How business, doctors and journalists prey on your food anxieties I

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Health scare
share a lot of things besides their neighbors' smoke-like
genetic heritage <strong>and</strong> social class (Fo1utES, Jan . 31, 1994) .
Both are extremehrelevant to cancer rsk-
In other %,nrds, the 1992 declaration bthe Emironmenral
Protection Agency that secondh<strong>and</strong> smoke kills
mavbe 3,000 :lmericans avear is simplv nor credible .
Some people even take serious,y the PanciPul connecion
between high-tension electric wires <strong>and</strong> "cancer clusters,"
a scare promoted by journalist Paul Brodeur in the New
Yorherin 1992 <strong>and</strong> in a book in 1993 . Most epidemiologists
dismiss his scientific
claims . "It's just garbage
epidemiology," says Professor
James Enstrom of
UCL~1 .
2.re lefties condemned
to short liNes? In 1991
two psachologists, Stanlev
Coren of the University
of British Columbia
<strong>and</strong> Diane Halpern of
California State Universitv
in San Bernardino,
questioned the relatives of
deceased people in California
<strong>and</strong> found that Pewer
<strong>and</strong> fewer left-h<strong>and</strong>ers
showed uo in ehe older
age groups . They corr
cluded that lefties were
dving off at a greater i-ate .
And they caladated that
the average life expectanev
of lefties was an astounding
nine years less than that of righties .
That's a bigger difference than that berneen smokers
<strong>and</strong> nonsmokers . If true, it would have easihbeen the
greatest epidemiological relationship to hase escaped
notice up to that time . The Coren-Halpern findings ran in
the New Era171<strong>and</strong> Journal aflledicine, giving them instant
credibiliry ; the story even l<strong>and</strong>ed on the front page of the
Wcuhexgtan Past .
"I just laughed," says left-h<strong>and</strong>ed biostatistician Donald
Hoover of the Johns Hopkins School of Public Health .
"In fact, the older people had gone to school at a time
sshen teachers forced lefties to ssrite with their right h<strong>and</strong>s .
People of that generation ~seren't allowed to be lefth<strong>and</strong>cd
." Hence the °surev" had covered onlv a fraction
of those born left-h<strong>and</strong>ed . Furthermure, actuaries criticized
the authors of the origittal stud}' for mish<strong>and</strong>ling
their statistics .
These subtleties escaped the <strong>journalists</strong> whn rushed to
publish the discovery of the supposed nine-vear gap .
Within a couple of years, protessional journals such as the
Britz`sh hledicnl Josr-nal <strong>and</strong> the American Journal of
PrrGlic Health published
articles debunking the
leftV hypothesis . But the
IS'ashin,gton Post, so far as
s~e can tell, never did a
follo~~-up storv confessing
that the earlicr one
ssas bunk .
In the 1980s a number
of papers came out sho«'-
ing a connection between
coffee drinking <strong>and</strong> pam
creatic cancer . The linkage
had no physiological
theon, to back it up, but it
had scare value, considerine
that tens of millions of
Americans begin their dat
with cups of rhe stut~~ .
Coffee drinkers had about
2 .5 times the risk of pancroatic
cancer as otbers,
claimed one 1981 studv .
Its authors speculated
that a bit more than half of all pancreatic cancers might
stem from coffee . The theony made it into the Nem
Engiaud Joru'sral af Mcdidne .
Relax<strong>and</strong> sip awav . I .arer studies failed to reproduce the
findings . Finally, in 1986, the authors of the origin°al study
reported that further study had led them to conclude that
"if there is any association bctween coffee consumptiorn
<strong>and</strong> cancer of[he pancreas, it is not as strong as our earlier
data suggested ." Translation : Coffee's as safe as orange
juice, for all «'e know .
<strong>How</strong> did this curious statistical correlation stuface? By a
jOgging kills
A[ i ntEniCNE has side effects~sgecially
the medicine
prescribed by health
fanatics .
Consider the not quite
$2 bitlion a year people
spend on organic foods .
Has it bought anyone an
extra day oflife? Bruce
Ames, a biochemist at
Berkeley, thinks not : "All
this fuss about pesticide residues
is counterproductive
. If you drive an extra
mile to go to your organic
food store, your risk of dying
in a car accident is
enormously higher than
any possible risk of those
pesticides ."
Do you jog? Have you
figured out your expected
benefit in years of life?
Now allow for your risk of
getting run over. It may
be a losing game .
A treadmill is no better .
Consider the hour a day,
three times a week, you
spend sweating at the gym .
Keep it up for 40 years,
adding, say, a year to your
lifespan . Guess what : The
number of waking hours
you gain in that year of
life is less than the number
of hours you lost to exercise
. Yes, exercise is good
for you, but overdoing it
isn't. -P .E .R. M
134
20466 7 3392 F,rbe, . A ,g .,stly .f9y,
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