Eat your spinach?
Spinach is touted as one of the most healthful of foods, and more people have been eating raw spinach salad in recent years, as consumers have heeded the advice of nutrition experts to load up with dark, leafy greens. Unfortunately, incidents of food poisoning from fresh produce have risen, too. Each year, E. coli 0157:H7 causes 73,000 illnesses and 60 deaths, according to the Centers for Disease Control and Prevention. During the latest outbreak, which has investigators scouring California spinach fields for clues, at least 114 people nationwide have been infected with a virulent strain of E. coli bacteria from eating fresh spinach; one 77-year-old woman has died, and 60 are hospitalized. Federal officials say the number of victims could rise through the week, as more cases are reported.
What's a health-conscious consumer to do? U.S. News has gleaned advice from the CDC, the Food and Drug Administration, and food safety experts.
E. coli outbreaks are usually associated with inadequately cooked ground beef. Why is this bug showing up in produce?
E. coli is present in the intestines of healthy cattle and in manure; it can contaminate meat in the slaughtering process. Heating food to 160 degrees kills the bacteria; that's why the federal government says to cook hamburger until it's no longer pink.
But leafy vegetables are now the second-leading source of E. coli infections in the United States. Since 1995, there now have been 20 known outbreaks from lettuce or spinach. At least eight were traced to California's Salinas Valley, the nation's main lettuce-growing region.
As a result, state and federal health officials sent teams to investigate farms in the valley in 2005 and 2006. But they haven't been able to figure out how the bacteria is getting from cattle to lettuce and spinach. Possible sources include inadequately composted manure; contaminated irrigation water; or contaminated water in used by processors to wash and bag greens.
How would I know if I've eaten contaminated spinach?
You'd be very sick! People infected with E. coli 0157:H7, the bug causing the current outbreak, suffer from abdominal cramps and bloody diarrhea for five to 10 days. Antibiotics don't reduce the severity or duration of symptoms. Most people recover on their own, but 2 to 7 percent of patients come down with hemolytic-uremic syndrome, a severe form of kidney failure that can kill or cause long-term health problems. Small children and the elderly are most vulnerable. In the current outbreak, 16 percent of the patients have developed HUS. The take-home message: This is one bad bug.
It can take up to a week after eating E. coli-tainted produce for symptoms to appear. The CDC recommends that anyone who develops diarrhea after eating fresh spinach go to the doctor and ask for a stool test for E. coli 0157. If you've eaten raw spinach recently and don't have diarrhea, the CDC says, you don't need to see a doctor.
Is organic produce safer?
Organically grown food is produced without synthetic pesticides or herbicides. But the same potential sources of E. coli contamination—cow manure and contaminated water at the farm or processing plant—could taint organic produce, too.
What about frozen and canned spinach?
Frozen spinach is blanched in boiling water before it's packed; canned spinach is heated to 250 degrees. Both processes should kill any lingering bacteria.
Am I better off buying heads of lettuce or spinach and washing it myself?
Food-safety experts are divided on this, with some arguing that contamination could be more widely spread in a facility that washes and bags thousands of pounds of produce in a day. But most experts say that the triple-washing process used for bag produce is far more effective than the typical home wash, and that having produce bagged eliminates the risk of contamination in transport and at the supermarket. Many processors also dip greens in a sanitizing solution, usually chlorine. However, those processes clearly haven't been enough to eliminate the risk. "There's no magic bullet, unless you cook it," says Doug Powell, associate professor and scientific director of the Food Safety Network at Kansas State University.
The very nature of leafy greens may be part of the problem. Unlike apples, lettuce and spinach leaves are rough, with crevices where bacteria can linger despite washing. The leaves may also absorb contaminated water, pulling bacteria inside the leaf where it is impossible to wash off.
What's the government doing about this?
Investigators from the CDC, FDA, and state and local health departments are tracing back the spinach eaten by victims to specific farms and processing plants, in an effort to pinpoint the source of the outbreak. That process began Sept. 8, when Wisconsin health officials called the CDC to report four cases of hemolytic-uremic syndrome, an unusually high number. On Sept. 14, the investigators concluded that fresh spinach was the most likely source of the E. coli outbreak. Investigators started checking Salinas Valley farms on Monday. Epidemiological investigations are painstaking, and often difficult, because of the many potential sources of contamination, and the fact that the prime evidence was eaten days before the victims got sick.
The USDA continuously inspects all slaughterhouses in an effort to reduce E. coli contamination in meat. But the Food and Drug Administration, which has oversight of food safety for fresh fruit and vegetables, does not have a similar inspection or enforcement program. "In light of continuing outbreaks, it is clear more needs to be done," Bob Brackett, director of the FDA's Center for Food Safety and Applied Sciences, told lettuce growers last November. Last month, the FDA issued a "Lettuce Safety Initiative," calling for more visits to farms and processing plants. "I'd like to see a robust program where everyone's thinking food safety 24-7," says Powell. "There are a lot of good growers, but you're only as good as your weakest link."
Consumer groups say more vigorous oversight is needed. "At this point we don't have a solution," says Dean Cliver, professor of food safety at the University of California-Davis. "It's really troubling."
Should I stop eating salad?
No, say nutritionists; the health benefits still outweigh the risks. But those risks do exist. People worried about potential E. coli contamination in salad greens can switch to cooked spinach, kale, and broccoli and reap the same health benefits.