Food Allergies


Robert Kennedy Jr.'s son Conor has been rushed to hospital emergency rooms 31 times and has been hospitalized nine times because of food allergies. He's six years old.

"We have to be hyper-vigilant," his mother, Mary, told the New York Post last year. "We have to make sure he doesn't come into contact even with someone who has eaten a peanut butter sandwich."

The Kennedys' son is one of an estimated seven million Americans who suffer from food allergies. Avoiding contact with peanuts or other foods is the only way to escape the uncomfortable--or in some cases life-threatening--reactions they cause.

That's easier said than done. The most common allergens (allergy-causing proteins) are in thousands of foods.

You can't count on a food's ingredient list to keep you safe. Some allergens are hidden in "natural flavors," and others may end up in foods by mistake. In a new study, a quarter of the food-processing plants checked by government inspectors in the upper Midwest were producing foods that contained allergens not listed on the labels.

Then there's eating out, where most food-allergy deaths occur. Can that harried server really guarantee that the chef didn't add a couple of crushed peanuts to the chili?

True Allergies
Food allergies occur when the immune system overreacts to certain proteins in food. "True food allergies affect as many as seven percent of children and about two percent of adults," says S. Allan Bock of the National Jewish Medical and Research Center in Denver.

Although more than 200 food ingredients can provoke an allergic reaction, the vast majority are caused by the "big eight": nuts (like walnuts and almonds), peanuts (they're legumes, not nuts), milk, eggs, fish, shellfish, soybeans, and wheat. Typical symptoms are nausea, hives, skin rash, nasal congestion, and wheezing.

Most kids outgrow their allergies by the time they reach adolescence, but some allergies--particularly to peanuts, nuts, and seafood--rarely go away. ' They require lifelong vigilance, says Hugh Sampson of the Jaffe Food Allergy Institute at the Mount Sinai School of Medicine in New York. And anyone can develop new allergies at any time. For most sufferers, allergic reactions to food are a temporary discomfort. But not for the estimated 30,000 people each year in the U.S. who eat the wrong food and go into anaphylactic shock, a swift and terrifying reaction in which their throats can swell enough to cut off breathing. About 150 of them die, despite the efforts of rescue squads and hospital emergency rooms:

In 1991, 12-year-old Umar Murtaza died in a Los Angeles hospital several hours after eating a piece of birthday cake that contained crushed pecans. He was allergic to nuts.
In 1998, 12-year-old Kristine Kastner, who was allergic to peanuts, took one bite of a neighbor's homemade chocolate-chip cookie. Her mother had checked the cookie, but didn't notice the finely chopped peanuts. Kristine's throat and tongue immediately began to swell and she started to wheeze and struggle for breath. The ambulance that responded didn't carry emergency epinephrine (adrenaline), which might have saved Kristine's life. She died in a Seattle-area hospital 45 minutes later.
In 1999, the day after hosting a cookout for his championship lacrosse team, 18-year-old Joe Murphy ate some pistachio nuts. The Boston-area resident knew he was allergic to peanuts but had no idea that he couldn't eat pistachios either. Murphy collapsed into anaphylactic shock, then fell into a coma. He died nine days later.
According to a new study of 32 people who died following an allergic reaction, fatal anaphylactic shock follows a clear pattern.(n1) All but two reactions were triggered by peanuts or nuts. Most of the victims were teenagers or young adults who had asthma, and most knew that they suffered from food allergies. Twenty-seven ate the food away from home. And only three were carrying emergency self-injectable epinephrine.

"Perhaps the most disturbing finding is that early administration of epinephrine may not always be life-saving," says co-author Hugh Sampson. "Four patients succumbed to a fatal reaction despite receiving epinephrine in a timely fashion."

That, says Sampson, "emphasizes the need for good education and good labeling. If treatment doesn't work, prevention becomes more critical.'

And even if epinephrine does work, victims can't depend on medics to have it. Many states permit only paramedics--not the emergency medical technicians who staff many ambulances-to carry epinephrine to treat anaphylactic shock.

Despite the serious consequences of peanut allergies, only about half of the adults in the U.S. who have experienced serious allergy-like symptoms after eating peanuts have seen a physician about it.(n2) And just seven percent keep emergency epinephrine handy.

Fighting Intolerance
Most reactions to food are caused not by allergies but by intolerances, which are less severe (except for those caused by sulfites). Intolerances could be triggered by most any food, which makes them harder to pin down. Here are the intolerances you're most likely to experience:

• Lactose. It's the most common intolerance. An estimated three out of every ten Americans adults--particularly people of African, Asian, or Mediterranean heritage--don't produce enough of the enzyme lactase to digest all the lactose (milk sugar) they consume. When too much undigested lactose reaches the large intestine, it can cause gas or diarrhea.

But people with lactose intolerance don't have to avoid all dairy products. Some--like cheese, ice cream, and yogurt--have much less lactose than milk does. And most lactose-intolerant people don't even have to give up milk.

