:

It is increasingly recognized that certain fundamental changes in diet and lifestyle that occurred after the Neolithic Revolution, and especially after the Industrial Revolution and the Modern Age, are too recent, on an evolutionary time scale, for the human genome to have completely adapted. This mismatch between our ancient physiology and the western diet and lifestyle underlies many so-called diseases of civilization, including coronary heart disease, obesity, hypertension, type 2 diabetes, epithelial cell cancers, autoimmune disease, and osteoporosis, which are rare or virtually absent in hunter–gatherers and other non-westernized populations. It is therefore proposed that the adoption of diet and lifestyle that mimic the beneficial characteristics of the preagricultural environment is an effective strategy to reduce the risk of chronic degenerative diseases.

At 343 references, the paper is an excellent resource for anyone with an academic interest in ancestral health, and in that sense it reminds me of Staffan Lindeberg's book Food and Western Disease. One of the things I like most about the paper is that it acknowledges the significant genetic adaptation to agriculture and pastoralism that has occurred in populations that have been practicing it for thousands of years. It hypothesizes that the main detrimental change was not the adoption of agriculture, but the more recent industrialization of the food system. I agree.

I gave Pedro my comments on the manuscript as he was editing it, and he was kind enough to include me in the acknowledgments.

Hearty Irish Lager Stew

You probably don't think "vegetarian" when you think of Irish food, but this dish is not only vegetarian, it's vegan. This recipe for Hearty Irish Lager Stew from the March, 2011 issue of Vegetarian Times magazine is made with no animal products at all so it's super healthy. That might not have you smackin' your lips, but this stew is very tasty and since it's made of mostly veggies, you can eat a huge amount and it won't go to your hips. And, it's made with beer! So that's kinda fun.

Make sure you cut your veggies on the small side. Ours were a bit large and with the cooking times listed in the recipe we found that the potatoes were still hard. We cooked it an extra 15-20 minutes and some of it was still al dente. It was good anyways; I don't mind chewing my vegetables. I'd rather that than have them be too mushy. And we munched on some Salt and Vinegar Potato Bites while we were waiting for the stew to finish so we had no complaints.

Hearty Irish Lager Stew Serves 8 1 Tbsp. vegetable oil 8 oz. button or shittake mushrooms, halved 2 cloves garlic, minced (2 tsp.) 1 medium leek, white part only, diced (1 cup) 2 medium carrots, peeled and sliced (2 cups) 2 small parsnips, peeled and sliced (1½ cups) 1½ tsp. tomato paste 1 15-oz. can crushed tomatoes 1½ cups low-sodium vegetable broth 2 sprigs fresh thyme, tied in bundle, plus 1 tsp. chopped fresh thyme, divided ½ lager beer 1½ Tbsp. quick-cooking tapioca 1 cup shredded cabbage 1 Tbsp. white miso 2 Tbsp. chopped parsley

Heat ½ Tbsp. oil in large pot over medium heat. Add mushrooms and garlic; saute 8 minutes, or until mushrooms are browned. Remove from pan. Add remaining ½ Tbsp. oil to pot. Add leek, and cook 5 minutes. Add potatoes, carrots, parsnips, and tomato paste. Cook 2 minutes. Add tomatoes, broth, and thyme sprigs; bring to a boil. Reduct heat to medium-low, cover, and simmer 40 minutes, stirring occasionally.

Add lager, tapioca, and mushrooms. Simmer 10 to 15 minutes, or until thickened, stirring often. Remove thyme sprigs, stir in cabbage and miso, and simmer 4 to 5 minutes, or until cabbage softens. Stir in chopped thyme and parsley, and season with salt and pepper, if desired.

Nutritional Information as provided in magazine:
Per 1-cup serving: 118 CAL; 4 G PROT; 2 G TOTAL FAT (<1 G SAT FAT); 23 G CARB; 0 MG CHOL; 204 MG SOD; 5 G FIBER; 5 G SUGARS

Salt and Vinegar Potato Bites

We love these potatoes! Way better then french fries, roasted potatoes are much healthier. Found in the March, 2011 issue of Vegetarian Times magazine I made these tonight as a snack.

The recipe says you can drizzle the sauce over the potatoes, but I think that would have made them soggy. We liked dipping them and that way we could each control the amount of vinegar that absorbed into to potato.

