News You Missed. WHI: Low Fat Diet Dramatically Worsens Diabetic Blood Sugars

Over the past month the media have been busy doing what they do best--reporting bady designed animal research as if it were human research. As a result we read "A high-fat diet during pregnancy may program a woman's baby for future diabetes, even if she herself is not obese or diabetic." This headline multiplied through the web appearing on dozens of newspaper sites.

Only by reading the full article do we learn that the researchers concluded this after an undisclosed, but probably low, number of "obesity-resistant rats" were "fed... either a high-fat or a control diet from the first day of gestation."

Rodents have evolved to eat a very different diet than humans and don't do well on high fat diets. They have very different pancreases and enzyme function than humans. And, of course, the "high fat diet" used in rat research is also a high carbohydrate diet. But that didn't deter the media from reporting this finding as if it were a human study.

Another study that was reported in the media claimed that "Pregnant women who tuck into fatty foods are at greater risk of having a stillbirth."

Further reading reveals that "The team studied two dozen pregnant Japanese macaque monkeys, an animal that has a placental structure similar to humans." Not mentioned here is the fact that Macaques, like other monkeys, have evolved to eat a very different diet from humans. They live mostly on fruits, herbs, and seeds, seasoned with the occasional insect, and can't tolerate the diet of fatty meat that humans evolved to not only tolerate but flourish on.

These are just a few of the animal research studies demonizing the impact of fat on females that appeared over the past month. But what about research that looked at the impact of fatty diets on female humans?

There was , it turns out, a blockbuster human study published this past month--an important study that described the impact of a low fat diet on real, live human women. Shockingly, it received no mention in the press at all.

But what a study it was! Unlike the studies that featured a dozen monkeys or a lab full of rats, this study tracked the outcomes for 2,263 human women, whose diet, blood sugar, and insulin were tracked for six full years.

And what it found was this: Low fat diets harm women with diabetes. Here's the study:

Effects of a low-fat dietary intervention on glucose, insulin, and insulin resistance in the Women's Health Initiative (WHI) Dietary Modification trial Shikany JM, et al. Am J Clin Nutr. 2011 May 11. [Epub ahead of print]

To understand how important a result this was, we need to back track a little and remind ourselves of what the largest and best designed study of the low fat diet has already proven, which is that in almost 49,000 middle aged women, tracked over eight years, the low fat diet was shown to have zero effect on preventing heart disease or stroke. None. Nada. Zip.

The earlier publication describing the WHI findings concluded

Over a mean of 8.1 years, a dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD in postmenopausal women.

You can find the report from that study here:

Low-Fat Dietary Pattern and Risk of Cardiovascular Disease:The Women's Health Initiative Randomized Controlled Dietary Modification Trial Barbara V. Howard et al. JAMAVol. 295 No. 6, February 8, 2006

When this result hit the press in 2006, the media and the high profile doctors who have been promoting the low fat diet for decades responded by asserting that the diet used in the study must not have been low enough in fat, or that the study hadn't lasted long enough to demonstrate the benefits that the low fat diet must have. No one was willing to admit that maybe the study had proven what it looked like it proved--that the low fat diet was a useless intervention.

Doctors continue to recommend low fat diets. Dietitians continue to warn people with diabetes about the dangers of eating fat.

But now, this lastest analysis of the WHI data shows just how wrong-headed they are, because what the researches did here is to take the further step of analyzing the results for the subset of women for whom they had blood sugar measurements at the start of the study.

What they found was that for women with diabetes, the low fat diet wasn't just useless, it was dangerous, because it raised their blood sugar significantly--and I don't mean just statistically significantly. I mean it raised it a lot.

In the study's words, "...diabetic women had an increase in glucose that was 7.9 ± 20.3 mg/dL greater in the DM [diabetes]-I[ntervention, i.e. low fat diet group] than in the DM-C[ontrol] group (P for interaction <0.001).

In short, women with diabetes who didn't eat a low fat diet ended up with much better blood sugars, even though both groups were eating a high carbohydrate diet!

Since these were diabetic women who were likely to be taking medications to lower their blood sugar, the rise in blood sugar seen on the low fat diet is worse than it looks, because it takes into account the higher doses of medications they were probably taking.

Science doesn't get any clearer than this. This is a huge, well designed study. It found that the low fat diet caused significant harm in people with diabetes by raising their blood sugars. The broader study already confirmed that the low fat diet didn't do squat to prevent heart disease in anyone who participated in the study.

Yet not a word about this study made it into any major newspaper. I only found this study thanks to an alert reader who posted the link in the comments section of the previous post.

Is this shameful? Yes. Typical. Yes. Tragic for the millions of people with diabetes who get their health information, such as it is, from mainstream media. You tell me . . .