"Our studies show that people who believe they are lactose intolerant can still consume the equivalent of a cup of milk in the morning and another one in the evening with little or no discomfort," says Michael Levitt, a gastroenterologist at the VA Medical Center in Minneapolis.(n3)

• Sulfites. These sulfur-containing additives are used as preservatives in dried fruits, wines, and dehydrated potato products like mashed potato flakes.

About one in every 100 people with asthma--some 100,000 Americans--are sensitive to sulfites, says allergy expert Steve Taylor of the University of Nebraska in Lincoln. If they eat a food that contains sulfites, their throats may constrict and cut off the flow of air. Sulfite sensitivity can develop at any age.

From 1980 to 1999, the FDA received 1,132 reports of bad--and in at least a dozen cases fatal--reactions to sulfites. More than 90 percent of them occurred in restaurants or other places outside the home. But the number of reported reactions has averaged only about ten a year since 1996, and no deaths have been recorded since 1990. That steep decline was no accident. Starting in 1982, the Center for Science in the Public Interest (CSPI), publisher of Nutrition Action Healthletter, waged a four-year campaign to get the FDA to ban sulfites from food.

In 1986, the Feds met CSPI half way. The FDA required labels to list sulfites if a food contains at least ten parts per million (that's the lowest concentration that can be reliably detected). It also prohibited restaurants, supermarkets, and food processors from using sulfites on fruits and vegetables (except grapes) that are sold raw or likely to be eaten raw. That got sulfites out of the hands of restaurant chefs, who may have been using too much on the salad-bar ingredients.

But the FDA has yet to act on CSPI's request to require restaurants to disclose which of their foods contain sulfites.

If you're sulfite-sensitive, avoid foods that contain sulfur dioxide, sodium sulfite, sodium or potassium bisulfite, or sodium or potassium metabisulfite.

• Monosodium Glutamate (MSG). This flavor-enhancer has been blamed for "Chinese Restaurant Syndrome," the headaches and flushing some people report after eating Chinese food, which is often prepared using MSG. But linking MSG to symptoms has been difficult.

Researchers at Harvard University tested 130 people who believed they were sensitive to MSG.(n4) In two separate tests, 19 of them reacted to five grams of MSG (an enormous dose), but not to a look-alike (but MSG-free) placebo. Twelve agreed to be retested. Only two of the 12 reacted to the large dose of MSG but not the placebo in the retest.

"Our research confirms that some people are sensitive to MSG, but it's not common and the symptoms are extremely mild," says Harvard researcher Raif Salim Geha.

The FDA requires food manufacturers who use MSG to list it on their labels as "monosodium glutamate." In 1993, the FDA proposed that companies put "contains glutamate" on the labels of foods made with hydrolyzed vegetable protein or other sources of glutamate (to which sensitive people say they also react). But it never followed through on its proposal.

Red wine. Some people report getting headaches after drinking red--but not white--wine. The culprit probably isn't the alcohol or the sulfites, but the phenolic flavonoids that are found in grape skins (red wine has more than white). Those same flavonoids may cut the risk of heart disease (but the evidence is sketchy).
Chocolate. Many of the ingredients used in making chocolate candy--including milk, nuts, soybeans, corn syrup, and chocolate itself--could be responsible for the headaches that some people report after eating chocolate. (No research comparable to the Harvard MSG study has ever tested people's reactions to chocolate.)
Food Colors. Some people react with itching or hives to a synthetic yellow food coloring called tartrazine, or Yellow No. 5. That's why the FDA requires manufacturers who use Yellow No. 5 to list it on their labels.
Synthetic food colors can also provoke behavior problems like irritability and restlessness in susceptible children (see "Diet and Behavior in Children," March 2000).

Obstacle Course
It isn't always easy to avoid foods that trigger allergic or intolerance reactions.

• 1) Offenders may show up where you don't expect them. Milk, soy, wheat, nuts, and eggs are staples of the food industry. Progresso Chicken Noodle Soup? It's made with soy, egg whites, and MSG. Thomas' English Muffins? It's got soy, milk, and whey. And you'll find wheat, soy, sulfites, and MSG in Rice-A-Roni Spanish Rice.

Restaurant foods are even trickier because chefs and waiters may not know what ingredients were added to the broths, sauces, breadings, and other prepared foods they cook with.

• 2) Trace amounts can trigger a reaction. People who are exquisitely sensitive to certain foods report that just being in the same room as the food can trigger an allergic reaction. Clearly, it doesn't take much. For example, a 14-year-old girl who was allergic to peanuts died during a camping trip after eating a sandwich. It had been made using a knife that had been used earlier to make a peanut-butter-and-jelly sandwich.(n1)

In a recent study, researchers gave 14 peanut-allergic volunteers small doses of ground-up peanuts on some days and look-alike (but peanut-free) placebos on other days. As little as one ten-thousandth of a teaspoon of peanut protein provoked mild symptoms in two of the 14.(n5)

• 3) Foods can be contaminated with allergens. In a disturbing new unpublished FDA study, inspectors found that only half of 85 randomly selected candy, ice cream, and baked-goods plants in Minnesota and Wisconsin were checking to see that the ingredients listed on their labels matched the ingredients in their foods.

