Food Sensitivities & Allergies Flashcards

Which enzyme deficiency is responsible for lactose intolerance?

Answer: Lactase

Lactase breaks down lactose into glucose and galactose; its deficiency allows undigested lactose to be fermented by gut bacteria, causing GI symptoms.

The 'Big 9' major food allergens in the US include all of the following EXCEPT:

Answer: Corn

Corn is not among the FDA-recognized Big 9 allergens, which include milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans, and sesame.

Mast cell activation disorder (MCAD) differs from classical food allergy because it can be triggered by:

Answer: A wide range of foods, chemicals, and physical stimuli without IgE involvement

MCAD involves mast cell degranulation from diverse triggers including temperature, stress, and various foods without requiring IgE sensitization.

FODMAPs worsen symptoms in IBS because they:

Answer: Are fermented by gut bacteria producing gas and osmotic fluid shifts

Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols draw water into the bowel and are fermented, causing bloating and altered motility.

Which test is considered the gold standard for diagnosing food allergies?

Answer: Double-blind placebo-controlled food challenge

The DBPCFC eliminates bias and is the most clinically reliable method to confirm or rule out a true food allergy.

Histamine intolerance differs from true food allergy primarily in that it involves:

Answer: Impaired histamine degradation by DAO or HNMT enzymes

Histamine intolerance results from reduced activity of diamine oxidase (DAO) or histamine N-methyltransferase (HNMT), allowing histamine accumulation.

Which nutrient most directly supports the production of secretory IgA in the gut?

Answer: Vitamin D

Vitamin D receptors on immune cells regulate sIgA production; deficiency is associated with impaired mucosal immunity and increased antigen penetration.