Exploring avocado consumption and health: a scoping review and evidence map

Abstract

Objective: This scoping review evaluates the breadth of research on avocado intake and health, considering all populations and health outcomes (registered on Open Science Foundation at https://osf.io/nq5hk).

Design: Any human intervention or observational study where effects could be isolated to consumption of avocado were included. A systematic literature search through April 2024 was conducted (PubMed, Web of Science, Scopus, and CENTRAL) and supplemented by backwards citation screening. Dual screening, data extraction, and conflict resolution were performed by three reviewers and an interactive evidence map was created.

Results: After deduplication, 8,823 unique records were retrieved; 58 articles met inclusion criteria, comprising 45 unique studies (28 interventions, 17 observational studies). Studies were largely conducted in the United States or Latin America and generally included adults, with overweight/obesity, frequently with elevated lipid concentrations. Interventions assessed the impact of diets enriched in monounsaturated fatty acids, diets higher/lower in carbohydrates, or in free-feeding conditions. Larger amounts of avocados were used in interventions than commonly consumed in observational studies (60-300 vs. 0-10 g/d, respectively). Blood lipids, nutrient bioavailability, cardiovascular risk, glycemia, and anthropometric variables were the most common outcomes reported across all studies.

Conclusion: Future recommendations for novel research include the study of: European, Asian, adolescent or younger, and senior populations; dose-response designs and longer length interventions; dietary compensation; and the need for greater replication. The results have been made public and freely available, and a visual, interactive map was created to aid in science translation. This evidence map should enable future meta-analyses, enhance communication and transparency in avocado research, and serve as a resource for policy guidance.

Keywords: Persea americana; cardiovascular health; dietary patterns; obesity; public health.

Figure 1

PRISMA diagram for searches performed on 10/17/2023 and 04/29/2024 (mm/dd/yyyy).

Figure 2

Publishing trends. (A) The line indicates the cumulative number of publications per year (totaling 58), with bars detailing yearly publications. (B) Each bubble represents a unique funding source (one article could come from multiple sources), with the size indicating the number of articles associated with a given funding source (smallest bubble = 1 article). (C) Number of primary reports (totaling 45) conducted on participants from a given country (one primary report was conducted in both the U.S. and Canada); color indicates the number of studies. (D) Number of primary reports of a given study design (one primary report analyzed as both a cross-sectional and a cohort).

Figure 3

(A-D) Histograms represent the number of primary reports that described a given participant characteristic (using an absolute value, mean, or median) of any analytical group/sub-group at any point during a study. (D) For lipids, values were classified as healthy if in the ranges of 125–200 for total cholesterol, < 100 for LDL, > 50 for HDL, and < 150 for triacylglycerols (all in mg/dL).

Figure 4

Histogram represents the number of primary reports that described a given level of avocado intake (e.g., using an absolute value, mean, median, or quantiles) of any group/sub-group at any point during a study. Excludes groups with non-zero intakes from control groups or non-consumers.

Figure 5

(A, B) Each bubble represents a primary report, organized according to sample size (size of bubble), length of intervention/follow-up (observational cohorts may have multiple follow-up periods according to different analyses and may thus be listed over multiple follow-up lengths), and a broad classification of the outcomes studied. (C) Heatmap depicts the number of primary reports and the number of distinct variables measured within the subdomain listed. For example, 10 interventions measured anthropometric outcomes using four different variables (e.g., weight, BMI, body fat, and body size). Each of those four variables may have then used a different method of measurement (not depicted), such as describing body fat using total fat % or mass of visceral adipose tissue. The greater the number in brackets, the greater the heterogeneity between studies in variables reported and methods of measurement used.