Even more shocking: Half of the plants that didn't check were turning out foods that contained allergens not disclosed on the labels. Many used the same utensils to make foods with peanuts or eggs and foods that were supposed to be allergen-flee.

Inspectors analyzed 118 samples of foods that they suspected of having undeclared allergens. One in ten samples contained egg allergens...and one in four contained peanut allergens.

"In all, about 25 percent of the firms had some products that were coming off the line with undeclared allergens in them," says the FDA's Kenneth Falci. "The goal should be that no foods come off the line that way."

No wonder people with severe allergies have to worry about packaged foods:

In 1997, a three-year-old boy in Bristol, Tennessee, who was allergic to milk ate half a cup of lemon sorbet. Within 20 minutes, his face started to swell and he began to vomit. It turned out that the sorbet contained tiny amounts of milk and whey protein, which didn't appear on the label. Those ingredients had been in the ice cream made during the previous four months using the same equipment.(n6)
Last fall, Ben & Jerry's recalled 80,000 pints of its Peanut Butter Cup ice cream after realizing that the company had accidentally added nuts to it. Six consumers reported suffering allergic reactions.
"In a case I was involved with," recalls Hugh Sampson, "a college student who was allergic to peanuts bought cookies from a vending machine. They did not have peanuts listed on the label." But there were peanuts in the cookies, and the student died after eating them. "Apparently, the company had a little bit of batter left over from some peanut butter cookies and just threw it into a batch of another kind of cookie and figured that it didn't matter."
U.S. food manufacturers were forced to recall 125 products last year because they contained undeclared allergens.

• 4) Labels don't have to disclose allergens in flavors. When a food contains flavorings that are derived from plants or animals, the ingredient list can simply say "natural flavor." Sounds innocent, but those flavorings could contain allergens from milk, eggs, nuts, or other foods.

"In 1996, the FDA asked the food industry to voluntarily label the sources of flavors if they contained known allergens," says Peter Skinner, a scientist in the New York State Attorney General's Office. "Some firms have more or less complied, but a lot of others haven't or are doing it in their own unique way, so there is no real consistency across the board."

Last year, tired of waiting for the FDA to close up this loophole, the Attorneys General of New York and eight other states, including Michigan, Ohio, and Tennessee, petitioned the FDA to change the law (see "Making Food Safe").

About 150 people a year in the United States die from anaphylactic shock caused by a food allergy.
Since there is no treatment or cure for food allergies, the only way to avoid an allergic reaction is to avoid the offending food.
Allergies to peanuts, nuts, and seafood seldom disappear with age.
If someone's mouth and throat start to swell, making breathing difficult, call for emergency medical help to take the person to a hospital.
If you have a severe allergy, always carry self-injectable epinephrine...and use it at the first hint of a strong reaction. Ask your doctor for a prescription.
Most food intolerances have been poorly studied. And except for those caused by sulfites, most are not serious.
In May 2000, the Attorneys General of Connecticut, Maryland, Massachusetts, Michigan, New York, Ohio, Tennessee, Vermont, and Wyoming asked the Food and Drug Administration to make it easier for consumers to identify and avoid foods that can trigger allergic reactions.

You can help support their sensible proposal by mailing this coupon.

To: FDA Commissioner 5600 Fishers Lane Rockville, Maryland 20857

Fax: (301) 827-1412 E-mail:



For More Information
The Food Allergy and Anaphylaxis Network (FAAN) is a non-profit group working to increase public awareness of food allergies.

Mail: 10400 Eaton Place, Suite 107 Fairfax, Virginia 22030-2208

Phone: (800) 929-4040



For more information about food allergies and the studies described in this article, visit our Web site at

National Institute of Allergy and Infectious Diseases (NIAID) is the division of the National Institutes of Health (NIH) that supports research on allergies, infectious diseases, and immunology.

Mail: NIAID Office of Communications and Public Liaison Building 31, Room 7A-50 31 Center Drive MSC 2520 Bethesda, Maryland 20892-2520

Web: Food-allergies fact sheet:

For a list of foods that have been recalled due to possible contamination with allergens:
(n1) J. Allergy Clin. Immunol. 107:191, 2001.

(n2) J. Allergy Clin. Immunol. 103: 559, 1999.

(n3) Amer. J. Clin. Nutr. 68: 1118, 1998.

(n4) J. Allergy Clin. Immunol. 106 (5 Pt 1): 973, 2000.

(n5) J. Allergy Clin. Immunol. 100: 596, 1997.

(n6) J. Food Protec. 61:1522, 1998.


By David Schardt son, Ph.D., Executive Director, Center for Science in the Public Interest

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