Perhaps you saw the headlines: "Just one high-fat meal can damage arteries!"
Kinda scary, isn't it? Well, not all is as it appears. While there is tremendous
promise in this research, unfortunately it's being conducted with a preconceived
bias - that dietary fat is "bad" for you.
The truth is
anything is bad for you in quantity, even oxygen. The truth
is also that, while these studies have good intentions, they fall short of delivering
what they claim: proof that fat is clogging your arteries faster than you can say
"Lipitor."
Wrong answer.
The type of fat consumed, along with the carbohydrate consumed with
it, is tainting these studies. However, in the most recent study on exercise
and arteries, there is good stuff. I will attempt to sort out the good from the
propaganda, and then let you decide.
Indiana University kinesiology researchers recently discovered that physical activity
after eating a high-fat meal does two things at once: reverses the damage to your
arteries
and improves their functioning as (get this) compared
to
before the meal. I found it interesting than in every review of this
study I found, hardly no one mentioned or elaborated on that last part.
Professor Janet Wallace and team looked at eight twenty-five-year-old subjects,
assuming that they were a safe set of "guinea pigs" I would imagine,
and fed them two meals. The first meal was "high-fat" (more on why that's
in quotes in a moment.) The second meal was low in dietary fat.
After the high-fat meal, scans of the subjects' brachial artery, which is
similar to coronary arteries in structure, revealed, in Wallace's words, "...arteries
that looks just like the arteries of a person who had heart disease." Clog
city.
However, when engaging in mere
brisk walking for 45 minutes two hours after
this meal, the arteries returned to normal...and then some. The arteries actually
showed improvement.
The test subjects also ate a low-fat meal for comparison.
What's Wrong With This Study?
Plenty. For starters, the fats used were highly processed and included
trans fats,
which have been strongly associated with the onset of heart disease. These fats
are biologically useless to the body. It's no wonder they clog up the plumbing.
But that's not all - the meal consumed was indeed high in fat, but also
very high in calories and high glycemic carbohydrates.
The researchers failed to test naturally occurring fats "only" in their
experiment, devoid of high-GI carbs (hash browns were used in this example). Would
the arteries have clogged then? Also, would one session of walking reverse, say,
three full meals of this kind of eating?
It's wonderful that we clearly see what exercise does to the arteries. This
is nothing new to readers of
Fit Over 40. The exercise and dietary recommendations in
my book easily fulfill the requirements of a super-healthy lifestyle - and
that can mean healthier arteries.
However, this is creating more "fat phobia." A bit of common sense will
dismiss it. First, fat and carbohydrate are both sources of fuel for the body. Fat
is a long-term energy source. Carbohydrate, a short-term energy source. What happens
when you mix, say, diesel fuel with unleaded in your car?
While this is an extreme example, the philosophy is sound: if your fat intake is
elevated in a meal, decrease your carbs. The other way around works as well, assuming
you have sufficient protein in the meal. Otherwise those carbs can cause spikes
in insulin, especially in cab-sensitive individuals.
Elevated insulin has been shown to clog arteries quickly as well, which is another
flaw in this study. The meal consumed would have done just that. Trans fats can
elevate insulin, an hash browns - well, that's insulin's playground.