TABLE 1.
Characteristics of case-control studies investigating the MDS, HEI, and DII and CRC risk identified in PubMed and published after 31 December 20081
| Reference | Location | Sample size, n | Sources of controls | Dietary assessment | Dietary index | Results2 | Covariates included in model |
| Djuric et al. (2012) (17) | Detroit, MI, United States | 1163 cases and 1501 controls | Random digit dialing from same county as case; matched on age, sex, and race | FFQ Block 98.2 (110 items) | HEI-1996 | In low quercetin consumers, ORQr4 vs. Qr13: 0.78 (95% CI: 0.55, 1.12) | Age, sex, education, family history of CRC, regular NSAID use, BMI, physical activity, dietary factors |
| In high quercetin consumers, ORQr4 vs. Qr13: 0.59 (95% CI: 0.42, 0.83) | |||||||
| Grosso et al. (2014) (18) | Catania, Italy | 338 cases and 676 controls | Patients without clinical symptoms of cancer from same hospital who previously were recruited for adherence to Mediterranean diet; matched on age and sex | Standardized questionnaire designed for the study | MDS | ORHigh vs. Low3: 0.46 (95% CI: 0.28, 0.75) | Smoking status, family history of CRC, obesity, diabetes, physical activity, alcohol intake |
| Kontou et al. (2012) (19) | Athens, Greece | 250 cases and 250 controls | Volunteers from general population without clinical symptoms of cancer; matched on age, sex, and SES | FFQ (69 items) for monthly consumption | MDS | OR3,4: 0.88 (95% CI: 0.84, 0.92) | Age, sex, BMI, physical activity, smoking status, family history of CRC, presence of metabolic syndrome |
| Miller et al. (2010) (20) | Pennsylvania | Men: 225 cases and 330 controls | Random digit dialing from same region | FFQ (137 times; modified version of Diet History Questionnaire) | HEI-2005 | Men, ORQr4 vs. Qr1: 0.56 (95% CI: 0.31, 0.99) | Age, education, smoking status, BMI, total energy intake, family history of CRC, NSAID use, postmenopausal hormone use (women) |
| Women: 206 cases and 396 controls | Women, ORQr4 vs. Qr1: 0.44 (95% CI: 0.24, 0.77) | ||||||
| Zamora-Ros et al. (2014) (21) | Barcelona, Spain | 424 cases and 401 controls | Randomly selected patients from the same hospital who were admitted for a newly incident disease | Spanish dietary history questionnaire (EPIC) | DII | ORQr4 vs Qr13: 1.65 (95% CI: 1.08, 2.56) | Age, sex, total energy intake, BMI, tobacco use, physical activity, medication use, family history of CRC |
CRC, colorectal cancer; DII, Dietary Inflammatory Index; EPIC, European Prospective Investigation into Cancer and Nutrition; HEI, Healthy Eating Index; MDS, Mediterranean Diet Score; NSAID, nonsteroidal anti-inflammatory drugs; Qn, quintile; Qr, quartile; SES, socioeconomic status.
OR estimates for studies in this table were calculated for CRC risk, comparing the highest diet score group with the lowest diet score group in the respective study, except where otherwise noted. The lowest diet score group indicates the least compliance to the diet guideline for articles with MDSs or HEI as exposure, or the most anti-inflammatory potential of diet for the articles with DII as exposure.
The estimated association is for overall study population, including both men and women.
Denotes odds of CRC for every 1-unit increase in MDS.