title: A prospective study of tomato products, lycopene, and prostate cancer risk.
abstract: BACKGROUND
  Some data, including our findings from the Health Professionals Follow-Up Study (HPFS) from 1986 through January 31, 1992, suggest that frequent intake of tomato products or lycopene, a carotenoid from tomatoes, is associated with reduced risk of prostate cancer. Overall, however, the data are inconclusive. We evaluated additional data from the HPFS to determine if the association would persist.
  
  
  METHODS
  We ascertained prostate cancer cases from 1986 through January 31, 1998, among 47 365 HPFS participants who completed dietary questionnaires in 1986, 1990, and 1994. We used pooled logistic regression to compute multivariate relative risks (RR) and 95% confidence intervals (CIs). All statistical tests were two-sided.
  
  
  RESULTS
  From 1986 through January 31, 1998, 2481 men in the study developed prostate cancer. Results for the period from 1992 through 1998 confirmed our previous findings---that frequent tomato or lycopene intake was associated with a reduced risk of prostate cancer. Similarly, for the entire period of 1986 through 1998, using the cumulative average of the three dietary questionnaires, lycopene intake was associated with reduced risk of prostate cancer (RR for high versus low quintiles = 0.84; 95% CI = 0.73 to 0.96; P(trend) =.003); intake of tomato sauce, the primary source of bioavailable lycopene, was associated with an even greater reduction in prostate cancer risk (RR for 2+ servings/week versus <1 serving/month = 0.77; 95% CI = 0.66 to 0.90; P(trend)<.001), especially for extraprostatic cancers (RR = 0.65; 95% CI = 0.42 to 0.99). These associations persisted in analyses controlling for fruit and vegetable consumption and for olive oil use (a marker for Mediterranean diet) and were observed separately in men of Southern European or other Caucasian ancestry.
  
  
  CONCLUSIONS
  Frequent consumption of tomato products is associated with a lower risk of prostate cancer. The magnitude of the association was moderate enough that it could be missed in a small study or one with substantial errors in measurement or based on a single dietary assessment.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA. edward.giovannucci@channing.harvard.edu
authors.forename: Edward
authors.initials: E
authors.lastname: Giovannucci
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rimm
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D001682:Biological Availability; D002338:Carotenoids / Q000008:administration & dosage / Q000494:pharmacology*; D005060:Europe / Q000208:ethnology; D005247:Feeding Behavior; D005511:Food Handling; D006801:Humans; D016015:Logistic Models; D000077276:Lycopene; D018551:Solanum lycopersicum; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000208:ethnology / Q000473:pathology / Q000517:prevention & control*; D012107:Research Design; D012306:Risk; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; D002338:Carotenoids; D000077276:Lycopene