[ RadSafe ] Fwd: Don't X-ray My Veggies

George Stanford gstanford at aya.yale.edu
Thu Jan 29 09:39:20 CST 2009

The Bottom Line Daily Health News probably reaches
a rather large audience.  Radsafers might be
interested in the excerpt below.
-- George Stanford


Date: Thu, 29 Jan 2009 02:04:14 -0500
From: "Daily Health News" <DailyHealthNews at dhn.bottomlinesecrets.com>
Subject: Don't X-ray My Veggies

  January 29, 2009

Don't X-ray My Veggies

     Though not exactly an outcry, there were
grumbles and groans when the US Food and Drug
Administration (FDA) ruled that food processors
could irradiate fresh or bagged spinach and
iceberg lettuce as a way to kill bacterial
contaminants such as E. Coli and Listeria. The
reasoning for irradiation is twofold: One,
irradiation would kill the microorganisms that
lead to spoilage, so the produce stays fresher,
longer -- and second, killing the bacteria might
potentially reduce headline-making outbreaks of
foodborne illness. Given that the FDA has been
known for having made some... shall we say,
perplexing... decisions, the question is whether
irradiated food is a positive safety ruling or yet
another well-intentioned protection attempt that
does more harm than good?


     Let's start with the basics. Irradiation is
the process of exposing food to ionizing energy
(gamma rays, electron beams, or X-rays). These
pulses of energy destroy bacteria on the food by
disrupting its DNA, though they do not make the
food radioactive per se.

     You may be surprised to hear that you've
likely been ingesting irradiated food for years.
The FDA approved irradiation of various meats back
in the 1990s (Omaha Steaks, for instance, uses the
technology for its gourmet burgers) and the
majority of dried spices, in particular, are
irradiated to kill microbes that can shorten shelf
life. So it's not new. But some new variables do
come into play when vegetables are irradiated, and
that's what has consumer advocates up in arms.
Their point -- irradiation destroys nutrients,
making foods less healthy... and we don't know
what other health problems may arise in the
future, due to processes that we are only
beginning to use without evidence showing safety
over long periods of time.


     To better understand the problem, I contacted
Bill Freese, science policy analyst for the Center
for Food Safety in Washington, DC. He and other
critics say the ruling is fraught with
imperfections, which ironically don't make sense
from either a health or business standpoint...

     Reduced nutrients. Much like cooking,
irradiation can lead to nutrient loss. Freese
doesn't believe the FDA takes this concern
seriously. "They approved irradiation of spinach
and iceberg lettuce at up to 4 kiloGray (4 kGy),
yet the studies reviewed by the FDA found that
spinach loses nearly all of its ascorbic acid
(Vitamin C) when irradiated with just 1 kGy, and
12% of its folate at 2.5 kGy. Separate research on
lettuce found a 24% to 53% lower ascorbic acid
(Vitamin C) level at just 1 kGy."

     Doesn't kill bacteria completely. Irradiation
at the low levels used in produce kills most but
not all bacteria. For instance, the Clostridium
bacterium that causes botulism is insensitive to
radiation. And it doesn't kill viruses, like
norovirus, which can cause viral gastroenteritis
(aka the stomach flu).

     Freshness. This process adds another step --
possibly a lengthy one -- to the journey from
field to table. Produce would have to be
transported to facilities equipped to irradiate
food before it could be delivered to stores, which
will add time to the shipping process.

     Unique radiolytic products and free radicals.
Irradiation of lettuce and spinach generates free
radicals from water in the leafy greens. These can
degrade the structural integrity of the leaves,
making them limp, and may also cause other
undesirable changes. Freese acknowledges, however,
that research into these particular problems is

     Is it worth the cost? Then, of course, comes
the question of cost-benefit. According to Trevor
V. Suslow, PhD, researcher at the University of
California, Davis, growers aren't likely to want
to pay the additional costs involved with
irradiating produce. The truth is, contamination
is very rare, though it does grab headlines since
it can be fatal. "If you evaluate the frequency or
likelihood of pathogen contamination versus the
cost of running everything through a treatment
facility, along with the limitations to shelf life
in the real world, I think you can see where this
doesn't make sense," he said.

     Mislabeling. Currently, all irradiated foods
need to carry the "Radura" label and the words
"treated with radiation" or "treated by
irradiation." The food industry is pushing to
change this for lettuce and spinach because they
fear consumers won't buy products so labeled.
Their hope is to use a more familiar term,
pasteurized, which would appear on labels as "cold
pasteurization" or "electronic pasteurization."
This request has not been granted -- but many are
concerned that if it is, it would be a
misrepresentation and deceitful to the public.


     Net-net, for the moment it appears unlikely
the market will be flooded with these products --
and second, it's not clearly dangerous, based on
what we know thus far. Irradiation reduces health
benefits of produce, but it doesn't appear to
render it "harmful."

     In my view, though, the best solution is to
avoid the issue altogether. I personally find that
farmers' markets are a great way to buy produce,
because I know it's fresh and I get to talk with
the grower face to face -- and that relationship
gives me peace of mind every time I set the table.


Trevor V. Suslow, PhD, extension research
specialist, University of California, Davis.

Bill Freese, science policy analyst, Center for
Food Safety, Washington, DC.

More information about the RadSafe mailing list