* Newly developed sensitivity: The immune system can change over time. Someone might have tolerated a food perfectly fine for years and suddenly develop an allergy. The exact reasons for this are complex and not fully understood, but it's a common occurrence.
* Exposure to a new food: Eating a food for the first time, or eating a food much more frequently than before, can trigger an allergic reaction. The body's immune system may recognize the food as a threat after repeated exposures.
* Cross-reactivity: Allergies can be related. For instance, someone allergic to pollen might develop symptoms when eating certain fruits or vegetables (like birch pollen allergy linked to apples or peaches). This is due to similar proteins in the pollen and the food.
* Changes in gut microbiome: The balance of bacteria in the gut is increasingly recognized as a factor in immune system function, and changes to this balance (due to diet, stress, illness, etc.) could theoretically influence the development of food allergies. This is an area of ongoing research.
* Genetics: While not directly causing allergies, a genetic predisposition can make a person more likely to develop them. If family members have food allergies, the student is at a higher risk.
How to determine if a food allergy is the cause of symptoms:
If a 22-year-old college student suspects a food allergy, they should:
1. Keep a detailed food diary: Note down everything eaten and any symptoms experienced, including the timing. This is crucial for identifying potential triggers.
2. Seek medical advice: A doctor or allergist is essential. They can perform allergy tests (skin prick tests, blood tests) to pinpoint specific allergens. Do not attempt self-diagnosis or treatment. Misidentifying a food allergy can be dangerous.
3. Elimination diet (under medical supervision): A doctor might suggest temporarily eliminating suspected foods from the diet to see if symptoms improve. This should *only* be done under medical guidance, as nutrient deficiencies can occur.
It's important to emphasize that self-treating suspected food allergies can be dangerous. A proper diagnosis and management plan from a healthcare professional are essential for safety and effective treatment.