Background

The goal of this systematic review was to determine whether dietary patterns are associated
with risk of lung cancer. Dietary patterns were defined as the quantities; proportions; variety or
combination of different foods, drinks and nutrients in diets; and the frequency with which they
are habitually consumed.

Conclusion statement

Limited evidence from a small number of studies suggests a lower risk of lung cancer
associated with dietary patterns containing more frequent servings of vegetables, fruits,
seafood, grains and cereals, legumes and lean vs. higher fat meats and lower fat or non-fat
dairy products. Despite reported modest significant reductions in risk, definitive conclusions
cannot be established at this time because of the small number of articles, as well as wide
variation in study design, dietary assessment and case ascertainment.

2015 DGAC Grade: Limited

Methods

Literature searches were conducted using PubMed, Embase, Navigator (BIOSIS, CAB Abstracts, and Food Science and Technology Abstracts) and Cochrane databases to identify studies that evaluated the association between dietary patterns and risk of lung cancer. Studies that met the following criteria were included in the review: randomized controlled trials (RCTs), non-randomized controlled trials, prospective cohort studies, or nested casecontrol studies; human subjects aged two years and older who were healthy or at elevated chronic disease risk; subjects from countries with high or very high human development (2012 Human Development Index); and published in English in peer-reviewed journals. The date range was from January 2000 to January 2014. The intervention or exposure was adherence to a dietary pattern (e.g., a priori patterns, data-driven patterns, reduced rank regression or patterns derived from other methods, and a description of the dietary pattern(s) (i.e., foods and beverages) consumed by subjects was provided. The outcome was incidence of lung cancer.

Data from each included article were extracted, and risk of bias was assessed. The evidence was qualitatively synthesized, a conclusion statement was developed and the strength of the evidence (grade) was assessed using pre-established criteria including evaluation of the quality and risk of bias, quantity, consistency, magnitude of effect and generalizability of available evidence.

Findings

• This systematic review included three prospective cohort studies and one nested case-cohort study published since 2000 that examined the relationship between dietary patterns and risk of lung cancer
• The studies used different methods to assess dietary patterns. Two studies used an index score to measure adherence to a dietary pattern, one study derived dietary Systematic Reviews of the Dietary Patterns, Food and Nutrients Subcommittee, 2015 DGAC 91 Archived from www.NEL.gov on March 21, 2017 patterns using principal components analysis and another based dietary patterns on participant reports of animal product intake.

Limitations

The ability to draw strong conclusions was limited by the following issues:

• With only four relevant studies that used different approaches for assessing or determining dietary patterns, the evidence available to examine the relationship between dietary patterns and risk of lung cancer is limited.