Living Low Carb (16 page)

I attended that conference, in which some of the smartest researchers investigating this issue participated; and I can sum up the answer to the question “What’s the Evidence?” for you in two words:
Not much
. (You can read an excellent report on this conference written for the general public by About.com’s official Guide to Low-Carb Diets, Laura Dolson. The article is called “Saturated Fat: Not Guilty” and can be found at
http://lowcarbdiets. about.com/b/2008/04/14/saturated-fat-not-guilty.htm
.

I’m sure you’re thinking right about now, “
What about all those studies I’ve read about that ‘link’ saturated fat consumption with heart disease
?” Well, to unpack the problems with those studies is a bigger project than I can take on in this book. But let’s consider just a few of the issues worth thinking about before you buy—hook, line, and sinker—the idea that saturated fat is always “bad.”

First—and this is an incredibly important point—the “fate” of saturated fat in the body varies significantly, depending on what else is eaten. “Saturated fat is a completely neutral fat,” says my friend Mike Eades, MD. “It burns like any other fat.” If you’re eating a high-carb diet, the effect of saturated fat may indeed be deleterious, but
if you’re eating a low-carb diet it’s a whole different ballgame
. “If carbs are low, insulin is low and saturated fat is handled more efficiently,” said Jeff Volek, PhD, RD, one of the major researchers in the area of diet comparisons. “When carbs are low, you’re burning that saturated fat as fuel, and you’re also making less of it.”

One recent study tested what happens when you take obese patients and put them on a high-saturated-fat diet—but
without
starch. The researchers took 23 patients with atherosclerotic cardiovascular disease and put them on a high-saturated-fat diet, but one in which all the starch had been removed. Here’s what happened: body weight decreased, body-fat percentage decreased, total triglycerides decreased. The researchers concluded that a “high-saturated-fat/starch-avoidance” diet resulted in weight loss after 6 weeks
without adverse effects on serum-lipid levels
.
⁴
I suspect the results would have been very different indeed if the participants had been eating a lot of carbs along with that saturated fat.

The Paradox

Remember, when you’re dealing with a diet in “free-living” humans—as opposed to lab rats—you have four dietary variables (at least) to deal with: total calories, percent protein, percent carbs, and percent fat.
It is impossible to change one without changing the others
. So whenever you “test” a diet that’s
high
in one of those elements, it’s by definition also
lower
in another (and vice versa).

Let’s say, for example, that you have a 1,500-calorie diet made up of 70% carbohydrates, 15% fat, and 15% protein. If you now raise the fat intake by 20% (from 15% to 35%), keeping overall calories and protein the same, you’ve automatically
lowered
the carb intake by the same 20% (from 70% of the diet to 50%). That lowering of carb intake may produce—in certain populations—a very beneficial effect, lowering both insulin levels and triglyceride levels (and possibly increasing HDL in the process). In such a scenario, it would be entirely possible to say that an
increase
in fat (even saturated fat!) was associated with a
lowered
risk for heart disease.

And that’s exactly what one study showed. Research by epidemiologist Dariush Mozaffarian, MD, at Harvard found that a “higher saturated fat intake is associated with
less
progression of coronary artery disease.” What? Saturated fat
good
for you? In research done at Harvard? How can this possibly be explained?

Well, some folks at the prestigious
American Journal of Clinical Nutrition
wondered the same thing. They wrote a fascinating editorial in the November 2004 issue titled “Saturated Fat Prevents Coronary Artery Disease? An American Paradox.” The authors posed the not-unreasonable question, “
How can this paradox be explained
?”

How, indeed. Since, as the authors point out, it’s an article of faith that saturated fat raises LDL cholesterol and
accelerates
coronary artery disease, how are we to account for a study that shows the exact opposite?

The answer that keeps emerging from the research is this: the metabolic fate of saturated fat—what it actually
does or does not do
in the body—depends largely on what
else
is eaten. Eat way fewer carbohydrates and way less sugar, and how much saturated fat you eat may not matter so much.
⁵

This is the explanation most scientists who are now researching lowcarb diets believe accounts for their findings that higher saturated fats aren’t a problem,
as long as people are not eating high amounts of carbohydrate
. But once you’re eating a ton of carbs, all bets are off. If you’re eating the standard Western mixed diet, high in sugar, high in processed carbs, high in fast food, and hugely high in calories, then yup, adding more saturated fat is a really bad idea. Added to a high-calorie, high-carb diet, saturated fat won’t be burned as “fuel” and will tend to get stored on your hips. In the context of that kind of diet, the “low-fat” folks are probably right.

But a much
better
approach would be to cut out the sugar and processed carbs! In that case, the amount of saturated fat you’re consuming probably wouldn’t matter so much. Remember that in the early part of the twentieth century, the American diet was much higher in saturated fat, and we had much lower rates of heart disease. Of course we also consumed less food in general, fast food hadn’t been invented, we ate much less sugar, and we moved around more. The point is that it’s not the saturated fat that’s the demon here.

A second reason that saturated fat has been demonized, in my opinion, is that much of the research on diet and disease has lumped saturated fat together with trans-fats. Trans-fats weren’t even a health issue until relatively recently, and for decades researchers didn’t distinguish between the two when doing studies of diet patterns. Why does this matter? Because manmade trans-fats really are the Spawn of Satan. They clearly raise the risk for heart disease and stroke, and, according to Harvard professors Walt Willett and Alberto Ascherio, are responsible for 30,000 premature deaths a year,
⁶
so obviously a study that lumps trans-fats together with saturated fat is going to show some nasty associations. The question is: are those nasty health effects caused by the trans-fats, or by the saturated fats?

