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.

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.