Salt and Vinegar Potato Bites Serves 8 6 medium red or yello potatoes, cut into 1-inch cubes (3 cups) 2 Tbsp. vegetable oil 1 cup malt vinegar 3 Tbsp. sugar Soak potatoes in large bowl of cold water 30 minutes. Drain, and pat dry. Preheat oven to 425°F. Toss potatoes with oil on baking sheet, and spread in single layer. Roast 45 minutes, or until golden and crisp, turning 2 or 3 times. Season with salt and pepper, if desired. Meanwhile, bring vinegar and sugar to a simmer in saucepan over medium heat. Cook 15 to 20 minutes, or until liquid is reduced by half, stirring occasionally. Serve malt sauce on side for dipping, or drizzle over potatoes.

Nutritional Information as provided in magazine:
Per ½-cup serving: 89 CAL; 1 G PROT; 4 G TOTAL FAT (<1 G SAT FAT); 14 G CARB; 0 MG CHOL; 3 MG SOD; <1 G FIBER; 5 G SUGARS

Gluten-Free January Survey Data, Part II: Health Effects of a Gluten-Free Diet

GFJ participants chose between three diet styles: a simple gluten-free diet; a "paleo light" diet diet that eliminated sugar and industrial seed (vegetable) oils in addition to gluten; and a "paleo full monty" diet that only included categories of food that would have been available to our pre-agricultural ancestors. The data in this post represent the simple gluten-free diet group, and do not represent the other two, which I'll analyze separately.

To get the data I'll be presenting below, first I excluded participants who stated on the survey that they did not adhere to the diet. Next, I excluded participants who were gluten-free before January, because they would presumably not have experienced a change from continuing to avoid gluten. That left us with 53 participants.

For each of these graphs, the vertical axis represents the number of participants in each category. They won't necessarily add up to 53, for several reasons. The most common reason is that for the questions asking about changes in health conditions, I didn't include responses from people who didn't have the condition in question at baseline because there was nothing to change.

Question #1: What is your overall opinion of the effect of gluten free January on you?

Participants had a very positive experience with the gluten-free diet. Not one person reported a negative overall experience.

Question #2: Did you note a weight change at the end of gluten free January?

And here are the data for people who described themselves as overweight at baseline:

Two-thirds of people who were overweight at baseline lost weight, and only one person out of 37 gained weight. That is striking. A number of people didn't weigh themselves, which is why the numbers only add up to 37.

Question #3: Before January 2011, did you have a problem with intestinal transit (frequent constipation or diarrhea)? If so, did your symptoms change during the month of January?


Responses are heavily weighted toward improvement, although there were a few instances where transit worsened. Transit problems are one of the most common manifestations of gluten sensitivity.

Question #4: Before January 2011, did you have frequent digestive discomfort (pain, bloating, etc.)? If so, did your symptoms change during the month of January?


Digestive discomfort was common, and the gluten-free diet improved it in nearly everyone who had it at baseline. I find this really impressive.

Question #5: Before January 2011, did you have acid reflux? If so, did your symptoms change during the month of January?

Acid reflux responded well to a gluten-free diet.

Question #6: Before January 2011, did you have a problem with tiredness/lethargy? If so, did your symptoms change during the month of January?
Lethargy was common and generally improved in people who avoided gluten. This doesn't surprise me at all. The recent controlled gluten study in irritable bowel syndrome patients found that lethargy was the most reliable consequence of eating gluten that they measured (1, 2). That has also been my personal experience.

Question #7: Before January 2011, did you have a problem with anxiety? If so, did your symptoms change during the month of January?

Anxiety tended to improve in most participants who started with it.

Question #8: Before January 2011, did you have a problem with an autoimmune or inflammatory condition? If so, did your symptoms change during the month of January?

Autoimmune and inflammatory conditions tended to improve in the gluten-free group, although one person experienced a worsening of symptoms.

Question #9: If you ate gluten again or did a gluten challenge after gluten free January, what was the effect?

Just under half of participants experienced moderate or significant negative symptoms when they re-introduced gluten at the end of the month. Two people felt better after re-introducing gluten.


