Table 1.
Characteristics of the studies included in the meta-analysis.
| First Author (Year) | Location | Study Name | Design | Study Population | Participants | Cases | Age, yrs | Study Duration | Years of Follow Up | Type of Vitamin E Intake | Intake Assessment Method | Vitamin E Cut-Offs | Adjustments for Covariates |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cano-Ibáñez N (2020) [27] |
Spain | CAPLIFE | Case-control study | Cases: Men diagnosed with prostate cancer at two main university hospitals Controls: Population-based controls |
704 | 402 | Mean: 66.7 Range: 40–80 |
2017–2019 | - | Dietary | FFQ | Adequate intake (8.6 mg/d to 300 mg/d) vs. inadequate intake | Age, smoking habits, physical activity level, educational level, alcohol intake, and first-degree family history of prostate cancer. |
| Lane JA (2017) [28] |
UK | - | Nested case-control study | Cases: Men in the Dietary Cohort Consortium Studies diagnosed with prostate cancer Controls: Cohort controls |
5245 | 1717 | Mean: 62.8 Range: 50–60 |
1991–2009 | Mean: 6.6–13.3 years | Dietary | Food diary | Quintiles: 7.1 mg/d, 9.0 mg/d, 11.1 mg/d, 14.1 mg/d |
Age, BMI, socioeconomic, smoking, and marital status, diabetes, and energy intake. |
| Sarre S (2016) [29] |
Finland | FinsRPC | Prospective cohort study | Men participating in the third round of the FrRSPC without previous diagnosis of prostate cancer | 11,795 | 757 | Median: 66.0 | 2004–2013 | Median: 6.6 years | Supplemental | Self-reported use of supplements | Use vs. no use | Age. |
| Roswall N (2013) [30] |
Netherlands | - | Prospective cohort study | Male residents in Denmark | 26,865 | 1571 | Median: 56.0 Range: 50–64 |
1993–2010 | Median: 14.3 years | Dietary, Supplemental, Total | FFQ, self-reported use of supplements | Quartiles for dietary: 7.3 mg/d, 9.5 mg/d, 12.0 mg/d; Supplements: 0 mg/d, 4.4 mg/d, 10 mg/d; Total: 8.6 mg/d, 12.0 mg/d, 17.7 mg/d | Intake of the three other micronutrients as well as dietary intake or supplemental intake of vitamin E. |
| Wang L (2014) [11] |
United States | PHS II | RCT | Male physicians aged 50 yrs and above | 13,980 | 1373 | Mean: 64.3 | 1997–2011 | - | Supplemental | Intervention | 400 IU vs. no use every other day | Age, PHS cohort and randomised assignment |
| Agalliu I (2011) [31] |
Canada | CSDLH | Case-cohort study | Male participants in the CSDLH study recruited from universities in Canada | 2525 | 661 | Mean: 68.4 | 1992–2003 | Mean: 4.3 years | Total | FFQ, self-reported use of supplements | Quintile (median value reported): 6.3 mg/d, 8.3 mg/d, 14.6 mg/d, 264.4 mg/d, 462.0 mg/d | Age, race, BMI, exercise activity, and education. Adjusted for energy intake using residual method. |
| Fleshner N (2011) [13] |
Canada | - | RCT | Men with high-grade prostatic interepithelial neoplasia diagnosed within 18 months of random assignment | 303 | 80 | Median: 62.8 | 1999–2004 | - | Supplemental | Intervention | 400 IU/d vs. no use | - |
| Klein EA (2011) [12] |
United States, Canada, Puerto Rico | SELECT | RCT | Men with prostate- specific antigen concentrations of <4.0 ng/mL | 17,433 | 1149 | Median: 62.5 | 2004–2011 | - | Supplemental | Intervention | 400 IU/d vs. no use | - |
| Raimondi S (2010) [32] |
Montreal, Canada | - | Case-control study | Cases: Men diagnosed with prostate cancer at major teaching hospitals Controls: Population-based controls identified by random-digit dialing |
394 | 197 | Range: 35–84 | 1989–1993 | - | Dietary | FFQ | Quartiles: 5.9 mg/d; 7.4 mg/d; 9.2 mg/d | Family history of prostate cancer, age group, total energy intake, and calcium intake. |
| Bidoli E (2009) [33] |
