What’s behind the rise in food allergies, autism, and autoimmune conditions?
If you follow health news like I do, you’ve heard about a series of “epidemics” of once-rare chronic conditions. I took a deeper dive into a few of the most well-known cases to try and sort out what’s behind the perceived rise in incidence and prevalence of these conditions in the US.
According to Food Allergy Research & Education (FARE), 32 million people in the US are allergic to one or more of the 170+ foods currently recognized as allergenic. And the prevalence of food allergy among children rose by 50% in the past few decades, led by sharp increases in peanut and tree nut allergies. (1)
Autism was once thought to be a relatively rare condition; today, CDC estimates that 1 in 59 8-year-olds is on the autism spectrum. (2) Compare that to earlier estimates that placed the prevalence at around 1 in 2000 in the 1960s, and 1 in 500 in the early 1990s. (3)
Autoimmune conditions appear to be on the rise worldwide as well. Celiac disease, rheumatic conditions, type I diabetes, multiple sclerosis and other conditions have shown steady annual increases across many industrialized nations in recent years. (4)
In the case of autism (formally known as autism spectrum disorder, or ASD), the surge in diagnoses was initially explained as the result of greater awareness and broader diagnostic criteria; by the mid-2000s, these explanations clearly failed to account for the entirety of the observed increase. (3) This unexplained increase left a void that was filled by pernicious claims linking autism to childhood vaccinations, claims that have persisted and grown, resulting in outbreaks of preventable diseases like measles among unvaccinated children.
The cause (or causes) of the increase in food allergies is unknown, but some associations have emerged. In the US, children in rural areas are less likely to develop food allergies than kids living in cities; and children with food allergies are far more likely to have asthma, respiratory allergies, and eczema than kids who don’t have food allergies.1 While it seems likely that environmental factors play a role, that role has yet to be fully characterized. Interestingly, while 11.4% of parents believe their child has a food allergy, the actual prevalence appears to be substantially lower, at 7.6%. (5)
Among autoimmune diseases, celiac disease has shown one of the sharpest rises. The increasing prevalence and awareness of celiac disease may have contributed to emergence of non-celiac gluten sensitivity (NCGS), a somewhat controversial condition thought to produce symptoms like bloating, diarrhea, and fatigue. (6) Concerns over detrimental health effects of eating gluten have led to an outsized response, with many people shunning this protein based on hearsay and questionable information from the internet.
Paging Doctor Google
The internet is a treasure trove of valuable health information; it is also a mire of ignorance and deceit. And most people are ill-equipped to analyze the validity and implications of biomedical research, even when presented without bias or agenda. That has led to another epidemic, an epidemic of patients who are convinced they have a certain condition—and need a specific treatment—much to the chagrin of harried healthcare providers who may not have the time (or, let’s face it, the inclination) to thoroughly disabuse patients of their misguided self-diagnoses.
...there is something real driving increased prevalence of these conditions.
To me, it boils down to two basic needs: We need to better understand the etiology of these chronic conditions, and we need to do a much better job of instilling scientific literacy (and skepticism!) in people’s minds.
These are big commitments, but they are the kind of work that pays enormous dividends for individual patients and society at large. Research into the complex interplay of genetics, environment, and nutrition for conditions like celiac, for instance, could help explain why most people with the genetic predisposition to Crohn’s disease do not, in fact, develop it. Comprehensive studies of ASD are needed to fill the knowledge gap into which the anti-vaccine brigade has so willingly, and destructively, charged. And we—everyone in the scientific and medical communities—should take every opportunity to contribute to scientific literacy and the public’s understanding of the methods, limits, and goals of scientific research. Because getting people invested in science is the best way to get our governments to invest in science.
References
FARE fact sheet
Baio J, Wiggins L, Christensen DL, et al. Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2014. MMWR Surveill Summ 2018;67(No. SS-6):1–23. DOI: https://www.cdc.gov/mmwr/volumes/67/ss/ss6706a1.htm?s_cid=ss6706a1_w
Nature 479, 22-24 (2011) | doi:10.1038/479022a. Accessed at https://www.nature.com/news/2011/111102/full/479022a.html
Aaron Lerner, Patricia Jeremias, and Torsten Matthias, “The World Incidence and Prevalence of Autoimmune Diseases is Increasing.” Int J Celiac Disease, vol. 3, no. 4 (2015):151-155. doi: 10.12691/ijcd-3-4-8.
Gupta RS, Warren CM, Smith BM, et al. The Public Health Impact of Parent-Reported Childhood Food Allergies in the United States. Pediatrics. 2018:142(6):e20181235
Healthline Health News: https://www.healthline.com/health-news/is-non-celiac-gluten-sensitivity-a-real-thing-041615#1
