Thursday, August 10, 2006

Step Away from the Burger and No One Will Get Hurt

Of all the headlines generated by the recent study, Consumption of Saturated Fat Impairs the Anti-Inflammatory Properties of High-Density Lipoproteins and Endothelial Function, from the August 15th issue of the Journal of the American College of Cardiology, one stands above all the others:

A Bite Of Burger Can Cause Heart Attack

The first sentence is equally ominous, "Scientists at The Heart Research Institute in Sydney, Australia warned that a single bite of a burger or one meal high in saturated fat is enough to cause a heart attack."

The use of argumentum ad metam (an appeal to fear) begs our attention; created in this instance, as a logical fallacy, to support the dogma that dietary saturated fat is deadly - if we eat it, even just one bite of it in a foof that has saturated fat, like a burger, we risk an immediate death by heart attack.

Really, who wants to risk taking a single bite of a burger if it might cause them immediate death?

This is exactly the fear cojured up in the headline and first sentence - eat that bite and you'll die of a heart attack.

Makes you wonder how many people died eating just one bite of a burger in the study? Oh, that would be none.

So, then, how many people died eating a high fat meal that included eating a whole burger? Oh, that too would be none.

Why then the histrionics about taking a bite of a burger?

Surely someone had to keel over eating just a bite of something laden with saturated fat, no?

No

But, we must convince the population that the evil, unnessasary, artery clogging, heart damaging saturated fat must be banished from their diet...NOW!

The American Heart Association, American Diabetes Association, American Dietetics Association, and well, every leading medical/disease oriented organization and even the US government all repeatedly insist saturated fat is deadly; recommendations over the past few decades have dropped steadily as more and more "proof" is presented that consuming saturated fat will give you a heart attack.

This particular study is being promoted in the media as evidence that the cause-and-effect of saturated fat is immediate in the body and therefore it is deadly to eat in even small or moderate amounts.

You may be wondering, what exactly did the study find?

The short answer - they found that when you give a small number of subjects a slice of carrot cake and a milkshake rich with poly-unsaturated fat (75% of the total fat was PUFA; safflower oil) it had a less damaging effect in the hours following the "meal" than when the slice of carrot cake and milkshake was rich with saturated fat (89.6% of the total fat was SFA; coconut oil).

Pay no mind to the fact that:

  • both types of fat had acute effects that could be called "damaging" but with no real statistically significant differences. As the researchers put it, "a non-significant trend toward impairment..." Not only was it a "trend" - it was a NON-SIGNIFICANT trend, basically nothing to get your panties in a wad about;
  • the high-polyunsaturated fat "meal" resulted in a statistically significant rise in LDL (remember that pesky "bad" cholesterol) compared to the saturated fat "meal";
  • there were NO STATISTICALLY SIGNIFICANT DIFFERENCES in HDL, triglycerides, insulin, non-esterfied fatty acids (NEFA), forearm bloodflow, peak flow, total hyperenemia, flow-mediated dialation, or blood vessel size;
  • the researchers failed consider or measure the effect of a major confounding variable - the effect of sugar on blood glucose levels and thus insulin levels when combined with either type of fat;
  • the researchers failed to completely isolate the effects of either fat type because they fed a high-fat, high-sugar mixed meal concoction that would not be replicated in a real world experience!

Add to this:

But, hey, it's the saturated fats....they're deadly. Just step away from the burger and no one will get hurt.

Facts, data or findings that go against the preconceived notions are going to be ignored. People who have made up their minds and don't want to be confused by the lack of hard data are no longer an exception these days, but accepted as "expert" as long as they continue to perpetuate the dogma that saturated fat is deadly in any and every dietary context.

These days, it is apparent that scholars, as well as journalists, have made their minds up and don't want to be confused by the facts and instead will make a massive effort to muddy the waters even more; sow confusion; and instill a fear that saturated fats are lethal - even with just one bite - in the diet of humans.

Thus, we're expected to be good little soldiers in the war against obesity and heart disease and ignore any potential defects in studies such as this.

By establishment standards, I'm not being a good little soldier here pointing out the glaring flaws with this data. I simply cannot, in good consciousness, ignore the methods used to scare the begeebers out of those reading the various headlines this week, nor the flaws in the very short study with too few subjects (that alone render it meaningless) that had confounding variables (fatty acid composition, fatty acid chain length, sugar, blood glucose, insulin) the researchers did not control for and completely failed to even mention in the findings and discussion!