Conclusion

I find these results striking. Participants overwhelmingly improved in every health category we measured. Although the data may have been somewhat biased due to the 53% response rate, it's indisputable that a large number of participants, probably the majority, benefited from avoiding gluten for a month. At some point, we're going to compile some of the comments people left in the survey, which were overwhelmingly positive. Here's a typical comment in response to the question " In your own words, how would you describe your January 2011 experience" (used with permission):

Amazing! I would recommend the experiment to anyone. I felt completely more alert, and less bloated. When I ate some gluten at the close of the experiment, I felt gross, bloated, and lethargic.

I think it's worth mentioning that some participants also eliminated other starches, particularly refined starches. Judging by the comments, the diet was probably lower in carbohydrate for a number of participants. We may try to assess that next year.

Gluten-Free January Survey Data, Part I: Demographics and Limitations

Thanks to Matt Lentzner for organizing Gluten-Free January, and everyone who participated and completed the survey, we have a nice data set illustrating what happens when a group of people stop eating gluten for a month. Janine Jagger, Matt and I have been busy analyzing the data, and I'm ready to begin sharing our findings.

GFJ had over 500 participants, 527 of which received the survey and 279 of which completed the survey at the end of the month. Of those who received the survey, 53 percent completed it. I think these are respectable numbers for a survey of this nature, and it reflects the conscientious nature of the people who participated in GFJ.

Demographics

Although respondents were primarily from the United States, I'm happy to say that the data represent 18 different nationalities:

Respondents represented a diversity of ages, the largest group being 30-39 years old, with similar numbers in the 20-29 and 40-49 year groups.
Respondents were just under 2/3 women.

Respondents represented a variety of weights, but the sample was biased toward lean people, in comparison with the general population. There were not many obese participants.
Overall, I was pleased to see that the demographics were quite diverse, particularly in the age and gender categories.

Limitations

There are a few caveats to keep in mind when interpreting the survey results:

1. GFJ participants do not represent a random cross-section of the population at large. They represent primarily health-conscious individuals who were motivated enough to make a substantial dietary change. In addition, many of the people who participated probably did so because they already suspected they had a problem with gluten.
   
2. The survey response rate was 53%. Although I think that's a reasonable number considering the circumstances, it leaves open the possibility that survey responders differ from non-responders. It's conceivable that participants with better adherence and better outcomes were more likely to complete the survey than those who did not adhere to the diet or had neutral or unfavorable outcomes, despite our efforts to encourage everyone to complete the survey regardless of adherence or outcome. So the results could be biased toward positive outcomes, meaning that we will need to see a strong effect for it to be believable.
   
3. This was a non-blinded diet trial without a control group. There's no way to know how much of the effect was due to avoiding gluten per se, how much was due to overall changes in diet patterns, and how much was a placebo effect.
   

With that in mind, what can we take from the survey data? I feel that we can use it to answer the following question: "what is likely to happen when a motivated, health-conscious person decides to avoid gluten for a month?" And I think we can also use it to generate (but not test) hypotheses about the effects of eating gluten on the general population.

Flu Season is Here

I've noticed everyone around me getting sick lately (I seem to have become mostly immune to colds and the flu in the last couple of years), so I took a look at Google Flu Trends. Lo and behold, the United States is currently near peak flu incidence for the 2010-2011 season. Here's a graph from Flu Trends. This year's trend is in dark blue:


Flu Trends also has data for individual US states and a number of other countries.

It's time to tighten up your diet and lifestyle if you want to avoid the flu this year. Personally, I feel that eating well, managing stress effectively, and taking 2,000 IU of vitamin D3 per day in winter have helped me avoid colds and the flu.

Gluten-Free January Raffle Winners Selected!

Raffle winners have been selected and shirts are on their way. You know who you are. Thanks to everyone who participated and filled out the survey! For those who didn't, there's always next year.

Janine Jagger, Matt Lentzner and I are busy crunching the mountain of data we collected from the GFJ survey. We got 279 responses, which is remarkable for a survey of this nature.

Stay tuned for data!

Oltipraz

Oltipraz is a drug that was originally used to treat intestinal worms. It was later found to prevent a broad variety of cancers (1). This was attributed to its ability to upregulate cellular detoxification and repair mechanisms.

Researchers eventually discovered that oltipraz acts by activating Nrf2, the same transcription factor activated by ionizing radiation and polyphenols (2, 3, 4). Nrf2 activation mounts a broad cellular protective response that appears to reduce the risk of multiple health problems.

