What is a food allergy?

A food allergy is an abnormal immune response in which the body mistakenly identifies proteins in food as harmful substances. Common food allergens include milk, eggs, fish, shellfish, nuts, peanuts, wheat, and soy.

Although proteins denature at high temperatures, their peptide sequences remain intact, allowing the body to recognize the allergens and trigger an allergic reaction. However, pollen-related food allergies can have their allergens destroyed through high-temperature cooking.

Allergic symptoms may appear within minutes to hours after consumption. Symptoms include tingling in the mouth, oral itching, swollen lips, throat swelling, and hives. Other symptoms may include wheezing, nasal congestion, abdominal pain, diarrhea, and dizziness. In severe cases, allergies can lead to anaphylactic shock, which can be life-threatening.

Have you ever considered that exercise might cause allergies?

When you exercise, the immune system is activated, which may lead to the release of histamine due to sweating, thereby worsening allergic symptoms. In addition, exercise can increase intestinal permeability, allowing more allergens to be absorbed. It can also trigger mast cells to release histamine.

What is Food Intolerance?

Although both food allergies and food intolerances are triggered by food, they are not the same. Food intolerance is not related to the immune system, but rather a reaction of the digestive system. This is because the body cannot digest certain components of food, usually due to a lack of specific enzymes.

Compared to food allergies, the symptoms of food intolerance may take longer to appear, ranging from a few hours to several days after consumption. In addition, the symptoms of food intolerance are usually milder than those of food allergies. Common symptoms include bloating, abdominal cramps, diarrhea, nausea, vomiting, heartburn, and stomach pain.

Take lactose intolerance as an example, which is caused by a deficiency of lactase. Our bodies do not have enough lactase to break down lactose into glucose and galactose, leading to an accumulation of lactose in the body. Lactose becomes food for the gut microbiota, producing lactic acid and gas. The accumulation of lactic acid in the intestines draws water from intestinal cells, causing diarrhea.

Interestingly, some people may not experience lactose intolerance in childhood, but it suddenly appears in later years. This is because they were able to produce enough lactase during childhood. However, as they age, their ability to produce lactase decreases. Continuously consuming foods containing lactose can help delay the loss of lactase activity.