Type 1, Not Type 2, Diabetes Rates Associated with Fast Food

David C. Lee, MD, MS

A retrospective cohort study has found that type 1 diabetes (T1D) — not type 2 — is more prominent in areas with poor food options.

Researchers from the New York University School of Medicine have found an association between T1D and “food swamps”: areas with food service categorized as fast food, or bodegas and small convenience stores, in lieu of larger grocery stores. The found association bucks previous notions that T1D is better linked to heredity and immunology, while T2D is linked to diet.

Researchers collected data on adults and children who visited a New York emergency department at least once between 2009-2013. In order to prioritize a non-institutionalized population, they included patients with home addresses that matched to New York City (NYC) census tracts, and excluded patients from correctional facilities or nursing homes.

They characterized the restaurant food environment from that time using inspection data from the NYC Department of Health and Mental Hygiene. Fast food “swamps” were defined as areas with a greater proportion of nearby restaurants only offering take-out or counter service. For both food environment measures, researchers counted restaurants and stores within a one-mile radius of patient’s central location based on the census.

Of the approximate 5 million unique adults and 1.6 million unique children with an NYC address to have visited an emergency department during the observed period, 540,423 adults were found to have diabetes (11,561 [0.23%] with T1D; 528,862 [10.5%] with T2D), and 5127 children were found to have diabetes (3333 [65%] with T1D; 1794 [35%] with T2D).

Save for pediatric T2D, the prevalence of all types of diabetes was higher in fast food swamps (P < 0.001). Areas identified as having the greatest proportion of fast food restaurants also reported 1.55 times greater adult T1D prevalence, 2.52 times greater adult T2D prevalence, and 2.03 times greater T1D prevalence compared to areas without any fast food.

Though a univariate analysis showed that pediatric T2D prevalence was 2.91 times greater in the highest-proportion food swamps, the multivariable approach provided to all other diabetes populations showed that this rate was not statistically significant.

There was no found association between retail food store swamps on local diabetes prevalence.

The disparity of fast food swamps significantly affecting pediatric patients with T1D but not those with T2D came as a surprise to author David C. Lee, MD, MS, of the New York University School of Medicine. He told MD Magazine that the perceived distinct line between the 2 conditions has always been diet.

“This association with fast food diets makes us call into question with what’s going on in the development of these diseases,” Lee said.

The findings lead researchers to believe that certain environmental factors may be contributing more to T1D than previously thought.

“There is some emerging literature which suggests that pregnant women in adverse food environments may have a higher likelihood of gestational diabetes, which some believe may affect health outcomes in their offspring,” researchers wrote. “Given the high prevalence of obesity among children with type 1 diabetes, the association we identified between the food environment and type 1 diabetes merits further research.”

The only association of T2D and a measured factor identified by researchers was a higher prevalence of the condition among black children. Even more consideration must be given as to the what influencers of the far more common T2D are.

“Overall, our results may suggest that the physical food environment may not play as strong a role in characterizing the risk of type 2 diabetes among children, and that other factors such as genetics, health behaviors, environmental exposures, or family influences may play more important roles,” researchers wrote.

Such analysis is very preliminary, as Lee noted that T2D has always been the much easier disease to track through population analyses and surveys, while T1D requires a significantly larger population. As diabetes prevalence has skyrocketed in the US in past years, he called the basics distinctions set between T1D and T2D an oversimplification of the problem.

“Some more critical thinking should improve how we view what’s been an epidemic,” Lee said.