Salads and colorectal cancer.

Colon cancer risk: Data about salad/lettuce was provided by a pooled analysis of 12 cohorts, but information about these dietary variables was not stratified (29). Though RRs for the highest 2 quartiles of consumption were lower than for the 2 lowest quartiles (RRs 0.89-0.90 vs 1.00, respectively), no association was found with colon cancer risk.
Colorectal cancer risk: Data from an article about 1 cohort was not stratified by cancer site (though information about colon cancer was used by the pooled analysis). No association of high vs low consumption was found with salad (17).
Mortality: Data about mortality was provided by 2 cohorts. No associations were found with colon (2), rectal (2), or total colorectal (10) cancer mortality.

Conclusion: No evidence was found for an association between salad consumption and any cancer end point.

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**Prospective studies of salads and colorectal cancer risk:**
Author	Cohort name	Subjects	Years of follow-up	Cases	End point	Consumption of	Relative Risk (RR)	Adjustments
29) Koushik A. (2007)	Pooled Analysis of 12 Cohort Studies.	713,783 subjects.	6-20 years	5,509	Colon cancer risk	Lettuce, salad	INCLUSION CRITERIA: Publication of a diet and cancer association. Diagnosis of at least 50 incident colorectal cancer cases. Assessment of usual diet. Conduct of a validation study of the dietary assessment method or a closely related instrument. INCLUDED STUDIES (Follow-up years/No. of colon cancer cases). In the analysis, an extended follow-up period for most of the studies was included: The Adventist Health Study. (1976-1982/52 men, 67 women) Singh PN, Fraser GE. Dietary risk factors for colon cancer in a low-risk population. Am J Epidemiol. 1998 Oct 15;148(8):761-74. Full text The Alpha-Tocopherol Beta-Carotene Cancer Prevention Study. (1984-1999/187 men) Pietinen P, Malila N, Virtanen M, Hartman TJ, Tangrea JA, Albanes D. Diet and risk of colorectal cancer in a cohort of Finnish men. Cancer Causes Control. 1999 Oct;10(5):387-96. Abstract The Cancer Prevention Study II Nutrition Cohort. (1992-1999/467 men, 349 women) McCullough ML, Robertson AS, Chao A, Jacobs EJ, Stampfer MJ, Jacobs DR. A prospective study of whole grains, fruits, vegetables, and colon cancer risk. Cancer Causes Control. 2003 Dec;14(10):959-70. Abstract The Health Professionals Follow-up Study. (1986-2000/456 men) Michels KB, Edward Giovannucci, Joshipura KJ, Rosner BA, Stampfer MJ, Fuchs CS. Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. J Natl Cancer Inst. 2000 Nov 1;92(21):1740-52. Full text The Netherlands Cohort Study. (1986-1993/393 men, 353 women) Voorrips LE, Goldbohm RA, van Poppel G, Sturmans F, Hermus RJ, van den Brandt PA. Vegetable and fruit consumption and risks of colon and rectal cancer in a prospective cohort study: The Netherlands Cohort Study on diet and cancer. Am J Epidemiol. 2000 Dec 1;152(11):1081-92. Full text The New York State Cohort. (1980-1987/335 men, 223 women) Bandera EV, Freudenheim JL, Marshall JR, Zielezny M, Priore RL, Brasure J. Diet and alcohol consumption and lung cancer risk in the New York State Cohort (United States). Cancer Causes Control. 1997 Nov;8(6):828-40. Abstract The Breast Cancer Detection Demonstration Project Follow-up Study. (1987-1999/349 women) Flood A, Velie EM, Chaterjee N, Subar AF, Thompson FE, Lacey JV Jr. Fruit and vegetable intakes and the risk of colorectal cancer in the Breast Cancer Detection Demonstration Project follow-up cohort. Am J Clin Nutr. 2002 May;75(5):936-43. Full text The Canadian National Breast Screening Study. (1980-2000/431 women) Terry P, Jain M, Miller AB, Howe GR, Rohan TE. Dietary intake of folic acid and colorectal cancer risk in a cohort of women. Int J Cancer. 