[Foodplanning] Feature: When Foods that Are "Good for You" Begin to Go Bad

[Ashwani Vasishth]

http://www.nytimes.com/2007/01/02/health/nutrition/02seco.html

Second Opinion
When Bad Things Come From 'Good' Food

Illustration Omitted:
  	These days, shopping in the produce aisle feels like a 
gamble. If you don't pick a winner, the costs could be high. Richard 
Turtletaub

By DENISE GRADY
Published: January 2, 2007

People in the United States have gotten used to the repulsive fact 
that raw chicken, meat and eggs are often contaminated with dangerous 
bacteria. Scrub the cutting board, we are warned, don't nibble the 
cookie dough, don't eat burgers rare. In other words, handle meat 
like a biohazard - and then eat it.

But until recently, getting sick from salad was something that most 
Americans didn't even think about unless they were traveling to a 
poor country. At home, fruits and vegetables have been regarded as 
clean and safe for as long as most people can remember.

Lately, though, produce has caused a disturbing number of disease 
outbreaks; just since September, bacteria-tainted tomatoes, spinach 
and lettuce have made hundreds of people sick, and killed three. 
There have been 20 serious outbreaks in the past decade or so, and 
many have come from crops grown in California, not from imports. 
Fruit juices, alfalfa sprouts and almonds have also been involved - 
all of them supposedly health foods, like salad, the things we feel 
most virtuous about eating.

The known outbreaks are just the tip of the iceberg, health officials 
say; far more illness is never reported. Most people don't call the 
health department about a few days of gut trouble. The government 
estimates that over all, food-borne microbes - not just the ones on 
produce - make 76 million people a year sick, put 325,000 in the 
hospital and kill 5,000.

In a modern country, a rise in disease caused by tainted food seems 
like a giant step backward in public health. But there hasn't been 
much public outrage or even disgust at the notion of filth seeping 
into the food supply.

Among the nastiest bacteria is E. coli 0157:H7, which makes a 
powerful toxin that can cause severe illness and sometimes even 
kidney failure. This is the germ found on spinach a few months ago, 
and more recently on iceberg lettuce served at Taco Bell restaurants. 
It comes from cow feces and was first identified in 1982. Feeding the 
animals grain instead of hay seems to promote its growth.

The strain is harmless to cows, but in people it is so dangerous, 
according to the Food and Drug Administration, that swallowing as few 
as 10 organisms may be enough to cause an infection. About 73,000 
people a year get sick from this type of bacteria, and 61 die, the 
Centers for Disease Control and Prevention reports.

"It's gotten more attention this fall, but we've seen these outbreaks 
due to lettuce and other leafy greens for a long time," said Dr. 
Christopher Braden, chief of the outbreak response and surveillance 
team for enteric diseases at the disease centers. "We are seeing this 
on an ongoing basis. That's not an acceptable outcome. We need to 
find ways to interrupt that contamination."

Last August, the F.D.A. announced a "lettuce safety initiative" in 
response to recurring E. coli outbreaks. It began with last fall's 
lettuce harvest and included visits by inspectors to farms and 
cooling and packing facilities. But the spinach and Taco Bell 
outbreaks happened anyway.

There are several ways that bacteria can contaminate lettuce. Water 
is an obvious route, whether from unsanitary irrigation or spraying, 
or from flooding. Animals can carry bacteria onto farmland, which is 
apparently how the spinach outbreak occurred - feral pigs wandered 
from cow pastures to spinach fields, taking E. coli with them. Sick 
workers who handle produce can also contaminate it, and so can dust 
blowing off pastures. One bad batch can spoil others when they are 
mixed for chopping and bagging.

Scientists think most contamination lies on the surface of crops, but 
studies have shown that it is possible for bacteria to be taken up 
through root systems and actually wind up inside the plants, where no 
amount of washing could get rid of it. In any case, E. coli 0157:H7 
tends to be sticky and is difficult or impossible to wash off, even 
when it's only on the surface of produce.

Over the past 30 years, diseases linked to produce have increased, 
Dr. Braden said. Increased ability to detect outbreaks may explain 
part of the increase, but not all of it, he added.

"We're convinced it's real in large part," he said. "We're seeing an 
increased number of outbreaks, an increased number of cases in 
outbreaks, and an increase in the number of types of produce 
involved."

The reason is not known for sure. But, Dr. Braden said: "The way 
produce is farmed and processed has changed. It's become more 
centralized, and you have these huge processors and distributors that 
produce tens of thousands of pounds of a particular produce in a 
particular day. If something goes wrong with that produce you've got 
a big problem, whereas with small farmers, if there is a problem it's 
much more limited."

In addition, he said, bagged and prewashed produce didn't exist 25 
years ago, and people today eat more raw vegetables than in the past.

"There's probably more susceptible people eating those things," Dr. 
Braden said. "We have an aging population, and more people with 
chronic medical conditions that might make them more susceptible."

The F.D.A. is responsible for produce safety, while the Agriculture 
Department oversees meat, poultry and eggs. Some politicians have 
urged that a single new agency be formed to take charge of all food 
safety, but even if that is done, it still may not answer basic 
questions about how to clean up produce.

Dr. David W. K. Acheson, chief medical officer at the center for food 
safety and applied nutrition at the F.D.A., said the agency was 
trying to find ways to prevent outbreaks.

But, Dr. Acheson said, it has nowhere near the resources to inspect 
the hundreds of thousands of facilities that handle fresh produce in 
the United States. The Agriculture Department has far more inspectors 
and is required by law to have one in every major meat processing 
plant.

One question the drug agency is trying to figure out, he said, is how 
close is too close when it comes to cattle and produce.

"We know that 0157 is a natural contaminant of cow feces," Dr. 
Acheson said. "Cow feces, if it gets on fresh produce, is not good. 
Should there be some limitation as to how close cattle should be to a 
leafy-greens field? Fifty feet, 5 miles, 50 miles? What's the 
science?"

Fifty feet may be plenty if the cows are downhill and downstream of 
the farm, he said - but if it's the other way around, five miles may 
not be enough.

"What's really going to work?" Dr. Acheson asked. "At this point, 
there are a lot of unknowns."

Another approach, instead of trying to prevent contamination, is to 
get rid of it after the fact. Nuts can be heat-treated and juices can 
be pasteurized. Some experts have recommended irradiating lettuce.

"People in the agency are looking at the impact of that," Dr. Acheson 
said. "There are two pieces: does it work, and what dose do you need? 
Then, what's the impact of that dose on the quality of the product? 
You could irradiate anything and sterilize it, but you may end up 
with mush. It's not quite that easy."

Dr. Braden said that so far, scientists had not found any way to 
prevent outbreaks.

"Not that people aren't working on it hard," he said, adding that the 
food industry itself is under pressure.

"There may be some self-regulation from the industry, the growers 
themselves," he said. "They have to do something themselves, or else 
they're going to lose their market."


Copyright 2007 The New York Times Company

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