Total vegetables and prostate cancer.
Total prostate cancer risk: Data about total vegetables in relation to total prostate cancer risk was provided by 11 cohorts, including
a total of 26,599 cases.
A protective association was found in the second (Wu K [7]), but not first (Giovannucci E [7]) part of follow-up of "The Health Professionals Follow-up Study".
But no information is available about the strenght or significance of the association, and no adjustments were made for possible confounders.
No other (non)significant associations were found. The average RR = 0.98 (excluding incomplete data from Tseng M [13], Wu K [7]).
Inclusion of intermediate levels of consumption:
A significantly increased risk was found in one cohort at the level of consumption of 140-193 g/day (Gonzalez A [21]). No other (non)significant associations were
found at any level of consumption in any cohort.
Advanced stage prostate cancer risk: Data about total vegetables in relation to advanced prostate cancer risk was provided by 5 cohorts,
including a total of 4,188 cases.
A significant protective effect against extraprostatic prostate cancer was found in one cohort, including 29,361 men in which the amount of cases
is not defined (Kirsh VA [18]). But a significantly increased risk of advanced prostate cancer was found in one larger cohort, including 288,109 men and 1,778 cancer
cases (George SM [24]). No other associations were found. The average RR = 1.08
Prostate cancer mortality: Data about total vegetables in relation to prostate cancer death was provided by 4 cohorts, including a total of 2,163 cases.
A signicantly increased risk of prostate cancer death was found in one cohort for low vs high consumption, but no specific amounts (servings/grams) of
consumption were defined (Rodriguez C [9]). No other associations were found. The average RR = 0.85 (excluding incomplete data from Snowdon DA [1]).
Conclusion: Few associations were found. No evidence was found for an association between total vegetables and total prostate cancer risk at any level of consumption.
Findings about the relation with advanced prostate cancer are contradictive, and no evidence was found for an association with advanced prostate cancer, or prostate
cancer death. In addition, no evidence was found for an association when advanced cancer and mortality are considered as one single end point (RR = 1.00),
or when advanced prostate cancer is stratified in disease stage and grade.
| Author | Cohort name | Cases | Relative Risk (RR) |
|---|---|---|---|
| 24) George SM (2008) | The NIH-AARP Diet and Health Study | 17,034 | RR = 0.97 (0.93-1.02; P = 0.106). |
| 23) Ambrosini GL (2008) | No cohort name | 97 | RR = 0.73 (0.38-1.40; P = 0.350). |
| 21) Gonzalez A (2009) | The VITAL Cohort | 761 | HR = 1.15 (0.93-1.42). |
| 18) Kirsh VA (2007) | The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial | 1,338 | RR = 0.88 (0.71-1.08; P = 0.24). |
| 17) Stram DO (2006) | The Multiethnic Cohort Study | 3,922 | RR = 1.00 (0.91-1.15; P = 0.466). |
| 15) Key TJ (2004) | The EPIC Study | 1,104 | RR = 1.00 (0.81-1.22; P = 0.738). |
| 13) Tseng M (2004) | The NHEFS Cohort | 136 | No association. |
| 11) Chan JM (2000) | The ATBC Study | 184 | RR = 0.8 (0.5-1.3; P = 0.84). |
| 10) Schuurman AG (1998) | The Netherlands Cohort Study | 606 | RR = 0.80 (0.57-1.12; P = 0.51). |
| 7) Wu K (2004) | The Health Professionals Follow-up Study (1993-1998) | 436 | Cases consumed less vegetables (no data). |
| 7) Giovannucci E (1995) | The Health Professionals Follow-up Study (1986-1992) | 773 | RR = 1.04 (0.81-1.34; P = 0.68). |
| 2) Shibata A (1992) | The Leisure World Study | 208 | RR = 1.04 (0.74-1.46). |
| Total number of cases: 26,599 | Average RR = 0.98 |
| Author | Cohort name | Cases | End point | Relative Risk (RR) |
|---|---|---|---|---|
| 24) George SM (2008) | The NIH-AARP Diet and Health Study | 1,778 | Advanced prostate cancer | RR = 1.18 (1.01-1.38; P = 0.04). |
