Food allergies are sort of like overprotective parents. Trying too hard to do the best for their children, they often cause more harm. In the case of food allergies, an overprotective immune system, attempting to defend you from harmful viruses and bacteria, misidentifies harmless substances in foods as harmful to your health and wages all-out warfare to purge them from your system.
This overreaction by the immune system may be enough to kill you. So what exactly is a food allergy? A food allergy is an immune system response that creates antibodies to attack substances in a food that your immune system identifies as harmful to you. In the process, the reaction releases huge stores of chemical substances, including histamines, which cause symptoms ranging from a mild case of hives to a potentially life-threatening system shutdown.
Food intolerances: The inability to digest a particular food, such as milk or wheat, is typically related to a missing enzyme in the digestive system that prevents a person from fully digesting the food.
Food poisoning: Some foods may have toxins or bacteria that make you sick. Just because a food makes you sick one time does not mean you’re allergic to it, although you should have your doctor check it out.
Histamine poisoning: When you have an allergic reaction, your body releases histamine into your system, which causes most of the symptoms you experience. Some foods, including strawberries, chocolate, wine, and beer, may contain enough histamine to produce similar reactions, but these are not bona fide allergic reactions.
Reactions to food additives: MSG (monosodium glutamate) and sulfites often cause reactions, but in these cases, the body has a chemical reaction, not an allergic reaction, to the additive, not to the food itself.
Other common ailments: Food allergy is blamed for everything from migraine headaches to irritable bowel syndrome, but most of these ailments are caused by something other than a food allergy. Don’t waste your time chasing the food allergy ghost. Work with your doctor to identify the real cause and obtain more effective treatment.
Signs and Symptoms
When your immune system flips out and starts dumping histamine into your system, all sorts of nasty stuff can happen. The histamine can attack just about every organ in your body, including your skin, lungs, and gastrointestinal (GI) tract, triggering these common symptoms:
- Hives, swelling, or an itchy rash
- Itching or swelling of the lips, tongue, or mouth
- Tightening of the chest, hoarseness, or coughing
- Abdominal cramps, vomiting, diarrhea, or nausea
- Fainting or passing out, paleness, blueness, irregular heartbeat
- Coughing, wheezing, difficulty breathing
- Fear of impending doom, panic, chills, sudden weakness
- Death, if effective emergency treatment is not immediately administered
Symptoms can appear within minutes after eating and completely disappear in an hour or two after you eat the problem food, making diagnosis a snap. In many cases, however, symptoms slowly creep up on you over the course of several hours. If you’re allergic to a common food, such as wheat or milk, or to several foods, and symptoms arise slowly and take a long time to go away, you may not even suspect food allergy as the cause, and diagnosis can be much more challenging. An accurate diagnosis is the first step toward obtaining effective treatment.
When you experience an allergic reaction, your immediate concern is probably not what caused it but how to make it stop. After receiving some relief, however, your curiosity is likely to get the better of you, and you may begin to wonder why you have this condition in the first place.
The following sections explore the two factors that lead to the onset of food allergies and the possible reason why some foods are more likely to trigger allergy onset than others.
Digging up the root cause of food allergy
Research shows that the onset of food allergies is primarily due to a one-two punch of nature and nurture — genetics and environment:
1. You’re born genetically susceptible to some sort of allergic condition.
2. Exposure to even a small amount of the food sensitizes your immune system to the food. Your immune system produces antibodies to attack the food next time it enters your system. Upon your first exposure, you may not experience symptoms; your immune system is just gearing up for next time.
3. You consume the problem food again, and your immune system, now sensitized to the allergen, leaps into action to purge the allergen from your system.
Food allergies typically show themselves in the first few months or years of life, and food allergy sufferers often outgrow their allergies by the time they’re teenagers. Some food allergies, however, such as allergies to fish and shellfish appear later in life and rarely disappear over time.