I think it’s pretty clear that it’s the trans-fats; and if you separate the two and look at their effects on the body as two distinct entities, you’re going to see some very big differences. If you lump them together—as many researchers did before we knew what we know now—saturated fats are likely to be tainted by the negative actions of trans-fats.

It’s as if your terrific kid was in a classroom with a really bad gang of troublemakers (let’s call them “The Gang”) who kept getting arrested. Your kid would have a really bad reputation, even though he hadn’t done anything wrong except being in the wrong homeroom: his bad reputation would be caused only by association. Saturated fats unfortunately are found in a lot of eating patterns (gangs) that also contain trans-fats, and have therefore been unfairly blamed for a lot of the damage caused by their neighbors.

Even the cholesterol-raising effect of saturated fat may be influenced by the presence of trans-fats. One study showed that palmitic acid (a saturated fatty acid) had no effect on cholesterol when the intake of omega-6 is greater than 4.5% of calorie intake, but if the diet contained trans-fats, the effect was completely different—LDL went up and HDL went down.
⁷
(How much this even matters is a whole different controversy—see below—but the fact that the combination of saturated fat and trans-fats has a different effect than saturated fat alone is still important to point out.)

The third reason saturated fat has such a bad reputation is that much of the saturated fat people consume comes from really crummy sources. Fried foods are not a great way to get fat in your diet. Neither are processed deli meats nor hormone-treated beef. But the saturated fat from healthy animals (like grass-fed beef or lamb) or the saturated fat in organic butter or in egg yolks is a different story.

I’ve never seen one convincing piece of evidence that saturated fat from
whole-food sources
like the ones I just mentioned has a single negative impact on heart disease, health, or mortality, especially when it’s part of a diet high in plant foods, antioxidants, fiber, and the rest of the good stuff you can eat on a controlled-carbohydrate eating plan!

The Big Reason Saturated Fat Has Been Demonized

And finally, the zinger—the
major
reason saturated fat has been demonized over the years is this:
cholesterol
. The perception that saturated fat
always raises cholesterol
is enough to scare anyone exposed to conventional health “wisdom,” and is so embedded in the national (and international) consciousness that it would take more than a crowbar to pry it loose from our belief system.

The truth about saturated fat raising cholesterol is this: Sometimes it does. And sometimes it doesn’t.

And the bigger truth—hold on to your hats—is this:
it may not even matter.

The Cholesterol Controversy

As of this writing—September 2008—two events occurred recently that may serve to illuminate the whole cholesterol controversy far better than any scientific, eye-glazing discussion ever could. One was in popular culture; one was in the economic and financial sector.

Event number one: the introduction of the new iPhone.

Shortly after the now-iconic iPhone first came out in 2007, it was selling nationally for $399. The new, improved version—which ran on the faster 3G network and carried a list price of $199—came out in 2008 with a slogan that was repeated endlessly on radio, print, and television ads that aired thousands and thousands of times. The slogan? “
The new iPhone: Twice as fast at half the price
.”

Sounds good, right?

Except it wasn’t true.

The new iPhone was indeed twice as fast, but it was hardly half the price. The cost of the monthly service charge had gone up by $10, so by the end of the typical 2-year contract, you had actually paid an
additional
$240 for the exact same service you would have had with the old iPhone. Together with the initial cost, that made the total price you’d have to spend to get the new phone (independent of the basic service charge) $440, or roughly 10%
more
than the initial, “old” iPhone.

The “half the price” didn’t really tell the whole story at all.

Now hold that thought for a moment.

Event number two: the subprime lending disaster and the collapse of the housing market.

This event—which was more of an ongoing crisis than a single event—was basically the result of unscrupulous lenders telling folks that they could buy houses that they clearly couldn’t afford. Through ridiculous “no interest” loans, they were able to sell people on the idea that they could live in multi-million-dollar homes in Beverly Hills for approximately what it would cost them to rent a studio apartment in Gavensport, Louisiana.

Which was sort of true.
For the first year
.

When the
real cost
of the mortgage showed up after that first “teaser” year, the dog-poo hit the proverbial fan, and the rest is history.

The initial cost
didn’t tell the whole story
. It was true that your mortgage would be
really cheap
for the first twelve months—but it was also quite
irrelevant
.

Which brings us to cholesterol.

When we focus on cholesterol, we’re
not telling the whole story
. In fact, we’re not even telling the most
important
part of the story, and—according to many—the part of the story we
are
telling may actually be virtually irrelevant.

Here’s why.

You don’t really
care
what your cholesterol level is; what you
care
about is your risk for
heart disease
. And you’ve come to believe they’re essentially the same thing. The only reason you even
know
your cholesterol level is that it has become embedded in your consciousness (as it was in mine) as an
important marker for heart-disease risk
. In fact, for many people, it is
synonymous
with heart-disease risk. (Doubt that? Try this party trick: ask five friends to say the first thing that comes to mind when you say the term “risk for heart disease.” Case closed.)

But here’s the thing: Fully half of the people with heart disease have perfectly “normal” cholesterol levels. And half the people who have what’s considered “elevated” cholesterol have perfectly normal hearts.

As long ago as 1994, a study published in the conservative and august
Journal of the American Medical Association (JAMA)
demonstrated a complete lack of association between cholesterol levels and coronary-heart-disease mortality in persons over 70 years old. It also demonstrated a complete lack of association between cholesterol levels and mortality from
any
cause in that same population.
⁸
Since we already know that the rate of heart disease in 65-year-old men is many times that of 45-year-old men, does it make sense that cholesterol suddenly “stops” becoming a risk factor when you get older? It makes
more
sense that it wasn’t that big a risk factor in the first place! As a terrific article in the online journal “The Healthy Skeptic” points out, this is akin to suggesting that smoking causes lung cancer in young men, but somehow stops doing it in older men!
⁹