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.

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.