Thursday, February 23, 2006

From the Fat Files

It's amusing to read all the excuses advanced to dismiss the null findings from the WHI Dietary Modification Trial - my favorite is the one that claims that reducing fat is passe, that we'd moved on from that thinking about the time the study was just getting underway.

We find this excuse in a number of articles, but a quote in the International Herald Tribune in their article, Chances a low-fat diet will help? Slim and none, really is the best - "The diets studied "had an antique patina," said Dr. Peter Libby, a cardiologist and professor at Harvard Medical School. These days, Libby said, most people have moved on from the idea of controlling total fat to the idea that people should eat different kinds of fat."

Oh really? Then why are the studies still being published in the medical journals so focused on total fat?

Yesterday I wrote about a study published in November 2005, last week, a study published this month, and today, let's take a look at one published in April 2004 - Effect of low and high fat diets on nutrient intakes and selected cardiovascular risk factors in sedentary men and women.

This one placed study subjects on two different diets - one that was just 19% fat and another than was an eye-popping 50% fat. Guess who did better? If you said those on the low-fat diet, you're wrong. Those on the 50% fat diet increased their HDL-C to an amazing 63! The researchers noted that those on the low-fat diet may not be able to consume ENOUGH calories on such a diet, that the low-fat diet was deficient in essential fatty acids, missed essential micronutrients (especially zinc and Vitamin E) and also lowered ApoA1.

Guess the media missed that one too, huh?

Amazing when you think about it - the media only seems to find and provide information about studies that support the low-fat paradigm - and even when they do include one that clearly shows no benefit, they advance the message that something was wrong with the study - be it not enough time or those in the study just didn't lower their fat enough!

How about another example that illustrates how diet can affect risk markers? Back in May 2003, the Tohoku Journal of Experimental Medicine published the findings of a study on diabetic patients - Effects of diet treatment on some biochemical and physiological parameters in patients with type 2 diabetes mellitus. The conclusions offer no real insight to what happened to those with diabetes: This study showed that diet treatment could not normalize the high systolic blood pressure in type 2 DM. Thus, an effective way of controlling blood pressure should be taken to improve healing in DM.

Want to know what really happened? Well, when they had their diet changed to 50-55% carbohydrate, 30% fat and 15-20% protein....heck I'm not afraid to tell you...
  • Total Cholesterol - decreased from 231 to 227
  • LDL - INCREASED from 139.4 to 150.9
  • HDL - DECREASED from 44.4 to 40.2
  • Triglycerides decreased from 290 to 192.4
  • TC/HDL Ratio - INCREASED from 5.2 to 5.64 (an increase is BAD)
  • Blood pressure - INCREASED from 114/87 to 139/85

Yet the best the researchers could conclude in their abstract was that the diet couldn't normalize systolic blood pressure? Good grief - the diet intervention made these folks worse! Here though, the researchers did at least have the guts to state "Increasing fat intake to 50% of calories improved nutritional status, and did not negatively affect certain cardiovascular risk factors," in the full-text portion of their paper.

Not a peep from the media though.

Not a word of caution to diabetics from the American Diabetes Association either.

Not even the review, published in the American Journal of Cardiology - High-density lipoprotein as a therapeutic target: clinical evidence and treatment strategies - received the attention it should have.

In it, the authors state, quite clearly, "The clinical importance of low serum levels of high-density lipoprotein (HDL) cholesterol is often under-recognized and underappreciated as a risk factor for premature atherosclerosis as well as for cardiovascular morbidity and mortality. Low serum levels of HDL are frequently encountered, especially in patients who are obese or have the metabolic syndrome. In prospective epidemiologic studies, every 1-mg/dL increase in HDL is associated with a 2% to 3% decrease in coronary artery disease risk, independent of low-density lipoprotein (LDL) cholesterol and triglyceride (TG) levels."

Yet we continue to see the media and experts hone in our lowering of total cholesterol and LDL as beneficial even when the cited studies show a decrease in HDL and worse TC/HDL ratios! Folks, that's NOT a benefit for long-term health.

If you haven't started to notice, there are a number of studies out there that show we're still looking in all the wrong places (trying to lower total fat intake) and that the contention that we're long past that is way off base. We're entrenched in it and still fail to appreciate how dietary fats - yes even the much maligned saturated fats - increase HDL while reducing the TC/HDL ratio, which is considered a good number to use to predict cardiovascular disease!

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