Most of us have experienced feeling sick after eating certain foods. We may feel bloated, nauseous, or even dizzy. But, what do these symptoms mean? It is a food allergy, intolerance, or a case of food poisoning? Terms to describe an abnormal reaction to foods and associated symptoms can be confusing. Fortunately, once we get these right, we can begin to take steps to prevent them and their symptoms.
Food allergies, or food-hypersensitivity reactions, are characterized by an acute reaction by the immune system. This happens when a particular substance in food (usually a protein) that acts as an antigen to which our immune system over-reacts. Mere proximity can spur a reaction, as trace amounts of the allergen are often enough to trigger a drastic immune response.
Symptoms associated with food allergies involve rapid inflammation or swelling in areas that came in contact with the allergen. A person might develop hives or acute swelling in particular areas of the body. Allergic reactions can prove fatal if not treated promptly. For example, swelling of the airway can interfere with normal breathing and cause anaphylaxis, a severe drop in blood pressure and loss of consciousness that can prove fatal.
Food intolerance involves a dysfunctional reaction by the digestive system. This happens when we eat food that our digestive tract cannot or will not digest. One of the most common intolerances is lactose intolerance, which is characterized by the inability to digest (break down) lactose due to a missing enzyme, lactase.
When lactose intolerant people consume lactose, symptoms like bloating, intestinal cramps, excessive gas, and diarrhea may occur. Unlike food allergies, symptoms from intolerance may not be as acute and the severity of symptoms may depend on the quantity consumed.
This refers to an adverse reaction to certain foods, combinations of foods as well as amounts. Symptoms are similar to those of food intolerance but are due to an immune response. Food sensitivity can be thought of as a very mild form of an allergic reaction. Symptoms include intestinal cramps, pain, and bloating, but also dizziness, fatigue, and headaches. Figuring out specific food sensitivities may require an elimination diet which can be difficult, and a dietitian should be consulted when necessary.
Food poisoning, or food contamination, refers to sickness as a result of a pathogenic microbe or toxin present in food or water. This may result from cross-contamination of food, inadequate cooking, or preparation. Symptoms of food poisoning usually take a few hours or days to onset and vary in severity. Depending on the type of infection or toxicity, a person may need medical attention. Learn more about how to avoid food poisoning here.
What To Do If I Have an Adverse Reaction?
Appropriate responses to an adverse food reaction can vary. It’s important to do your homework beforehand and to seek medical attention when necessary. Food allergies and food poisoning can be fatal so it’s important to know their symptoms.
Food sensitivities and intolerances can be more subtle and but their symptoms are still troublesome. Figuring out which foods are best and which to avoid in these instances requires expertise in nutrition. A dietitian or nutritionist should be consulted if possible.
- Whitney, Eleanor, et al. Understanding Nutrition. Cengage Learning Australia Pty Limited, 2019.