2002 Feb 20;97(6):864-7. Abstract The Iowa Women's Health Study. (1986-2001/799 women) Steinmetz KA, Kushi LH, Bostick RM, Folsom AR, Potter JD. Vegetables, and fruit colon cancer in the Iowa Women's Health Study. Am J Epidemiol. 1994 Jan 1;139(1):1-15. Abstract The Nurses' Health Study B. (1986-2000/429 women) Michels KB, Edward Giovannucci, Joshipura KJ, Rosner BA, Stampfer MJ, Fuchs CS. Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. J Natl Cancer Inst. 2000 Nov 1;92(21):1740-52. Full text The Swedish Mammography Cohort. (1987-2003/484 women) Terry P, Giovannucci E, Michels KB, Bergkvist L, Hansen H, Holmberg L. Fruit, vegetables, dietary fiber, and risk of colorectal cancer. J Natl Cancer Inst. 2001 Apr 4;93(7):525-33. Full text The Women's Health Study. (1993-2003/163 women) Lin J, Zhang SM, Cook NR, Rexrode KM, Liu S, Manson JE. Dietary intakes of fruit, vegetables, and fiber, and risk of colorectal cancer in a prospective cohort of women (United States). Cancer Causes Control. 2005 Apr;16(3):225-33. Abstract RELATIVE RISK: RR = 0.90 (0.79-1.03; P = 0.13) for the highest vs lowest quartile of consumption. Amount specific data (servings): 0: RR = 1. > 0 to < 1/wk: RR = 1.00 (0.89-1.13). 1/wk to < 0.5/day: RR = 0.89 (0.77-1.02). ≥ 0.5/day: RR = 0.90 (0.79-1.03). One serving = 1 cup.	BMI; height; education; physical activity; family history of colorectal cancer; postmenopausal hormone use; oral contraceptive use; use of nonsteroidal anti-inflammatory drugs; multivitamin use; smoking habits (never/past/current + amount); red meat; total milk; alcohol; and total energy. Age in years and year of questionnaire return were included as stratification variables.
17) Flood A. (2002)	The Breast Cancer Detection Demonstration Project (BCDDP).	45,490 women. (USA)	8.5-8.7 (1987-89 to 1995-98)	485?	colorectal cancer risk	salad	RR = 1.03 (0.78-1.35) for the highest vs lowest quintile of consumption. Amount specific data (servings per 1000 kJ/day): 0.021: RR = 1. 0.078: RR = 0.69 (0.51-0.92). 0.134: RR = 0.84 (0.64-1.11). 0.204: RR = 0.82 (0.62-1.09). 0.350: RR = 1.03 (0.78-1.35).	Energy, multivitamin supplement use, BMI, height, use of nonsteroidal antiinflammatory drugs, smoking status, education level, physical activity, and intakes of fruit, grains, red meat, calcium, vitamin D, and alcohol.
2) Singh PN. (1998)	The Adventist Health Study.	32,051 non-Hispanic white cohort members aged ≥ 25. (USA)	6 (1977-1982)	143	colon cancer risk (adenocarcinomas)	Salad	RR = 0.75 (0.47-1.21; P = 0.08) for the highest vs lowest tertile of consumpion. Amount specific data (frequency of consumption): Never to 2/week: RR = 1. 3-6/week: RR = 1.27 (0.85-1.90). ≥ 1/day: RR = 0.75 (0.47-1.21).	Age, sex, BMI, physical activity, parental history of colon cancer, current smoking, past smoking, alcolhol consumption, and aspirin use.
2) Morgan JW (1988)	The Adventist Health Study.	35,000 Californian Seventh-day Adventists.	6 (1977-1982)	141?	Colon cancer incidence (adenocarcinomas)	Salad	RR = 0.54 (P = 0.02) for the highest vs lowest tertile of consumption. Amount specific data (tertiles not defined): T1: RR = 1. T2: RR = 1.06. T3: RR = 0.54. The univariate salad association was substantially dependent on other covariates.	Age and sex.

Prospective studies of salads and colorectal cancer risk:

Author

Cohort name

Subjects

Years of follow-up

Cases

End point

Consumption of

Relative Risk (RR)

Adjustments

29) Koushik A. (2007)

Pooled Analysis of 12 Cohort Studies.

713,783 subjects.

