Table 1.
Main characteristics of the studies included in this meta-analysis
| Study | Year | Country | Cases | Controls or cohort | Age (years) | Quality score | Type of exposure | Matched or adjusted variables |
|---|---|---|---|---|---|---|---|---|
| Sawada et al13 | 2015 | Japan | 825 | 43,435 | 45–74 | 8 | Fiber | Age, public health center area, smoking status, drinking frequency, marital status, BMI, and intake of green tea, genistein, SFAs, and carbohydrate |
| Vidal et al12 | 2015 | USA | 156 | 274 | 63 (SD 6.0) | 6 | Fiber, carbohydrate, GI | Age, race, family history, caloric intake, carbohydrate/fiber intake, BMI, diabetes, physical activity, alcohol, and smoking status |
| Deschasaux et al5 | 2014 | France | 139 | 3,313 | 63 | 8 | Fiber | Age, energy intake without alcohol, intervention group, number of 24-h dietary records, smoking, educational level, physical activity, height, BMI, alcohol intake, family history, PSA calcium intake, processed meat intake, tomato product intake, vitamin E intake, and blood selenium |
| Hu et al7 | 2013 | Canada | 1,799 | 5,039 | 67 | 7 | GI, GL | 10-year age group, province, education, BMI, alcohol consumption, pack-year smoking, and energy intake (noncarbohydrate and alcohol) |
| Drake et al14 | 2012 | Sweden | 817 | 8,128 | 45–73 | 7 | Fiber, carbohydrate, whole grains | Age, year of study entry, season of data collection, energy intake, height, waist, physical activity, smoking, educational level, birth in Sweden, alcohol, calcium, and selenium |
| Egeberg et al18 | 2011 | Denmark | 1,081 | 26,691 | 50–64 | 7 | Whole grains | Height, weight, school education, intake of red meat, processed meat and dairy products, and smoking status |
| Hardin et al17 | 2011 | USA | 470 | 512 | 65.8 (SD 8.3) | 6 | Whole grains | Age, race, institution, energy intake, and history of first-degree relative with prostate cancer |
| Nimptsch et al16 | 2011 | USA | 5,112 | 49,934 | 40–75 | 7 | Fiber, whole grains, GI, GL | Age, BMI, height, history of diabetes, family history, race/ethnicity, smoking, vigorous physical activity, energy intake, alcohol intake, calcium intake, alpha-linolenic acid, and tomato sauce |
| Shikany et al15 | 2011 | USA | 2,436 | 30,482 | 55–74 | 8 | Carbohydrate, GI, GL | Age, year of entry, race, center, compliant for baseline screen, marital status, BMI, vigorous physical activity, smoking, history of diabetes, history of cancer, aspirin use, family history, any prostate problems, prior PSA test, prostate biopsy prior to entry, and dietary factors |
| Hu et al19 | 2010 | Canada | 1,797 | 2,547 | 20–76 | 7 | Carbohydrate | Age, province, education, family income, BMI, total alcohol intake, and total energy intake |
| Lewis et al4 | 2009 | USA | 478 | 382 | 63.3 (SD 8.2) 66.9 (SD 8.1) | 6 | Fiber, carbohydrate, whole grains | Age, education, BMI, smoking history, family history of prostate cancer in first-degree relatives, and total caloric intake |
| Suzuki et al20 | 2009 | Multicenter | 2,747 | 142,590 | 52 | 8 | Fiber | Study center, age, energy intake, height, weight, smoking, education, and marital status |
| George et al21 | 2009 | USA | 15,949 | 262,642 | 50–71 | 7 | GI, GL | Age, race/ethnicity, education, marital status, BMI, family history of any cancer, physical activity, smoking, alcohol consumption, and energy intake |
| McCann et al23 | 2005 | USA | 433 | 538 | NA | 6 | Fiber, carbohydrate | Age, county of residence, education, BMI, cigarette smoking status, total energy, and vegetable intake |
| Walker et al22 | 2005 | Canada | 80 | 334 | 65.0 (SD 6.0) | 5 | Fiber, carbohydrate | Age, alcohol intake, carbohydrate/fiber, total energy, protein, fat, cholesterol, and calcium |
| Pelucchi et al24 | 2004 | Italy | 1,294 | 1,451 | 66 (46–74) | 6 | Fiber | Age, study center, education, family history, smoking, alcohol consumption, and energy intake |
| Augustin et al6 | 2004 | Italy | 1,204 | 1,352 | 66 (46–74) | 6 | GI, GL | Age, study center, education, family history, energy intake, alcohol consumption, smoking, BMI, occupational physical activity at 50 years, intake of fiber, and intake of lycopene |
| Lu et al25 | 2001 | USA | 65 | 132 | 59.98 | 5 | Fiber | Age, race, education, alcohol drinking, smoking, family history, and total dietary caloric intake |
| Ramon et al26 | 2000 | Spain | 217 | 434 | ≤80 | 6 | Fiber, carbohydrate | Age, residence, calories, family history, and BMI; carbohydrate further adjusted for total protein and total fat intake |
| Chan et al27 | 2000 | Finland | 184 | 27,062 | 50–69 | 7 | Carbohydrate | Supplementation group, education, age, BMI, energy, and number of years as a smoker |
| Deneo-Pellegrini et al29 | 1999 | Uruguay | 175 | 233 | 40–89 | 6 | Fiber, carbohydrate, whole grains | Age, residence, urban/rural status, education, family history, BMI, and total energy intake |
| Jain et al28 | 1999 | Canada | 617 | 636 | 69.8 | 7 | Whole grains | Total energy, vasectomy, age, ever-smoked, marital status, study area, BMI, education, ever-used multivitamin supplements, area of study, and log-converted amounts for grains, fruit, vegetables, total plants, total carotenoids, folic acid, dietary fiber, conjugated linoleic acid, vitamin E, vitamin C, retinol, total fat, and linoleic acid |
| Chatenoud et al30 | 1998 | Italy | 127 | 7,990 | <75 | 6 | Whole grains | Age, sex, education, smoking, alcohol, and BMI |
| Andersson et al31 | 1996 | Sweden | 526 | 536 | 70.7 (SD 5.9) | 6 | Fiber, carbohydrate | Age and energy |
| Walker et al3 | 1992 | South Africa | 166 | 166 | 69.2 (SD 8.9) | 5 | Fiber | Age and residence |
| West et al32 | 1991 | USA | 358 | 679 | 45–74 | 6 | Carbohydrate | Since interaction and confounding did not exist, crude ORs are presented |
| Oishi et al33 | 1988 | Japan | 100 | 100 | 50–79 | 5 | Fiber, carbohydrate | Age, date of admission |
Abbreviations: BMI, body mass index; SD, standard deviation; GI, glycemic index; h, hours; PSA, prostate specific antigen; GL, glycemic load; ORs, odds ratios; SFAs, saturated fatty acids; NA, not available.