| 18) Kirsh VA (2007) | The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial | Aggressive: 520. Extraprostatic: Not defined. | Aggressive or extraprostatic cancer | Aggressive cancer: RR = 0.81 (0.58-1.13; P = 0.27). Extraprostatic cancer: RR = 0.41 (0.22-0.74; P = 0.01). |
| 17) Stram DO (2006) | The Multiethnic Cohort Study | 1,345 | Nonlocalized and high grade disease | RR = 1.00 (0.90-1.10; P = 0.467). |
| 10) Schuurman AG (1998) | The Netherlands Cohort Study | 153 | Poorly- or undifferentiated prostate cancer | RR = 0.99 (0.94-1.05). |
| 7) Chan JM (2006) | The Health Professionals Follow-up Study | 392 | Prostate cancer progression | RR = 1.26 (0.85-1.87). |
| Total number of cases: 4,188 | Average RR = 1.08 |
| Author | Cohort name | Cases | Relative Risk (RR) |
|---|---|---|---|
| 22) Smit E (2007) | The Puerto Rico Heart Health Progeam | 167 | OR = 1.61 (0.68-3.83; P = 0.48). |
| 9) Rodriguez C (1997) | The Cancer Prevention Study | 1,748 | RR = 1.26 (1.07-1.48) for low vs high consumption. |
| 5) Hsing AW (1990) | The Lutheran Brotherhood Cohort Study | 149 | RR = 0.7 (0.4-1.2). |
| 1) Snowdon DA (1984) | The Adventist Health Study | 99 | No association. |
| Total number of cases: 2,163 | Average RR = 0.85 |
| Author | Cohort name | Subjects | Years of follow-up | Cases | End point | Consumption of | Relative Risk (RR) | Adjustments | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 24) George SM (2008) | The National Institutes of Health-AARP Diet and Health Study. | 195,229 women and 288,109 men aged 50-71. (USA) | 1995-2003 | Total prostate: 17,034. Advanced : 1,778. | Prostate cancer incidence | Vegetables (excluding potatoes) |
1 cup = 237 mL. One cup is 1 cup of raw/cooked vegetable, 1 cup of 100% juice, or 2 cups of raw leafy greens. Age, smoking, energy intake, BMI, alcohol, physical activity, education , race, marital status, family history, and fruit intake. |
23) Ambrosini GL (2008) | No cohort name. | 1985 blue asbestos-exposed men. | (Australia) Median 12.7 | (1990-96 to 2004) 97 | Prostate cancer incidence | Total vegetables (not defined, but including carrot, sweet potato, pumpkin, bell peppers, cooked and raw tomatoes, bell peppers, broccoli, and spinach) |
RR = 0.73 (0.38-1.40; P = 0.350) for the highest vs lowest tertile of consumption. | Amount specific data (serves per day): 0-1.6: RR = 1. > 1.6-2.8: RR = 0.80 (0.46-1.38). > 2.8: RR = 0.73 (0.38-1.40). Age, total fruit and vegetable intake, randomly assigned retinol or beta carotene supplement and source fo crocidolite exposure. |
21) Gonzalez A (2009) | The VITamins And Lifestyle cohort | 35,242 men aged 50-76. | (USA) 2000-02 to 2004 | 761 | Invasive prostate cancer incidence | Vegetables (not defined) |
HR = 1.15 (0.93-1.42; No P-value) for the highest vs lowest quartile of consumption. | Amount specific data (servings/day): 0-1.2: HR = 1. 1.21-1.8: HR = 1.13 (0.91-1.39). 1.81-2.5: HR = 1.25 (1.01-1.53). > 2.51: HR = 1.15 (0.93-1.42). Age. |
21) Gonzalez A (2007) | The VITamins And Lifestyle (VITAL) cohort. | 35,244 men aged 50-76. | (USA) 3.3 | (2000-02 to 2004) 761 | Prostate cancer risk | Vegetables (not defined) |
HR = 1.15 (0.93-1.42; No P-value) for the highest vs lowest quartile of consumption. | Amount specific data (servings/day): 0-1.2: HR = 1. 1.21-1.8: HR = 1.13 (0.91-1.39). 1.81-2.5: HR = 1.25 (1.01-1.53). > 2.5: HR = 1.15 (0.93-1.42). Age. |
18) Kirsh VA. (2007) | The screening arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. | 29,361 men aged 55-74. | (USA) mean 4.2 | (1993-2001) 1,338? | of which 520 aggressive (Stage III-IV or gleason score ≥ 7), and ? extraprostatic (Stage III-IV only) prostate cancer risk | Vegetables (included cooked dried beans and potatoes) |
|
Results were not markedly changed when potatoes and/or other starchy vegetables were excluded from the vegetable index (no data shown). age, total energy, race, study center, family history of prostate cancer, BMI, smoking status, physical activity, supplemental vitamine E intake, total fat intake, red meat intake, diabetes, aspirin use, and previous number of prostate cancer screening examinations during the follow-up period. |
