Studies show that while the overall rates of colorectal cancer are decreasing, for individuals younger than age 50, the incidence has risen by an alarming 50% since the mid-1990s. While the exact causes are unknown, poor diet and alcohol consumption are believed to be contributing factors. A study by Buchalter et al investigating the relationships between fast food, alcohol use, and fruit and vegetable expenditures in Alabama and early-onset colorectal cancer rates has found that just a 1% increase in mean fast food expenditure per block group in Alabama was associated with a 14.25% increase of early-onset colorectal cancer. In contrast, a 1% increase in mean fruit/vegetable expenditure corresponded to a 17.72% decrease in early-onset colorectal cancer.
The study was presented during the American Association for Cancer Research Special Conference: The Rise of Early-Onset Cancers—Knowledge Gaps and Research Opportunities (Abstract B008).
Study Methodology
The researchers analyzed colorectal cancer incidence data from 2010 to 2019 obtained from the Alabama Statewide Cancer Registry. They then assessed the annual average fast food, alcohol, fruit/vegetable, and total food/beverage expenditure data by block group sourced from 2025 Esri data, based on U.S. Bureau of Labor Statistics consumer expenditure surveys. Model covariates included area deprivation index; percentages of non-Hispanic Black, Hispanic, female, and uninsured residents from 2019 American Community Survey 5-year estimates; and 2010 U.S. Department of Agriculture rural-urban commuting area codes.
The primary outcome was the ratio of early-onset colorectal cancer cases (< 50 years at diagnosis) to average-onset colorectal cancer cases (50+ years at diagnosis) across 3,357 block groups in Alabama. Primary predictors, including fast food, alcohol, and fruit/vegetable expenditure, were converted to proportions of the total food/beverage expenditure per block group. A hierarchical Bayesian spatial hurdle model was fit, where inverse-variance weighting was employed to synthesize fixed effects. The same analyses were performed for late-stage colorectal cancer from regional/distant SEER Summary Staging Manuals.
Results
The researchers found that of 24,926 new cases of colorectal cancer in Alabama from 2010 to 2019, 12,727 were diagnosed at a late stage, 2,607 were early-onset colorectal cancer, and 1,596 were late-stage early-onset colorectal cancer.
Of the early-onset colorectal cancer cases, 61.2% were diagnosed at a late stage, while 49.8% of average-onset colorectal cancer cases were diagnosed at a late stage. Across Alabama block groups, an annual mean of 17.3% of food/beverage expenditures were allocated to fast food, 10.8% to fruits/vegetables, and 5.2% to alcohol.
A 1% increase in mean fast food expenditure per block group was associated with a 14.25% increase (95% credible interval [CrI] = 9.72%–18.75%) and 5.23% increase (95% CrI = 3.03%–11.16%), respectively, in the proportion of all-stage and late-stage cases that were early-onset colorectal cancer rather than average-onset colorectal cancer.
In contrast, a 1% increase in mean fruit/vegetable expenditure corresponded to a 17.72% decrease (all-stage; 95% CrI = –31.20% to –4.33%) and 33.77% decrease (late-stage; 95% CrI: –50.95% to –16.58%), respectively, in early-onset colorectal cancer cases. Alcohol expenditure was not significantly associated with an increased or decreased share of all- or late-stage early-onset colorectal cancer cases.
“Higher fast-food expenditure at the neighborhood level was strongly associated with a greater proportion of both all-stage and late-stage early-onset colorectal cancer in Alabama, while higher fruit/vegetable spending appeared strongly protective. These findings provide preliminary ecological evidence that westernized dietary patterns may contribute to increased early-onset colorectal cancer risk. Further individual-level research is warranted to better understand how specific food exposure influence early-onset colorectal cancer risk,” concluded the study authors.
