Meat kills, confirms National Cancer Institute study of half million Americans

From ANIMAL PEOPLE, April 2009:
WASHINGTON D.C.–“High intakes of red or
processed meat may increase the risk of
mortality,” National Cancer Institute
researchers conservatively reported in the March
23, 2009 edition of Annals of Internal Medicine.
Annals of Internal Medicine is a
peer-reviewed journal published by the American
Medical Association–and what the study authors
actually found was the strongest scientific
condemnation yet of the health effects of a
meat-centered diet, regardless of the type of
meat consumed.
The National Cancer Institute examined
the relationship of diet and mortality among more
than half a million middle-aged and elderly
Americans from 1995 until the end of 2005. The
participants, all between 52 and 71 years old,
joined the study by completing a 124-question
survey about their eating habits, distributed by
the American Association of Retired Persons.
“Follow-up for vital status was performed
by annual linkage of the cohort to the Social
Security Administration Death Master File, and
cause of death information was provided by
follow-up searches of the National Death Index,”
explained study authors Rashmi Sinha, Amanda J.
Cross, Barry I. Graubard, Michael F. Leitzmann,
and Arthur Schatzkin.

The authors corrected the findings to
exclude the effects of smoking. The study
examined many other potential variables affecting
mortality, but none of the others appeared to
have statistical significance approaching that of
meat consumption–especially red and processed
meat intake.
There were 47,976 male deaths and 23,276
female deaths among the study cohort of 322,263
men and 223,390 women.
“Red and processed meat intakes were
associated with modest increases in total
mortality, cancer mortality, and cardiovascular
disease mortality,” Sinha et al found, as
compared to the norms of the study group.
But the differences between the people
who ate the most red and processed meat and those
who ate the least were much greater. The 20% of
men who ate the most red meat were 35% more
likely to likely to die than the 20% who ate the
least. The 20% of women who ate the most red
meat were 43% more likely to likely to die than
the 20% who ate the least. The differentials for
the highest and lowest consumption of processed
meat were 20% for men, 31% for women.
“Eleven percent of deaths in men and 16%
of deaths in women could be prevented if people
decreased their red meat consumption to the level
of intake in the first quintile,” the study
authors determined.
“Red meat intake was calculated using the
frequency of consumption and portion size
information of all types of beef and pork,” said
the study, “and included bacon, beef, cold
cuts, ham, hamburger, hotdogs, liver, pork,
sausage, steak, and meats in foods such as
pizza, chili, lasagna, and stew. Processed
meat included bacon, red meat sausage, poultry
sausage, luncheon meats, cold cuts, ham,
regular hotdogs, and low-fat hotdogs made from
poultry.”
“There are various mechanisms by which
meat may be related to mortality,” Sinha et al
explained. “In relation to cancer, meat is a
source of several multisite carcinogensŠIron in
red meat may increase oxidative damage and
increase the formation of N-nitroso compounds.
Furthermore, meat is a major source of saturated
fat, which has been positively associated with
breast and colorectal cancerŠElevated blood
pressure has been shown to be positively
associated with higher intakes of red and
processed meat.”

White meat

“It would be better to shift from red
meat to white meat such as chicken and fish,”
Harvard School of Public Health nutrition
scientist Walter Willet told Rob Stein of the
Washington Post, “which if anything is
associated with lower mortality.”
Similar comments from others were widely echoed.
But that is not what the study found.
Mortality among the 20% of the study cohort who
ate the most poultry and fish was slightly lower
than among those who ate the least, but the
participants who ate the most poultry and fish
tended to eat the least red meat. “In general,
those in the highest quintile of red meat intake
tended to consume a slightly lower amount of
white meat but a higher amount of processed meat
compared with those in the lowest quintile,” the
study reported.
“From Table 1 of the paper,” commented
Burnham Institute for Medical Research biochemist
Shi Huang in a posting to Med Page Today, “it is
shown that the group with the highest red meat
intake consumed 119 grams [of all forms of meat] per kilogram of caloric intake. The data of
total amount of all meat [consumed] for the group
with the highest white meat intake is not shown,
but my estimate based on the reported data for
this group is 69 grams per kilogram of caloric
intake. So, it seems that people who mostly eat
white meat consumed [about half as much meat of
all types] than people who eat red meat. The
people with the highest intake of white meat have
a lower risk of death than those with lowest
intake, as reported. But those with low intake
of white meat actually consume more red meat and
total meat in general. The bottom line,” Huang
concluded, is that “the data overall shows a
link between total amount of meat and mortality.
The color of meat is irrelevant.”
The study did not separately investigate
mortality among vegetarians, who in the
middle-aged and elderly age brackets would be
only about 2% of the U.S. population.
Editorialized Barry M. Popkin, Ph.D., of
the University of North Carolina at Chapel Hill,
in the same edition of the Annals of Internal
Medicine that published the Sinha et al findings,
“We are seeing the confluence of growing
constraints on water, energy and food supplies
combined with the rapid shift toward greater
consumption of all animal source foodsŠThe need
is for a major reduction in total meat intake,
an even larger reduction in processed meat and
other highly processed and salted animal source
food products, and a reduction in total
saturated fat.”
A recent study by agricultural economists
James Mintert, Ted Schroeder, and Glynn Tonsor
found that the number of medical journal articles
linking dietary fat to cholesterol and heart
disease nearly quadrupled from 1982 to 2004,
coinciding with a 9% decline in U.S. beef
consumption.