Eating
a fast food burger and fries every day for lunch is not
a good idea–and for more reasons than you might think.
We all know about the calories, the saturated fat and the
cholesterol and the damage they can do. But the typical
fast food meal is also high in unhealthy trans fatty acids
or trans fats.
Researchers at Wake Forest University recently fed a group
of African green monkeys a diet obtaining eight percent
of its calories from trans fats–the equivalent for
a human of eating a fast food hamburger and french fries
once a day. A control group was fed a diet with the same
percentage of fat (about 35 percent), but no trans fats.
Both groups were fed only enough calories to maintain their
weight.
After six years, the monkeys fed the trans fat diet put
on 30 percent additional abdominal fat and gained weight
equal to 7.2 percent of their original body weight. Monkeys
in the control group had only a 1.8 percent weight gain
over the same period.
Scientific research has demonstrated that consumption of
trans fatty acids can raise a person’s blood level
of LDL while lowering HDL or good cholesterol, increasing
the risk of heart disease. This combined effect of trans
fatty acids, according to some accounts, is double that
of saturated fats. And there’s also an effect on triglycerides,
lipoprotein(a) and c-reactive protein.
The study with monkeys suggests that, even with a subsistence
intake of calories, trans fats may cause weight gain and
excess abdominal fat–risk factors for heart disease
and diabetes in their own right.
Trans fatty acids are a relative newcomer on the list of
fats to avoid. Since 1993, the Food and Drug Administration
has required manufacturers to identify the saturated fat
and cholesterol content in each food product. A similar
requirement for trans fat was initiated in January of 2006.
Before that time, many consumers may have thought they were
making healthy food choices–low in saturated fat and
cholesterol–when in fact they were not.
Even
Vegans Can Eat Them
Without labels to use as a guide, trans fatty acids
are not so easy to track down. Cholesterol comes mainly
from red meat, eggs and shellfish; saturated fats, from
meat and dairy products. Alterations in your eating patterns
can remove most of these fats from your diet. Even a vegan,
however, can eat too many trans fats, sometimes without
knowing it.
While small amounts occur naturally in meat and dairy products,
the vast majority of trans fats come from unsaturated vegetable
oils put through a process of partial hydrogenation (heating
in the presence of metal catalysts and hydrogen) to increase
their shelf life and stability. You’ll find trans
fats in abundance in vegetable shortening, margarine, baked
goods, fried foods, cookies, crackers, granola bars and
salad dressings.
Any time you grab something to eat on the run (unless it’s
an apple or a handful of grapes), you’re likely to
get a big hit of trans fatty acids. It’s estimated
that about a quarter of the trans fats Americans consume
are eaten away from home.
When eating at home, being able to check for trans fats
listed on the label is a huge advantage. The FDA recommends
trying to avoid all harmful fats–saturated fat, cholesterol
and trans fat–and replacing them with monounsaturated
and polyunsaturated fats that do not increase LDL cholesterol.
Whereas previously you may have looked for saturated fats
on the label, you might now want to add the grams of saturated
and trans fats. A candy bar, for example, has 4 grams of
saturated fat and 3 grams of trans fat for a total of 7.
Three cream-filled cookies have 1 gram saturated plus 2
grams trans fats for a total of 3.
To avoid trans fats, go for tub margarine (1.5 grams combined
per tablespoon) rather than stick margarine (5 grams combined).
For cooking, use olive, canola or nut oils–monounsaturated
fats which may actually improve a person’s total cholesterol
profile when eaten in moderation. Polyunsaturated fats such
as soybean, corn and sunflower oils are also preferred;
as long as they are not partially hydrogenated, they do
not raise LDL cholesterol.
It’s easy to make your own salad dressing by combining
olive oil with red wine vinegar and your choice of herbs
and seasonings. Dipping bread in olive oil is also generally
better than spreading it with butter or stick margarine,
depending, of course, on how much you use.
The trans fatty acids in a fast food meal come mainly from
the french fries, bun and condiments. Fast food french fries
have 7 grams saturated and 8 grams trans fats for a total
of 15. That’s three times more than a small bag of
potato chips.
When eating out, you can cut back on saturated fat and cholesterol
by choosing fish, chicken or lean meat entrees. Fish is
not only low in saturated fat but high in omega-3 fatty
acids, which offer some protection against heart disease.
You may feel uncomfortable asking what oil a restaurant
uses for cooking, but you can try to avoid fried foods and
baked goods that are likely to be high in trans fat.
Deep frying is a particular danger since re-heating oil
tends to increase trans fatty acids. Deep fried fish or
chicken are not healthy alternatives–even to a grilled
hamburger or steak.
The New York City Department of Health in 2005 asked restaurants
and food services to avoid cooking with and serving foods
than contain trans fats. It was a request, not an edict,
and for about half of the city’s restaurants, it required
a large-scale change in cooking and buying habits.
A Chicago city alderman recently introduced a law that would
make it illegal or serve or cook with trans fats in city
restaurants. Restaurant owners in Tiburon, California (a
small town north of San Francisco) voluntarily imposed a
similar ban a few years ago. Denmark has made it illegal
to sell oils that contain more than two percent trans fats,
and Canada has formed a task force to address the best ways
of reducing the use of trans fats in food products.
There is cost involved in choosing cooking oils and products
with a shorter shelf life, but that cost is usually accompanied
by a step up in freshness and quality. And a few dollars
spent avoiding trans fatty foods is small compared to the
health costs of continuing to use them.
