ArticleCureus2025
Onion Shipment Volume and Colorectal Cancer Mortality in Japan: An Ecological Study Using a Nationwide Health Insurance Claims Database.
Article in Cureus, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
aimColorectal cancer is a leading cause of cancer-related mortality in Japan, particularly among older adults. While vegetable intake has been implicated in cancer prevention, most previous studies relied on self-reported dietary surveys, which are prone to recall bias. We aimed to examine the association between onion shipment volume, a novel proxy for consumption opportunity, and age-standardized colorectal cancer mortality among elderly populations in Japan. MATERIALS AND
methodsThis nationwide ecological cross-sectional study analyzed all 47 prefectures of Japan. Shipment data for onions and other sulfur-containing vegetables (garlic, Chinese chives, green onions) in 2022 were obtained from the Ministry of Agriculture, Forestry and Fisheries. Age-standardized colorectal cancer mortality among individuals aged ≥75 years was obtained from the National Cancer Center. Data were evaluated using visual inspection, box plot analysis, Kruskal-Wallis tests, effect size (Cohen's d), and Spearman's correlation coefficients.
resultsPrefectures with higher onion shipment volumes tended to have lower colorectal cancer mortality rates. Although the difference across prefectures was not statistically significant (Kruskal-Wallis p = 0.643), the effect size was moderate (Cohen's d = 0.524). Spearman's correlation indicated a weak negative association between onion shipments and mortality (r = -0.205, p = 0.168). No consistent associations were observed for other sulfur-containing vegetables.
conclusionBy using objective shipment data instead of self-reported dietary surveys, this study provides a novel methodological approach to ecological dietary assessment. The findings suggest a possible inverse relationship between onion consumption and colorectal cancer mortality in older adults. Future individual-level studies are warranted to validate these ecological trends and investigate underlying biological mechanisms.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.