Table 1 Descriptions of the studies included in the systematic review and meta-analysis of whole grain intake and breast cancer risk

Farvid et al., 2016 [15]

United States

NHSII Cohort (22)

44,263(3235 cases)

36 ± 5

Adult diet was evaluated using FFQ (130 items, past year); Adolescent diet was evaluated using 124-item high school FFQ (1960–1980)

Age, smoking, race, parity and age at first birth, height, BMI, weight, family history of breast cancer, history of benign breast disease, oral contraceptive use, adult alcohol intake, physical activity, energy intake, hormone use and menopausal status, age at menopause.

Mourouti et al., 2016 [16]

Greece

Case-control

250 cases/250 controls

56 ± 12

FFQ (86 items, last year prior to diagnosis)

Age, BMI, International Physical Activity Questionnaire, Smoking ever, Menopausal status, Family history of breast cancer, MedDietScore.

Tajaddini et al., 2015 [18]

Iran

Case-control

306 cases/309 controls

25–65

FFQ(136 items, a previous year before diagnosis for cases or before interview for controls)

Age at diagnosis, menopause, total calorie, parity, and BMI.

Yun et al., 2010 [17]

Korea

Case-control

362 cases/362 controls

30–65

quantitative food frequency questionnaire (FFQ) with 121 items

BMI, alcohol drinking, multivitamin use, number of children, breast feeding, and dietary factors including soy protein, folate, vitamin E, and fiber.

Egeberg et al., 2009 [23]

Denmark

Danish Diet, Cancer and Health cohort study (9.6)

25,278 (978 cases)

50–64

FFQ(192 items, at baseline 1993–1997)

Parity (parous/nulliparous and number of births), age at first birth, education, duration of hormone replacement therapy use, use of hormone replacement therapy, intake of alcohol and BMI.

Sonestedt et al.,2008 [19]

Sweden

Malmo Diet and Cancer cohort(10.3)

15,773(544 cases)

46–75

a 168-items dietary questionnaire

Season of data collection, diet interviewer, method version, age, total energy, weight, height, educational status, smoking habits, leisure time physical activity, hours of household activities, alcohol consumption, age at menopause, parity and current use of HRT.

Adzersen et al., 2003 [20]

Germany

Case-control

310 cases/353 controls

25–75

FFQ (161items, Hospital interview)

Age, total energy without alcohol intake, age at menarche, age at first birth, age at menopause, mother/sister with breast cancer, current smoking, history of benign breast disease and/or operation, BMI, consumption of alcohol, current HRT or HRT during the past year.

Nicodemus et al.., 2001 [22]

United States

Cohort Iowa Women’s Health Study(9)

29,119 (977 cases)

55–69

a standard FFQ and an additional question that asked for the type of breakfast cereal usually eaten

Age, energy intake, estrogen use, personal history of benign breast disease, family history of breast cancer, mammography status, age at first live birth, number of live births, current weight, waist-to-hip ratio, vitamin use, educational attainment, vitamin A and refined grain intake.

Chatenoud et al., 1998 [21]

Italy

Case-control

3412 cases/7990 controls

< 74

FFQ(14-37items, during the 2 years before diagnosis for cases or before interview for controls)

Age, sex, education, smoking habits, alcohol intake and BMI.

Levi et al., 1993 [25]

Switzerland

Case-control

107 cases/318 controls

30–75

Hospital interview, FFQ (50 foods, since 1990)

Age, sex, education, BMI, physical activity, energy, parity.

LaVecchia et al., 1987 [24]

Italy

Case-control

1108 cases/1281 controls

25–74

Frequency of consumption of major food sources year before interview of first symptoms (1979–1984)

Age, sex, education, green vegetables, fresh fruit, 7 reproductive variables, history of benign breast cancer for patient, mother, and sisters.