Italy | - | Case-control study | Cases: Men diagnosed with prostate cancer at teaching and general hospitals Controls: Hospital-based controls |
2745 | 1294 | Median: 66 Range: 46–74 |
1992–2002 | - | Dietary | FFQ | Tertiles: 12.3 mg/d, 16.7 mg/d | Age, study center, period of interview, education, body mass index, alcohol intake, smoking habits, family history of prostate cancer and total energy intake. |
| Peters U (2008) [34] |
United States | VITAL | Prospective cohort study | Men living in western Washington State covered by the Surveilance, Epidemiology, and End Results cancer registry | 35,242 | 830 | Range: 50–76 | 2000–2004 | Not reported | Dietary, Supplemental, Total | FFQ, self-reported use of supplements | Quartiles for dietary: 8.6 mg/d, 12.2 mg/d, 17.1 mg/d. For supplemental: None, 0–30 IU/d, >30–< 400 IU/d, ≥ 400 IU/d. Categories for total: <14.3 mg/d, 14.3–29.3 mg/d, 29.4–98.0 mg/d, ≥98.1 mg/d | Age, family history of prostate cancer, benign prostatic hyperplasia, income, multivitamin use, and stratified on PSA screening in the 2 years before baseline (yes/no), energy intake. |
| Zhang YQ (2009) [35] |
United States | - | Case-control study | Cases: Men diagnosed with prostate cancer at participating hospitals Controls: Hospital-based controls |
4110 | 1706 | Mean: 60.1 Range: 40–79 |
1976–2006 | - | Supplemental | Self-reported use of supplements | Duration of use: 10+ years, 5–9 years, 1–4 years, Never or <1 yr use | Age, years of education, body mass index, current alcohol drinking, current smoking, family history of prostate cancer and use of other vitamin/mineral supplements. |
| Weinstein SJ (2007) [36] |
United States | ATBC | Prospective cohort study within trial | Male smoker residents | 29,133 | 1732 | Mean: 57.2 Range: 50–69 |
1985–2004 | Up to 19 years | Dietary, Total | FFQ, self-reported use of supplements | Quintiles for total: 7.06 mg/d. 8.36 mg/d, 10.32 mg/d, 14.72 mg/d; Quintiles for dietary: 6.96 mg/d, 8.13 mg/d, 9.65 mg/d, 13.01 mg/d | Age, trial arm, weight, urban residence, education, intakes of total energy, fat, polyunsaturated fatty acids, vitamin C and lycopene. |
| Wright ME (2007) [37] |
United States | NIH-AARP | Prospective cohort study | Men enrolled in the NIH-AARP Diet and Health study | 295,344 | 10,241 | Range: 50–71 | 1995–2000 | Up to 5 years | Dietary, Supplemental | FFQ, self-reported use of supplements | Quintile medians for dietary: 4.8 mg/d, 6.5 mg/d, 7.0 mg/d, 8.0 mg/d, 10.0 mg/d; For supplement: 0 IU/d, >0–99 IU/d, 100–199 IU.d, 200–399 IU/d, 400–799 IU/d. ≥800 IU/d | Age, race, smoking status, education, personal history of diabetes, family history of prostate cancer, body mass index, and dietary intakes of red meat, a-linolenic acid, vitamin C, B carotene intake. Dietary tocopherols were adjusted for energy intake using theresidual method. |
| Kirsh VA (2006) [38] |
United States | PLCO Cancer Screening Trial | Prospective cohort study | Men in the screening arm of the PLCO trial | 29,361 | 1338 | Mean: 63.3 Range: 55–74 |
1993–2001 | Mean: 4.2 years | Dietary, Supplemental | FFQ, self-reported use of supplements | Quintiles medians for dietary: 8.6 mg/d, 10.2 mg/d, 11.3 mg/d, 12.6 mg/d, 15.8 mg/d; For supplements: 0 IU/d, >0–30 IU/d, >30–400 IU/d, | Age, total energy, race, study center, family history of prostate cancer, BMI, smoking status, physical activity, total fat intake, red meat intake, history of diabetes, aspirin use, number of screening examinations during follow-up period. |
| Stram DO (2006) [39] |