6-20 years

5,509

Colon cancer risk

Lettuce, salad

INCLUSION CRITERIA:

Publication of a diet and cancer association.
Diagnosis of at least 50 incident colorectal cancer cases.
Assessment of usual diet.
Conduct of a validation study of the dietary assessment method or a closely related instrument.

INCLUDED STUDIES (Follow-up years/No. of colon cancer cases).
In the analysis, an extended follow-up period for most of the studies was included:

The Adventist Health Study. (1976-1982/52 men, 67 women)
Singh PN, Fraser GE. Dietary risk factors for colon cancer in a low-risk population. Am J Epidemiol. 1998 Oct 15;148(8):761-74. Full text
The Alpha-Tocopherol Beta-Carotene Cancer Prevention Study. (1984-1999/187 men)
Pietinen P, Malila N, Virtanen M, Hartman TJ, Tangrea JA, Albanes D. Diet and risk of colorectal cancer in a cohort of Finnish men. Cancer Causes Control. 1999 Oct;10(5):387-96. Abstract
The Cancer Prevention Study II Nutrition Cohort. (1992-1999/467 men, 349 women)
McCullough ML, Robertson AS, Chao A, Jacobs EJ, Stampfer MJ, Jacobs DR. A prospective study of whole grains, fruits, vegetables, and colon cancer risk. Cancer Causes Control. 2003 Dec;14(10):959-70. Abstract
The Health Professionals Follow-up Study. (1986-2000/456 men)
Michels KB, Edward Giovannucci, Joshipura KJ, Rosner BA, Stampfer MJ, Fuchs CS. Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. J Natl Cancer Inst. 2000 Nov 1;92(21):1740-52. Full text
The Netherlands Cohort Study. (1986-1993/393 men, 353 women)
Voorrips LE, Goldbohm RA, van Poppel G, Sturmans F, Hermus RJ, van den Brandt PA. Vegetable and fruit consumption and risks of colon and rectal cancer in a prospective cohort study: The Netherlands Cohort Study on diet and cancer. Am J Epidemiol. 2000 Dec 1;152(11):1081-92. Full text
The New York State Cohort. (1980-1987/335 men, 223 women)
Bandera EV, Freudenheim JL, Marshall JR, Zielezny M, Priore RL, Brasure J. Diet and alcohol consumption and lung cancer risk in the New York State Cohort (United States). Cancer Causes Control. 1997 Nov;8(6):828-40. Abstract
The Breast Cancer Detection Demonstration Project Follow-up Study. (1987-1999/349 women)
Flood A, Velie EM, Chaterjee N, Subar AF, Thompson FE, Lacey JV Jr. Fruit and vegetable intakes and the risk of colorectal cancer in the Breast Cancer Detection Demonstration Project follow-up cohort. Am J Clin Nutr. 2002 May;75(5):936-43. Full text
The Canadian National Breast Screening Study. (1980-2000/431 women)
Terry P, Jain M, Miller AB, Howe GR, Rohan TE. Dietary intake of folic acid and colorectal cancer risk in a cohort of women. Int J Cancer. 2002 Feb 20;97(6):864-7. Abstract
The Iowa Women's Health Study. (1986-2001/799 women)
Steinmetz KA, Kushi LH, Bostick RM, Folsom AR, Potter JD. Vegetables, and fruit colon cancer in the Iowa Women's Health Study. Am J Epidemiol. 1994 Jan 1;139(1):1-15. Abstract
The Nurses' Health Study B. (1986-2000/429 women)
Michels KB, Edward Giovannucci, Joshipura KJ, Rosner BA, Stampfer MJ, Fuchs CS. Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. J Natl Cancer Inst. 2000 Nov 1;92(21):1740-52. Full text
The Swedish Mammography Cohort. (1987-2003/484 women)
Terry P, Giovannucci E, Michels KB, Bergkvist L, Hansen H, Holmberg L. Fruit, vegetables, dietary fiber, and risk of colorectal cancer. J Natl Cancer Inst. 2001 Apr 4;93(7):525-33. Full text
The Women's Health Study. (1993-2003/163 women)
Lin J, Zhang SM, Cook NR, Rexrode KM, Liu S, Manson JE. Dietary intakes of fruit, vegetables, and fiber, and risk of colorectal cancer in a prospective cohort of women (United States). Cancer Causes Control. 2005 Apr;16(3):225-33. Abstract

RELATIVE RISK:

RR = 0.90 (0.79-1.03; P = 0.13) for the highest vs lowest quartile of consumption.

