Table 3: Observational studies of adverse events associated with human exposure to cruciferous plants, their derivatives or their constituents.

      Study details    Patient details            Intervention              Outcome
ReferenceStudy design1SettingNo. of patients/
comparators2
Age rangeConcurrent conditions/
treatments
Plant/
substance
Route3Duration4Dose5Adverse events6Outcome7Causality8

Fell et al. 1992 [31]CohortMulti-site1515 (1478: natural exposure, 37: occupational exposure)AdultsAtopy in some subjectsOilseed rapeRespiratory and topical allergy testsAcute to chronicNAIn naturally exposed, 4/1478 showed positive skin test and 3/1478 showed positive RAST and nasal sensitivity. In occupationally exposed, 9/37 showed positive skin test and 5/37 showed positive RAST and nasal sensitivityNot specifiedPossibly

Hemmer et al. 1997 [32]Cohort Single site4468Not givenSuspected inhalant allergy to oilseed rape. Multiple allergies to other pollen allergensOilseed rapeRespiratory1 yearNA147 showed positive skin prick test to oilseed rapeNA Possibly

Parrat et al. 1995 [33]CohortCommunity 22AdultsNot givenOilseed rapeRespiratorySeasonalNAAllergy (sneezing, coughing, eye irritation) in 10Improvement when not exposedPossibly

Lerbaek et al. 2004 [36]CohortHospital259Not givenSuspected contact allergy to foods containing allyl isothiocyanateAllyl isothiocyanate 0.1% in petrolatumTopical allergy testAcuteNAIn 43patients: ?+ reaction, of whom 15 had irritation and 3 had follicular reaction. Two showed a true + reaction but one lost to follow upSpontaneous resolutionPossibly

Sakauchi et al. 2007 [37]CohortCommunity64327 women40–79 yrsNot givenCabbage, Chinese cabbage, green leafy vegetables, and other foodsOralChronic (exact time frame given)Varies: 0 times a week to almost every dayNo adverse events with consumption of cabbage or green leafy vegetables. Of 100 women who reported moderate-high consumption of Chinese cabbage, 46 had ovarian cancerDeathPossibly

Michnovicz and Bradlow 1997 [44]Cohort Community1222–48 yrsNo history of recent or chronic illness, drug use, or recent changes in weightIndole-3-carbinolOral7 days5–7 mg/kg/dayNo adverse eventsNA NA

Michaud et al. 2002 [45]CohortCommunity 2711150–69 yrs Male smokers with no history of cancer, not using vitamins A, E or beta-carotene in excessCruciferous vegetablesOralchronic (reported intake in last 12 months)NANo adverse eventsNANA

Soutar et al. 1995 [34]CCSHospital37/2417–54 yrsSeasonal allergic symptoms and bronchial reactivityOilseed rapeRespiratorySeasonalNAOf the 23 cases tested, only 2 were found to be truly allergic to oilseed rape, and only 10 (including these 2) were atopicNot mentionedPossibly (for 2 who are allergic) Unlikely (for the rest)

Memon et al. 2002 [42]CCSKuwait cancer control center313/3135–70 yrsCases: thyroid cancer. Either cases or controls: asthma, diabetes mellitus, gall bladder disease, hyper-tension, lupous, polyposis coli, skin allergy, skin disease (not specified)Cabbage, cauliflower, broccoliOralChronic (exact time frame given)Varies: 0 to 7 days a weekNo adverse events with consumption of broccoli. 63/101 people with high cabbage consumption and 55/91 people with high cauliflower consumption had thyroid cancer; however, P trends were not statistically significant (0.08 and 0.16, resp.)Not mentionedPossibly

Galanti et al. 1997 [43]CCS Community246/44018–75 yrsNot givenWhite and red cabbages, cauliflower, broccoli, Brusselss sproutsOralChronic (exact time frame given)Varies: <2 to >6 times a week56/110 people who at anytime lived in areas in Sweden where goiter and iodine deficiency were endemic until the 1960’s and who reported moderate-high consumption of cruciferous vegetables had thyroid cancerNot mentionedPossibly

Soutar et al. 1994 [35]CSSCommunity869/86714–50 yrsBoth villages: 448 smokers, 325 ex-smokersOilseed rapeRespiratoryChronic: monthsNA683 of 869 who were exposed had seasonal cough, wheeze, and headachesNot mentionedPossibly

Sato et al. 2004 [46]CSSCommunity43839–60 yrsNo history of gastric cancer or gastric ulcer BroccoliOralChronic (exact time frame given)Varies: never to few times a week 46/186 people who consumed broccoli once or more a week had changes in enzymes which might indicate chronic atrophic gastritisOngoingPossibly

Lust et al. 1996 [47]QS Community273<4 moNot givenVarious foods, including cruciferous vegetables (specifically cabbage, cauliflower, broccoli)Oral (through breast milk) Unclear (mothers were asked whether they ate different items the previous week)Not given63/273 exhibited colic symptoms (abdominal pain, irritability, intense crying)Not mentioned Possibly

1CCS, case-control study; CSS, cross-sectional study; QS, qualitative survey.
2Comparator numbers appear only for case-control and cross-sectional surveys.
3Route of exposure.
4Duration of exposure.
5NA, not applicable, in cases where dose cannot be quantified.
6RAST, radioallergosorbent test.
7Degree of resolution in cases were adverse events were reported; NA, not applicable.
8The degree of association between the intervention and the adverse event, as rated by reviewers; NA, not applicable.