Results were not statistically significantly altered by additional adjustment for total fruit or vegetable intake (as appropriate) and tomato intake or for history of PSA tests before study enrollment. 17) Stram DO. (2006) | The multiethnic cohort study. | 82,486 African-American, Japanese-American, Native-Hawaiian, Latino and White males aged 45-75. | (USA) 1993-96 to 2001 | 3,922? | (1,345 nonlocalized and high grade disease) prostate cancer risk | Vegetables (not defined) |
|
Total vegetables & non-localized or high grade prostate cancer risk: RR = 0.96 (0.80-1.14; P = 0.586) for the highest vs lowest quintile of consumption. Amount specific data (g/1000 kcal): ≤ 90.7: RR = 1. > 90.7-≤ 120.03: RR = 1.10 (0.92-1.30). > 120.03-≤ 150.1: RR = 1.13 (0.95-1.34). > 150.1-≤ 193.94: RR = 1.04 (0.87-1.24). > 193.94: RR = 0.96 (0.80-1.14). age, BMI, education and family history of prostate cancer |
15) Key TJ (2004) | The EPIC Study. | 130.544 men aged 20-97 in 7 countries. | 4.8 | (1993-99 to 2000) 1,104 | Prostate cancer risk | Total vegetables (not defined, but excluding potatoes and other tubers. |
RR = 1.00 (0.81-1.22; P = 0.738) for the top compared to the bottom quintile. | Amount specific data (g/day): 97.1: RR = 1. 124.6: RR = 0.94 (0.79-1.12). 152.7: RR = 0.88 (0.73-1.07). 176.2: RR = 1.05 (0.87-1.27). 242.1: RR = 1.00 (0.81-1.22). There was no association between total vegetable consumption and prostate cancer risk in any of the individual countries, and no evidence of heterogeneity between countries in the linear association between vegetable intake and risk. Restricting the analysis to men diagnosed with prostate cancer under the age of 65 years also made no appreciable difference to the associations. 7 countries included in this analysis: Denmark, Germany, Italy, The Netherlands, Spain, Sweden and the UK. Stratified for recruitment center and adjusted for height, weight and energy intake. Various potential confounding variables, including education level, smoking and physical activity, were not clearly associated with prostate cancer risk; these variables were therefore omitted from the final analysis. |
Adjustment for total fruits made no material difference. 13) Tseng M (2004) | The National Health and Nutrition Examination Survey Epidemiological Follow-up Study (NHANES) I Epidemiological Follow-up Study (NHEFS) | 3,779 men aged 25-74. | (USA) 1982-84 to 1992 | 136? | Invasive prostate cancer incidence | (excluding in situ cases) Vegetables (not defined) | No association with prostate cancer risk (results not shown). | ? |
11) Chan JM (2000) | The Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC Study). | 27,062 male smokers aged 50-69. | (Finland) 1985-1993 | 184? | Stage 2-4 prostate cancer risk | Vegetables (not defined) |
RR = 0.8 (0.5-1.3; P = 0.84) for the highest vs lowest quintile of consumption. | Amount specific data (g): 40: RR = 1. 71: RR = 0.7 (0.5-1.2). 99: RR = 0.8 (0.5-1.2). 135: RR = 0.9 (0.6-1.5). 204: RR = 0.8 (0.5-1.3). supplementation group (alpha-tocopherol, beta-carotene, both or placebo), education, age, BMI, energy, number of years as a smoker. |
10) Schuurman AG (1998) | The Netherlands Cohort Study. | 58,279 men aged 55-69 | 6.3 | (1986-1992) 606 | (181 well differentiated, 217 moderately differentiated, and 153 poorly- or undifferentiated) prostate cancer risk | Total vegetables (defined as: string/French beans, broad beans, cauliflower, cabbage (white/green), kale, Brussels sprouts, endive prepared, endive raw, spinach, lettuce, leek, onions, carrots prepared, carrots raw, sauerkraut, red beets, sweet peppers, mushrooms, tomatoes, tomato juice, gherkins, rhubarb) |
RR = 0.80 (0.57-1.12; P = 0.51) for the highest vs the lowest quintile of consumption. | Amount specific data (g/day): 100.0: RR = 1. 144.0: RR = 1.06 (0.77-1.46). 175.0: RR = 1.08 (0.78-1.49). 214.0: RR = 1.28 (0.94-1.75). 285.0: RR = 0.80 (0.57-1.12).
