Adverse food reactions are increasingly common in today’s society, with conditions such as food allergies, intolerances, and celiac disease affecting a significant number of individuals. These reactions are rooted in the body’s evolved defense mechanisms designed to protect against harmful components in food. However, modern diets, which often contain new or highly processed foods, can overwhelm or misdirect these defenses, leading to adverse health outcomes.
The quality of food plays a critical role in these reactions. Foods consist of macronutrients such as carbohydrates, proteins, and fats, along with various non-nutritive compounds. These non-nutritive elements can include plant toxins or food additives that may disrupt the body’s normal function. For instance, plant secondary metabolites (PSMs) evolved to deter herbivores from consuming plants. Although these substances may not be harmful in small quantities, they can interfere with nutrient absorption and damage the intestinal lining when consumed in larger amounts.
Table 1: PSMs include tens of thousands of individual structures; this table provides some relevant examples of PSMs with potentially harmful effects that include a range of toxicities. Abbreviations: ConA, concanavalin A; DIMBOA, 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one; PHA, phytohemagglutinin.
The body employs a range of defense mechanisms to protect against these harmful food components. These mechanisms, known as “antitoxin defenses,” are similar to antimicrobial defenses and include both behavioural and physiological processes. The body can recognize harmful substances directly through taste and smell, or indirectly through their effects on physiological functions. If harmful substances are detected, the body may respond with symptoms such as vomiting or diarrhea to expel the toxins.
In cases where these defenses fail or are over-activated, individuals may experience adverse food reactions. Food allergies, for example, occur when the immune system mistakenly identifies harmless food proteins as threats and triggers an immune response. Food intolerances, on the other hand, occur when the body cannot properly process certain food components, such as lactose or gluten.
As our understanding of these mechanisms improves, it becomes clear that adverse food reactions are complex and multifaceted. They represent a delicate balance between the body’s need to extract nutrients from food and its need to protect against potentially harmful substances. Moving forward, a deeper understanding of these defenses will be critical in developing effective treatments for those affected by adverse food reactions.
Journal Article: Korn, Lisa L, et al. “Adverse Food Reactions: Physiological and Ecological Perspectives.” Annual Review of Nutrition.
Summary by Faith Oluwamakinde