A recent paper in Diabetologia illustrates this (5). Investigators put mice on a long-term refined high-fat diet, with or without oltipraz. These carefully crafted diets are very unhealthy indeed, and when fed to rodents they rapidly induce fat gain and something that looks similar to human metabolic syndrome (insulin resistance, abdominal adiposity, blood lipid disturbances). Adding oltipraz to the diet prevented the fat gain, insulin resistance and inflammatory changes that occurred in the refined high-fat diet group.

The difference in fasting insulin was remarkable. The mice taking oltipraz had 1/7 the fasting insulin of the refined high-fat diet comparison group, and 1/3 the fasting insulin of the low-fat comparison group! Yet their glucose tolerance was normal, indicating that they were not low on insulin due to pancreatic damage. The low-fat diet they used in this study was also refined, which is why the two control groups (high-fat and low-fat) didn't diverge more in body fatness and other parameters. If they had used a group fed unrefined rodent chow as the comparator, the differences between groups would have been larger.

This shows that in addition to preventing cancer, Nrf2 activation can attenuate the metabolic damage caused by an unhealthy diet in rodents. Oltipraz illustrates the power of the cellular hormesis response. We can exploit this pathway naturally using polyphenols and other chemicals found in whole plant foods.

Polyphenols, Hormesis and Disease: Part II

In the last post, I explained that the body treats polyphenols as potentially harmful foreign chemicals, or "xenobiotics". How can we reconcile this with the growing evidence that at least a subset of polyphenols have health benefits?

Clues from Ionizing Radiation

One of the more curious things that has been reported in the scientific literature is that although high-dose ionizing radiation (such as X-rays) is clearly harmful, leading to cancer, premature aging and other problems, under some conditions low-dose ionizing radiation can actually decrease cancer risk and increase resistance to other stressors (1, 2, 3, 4, 5). It does so by triggering a protective cellular response, increasing cellular defenses out of proportion to the minor threat posed by the radiation itself. The ability of mild stressors to increase stress resistance is called "hormesis." Exercise is a common example. I've written about this phenomenon in the past (6).

The Case of Resveratrol

Resveratrol is perhaps the most widely known polyphenol, available in supplement stores nationwide. It's seen a lot of hype, being hailed as a "calorie restriction mimetic" and the reason for the "French paradox."* But there is quite a large body of evidence suggesting that resveratrol functions in the same manner as low-dose ionizing radiation and other bioactive polyphenols: by acting as a mild toxin that triggers a hormetic response (7). Just as in the case of radiation, high doses of resveratrol are harmful rather than helpful. This has obvious implications for the supplementation of resveratrol and other polyphenols. A recent review article on polyphenols stated that while dietary polyphenols may be protective, "high-dose fortified foods or dietary supplements are of unproven efficacy and possibly harmful" (8).

The Cellular Response to Oxidants

Although it may not be obvious, radiation and polyphenols activate a cellular response that is similar in many ways. Both activate the transcription factor Nrf2, which activates genes that are involved in detoxification of chemicals and antioxidant defense**(9, 10, 11, 12). This is thought to be due to the fact that polyphenols, just like radiation, may temporarily increase the level of oxidative stress inside cells. Here's a quote from the polyphenol review article quoted above (13):

We have found that [polyphenols] are potentially far more than 'just antioxidants', but that they are probably insignificant players as 'conventional' antioxidants. They appear, under most circumstances, to be just the opposite, i.e. prooxidants, that nevertheless appear to contribute strongly to protection from oxidative stress by inducing cellular endogenous enzymic protective mechanisms. They appear to be able to regulate not only antioxidant gene transcription but also numerous aspects of intracellular signaling cascades involved in the regulation of cell growth, inflammation and many other processes.

It's worth noting that this is essentially the opposite of what you'll hear on the evening news, that polyphenols are direct antioxidants. The scientific cutting edge has largely discarded that hypothesis, but the mainstream has not yet caught on.

Nrf2 is one of the main pathways by which polyphenols increase stress resistance and antioxidant defenses, including the key cellular antioxidant glutathione (14). Nrf2 activity is correlated with longevity across species (15). Inducing Nrf2 activity via polyphenols or by other means substantially reduces the risk of common lifestyle disorders in animal models, including cardiovascular disease, diabetes and cancer (16, 17, 18), although Nrf2 isn't necessarily the only mechanism. The human evidence is broadly consistent with the studies in animals, although not as well developed.

