In July 2006, a research database was constructed to manage the most up-to-date research describing the diet-disease relationship for tomatoes, tomato products and lycopene. This database was updated in 2007, 2009 and now again in 2011 (cut off Oct 2011 for published original research). All qualified research for this review is in humans and from original journal communication. In 2009, the review was expanded to cover published science in humans investigating the relationship between tomato, tomato products and lycopene on skin protection (Skin), bone health (Bone), cognitive function (Brain), and body weight management (BW) in addition to cancer and cardiovascular disease (CVD); the latter two being the original focus areas. New to this update is a review of the published research on diabetes along with updating all other sections. The format of the summary report is described below. Results and study information from previous versions have been integrated. A total of 644 abstracts are included: Cancer, n=232; CVD, n=116; Diabetes, n=34; Skin, n=9; Bone, n=9; Brain, n=8; BW, n=9; Tomato intake and plasma/serum lycopene concentrations, n=33; Reviews, n=71; and Special interest, n=123.

Published research abstracts are organized into the following sections

Each disease/health-related section includes 4 subsections:

Special interest studies are those that were reviewed, are related to the topic area and considered of “interest” but do not specifically associate tomato or lycopene with a disease risk outcome in humans. These studies are generally older publications and focus on fruit and vegetable intake on disease risk or in the case of newer investigations focus on mechanism of action in in vivo animal or in vitro models. The summary of research database includes published work up to October 2011. The review is based on abstracts of human studies and review of full journal articles where required.

The review provides substantial information for identifying research gaps and opportunities for developing industry direction and research strategy by referencing quickly the state of the science by disease in table format.

Qualifying results

Research investigations were qualified by disease/health-related condition, study type, sample size and main result as reported in abstracts and confirmed as necessary by full article. Results were designated as (-), N, (+), (-)/N in tabular format. Each Table of results is accompanied by a brief summary of main findings.

Study type

  • RCT: Randomized Control Trial
  • Interv: Intervention, baseline control, no Pbo
  • PC: Prospective cohort
  • CC: Case-Control
  • CS: Cross Sectional
  • Eco: Ecological

Sample size classification

  • RCT/ n= based on total # of subjects
  • Interv/ n= based on total # of subjects
  • PC/ n= based on cases identified in population
  • CC/ n= based on number of cases studied (case-control ratios 1:1, 1:2 or 1:4)
  • CS/ n= based on total # of subjects  Eco/n=based on total # of subjects

Result designations

  • (-) = Inverse relationship between dietary variable and disease risk or other specified endpoint.
  • N = Neutral relationship between dietary variable and disease risk or other specified endpoint.
  • (+) = Direct relationship between dietary variable and disease risk or other specified endpoint.
  • (-)/N = Studies that had multiple endpoints and were mixed in outcomes were designated a combination result.

For all studies, except for those investigating a diet/serum lycopene relationship, the beneficial outcome is (-).