Cattle Drive: What's in that burger you're eating?
Every
hamburger has meat and fat from 50 to 100 cattle, coming
from two to four countries.
By Alex Pulaski and Andy Dworkin
Newshouse News Service
Published in the Jackson Citizen Patriot
February 22, 2004
In
just 4 ounces, a typical burger patty is packed with the
meat and fat of 50 to 100 cattle from multiple states and
two to four countries.
Eat
two hamburgers a week — as the average American does — and
in a year's time the consumer samples a stampede: 5,200
to 10,400 cattle.
As
the nation's first mad cow case redefines the rules of beef
production, the numbers create new questions about America's
favorite meat: What health risk does a hamburger pose? Does
it accelerate the spread of mad cow disease to humans? Is
it possible to know, definitely, where hamburger comes from?
In
Britain, "minced beef" is a leading culprit for
causing a human version of mad cow disease that killed 139
people and decimated the country's beef industry. U.S. officials,
meanwhile, say Americans face almost no risk from that disease.
Experts
think cattle don't develop mad cow disease until at least
30 months of age — older than most U.S. beef steers. But
millions of older dairy and beef cows and bulls go to slaughter
each year, too, and their meat is mixed with imported beef
of undetermined age to make burgers.
For
two decades, ground beef has been a leading cause of food-borne
disease and recalls in the United States. Because the meat
in burgers is so thoroughly mixed, pathogens get pushed
to the centers of patties. They are therefore tricky to
fully cook and keep disease-free. Ground beef is most notably
linked to infection by harmful E. coli bacteria, which kill
an average of 61 Americans each year. The meat is more rarely
linked to other bugs, such as salmonella bacteria and the
Norwalk virus.
Now,
some consumers also are worrying about burgers and a human
form of mad cow disease, thought to be spread by errant
proteins called prions that can nest in a cow's central
nervous system and may get loose during slaughter.
Tough to get the disease
Yet scientists think it's tough to get mad cow disease —
even for frequent beef eaters.
The
health impact of the mix of many cows in the average burger
makes risk hard to gauge. The blending process can spread
infectious agents, but it also can dilute them.
A burger's
meaty hodge-podge can spread infectious material from an
average 1,200-pound cow into vast quantities of meat, as
Washington's mad cow case showed. Though officials thought
meat from that Holstein posed almost no risk, they started
a meat recall that covered 38,000 pounds once that cow was
ground and mixed with others.
Grinding
may be ground beef's biggest health risk. The process takes
bacteria that normally live on the surface of muscle meat
and mixes them deep inside patties, where incomplete cooking
may not kill them.
"I
do think ground beef is riskier than a steak", said
Dr. Paul Cieslak, an epidemiologist with the Oregon Department
of Human Services. "If no one is going out and injecting
it with fecal matter", including bacteria.
In
random testing — one in about ever 1 million pounds of ground
beef — the U.S. Agriculture Department found E. coli in
fewer than 1 percent of all samples in the past three years.
Cooking
burgers to an internal temperature of 160 degrees kills
the threat. Few people, however, use meat thermometers with
hamburgers, and color is not an accurate measure of temperature.
But
cooking does not kill prions. The way to make burgers safe
from mad cow disease is to make sure the proteins never
get in the meat.
Many
studies show that solid cuts of boneless meat are prion-free,
said David Lineback, director of the Joint Institute for
Food Safety at the University of Maryland. But prions could
sneak onto beef if bits of brain and spinal cord — such
as from nerves connected to the vertebrae in a T-bone steak
— contaminate meat. Nerve tissue could also accidentally
slip into ground beef, Lineback said.
Much
of the U.S. ground beef supply contains "trimmings"
— odd bits of meat and fat cut off carcasses — as well as
beef processed in "advanced meat recovery systems".
Those are machines that detach soft meaty tissue from bones.
In
Europe, doctors think such practices may have helped channel
the errant proteins that cause mad cow disease in humans.
In cattle, those proteins mostly gather in the brain and
spinal column.
Spinal
bones and tissues sometimes found their way into ground
beef, including when vertebrae were put in machines to separate
soft tissues. Researchers in France and the United Kingdom
found that "mechanically separated" beef, mixed
into burgers, represented the biggest risk.
Mechanically
separated beef is distinct from the product of advanced
meat recovery systems. The first results from high pressure
and a sieve, contains much more pulverized bone and looks
like a paste or batter; the second must look like standard
meat to be labeled as such.
Federal rules followed
In the United States, federal rules have banned companies
from marking "mechanically separated" beef as
meat or mixing it into hamburger.
Until
last month, companies could put spinal bones through advanced
meat recovery machines. The U.S. Agriculture Department
banned the practice for cattle 30 months and older.
As
far back as 1997, however, the USDA was warning that the
presence of spinal cord tissue in meat "is not expected
and cannot be allowed" in products from advanced meat
recovery systems. Yet in a study of the systems in 2002,
the agency found such tissue in one-third of all samples.
In
a 2003 follow-up study of processors that had spinal cord
contamination, one-third of the meat samples again contained
spinal tissue. Most of that contaminated beef was sent to
rendering plants and not eaten. But surveyors noted that
8 percent was relabeled as mechanically separated beef and
processed in products such as chili.
Decades
ago, hamburger was ground in small lots from a single source
at the corner butcher shop. A deli or butcher can still
do it that way.
But
meat production has gravitated to large-scale plants, where
as many as 4,500 head are slaughtered daily. And 80 percent
of beef slaughter rests in the hands of four companies nationwide.
Grass no longer used
At the same time, most beef cattle have been pushed off
their natural feed — grass — and bulked up on grains and
hormones with the help of antibiotics. They grow fast, and
their meat is fatty and flavorful.
One
byproduct is 100 to 250 pounds of fatty trim per cow, which
runs as much as half-fat and half-meat. It's worth practically
nothing to a renderer. A grinder, though, will pay 30 cents
to 80 cents a pound.
But
the fat content of trim exceeds federal maximums of 30 percent
for ground beef.
That's
where dairy and imported cattle come in. Raised on hay and
pasture, their leaner meat can be mixed with trimmings from
beef cattle to create a cheap, high-protein, homogenous
mix.
Of
the 7.5 billion pounds of ground beef processed annually
in this country, about three-fifths comes from young beef
cattle. Another one-fifth comes from imported cattle and
meat. The last fifth is roughly split between 5- to 7-year-old
dairy cows and older beef cows and bulls, usually 6 to 10
years old.
Consumers
have several ways to make their ground beef safer from germs,
food-safety experts say: Buy meat that has been irradiated
to kill bacteria. Have a butcher specially grind a steak.
Thoroughly wash hands and utensils after handling raw ground
beef. And use a meat thermometer to make sure the center
of a burger reaches 160 degrees.
If
that sounds too done, Lineback offers an option for lovers
of pink meat: "You can have a rare burger if you want",
he said. "Just take a steak and sear the surface. ...
Then grind it up."
