What is the question?

• The question is: What is the relationship between seafood consumption during childhood and adolescence (up to 18 years of age) and risk of cardiovascular disease? 

What is the answer to the question?

• Insufficient evidence is currently available to accurately determine the relationship between seafood consumption during childhood and adolescence and risk of developing cardiovascular disease. 

Why was this question asked?

• This important public health question was identified by the U.S. Departments of Agriculture (USDA) and Health and Human Services (HHS) to be examined by the 2020 Dietary Guidelines Advisory Committee.

How was this question answered?

• The 2020 Dietary Guidelines Advisory Committee, Dietary Fats and Seafood Subcommittee, conducted a systematic review to answer this question with support from the Nutrition Evidence Systematic Review (NESR) team.

What is the population of interest? 

• For the intervention or exposure, generally healthy children and adolescents ages 18 years and younger. For the outcome, children and adolescents ages 2 years and older and adults ages 19 years and older for blood lipids or blood pressure and adults for cardiovascular disease endpoint outcomes. 

What evidence was found? 

• This review identified four articles that met inclusion criteria.
• Few studies examined the relationship between seafood intake during childhood and adolescence and blood pressure and/or lipid levels in childhood and adulthood, or cardiovascular-related mortality in adulthood. 
• The 2020 Advisory Committee could not draw conclusions due to serious methodological limitations of the included studies.

How up-to-date is this systematic review?

• This review searched for studies from January 2000 to July 2019.

Background

• This important public health question was identified by the U.S. Departments of Agriculture (USDA) and Health and Human Services (HHS) to be examined by the 2020 Dietary Guidelines Advisory Committee.
• The 2020 Dietary Guidelines Advisory Committee, Dietary Fats and Seafood Subcommittee conducted a systematic review to answer this question with support from the Nutrition Evidence Systematic Review (NESR) team.
• The goal of this systematic review was to examine the following question: What is the relationship between seafood consumption during childhood and adolescence (up to 18 years of age) and risk of cardiovascular disease? 

Conclusion statement and grade

• Insufficient evidence is currently available to accurately determine the relationship between seafood consumption during childhood and adolescence and risk of developing cardiovascular disease. (Grade: Grade not assignable)

Methods

• A literature search was conducted using four databases (i.e., PubMed, Cochrane, Embase, and CINAHL) to identify articles that evaluated the intervention or exposure of seafood consumption during childhood and adolescence and the outcomes of cardiovascular disease. A manual search was conducted to identify articles that may not have been included in the electronic databases searched. Articles were screened by two NESR analysts independently for inclusion based on pre-determined criteria. 
• Data extraction and risk of bias assessment were conducted for each included study, and both were checked for accuracy. The Committee qualitatively synthesized the body of evidence to inform development of a conclusion statement, and graded the strength of evidence using pre-established criteria for risk of bias, consistency, directness, precision, and generalizability.

Summary of the evidence

• Four articles, two randomized controlled trials and two prospective cohort studies, met inclusion criteria for this systematic review. 
• The 2020 Dietary Guidelines Advisory Committee used the following seafood definition: marine animals that live in the sea and in freshwater lakes and rivers. Seafood includes fish (e.g., salmon, tuna, trout, and tilapia) and shellfish (e.g., shrimp, crab, and oysters).
• Few articles were identified that examined the relationship between seafood intake during childhood and adolescence and blood pressure, lipid levels, and cardiovascular-related mortality, and no articles examined the relationship with incidence of cardiovascular disease. 
• Two of four included articles had serious methodological limitations that made interpretation of the results difficult. 
• Evidence was insufficient and no conclusion could be drawn.