Feature Article
Fat Chance
Once upon a time, a man named Ancel Keys, American scientist and developer of
K-rations,
led a study to examine the relationship between diet and cardio-vascular disease (CVD).
This was the
Seven Countries Study.
He found a correlation between high cholesterol levels
and CVD, and his primary dietary conclusion was that fat
consumption was the leading culprit. He later determined that the real culprit was
specifically saturated fat, and began crusading for the low-fat diet. He is responsible
for coining the Mediterranean Diet as an example of a low-saturated fat, heart-healthy
way of eating.
Ancel Keys was a smart guy. Unfortunately, he was
wrong on this one. Even worse, so many
people (and governments) bought into the connection between saturated fat and heart
disease that even today, some 40 years later, it's Common Knowledge. So what happened?
The big problem with the Seven Countries Study was the scope of the data. Why only seven
countries? As it turns out, when other countries are added into the mix, the correlation
is much less clear. (And is still only correlation, not causation.) This was pointed out at the time,
but for whatever reason (though one could guess that money played a role) was
ignored. In fact, a peer of Keys named John Yudkin found a better correlation
between sugar and CVD, but that was largely spurned. (Yudkin advocated a low-carb diet,
well before Atkins.) Keys was a bigger name, and appeared on the cover of Time in
1962. Go figure.
And since then, additional studies have found no clear correlation between saturated
fat consumption and CVD, leading to some calls to
stop making official recommendations based
on poor evidence. Seems sensible, no?
There's also the example of the
Masai,
a nomadic tribe with a diet that is 60% fat, about half saturated, yet they
are lean and virtually free of heart disease. Attempts to explain this as a genetic protection were set back by the
result of some Masai moving to a modern diet: they got fat and all the side-effects thereof. And it wasn't just
the Masai. The
Tokelauans
and the
Inuit are similar cases, plus
the Samburu and the Fulani. (I know, it sounds like I'm just making up names.)
But wait, doesn't saturated fat clog arteries? After all, it is "artery-clogging saturated fat",
isn't it? Hey, I'm no doctor, nor do I play one on TV, but the idea that saturated fat clogs arteries
is rather absurd. Here's the thing: the fat we store in our bodies--and even thin people are typically
around 10% fat--is saturated fat. Why would the body
store excess calories as a substance that will clog its arteries? That doesn't seem right.
Well, it's kind of funny, because
wikipedia says clogged arteries (leading to atherosclerosis) are " a result of the accumulation of fatty materials such as cholesterol"
and in the next sentence says it's "a chronic inflammatory response in the walls of arteries, caused largely by the accumulation of
macrophage white blood cells and promoted by low-density lipoproteins (LDL...) without adequate removal of fats and cholesterol from
the macrophages by functional high-density lipoproteins (HDL)." So first it's the accumulation of fatty materials, which conjures up
the "clogging the pipes" visual, but then it's an inflammatory response. Huh. But it's still a better explanation
than you'll find at
more "official" sites
that still emphasize the "build up in the walls of arteries" with no mention of the inflammatory response.
But we've now introduced cholesterol into the mix, and it's surely responsible for heart disease, right? Right? Oh, come on!
Well, I'll leave the cholesterol discussion for next time, along with the claims that saturated fat consumption raises
cholesterol levels and is therefore evil.
Look, I know many people are going to cling to the "artery-clogging saturated fat is bad!" thing like grim death,
especially with so many authoritative sources still spouting it. I'm just asking that everyone maybe consider the remote
possibility that it's not so clear. And while perhaps irrelevant, I'm compelled to point out there's about twice as
much saturated fat in an avocado as in a Twinkie. Just sayin'.
Oh, and as an aside, Ancel Keys also popularized the use of the body mass index (BMI) as a measure of body fat, following a 1972 paper.
Personally, I always thought it was quite lame not only because it doesn't account for fat distribution in the body but also
because it doesn't account for musculature since it only uses weight and height. (A six foot 220 pound NFL safety will not have
the same body fat composition as the average office worker with the same stats, yet they'll have the same BMI.) Well guess what? The
idea that
BMI isn't so great is catching on. But
Ancel needn't have worried. He'll always have K-rations!
Anyway, saturated fat should not be lumped together with the deservedly maligned
trans fat. There's no compelling evidence
it's the health-destroying substance it's been
made out to be, and some irrefutable evidence that it hasn't been bad at all for some people that rely on it as
a nutrient source. And it can be very tasty! Personally, I'm partial to coconut oil. And bacon, of course.
Next time: cholesterol and saturated fat. (Guess how that one turns out.)
Be seeing you.
-gary
For those of you who know what "AGC" ("We're not so much advanced as slightly above average.") means, a version of it is returning in the
StrongFast Fitness schedule. For everyone else, a kickboxing (with a little bit of groundfighting) training class is coming to StrongFast on
Tuesday nights at 7:30 starting September 18th. This one is for guys only, and while no actual fighting or sparring is involved, it is a
little bit intense sometimes, though always friendly. And it's a fantastic workout! This is a four-week test run before we decide whether to make
it a regular feature.
