system
Given the following post, respond as if you're commenting on Reddit:
human
Were food allergies as common 20 years ago?

When I was growing up, I don't think I knew or met anyone with a gluten, or peanut allergy. Nowadays it seems like a lot of people have these allergies. I suspect its fairly new.
gpt
I work in this field, and have written textbook chapters on the subject. Food allergy HAS INCREASED, along with other allergic diseases. It is not simply a matter of increased diagnosis. If you're really interested, here are some papers describing the increase in prevalence. 

Grundy, J., et al. (2002). "Rising prevalence of allergy to peanut in children: Data from 2 sequential cohorts." J Allergy Clin Immunol 110(5): 784-789.

Gupta, R. S., et al. (2011). "The Prevalence, Severity, and Distribution of Childhood Food Allergy in the United States." Pediatrics.

Jarvis, D., et al. (2005). "Change in prevalence of IgE sensitization and mean total IgE with age and cohort." J Allergy Clin Immunol 116(3): 675-682.

Branum, A. M. and S. L. Lukacs (2009). "Food allergy among children in the United States." Pediatrics 124(6): 1549-1555.

Liu, A. H., et al. (2010). "National prevalence and risk factors for food allergy and relationship to asthma: results from the National Health and Nutrition Examination Survey 2005-2006." J Allergy Clin Immunol 126(4): 798-806 e713.

Sicherer, S. H., et al. (2010). "US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up." J Allergy Clin Immunol 125(6): 1322-1326.