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Sidestepping The Trans Fat Follies
By Dr. David L. Katz
(Distributed by The New York Times Syndicate)
You have doubtless heard that "trans fat"
is bad for us. As of next January, the FDA will require food labels
to list trans fat. And food companies are now busily preparing
for the trans fat-free era.
And a good thing they are. We nutrition scientists often refer
to trans fat as "Frankenfat." Like the product of a
mad scientist's laboratory, trans fat is an artificial creation
fraught with danger. Trans fat damages blood vessels, raises cholesterol,
increases inflammation and contributes to the risk of both heart
disease and cancer.
But in the rush to get the trans fat out, some companies are turning
to the very oils that trans fat was introduced to replace.
To understand why we may be headed back to the future of dietary
fat, it's helpful to revisit the past.
Before the mid-1980s, the predominant fat sources in processed
foods in the United States were animal fats, principally beef
tallow and lard. But the so-called animal fats acquired a well-deserved
bad reputation as our ability to measure blood cholesterol improved,
and as the link between diet and heart disease became clear, thanks
to the Framingham Heart Study, which has been tracking thousands
of heart patients since 1948, and other research.
History has repeatedly proven that the ultimate power over the
food supply resides with the consumer, because the industry is
just trying to keep the customer satisfied. Demand dictates supply.
So when we all learned that animal fats -- in chips, crackers,
cookies frostings and spreads -- were best avoided, we managed
to refashion the food supply just by casting our votes at every
grocery store checkout counter. As we stopped buying products
laden with animal fat, the food industry stopped producing them.
But the industry faced difficult challenges while removing lard
from products like chocolate frosting. Saturated fats are stable
and have a high melting point -- desirable commercial properties,
not easily surrendered.
Rather than surrender the commercial benefits of saturated fat,
the industry found them in a new source, beginning in the 1980s:
tropical oils.
Palm kernel oil and coconut oil are among the very few highly-saturated
plant oils. Just so you know, a saturated fat has no carbon-carbon
double bonds, because all the binding sites on every carbon are
occupied or "saturated." An unsaturated oil has one
or more carbon-carbon double bonds.
In the late 1980s and early 1990s, products on every supermarket
shelf proclaimed in bold letters "no animal fats." They
did not say that they now contained "highly saturated plant
fats that are probably just as bad for you."
Eventually, without any help from food packages, word about "tropical
oils" did get out. In 1990, the Council on Scientific Affairs
of the American Medical Association published a position statement
calling for clear disclosure to the public that tropical oils
were highly saturated, and potentially dangerous. That marked
the beginning of the end of the tropical oils ploy.
Once again, consumer knowledge turned into consumer power, and
a change in demand remade the food supply.
But at this point the food industry was running out of options.
Manufacturers needed the commercial properties of saturated fats
but could not get away with using saturated fats. The creative
solution was to invent a new kind of fat.
The industry took naturally unsaturated fats, found in soybean
oil and cottonseed oil, for instance, and "partially hydrogenated"
them. In other words, they saturated some of the binding sites
on the carbons in these fats with hydrogen.
The unfortunate result, as we now know, was "trans"
fat. Trans refers to a particular shape a monounsaturated oil
(one with a single carbon-carbon double bond) can take. This shape
causes the fat molecules to pack closely together, resulting in
stability, and a high melting point.
For this reason, partially hydrogenated oils can be used to make
margarine in the shape of a stick at room temperature, whereas
margarine made from natural, unsaturated oils, with their lower
melting points, must be put in a tub. The trans fat era was ushered
in by food packages that proclaimed "no tropical oils!"
Trans fat is a food industry experiment gone bad. But now we've
come full-circle. Perhaps hoping that our memory isn't long, some
companies, including Kraft and the generally laudable Newman's
Own, are replacing some trans fats with tropical oils.
The only bit of good news in this sordid and oily tale is that
we now have science to suggest that not all saturated fats are
equally harmful to health. It may yet prove that tropical oils
were excessively vilified. But that verdict is not yet in, so
a return to tropical oils is premature at best.
By now the whole debate may leave you feeling helpless -- but
you aren't. You control what you eat if you exercise choice. If
your diet is comprised of mostly wholesome, minimally processed
foods -- vegetables, fruits, unrefined grains, fish and poultry,
nuts and seeds, non-fat dairy -- you are safely on the sidelines
of these dietary fat follies. I'll see you there.
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