MISSISSIPPI STATE -- Food that is good for one person can be dangerous to another because of food allergies that affect about 7 million Americans.

Common foods that people are allergic to include milk, eggs, peanuts, tree nuts, soy, wheat, fish and shellfish. More children than adults have food allergies, although many outgrow their allergies as they mature.

Rebecca Kelly, human nutrition specialist at Mississippi State University's Extension Service, said food intolerances are often confused with true food allergies.

"An allergy is an immune response in which the body produces antibodies to a harmless food protein," Kelly said. "An intolerance is an adverse reaction that does not involve the immune system."

Differentiating between a food intolerance and an allergy is a distinction for medical professionals.

"Be careful to not self-diagnose," Kelly said. "With a food allergy, we restrict our diets to eliminate that food and this could cause nutrient deficiencies. We could also misdiagnose ourselves and postpone treatment of the real problem."

Symptoms of food allergies can include swelling of the lips, tongue and face; itchy eyes; hives; rash; itchy or tight throat; shortness of breath; dry, raspy cough; abdominal pain; nausea; vomiting; and diarrhea. Someone suffering from a severe food allergy reaction can go into anaphylactic shock, a state that includes these symptoms in addition to a drop in blood pressure, loss of consciousness and even death if untreated.

Food allergies often are passed through families, with 10 to 15 percent of children from allergic families having a food allergy themselves. Kelly said preventative measures can be followed for children considered at high risk for developing a food allergy.

"Breast feeding provides the greatest protection against allergy during the first two to three years of life and promotes the faster and more efficient development of the infant's immune system," Kelly said.

Another way to decrease, prevent or delay a food allergy in a child is to delay introduction of the eight major food allergens.

"All new foods are added one at a time for five to seven days. If the child does not have an allergic reaction, the next new food can be added," Kelly said.

High risk children should start on their first solid food, a single grain, iron-fortified rice cereal at 6 months rather than 4. At 7 months, begin introducing fruits and vegetables, beginning with the orange vegetables squash, sweet potatoes and then carrots. Fruits such as applesauce, pears, peaches and bananas can be given in any order.

At 9 months, add other grains such as oats, corn, white potatoes, barley and wheat. At 9 to 10 months, the child can have table foods such as vegetables and legumes the family is eating. Meat baby foods such as lamb, pork, turkey, chicken and then beef are introduced at 1 year.

Some foods are highly allergic and should be avoided longer. Kelly said cow's milk or soy is not recommend before the child is 1 year old. Avoid eggs until the child reaches 2 and peanuts, tree nuts, fish and shellfish until the child is 3 to 4 years old.

For those living with a food allergy, a few precautions can make life easier. Avoid foods that cause a reaction by reading food labels and looking for key words. For example, someone with a peanut allergy must avoid foods that have words such as beer nuts, ground nuts, mixed nuts, Nu-Nuts or any item with peanut in the name.

Substitute foods for the ones being avoided to ensure the body's nutrient requirements are met. Beware of cross-contamination from safe foods coming in contact with foods to which a person is allergic. This can happen when french fries and fish are cooked in the same oil or when deli cheese and meat are sliced on the same machine.

Carefully select restaurants. If necessary avoid restaurants such as Chinese, Thai or Indian which serve a lot of dishes with nuts and shellfish. Examine the menu in advance and visit at non-peak hours to allow time to ask questions of the wait staff.

A final precaution for someone with a food allergy is to have an emergency plan of action. This should include such things as a list of food allergies, medications and dosages needed if there is a reaction, the individual's symptoms, and the names and phone numbers of emergency contacts and doctor.

For more information, contact: Dr. Rebecca Kelly, (662) 325-3080