One of the most interesting effects of hormesis is that exposure to one stressor can increase resistance to other stressors. For example, long-term consumption of high-polyphenol chocolate increases sunburn resistance in humans, implying that it induces a hormetic response in skin (19). Polyphenol-rich foods such as green tea reduce sunburn and skin cancer development in animals (20, 21).

Chris Masterjohn first introduced me to Nrf2 and the idea that polyphenols act through hormesis. Chris studies the effects of green tea on health, which seem to be mediated by polyphenols.

A Second Mechanism

There is a place in the body where polyphenols are concentrated enough to be direct antioxidants: in the digestive tract after consuming polyphenol-rich foods. Digestion is a chemically harsh process that readily oxidizes ingested substances such as polyunsaturated fats (22). Oxidized fat is neither healthy when it's formed in the deep fryer, nor when it's formed in the digestive tract (23, 24). Eating polyphenol-rich foods effectively prevents these fats from being oxidized during digestion (25). One consequence of this appears to be better absorption and assimilation of the exceptionally fragile omega-3 polyunsaturated fatty acids (26).

What does it all Mean?

I think that overall, the evidence suggests that polyphenol-rich foods are healthy in moderation, and eating them on a regular basis is generally a good idea. Certain other plant chemicals, such as suforaphane found in cruciferous vegetables, and allicin found in garlic, exhibit similar effects and may also act by hormesis (27). Some of the best-studied polyphenol-rich foods are tea (particularly green tea), blueberries, extra-virgin olive oil, red wine, citrus fruits, hibiscus tea, soy, dark chocolate, coffee, turmeric and other herbs and spices, and a number of traditional medicinal herbs. A good rule of thumb is to "eat the rainbow", choosing foods with a variety of colors.

Supplementing with polyphenols and other plant chemicals in amounts that would not be achievable by eating food is probably not a good idea.


* The "paradox" whereby the French eat a diet rich in saturated fat, yet have a low heart attack risk compared to other affluent Western nations.

** Genes containing an antioxidant response element (ARE) in the promoter region. ARE is also sometimes called the electrophile response element (EpRE).

Polyphenols, Hormesis and Disease: Part I

What are Polyphenols?

Polyphenols are a diverse class of molecules containing multiple phenol rings. They are synthesized in large amounts by plants, certain fungi and a few animals, and serve many purposes, including defense against predators/infections, defense against sunlight damage and chemical oxidation, and coloration. The color of many fruits and vegetables, such as blueberries, eggplants, red potatoes and apples comes from polyphenols. Some familiar classes of polyphenols in the diet-health literature are flavonoids, isoflavonoids, anthocyanidins, and lignins.

The Case Against Polyphenols

Mainstream diet-health authorities seem pretty well convinced that dietary polyphenols are an important part of good health, due to their supposed antioxidant properties. In the past, I've been critical of the hypothesis. There are several reasons for it:

1. Polyphenols are often, but not always, defensive compounds that interfere with digestive processes, which is why they often taste bitter and/or astringent. Plant-eating animals including humans have evolved defensive strategies against polyphenol-rich foods, such as polyphenol-binding proteins in saliva (1).
2. Ingested polyphenols are poorly absorbed (2). The concentration in blood is low, and the concentration inside cells is probably considerably lower*. In contrast, essential antioxidant nutrients such as vitamins E and C are efficiently absorbed rather than excluded from the circulation.
   
3. Polyphenols that manage to cross the gut barrier are rapidly degraded by the liver, just like a variety of other foreign molecules, again suggesting that the body doesn't want them hanging around (2).
4. The most visible hypothesis of how polyphenols influence health is the idea that they are antioxidants, protecting against the ravages of reactive oxygen species. While many polyphenols are effective antioxidants at high concentrations in a test tube, I don't find it very plausible that the low and transient blood concentration of polyphenols achieved by eating polyphenol-rich foods makes a meaningful contribution to that person's overall antioxidant status, when compared to the relatively high concentrations of other antioxidants in blood (uric acid; vitamins C, E; ubiquinone) and particularly inside cells (SOD1/2, catalase, glutathione reductase, thioredoxin reductase, paraoxonase 1, etc.).
   