United States | MEC | Prospective cohort study | Men from a large population-based multiethnic cohort | 82,486 | 3922 | Range: 45–75 | 1993–2001 | Up to 7 years | Dietary, Supplemental | FFQ | Quintiles for dietary: 3.9 mg/1000 kcal, 4.5 mg/1000 kcal, 5.1 mg/1000 kcal, 6.0 mg/1000 kcal; For supplements: 0–<33.75 mg/d, ≥33.75 mg/d | Age, ethnicity, BMI, education and family history of prostate cancer. Intake of all foods and nutrients were analysed as nutrient densities. |
| Lonn E (2005) [14] |
Canada, United States, Argentina, Brazil, Mexico and 14 Western European countries | HOPE and HOPE-TOO | RCT | Male patients at high risk for cardiovascular events | 6996 | 235 | Mean: 66.0 | 1993–1999; 1999–2003 | - | Supplemental | Intervention | 400 IU/d vs. 0 IU.d | - |
| McCann SE (2005) [40] |
United States | WNYDS | Case-control study | Cases: Men diagnosed with prostate cancer from major hospitals Controls: Population-based controls |
971 | 433 | Mean: 69.5 | 1986–1991 | - | Dietary | FFQ | Quartile range: <7 mg/d. 7–9 mg/d, 9–11 mg/d, >11 mg/d | Age, education, BMI, cigarette smoking status, total energy, vegetable intake. |
| Meyer F (2005) [10] |
Canada | SU.VI.MAX | RCT | Healthy male volunteers | 5034 | 103 | Mean: 51.3 Range: 45–60 |
1994–2002 | - | Supplemental | Intervention | 30 mg/day vs. no use | - |
| Hodge M (2004) [41] |
Australia | - | Case-control study | Cases: Australian male residents with prostate cancer Controls: Population-based controls |
1763 | 858 | Range: < 70 | 1994–1997 | - | Dietary | FFQ | Quintile range: <6.9 mg/d, 6.9–8.0 mg/d, 8.1–9.0 mg/d. 9.1–10.3 mg/d, ≥10.4 mg/d | State, age group, year, country of birth, socio-economic group, family history of prostate cancer. Nutrient adjusted for energy intake by residual method. |
| Rodriguez C (2004) [42] |
United States | CPS-II | Prospective cohort study | Men selected from the CPS-II Nutrition Cohort | 72,704 | 4281 | Range: 50–74 | 1992–1999 | Not reported | Supplemental | FFQ | None, 1–31 IU/d, 32–≤400 IU/d, ≥400 IU/d | Age, race, smoking status, BMI, education, energy adjusted calcium, total fat, lycopene intake, total calorie intake, family history of prostate cancer, and PSA history. |
| Schuurman (2002) [43] |
Netherlands | NLCS | Case-cohort study | Men from the study population in NLCS | 2167 | 642 | Mean: 62.1 Range: 55–69 |
1986–1992 | Up to 6.3 years | Dietary, Supplemental | FFQ, self-reported use of supplements | Quintile medians: 7.1 mg/d, 10.4 mg/d, 13.5 mg/d, 17.3 mg/d, 23.6 mg/d | Age, family history of prostate cancer, socioeconomic status, and alcohol from white or fortified wine. |
| Ramon JM (2000) [44] |
Spain | - | Case-control study | Case: Men diagnosed with prostate cancer in hospital records Controls: Hospital and population-based controls |
651 | 217 | - | 1994–1998 | - | Dietary | FFQ | Quartile medians: 6.1 mg/d, 7.6 mg/d, 9.9 mg/d, 12.8 mg/d | Age, residence, calories, family history and BMI. |
| Chan JM (2000) [45] |
United States | HPFS | Prospective cohort study | Male health professionals | 47,780 | 1896 | Mean: 54.6 Range: 40–75 |
1986–1996 | Not reported | Supplemental | FFQ and self-reported use of supplements | 0 IU/d, 0.1–15.0 IU/d, 15.1–99.9 IU/d, ≥100 IU/d | Age, period, family history of prostate cancer, vasectomy, smoking, quintiles of BMI, BMI at age 21, physical activity, quintiles of total calories, calcium, lycopene, fructose, and fat intake per day. |
| Deneo-Pellegrini H (1999) [46] |
Uruguay | - | Case-control study | Case: Men diagnosed with prostate cancer admittted to major hospitals Controls: Hospital-based controls |
408 | 175 | Range: 40–89 | 1994–1997 | - | Dietary | FFQ | Quartile ranges: ≤5.0 mg/d, 5.1–6.0 mg/d, 6.1–7.8 mg/, ≥7.9 mg/d | Age, residence, urban/rural, family history of prostate cancer, BMI, total energy intake. |
| Jain MG (1999) [47] |
