Prospective Study of Avocado Consumption and Cancer Risk in U.S. Men and Women

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

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.

Discovery of Natural Products for Cancer Prevention

ABSTRACT

"Cancer chemoprevention" is a term referring to the slowing or reversal of this disease, using nontoxic natural or synthetic compounds. For about 50 years, there has been a strong scientific interest in discovering plant-derived compounds to prevent cancer, and strategies for this purpose using a concerted series of in vitro, ex vivo, and in vivo laboratory bioassays have been developed. Five examples of the more thoroughly investigated agents of this type are described herein, which are each supported by detailed literature reports, inclusive of ellagic acid, isoliquiritigenin, lycopene, trans-resveratrol, and sulforaphane. In addition, extracts of the plants avocado (Persea americana), noni (Morinda citrifolia), açai (Euterpe oleracea), and mangosteen (Garcinia mangostana) have all shown inhibitory activity in an in vivo or ex vivo bioassay using a carcinogen and germane to cancer chemoprevention, and selected in vitro-active constituents are described for each of these 4 species.

Avocado and Guacamole Consumption and Colorectal Cancer Risk: The Multiethnic Cohort Study

Dietary fiber and phytonutrients can protect against colorectal cancer, yet their consumption is low in the US. Avocados are a potential source of these beneficial nutrients. Therefore, this study aimed to examine the relationship between avocados/guacamole consumption and colorectal cancer risk in the Multiethnic Cohort Study. We assessed avocados/guacamole consumption by using a food frequency questionnaire. We classified participants into three consumer groups: <1 serving/month, 1-3 servings/month, and ≥1 serving/week with one serving defined as ½ avocado or ½ cup. Colorectal cancer cases were ascertained through the Surveillance, Epidemiology and End Results Program cancer registries. Cox proportional hazards models of colorectal cancer were used to calculate hazard ratios and 95% confidence intervals across avocados/guacamole intake groups in each sex overall and by anatomic subsite (i.e., right colon, left colon, and rectum) and race and ethnicity. Of 192,651 eligible participants, 62.8% reported consuming <1 serving/month avocados/guacamole, 26.7% reported 1-3 servings/month, and 10.5% reported ≥1 serving/week. When adjusted for relevant covariates, there was no significant association with incident colorectal cancer overall, for subsites, or within racial and ethnic subgroups (all p for trend ≥ 0.06). In this large prospective cohort study, we did not find that consumption of avocados/guacamole was associated with colorectal cancer risk.

Avocado (Persea americana Mill) and its phytoconstituents: potential for cancer prevention and intervention

Dietary compounds, including fruits, vegetables, nuts, and spices, have been shown to exhibit anticancer properties due to their high concentrations of vitamins, minerals, fiber, and secondary metabolites, known as phytochemicals. Although emerging studies suggest that avocado (Persea americana Mill) displays antineoplastic properties in addition to numerous other health benefits, current literature lacks an updated comprehensive systematic review dedicated to the anticancer effects of avocado. This review aims to explore the cancer-preventive effects of avocados and the underlying molecular mechanisms. The in vitro studies suggest the various avocado-derived products and phytochemicals induced cytotoxicity, reduced cell viability, and inhibited cell proliferation. The in vivo studies revealed reduction in tumor number, size, and volume as well. The clinical studies demonstrated that avocado leaf extract increased free oxygen radical formation in larynx carcinoma tissue. Various avocado products and phytochemicals from the avocado fruit, including avocatin-B, persin, and PaDef defensin, may serve as viable cancer prevention and treatment options based on current literature. Despite many favorable outcomes, past research has been limited in scope, and more extensive and mechanism-based in vivo and randomized clinical studies should be performed before avocado-derived bioactive phytochemicals can be developed as cancer preventive agents.

Relationship between Bladder Cancer, Nutritional Supply, and Treatment Strategies: A Comprehensive Review

Bladder cancer (BC) is the predominant neoplasm affecting the urinary system and ranks among the most widespread malignancies globally. The causes of bladder cancer include genetic factors; age; sex; and lifestyle factors, such as imbalanced nutrition, obesity, and metabolic disorders. The lack of proper nutrient intake leads to the development of bladder cancer because insufficient nutrients are consumed to prevent this disease. The purpose of this review was to analyze the nutrients closely linked to the onset and advancement of bladder cancer and to explore the relationship between dietary nutrients and bladder cancer. Particular emphasis was placed on nutrients that are frequently ingested in daily life, including sugar, fat, protein, and others. The focus of this research was to analyze how nutritional intake before and after surgery affects the recovery process of patients who have been diagnosed with bladder cancer. This article seeks to increase awareness among both society and the medical community about the significance of implementing appropriate dietary nutrition to reduce the chances of developing bladder cancer, enhance perioperative care for patients with bladder cancer, and aid in their recuperation.