FJ: Background Information (2014)
Research varies on the topic of fruit juice intake and outcomes associated with juice consumption. In order to comprehensively evaluate the body of research, the following assumptions and limitations are associated with this project:- Defining 100% fruit juice: In order to include a study in this project, the Food and Drug Administration’s definition published in the Code of Federal Regulations was used to determine if juices investigated were 100% fruit juice. According to 21CFR101.30, “juices directly expressed from a fruit or vegetable (i.e., not concentrated and reconstituted) shall be considered to be 100% juice and shall be declared as 100% juice." For this EAL Project, the above definition was expanded to include juices from concentrate that were reconstituted to the original concentration. Additional studies included in data analysis must have specified 100% fruit juice or provided information about the processing and composition of the studied juice such that it could be determined if 100% fruit juice was investigated.
- Methods for evaluating intake and outcomes: Differing methods for assessing dietary intake and clinical markers or measures were used in the studies evaluated. With each assay or method utilized, there are inherent limitations. For example, one limitation of dietary records and recalls is the ability of responders to accurately report intake and estimate portion sizes. With fruit juice in particular, another limitation is the lack of detail related to the juice and the possibility that self-reported data may include juice that is not by definition “100%," including fortified products. Thus, the limitations of single studies must be acknowledged as a limitation of this type of integrative research project.
- Juice consumption: Among the studies evaluated, varying amounts of juice were consumed with results analyzed collectively. Therefore, evidence summaries are based on the relationship between a range of juice intake levels and specific outcomes.
- Study design: Evidence from cross-sectional studies as well as clinical trials were evaluated as part of this project. However, study designs do not always allow for causal determination of individual outcomes being solely attributed to fruit juice consumption unless appropriate study controls and adjustment for confounders are utilized.
Reference:
U.S. Food and Drug Administration Code of Federal Regulations. Title 21. Department of Health and Human Services website. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=101.30. Published April 1, 2013. Updated June 1, 2013. Accessed February 21, 2014.