Amount specific data (servings):
0: RR = 1.
> 0 to < 1/wk: RR = 1.00 (0.89-1.13).
1/wk to < 0.5/day: RR = 0.89 (0.77-1.02).
≥ 0.5/day: RR = 0.90 (0.79-1.03).

One serving = 1 cup.

BMI; height; education; physical activity; family history of colorectal cancer; postmenopausal hormone use; oral contraceptive use; use of nonsteroidal anti-inflammatory drugs; multivitamin use; smoking habits (never/past/current + amount); red meat; total milk; alcohol; and total energy. Age in years and year of questionnaire return were included as stratification variables.

17) Flood A. (2002)

The Breast Cancer Detection Demonstration Project (BCDDP).

45,490 women.
(USA)

8.5-8.7
(1987-89 to 1995-98)

485?

colorectal cancer risk

salad

RR = 1.03 (0.78-1.35) for the highest vs lowest quintile of consumption.

Amount specific data (servings per 1000 kJ/day):
0.021: RR = 1.
0.078: RR = 0.69 (0.51-0.92).
0.134: RR = 0.84 (0.64-1.11).
0.204: RR = 0.82 (0.62-1.09).
0.350: RR = 1.03 (0.78-1.35).

Energy, multivitamin supplement use, BMI, height, use of nonsteroidal antiinflammatory drugs, smoking status, education level, physical activity, and intakes of fruit, grains, red meat, calcium, vitamin D, and alcohol.

2) Singh PN. (1998)

The Adventist Health Study.

32,051 non-Hispanic white cohort members aged ≥ 25.
(USA)

6
(1977-1982)

143

colon cancer risk (adenocarcinomas)

Salad

RR = 0.75 (0.47-1.21; P = 0.08) for the highest vs lowest tertile of consumpion.

Amount specific data (frequency of consumption):
Never to 2/week: RR = 1.
3-6/week: RR = 1.27 (0.85-1.90).
≥ 1/day: RR = 0.75 (0.47-1.21).

Age, sex, BMI, physical activity, parental history of colon cancer, current smoking, past smoking, alcolhol consumption, and aspirin use.

2) Morgan JW (1988)

The Adventist Health Study.

35,000 Californian Seventh-day Adventists.

6
(1977-1982)

141?

Colon cancer incidence (adenocarcinomas)

Salad

RR = 0.54 (P = 0.02) for the highest vs lowest tertile of consumption.

Amount specific data (tertiles not defined):
T1: RR = 1.
T2: RR = 1.06.
T3: RR = 0.54.

The univariate salad association was substantially dependent on other covariates.

Age and sex.

Colon (men):

Colon (women):

Rectal (both sexes):

RR = 1.7 (0.9-3.4; P = 0.12) for the highest vs lowest tertile of consumption.

Amount specific data (Frequency of use in days/wk):
< 4: RR = 1.
4-6: RR = 1.3 (0.6-2.7).
≥ 7?: RR = 1.7 (0.9-2.4).

RR = 0.7 (0.4-1.1; P = 0.50) for the highest vs lowest tertile of consumption.

Amount specific data (Frequency of use in days/wk):
< 4: RR = 1.
4-6: RR = 1.1 (0.7-1.9).
≥ 7?: RR = 0.7 (0.4-1.1).

RR = 0.7 (0.3-1.5; P = 0.50) for the highest vs lowest tertile of consumption.

Amount specific data (Frequency of use in days/wk):
< 4: RR = 1.
4-6: RR = 0.5 (0.2-1.2).
≥ 7?: RR = 0.7 (0.3-1.5).

Cancer & Diet. A systematic review.

Literature review.

Relating various aspects of our diet
to colorectal cancer risk & mortality.

Salads and colorectal cancer.

Cancer & Diet. A systematic review.

Literature review.

Relating various aspects of our dietto colorectal cancer risk & mortality.

Salads and colorectal cancer.

Relating various aspects of our diet
to colorectal cancer risk & mortality.