RRs between subgroups of tumor sizes did not differ to a large extent and were mostly around the null value; the same applied to latent and nonlatent tumors (data not shown). age, family history of prostate cancer, socioeconomic status and total fruit. |
7) Chan JM (2006) | The Health Professionals Follow-up Study. | Post-diagnostic food group consumption of 392 progression outcomes among 1,202 men diagnosed with incident localized/regional (not metastatic [Stage D]) prostate cancer | Average 6 | (1986-2000) 392? | [among which: PSA recurrences (312), metastases (7), or prostate cancer mortality (50)] prostate cancer progression | Vegetables (included string beans, mushrooms, broccoli, sauerkraut, coleslaw, cabbage, cauliflower, brussels sprouts, alfalfa sprouts, raw and cooked carrots, corn, peas/lima beans, mixed vegetables, beans, eggplant, yams/sweet potatoes, raw spinach, cooked spinach, kale, iceberg lettuce, romaine lettuce, celery, yellow squash, orange squash, green pepper, garlic, onions, beets, and tofu) |
RR = 1.26 (0.85-1.87; No P-value) for the highest vs lowest quartile of consumption. | Amount specific data (Quartiles not defined): Q1: RR = 1. Q2: RR = 1.50 (1.09-2.08). Q3: RR = 1.44 (1.02-2.03). Q4: RR = 1.26 (0.85-1.87). HR for one serving/day increase = 1.04 (No 95% CI; P = 0.14). The more modest results for a two serving/week increase, which better reflects the more likely changes for less commonly eaten foods, was 1.01. Associations within strata of known treatment groups (i.e. surgery, radiation, or hormones), and prognostic group (i.e. low, intermediate, or high) were similar. RR = adjusted for age, total energy, pre-diagnostic diet (continuous variables), and all other post-diagnostic food groups (grains, vegetables, fruits, red meat, milk, fish, tomato sauce, fresh tomato products). |
HR = adjusted for all pre-and post-diagnostic food group consumption. Models were additionally adjusted for smoking habits, exercise level, body mass index, family history of prostate cancer, and race. There was little evidence of confounding by these factors, and they were not included in the primary multivariate analyses 7) Wu K (2004) | The Health Professionals Follow-up Study. | 18,259 US men aged 40-75. | (Nested case-control) 1993-1998 | 436 | Prostate cancer incidence | (excluding Stage A1 cases) Vegetables (not defined) | Cases tended to have lower vegetable intake (no data shown). | Unadjusted. |
7) Giovannucci E (1995) | The Health Professionals Follow-Up Study. | 47,894 men aged 40-75. | (USA) 1986-1992 | 773? | Non-stage A1 prostate cancer risk | Total vegetables (not defined) | RR = 1.04 (0.81-1.34; P = 0.68) for consumption > 5 vs < 2 servings/day. | Age and energy. |
2) Shibata A. (1992) | The Leisure World Study. | 11,580 residents of a retirement community. | (USA) 1981-1989 | 208 | Prostate cancer risk | Vegetables (Leafy green lettuce [Romaine, Boston, bibb, butterhead, endive, escarole, salad bowl, red leafy lettuce], other leafy greens [spinach, chard, beet greens, turnip greens, mustard greens, collards, kale, dandelion greens], iceberg or head lettuce, cabbage [incude sauerkraut and coleslaw], white potatoes or turnips, sweet potatoes, yams, pumpkin [including in pie or soup], carrots, winter squash [butternut, hubbard, acorn squash [including in pie or soup], summer squash [zucchini, yellow crookneck, yellow straightneck, cocozelle, scallop squash, broccoli, tomatoes [fresh or cooked, including tomatoes in a sauce such as spaghetti or tomato soup], green peas [including snow peas and Chines pea pods], green beans or string beans, lima beans or blackeye beans, corn, asparagus, sweet green peppers, sweet red peppers, hot red chili peppers [including hot pepper sauce, chili powder, cayenne pepper, tobasco sauce, Brussels sprouts, cauliflower) |
RR = 1.04 (0.74-1.46; No P-value) for the highest vs lowest tertile of consumption. | Amount specific data (servings/day): < 3.0: RR = 1. 3.0-< 4.5: RR = 1.18 (0.85-1.65). ≥ 4.5: RR = 1.04 (0.74-1.46). Age and smoking. |
Adjustment for BMI or physical activity did not materially alter the results (data not shown).
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