Canada | - | Case-control study | Cases: Men recently diagnosed with prostate cancer identified by hospital admission offices or cancer registries Controls: Population-based controls |
1253 | 617 | Mean: 69.9 | 1989–1993 | - | Dietary | FFQ | Quartile ranges: <17.17 mg/d, 17.17–25.30 mg/d, 25.31 mg/d, 37.25 mg/d, ≥37.25 mg/d | Age, log total energy intake, vasectomy, marital status, ever smoke study area, BMI, education, ever-used multivitamin supplements, area of study, log-amounts for grains, fruits, vegetables, total plants, total carotenoids, folic acid, dietary fibre, conjugated linoleic acid, vitamin E, vitamin C, retinol, total fat, and linolenic acid. |
| Kristal AR (1999) [48] |
United States | - | Case-control study | Men diagnosed with prostate cancer, identified from the Seattle-Puget Sound SEER cancer registry Controls: Population-based controls |
1363 | 697 | Range: 40–64 | 1993–1996 | - | Supplemental | Self-reported use of supplements | Frequency of use: 0/week, <1/week, 1–6/week, ≥7/week | Age, race, education, energy, family history of prostate cancer, body mass index, number of PSA tests in previous 5 years, dietary fat intake. |
| Heinonen OP (1998) [9] |
Finland | ATBC | RCT | Male smokers residents | 29,133 | 246 | Mean 57.1 Range: 50–69 |
1985–1993 | - | Supplemental | Intervention | 50 mg/d vs. no use | - |
| Key TJA (1997) [49] |
UK | - | Case-control study | Cases: Men diagnosed with prostate cancer based on hospital registry records Controls: Patients of the general pracitioners for cases |
656 | 328 | Mean: 68.1 | 1990–1994 | - | Dietary, Total | FFQ | Tertile ranges for dietary: <9.59 mg/d, 9.59–16.33 mg/d, ≥16.34 mg/d; Tertile ranges for total: <9.94 mg/d, 9.94–17.87 mg/d, ≥17.88 mg/d | Energy. |
| Vlajinac HD (1997) [50] |
Serbia | - | Case-control study | Cases: Patients diagnosed with prostate cancer Controls: Hospital-based controls |
303 | 101 | Mean: 71.2 | 1990–1994 | - | Dietary | FFQ | Tertiles; no cut-off values reported | Energy, protein, fat-total, saturated fatty acids, carbohydrate, sugar, fibre, retinol, retinol equivalent, folic acid, vitamin B12, sodium, potassium, calcium, phosphorous magnesium and iron. |
| Andersson SO (1996) [51] |
Sweden | - | Case-control study | Cases: Male residents in Sweden diagnosed with prostate cancer, identified through hospital records Controls: Population-based controls |
1062 | 526 | Mean: 70.6 | 1989–1994 | - | Dietary | FFQ | Quartiles: 4.5 mg/d, 5.7 mg/d, 7.3 mg/d | Age and energy adjusted, based on nutrient residuals and energy in quartiles. |
| Shibata A (1992) [52] |
United States | - | Prospective cohort study | Male residents of a retirement community | 4252 | 207 | Mean: 74.9 | 1981–1989 | Up to 8 years | Supplemental | Self-reported use of supplements | Use vs. no use | Age and smoking habits. |
ATBC: Alpha-tocopherol, Beta-Carotene Cancer Prevention Study; BMI: Body mass index; CAPLIFE: Prostate cancer lifestyles study; CPS-II: Cancer Prevention Study II; CSDLH: Canadian Study of Diet, Lifestyle, and Health; FFQ: Food frequency questionnaire; FinsRPC: Finnish Prostate Cancer Screening Trial; HPFS: Health Professionals Follow-up Study; HOPE: Heart Outcomes Prevention Evaluation; HOPE-TOO: Heart Outcomes Prevention Evaluation–The Ongoing Outcomes; MEC: Multiethnic Cohort; NIH-AARP: National Institutes of Health-American Association of Retired Persons; NLCS: Netherlands Cohort Study; PHS II: Physicians’ Health Study II; PLCO: Prostate, Lung, Colorectal, and Ovarian Cancer; PSA: Prostate-specific antigen; RCT: Randomised controlled trial; SELECT: Selenium and Vitamin E Cancer Prevention Trial; SU.VI.MAX: Supplementation en Vitamines et Mineraux Antioxydants;VITAL: VITamin D and OmegA-3 TriaL; WNYDS: Western New York Diet Study.