The lead researcher, Dr. Stephen Nicolls was quoted in the media, "The take-home, public-health message is this: It's further evidence to support the need to aggressively reduce the amount of saturated fat consumed in the diet."

Even though the full-text of the paper was specific, "In summary, the present study raises the possibility that the differential effects of dietary fats on the anti-inflammatory potential of HDL and endothelial function may contribute to the apparent benefits of polyunsaturated over saturated diets observed in the epidemiologic literature."

Pray tell, which population can we find that observation in the literature?

It's certainly not obeserved in the French, where "[c]onsumption studies...show a high dietary fat contribution (37-38% even 40% of total energy) with over-consumption of saturated fatty acids, under-consumption of monounsaturated fat and, to a lesser extent of polyunsaturated fatty acids." That is, of course "over consumption" defined by our dogma that any level above 7-10% of calories is excessive and harmful. Ignore the fact the French live longer than we, in better health, with significantly less cardiovascular disease.

Let's just call them a "paradox."

Oh no, we better call Spain a paradox too since "[t]rends in food consumption show increases in intakes of meat, dairy products, fish, and fruit, but decreases in consumption of olive oil, sugar, and all foods rich in carbohydrates. Although fat and saturated fat intakes increased, these changes were not accompanied by an increase in CHD mortality rates." Ignore the fact they live longer than we, in better health, with significantly less cardiovascular disease and declining rates of cardiovascular disease despite increases in their consumption of saturated fat!

Gosh, even the epidemiologists concede "Between-population ecologic studies have demonstrated an association between intake of fat, specifically saturated fat and total cholesterol and coronary heart disease (CHD) mortality. However, results are inconsistent from within-population cohort studies."

So, again, where is that proof in the literature? Where's the data? Where's the evidence?

Rather than present hard data, the tactic now is to scare the daylights out of people with headlines that warn of immediate death by heart attack if they take just one bite of a burger.

Repeat the lie often enough and people hold it as truth.

Except of course by those who take the time to actually read the studies, investigate the referenced citations of support of the findings, review the design and methods in various studies, check to see if statistically significant findings synch with the abstract, figure out if the study had any statistical power, and examine if all confounding variables were controlled for.

Or those who take the time to read the analysis of those of us who do!

3 comments:

  1. Using the French and Spanish as examples of High Sat fat diets where the people are still healthy is a bit disingenuous. Their diet is also higher in MUFA, they eat more vegetables, have far fewer additives in the food the consume, are more active in daily life,work fewer hours a week, get more vacation time, and generally eat less than most Americans. Exactly how from all of these factors do you tease out that SFA are healthy? It seam to me that the most logical conclusion would be that SFA as part of an otherwise healthy lifestyle, are not harmful. Diet is only one facet of lifestyle.

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  2. It seam to me that the most logical conclusion would be that SFA as part of an otherwise healthy lifestyle, are not harmful.

    Ahhh, my point exactly - if you haven't read the majority of my blog, it's difficult to see my perspective is CONTEXT of diet, nutrients and lifestyle.

    That said, I clearly stated in my post that "they continue to perpetuate the dogma that saturated fat is deadly in any and every dietary context."

    And it was only later, after pointing to their assertion that "benefits of polyunsaturated over saturated diets observed in the epidemiologic literature."

    Such an apparent benefit is not "apparent" nor abundant in the epidemiologic reviews as suggested. And, in fact, the French are a perfect example of a dietary pattern, rich with saturated fats and animal foods is NOT causing death by heart attack!

    The French diet is swimming in animal fats and animal proteins in their diet. Of the 3,575 calories available in their food supply (FAO data 2004) they consume 3,551 each day; of that 43% - 1527 calories is from fat (170g total) with 108g of animal-origin fats and just 62g of plant-based oils/fats.

    Tell me again the majority of their fat intake is MUFA? From which animal source?

    You're correct about vegetable intake. The French consume higher - significantly higher - vegetables, cheese, butter, pork and yogurt than we do....and significantly less vegetable oils, trans-fats, fruits, and sugar.

    Also, you are correct, the Spainish do indeed have a diet rich with MUFA, predominently from olive oil. This does not take away from the fact they still consume significantly higher that recommended intake of saturated fat and remain healthier despite the saturated fat intake.

    In case you missed the point - it was that the hysteria over saturated fats per se is not only unfounded, it's not supported in the literature, and certainly may be problematic in the CONTEXT of the total diet and lifestyle; but the article I highlighted and the study did not make such a distinction.

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  3. You could die of a single bite of hamburger if it went into your trachea and no one Heimlich'd you...

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