5. There are a number of studies showing that the antioxidant capacity of the blood increases after eating polyphenol-rich foods. These are often confounded by the fact that fructose (in fruit and some vegetables) and caffeine (in tea and coffee) can increase the blood level of uric acid, the blood's main water-soluble antioxidant. Drinking sugar water has the same effect (2).
6. Rodent studies showing that polyphenols improve health typically use massive doses that exceed what a person could consume eating food, and do not account for the possibility that the rodents may have been calorie restricted because their food tastes horrible.
   

The main point is that the body does not seem to "want" polyphenols in the circulation at any appreciable level, and therefore it gets rid of them pronto. Why? I think it's because the diversity and chemical structure of polyphenols makes them potentially bioactive-- they have a high probability of altering signaling pathways and enzyme activity, in the same manner as pharmaceutical drugs. It would not be a very smart evolutionary strategy to let plants (that often don't want you eating them) take the reins on your enzyme activity and signaling pathways. Also, at high enough concentrations polyphenols can be pro-oxidants, promoting excess production of free radicals, although the biological relevance of that may be questionable due to the concentrations required.

A Reappraisal

After reading more about polyphenols, and coming to understand that the prevailing hypothesis of why they work makes no sense, I decided that the whole thing is probably bunk: at best, specific polyphenols are protective in rodents at unnaturally high doses due to some drug-like effect. But-- I kept my finger on the pulse of the field just in case, and I began to notice that more sophisticated studies were emerging almost weekly that seemed to confirm that realistic amounts of certain polyphenol-rich foods (not just massive quantities of polyphenol extract) have protective effects against a variety of health problems. There are many such studies, and I won't attempt to review them comprehensively, but here are a few I've come across:

• Dr. David Grassi and colleagues showed that polyphenol-rich chocolate lowers blood pressure, improves insulin sensitivity and lowers LDL cholesterol in hypertensive and insulin resistant volunteers when compared with white chocolate (3). Although dark chocolate is also probably richer in magnesium, copper and other nutrients than white chocolate, the study is still intriguing.
• Dr. Christine Morand and colleagues showed that drinking orange juice every day lowers blood pressure and increases vascular reactivity in overweight volunteers, an effect that they were able to specifically attribute to the polyphenol hesperidin (4).
• Dr. F. Natella and colleagues showed that red wine prevents the increase in oxidized blood lipids (fats) that occurs after consuming a meal high in oxidized and potentially oxidizable fats (5).
• Several studies have shown that hibiscus tea lowers blood pressure in people with hypertension when consumed regularly (6, 7, 8). It also happens to be delicious.
  
• Dr. Arpita Basu and colleagues showed that blueberries lower blood pressure and oxidized LDL in men and women with metabolic syndrome (9).
• Animal studies have generally shown similar results. Dr. Xianli Wu and colleagues showed the blueberries potently inhibit atherosclerosis (hardening and thickening of the arteries that can lead to a heart attack) in a susceptible strain of mice (10). This effect was associated with a higher expression level of antioxidant enzymes in the vessel walls and other tissues.

Wait a minute... let's rewind. Eating blueberries caused mice to increase the expression level of their own antioxidant enzymes?? Why would that happen if blueberry polyphenols were themselves having a direct antioxidant effect? One would expect the opposite reaction if they were. What's going on here?

In the face of this accumulating evidence, I've had to reconsider my position on polyphenols. In the process, and through conversations with knowledgeable researchers in the polyphenol field, I encountered a different hypothesis that puts the puzzle pieces together nicely.


* Serum levels briefly enter the mid nM to low uM range, depending on the food (2). Compare that with the main serum antioxidants: ~200 uM for uric acid, ~100 uM for vitamin C, ~30 uM for vitamin E.

My Gluten-Free January

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!

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!

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:

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.

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.

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.

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!

Overall, I think their recommendations for fat loss are not very satisfying because they don't address the core reasons Americans aren't in energy balance. Eliminating sweetened beverages and exercising are the most solid advice they offered in my opinion. The rest strikes me as wishy-washy advice that's offered because they have to say something.

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.

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.

The Diabetes Epidemic

The CDC just released its latest estimate of diabetes prevalence in the US (1):

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:

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.

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.