Avocado Intake, and Longitudinal Weight and Body Mass Index Changes in an Adult Cohort

Avocado Consumption and Cardiometabolic Health: A Systematic Review and Meta-Analysis

BACKGROUND

Avocados are a rich source of unsaturated fats and bioactives, however, their role in altering cardiometabolic risk factors is unclear.

OBJECTIVE

The aim was to review the effects of consuming diets containing avocado compared with control diets containing no or low amounts of avocado on cardiometabolic risk factors in adults who were healthy, had clinical cardiovascular disease, or were at increased risk of cardiovascular disease.

METHODS

Five electronic databases were searched (PubMed, Web of Science, Scopus, ProQuest, and a Clinical Trials Registry) along with Google Scholar to identify studies published between January 1990 and November 10, 2021. Randomized controlled trials ≥3 weeks and prospective cohort studies were included. Ten studies-9 randomized controlled trials (n = 503 participants) and 1 prospective observational study (n = 55,407)-met the inclusion criteria. Outcomes assessed by means of meta-analysis were low-density lipoprotein cholesterol (LDL-C) (primary), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides. Outcomes assessed by narrative review were TC to HDL-C ratio, non-HDL-C, apolipoprotein B, blood pressure, body weight, body mass index (calculated as kg/m2), waist circumference, waist-to-hip ratio, body composition, and blood glucose and insulin concentrations. Risk of bias was assessed using the Cochrane Risk of Bias tool, version 2.0 and Newcastle-Ottawa Scale; quality of evidence was examined using the Grading of Recommendations, Assessment, Development and Evaluation method. Random-effects models meta-analyses were performed when there were ≥3 studies of the same design (ie, randomized controlled trial) and reporting the same outcome. Statistical heterogeneity was assessed by calculating χ2 and I2 statistics and publication bias was assessed by funnel plots.

RESULTS

Overall, there was a small, significant reduction in TC (-5.08 mg/dL [to convert to mmol/L, divide by 38.67]; 95% CI -9.29 to -0.87 mg/dL; P = .02) in avocado vs the control groups and no significant difference in LDL-C, HDL-C, or triglycerides. Subgroup analysis demonstrated significant reductions in LDL-C (-9.4 mg/dL [to convert to mmol/L, divide by 38.67]; 95% CI -10.84 to -7.95 mg/dL; P < .00001) and TC (-7.54 mg/dL; 95% CI -9.40 to -5.68 mg/dL; P < .00001) in avocado vs control groups in hypercholesterolemic populations, and no differences were seen in normocholesterolemic populations. However, the certainty in the findings was graded as low to very low. Body weight and composition were not negatively affected by avocado consumption.

CONCLUSIONS

Avocado consumption may reduce TC and LDL-C in people with hypercholesterolemia. Avocado consumption does not negatively impact body weight. Larger, well-conducted studies are needed to have greater confidence in the role of avocado consumption on cardiovascular disease risk factors.

Consumption of avocado and associations with nutrient, food and anthropometric measures in a representative survey of Australians: a secondary analysis of the 2011-2012 National Nutrition and Physical Activity Survey

Avocados are a rich source of nutrients including monounsaturated fats, dietary fibre, potassium and Mg, as well as phytochemicals. However, no epidemiological analysis for the associations between avocado consumption and participant anthropometric measures has been conducted in Australia. The present study aimed to perform a secondary analysis of the 2011-2012 National Nutrition and Physical Activity Survey (NNPAS) to quantify avocado consumption in the Australian population and explore the associations between avocado intakes, consumption of nutrients and food groups based on the Australian Dietary Guidelines and anthropometric measurements. Usual avocado consumption in the 2011-2012, NNPAS was determined using the multiple source method regression model. The relationship between avocado consumption and intakes of key nutrients and food groups and participant weight, BMI and waist circumference were examined using linear regression. Mean avocado intake was 2·56 (95 % CI: 2·37, 2·75) grams per day with 15·9 % of Australians considered to be 'avocado consumers' (n 21 526 456 population size; n 12 153 observations). Greater consumption (g) of avocados was associated with significantly higher consumption of monounsaturated fats, polyunsaturated fats, dietary fibre, vitamin E, Mg and potassium, as well as 'whole grains', 'vegetables', 'fruit' and 'meat and alternatives' food groups. Greater consumption (g) of avocados was associated with significantly lower consumption of carbohydrates and discretionary foods. When adjusted for covariates, greater consumption of avocados was significantly associated with a lower body weight (P = 0·034), BMI (P < 0·001) and waist circumference (P < 0·001). Avocados may be incorporated into an eating pattern and may be beneficial in weight management.

Cytotoxicity Evaluation and Antioxidant Activity of a Novel Drink Based on Roasted Avocado Seed Powder

The avocado seed is an underused waste resulting from the processing of pulp. Polyphenols, fibers, and carotenoids are present in the seed, which also exhibits prophylactic, fungicidal, and larvicidal effects. Developing food products with avocado seed as an ingredient or spice is highly desired for nutritional, environmental, and economic reasons. The present study proposed its valorization in a hot drink, similar to already existing coffee alternatives, obtained by infusing the roasted and grinded avocado seed. The proximate composition of the raw or conditioned avocado seed and that of the novel drink were determined. The total phenolic content was assessed using the Folin-Ciocâlteu method. The total carotenoids were extracted and assessed spectrophotometrically. Starch determination was performed by the Ewers Polarimetric method. The highest content of polyphenols, 772.90 mg GAE/100 g, was determined in the crude seed, while in the drink was as low as 17.55 mg GAE/100 g. However, the proposed drink demonstrated high antioxidant capacity, evaluated through the DPPH method. This might be due to the high content of the total carotenoid compounds determined in the roasted seed (6534.48 µg/100 g). The proposed drink demonstrated high antiproliferative activity on Hs27 and DLD-1 cell lines.

Associations between Avocado Consumption and Diet Quality, Dietary Intake, Measures of Obesity and Body Composition in Adolescents: The Teen Food and Development Study

Avocado is a nutrient-rich food that has been shown to benefit the health and diet quality of adults. In this paper, we examined if habitual intake of avocado among adolescents is associated with their diet quality, food and nutrient intake, and measures of obesity and body composition. Participants aged 12-18 years old (n = 534) from selected public and Adventist middle-high schools reported their dietary intake in a web-based food frequency questionnaire (FFQ); anthropometrics were measured during school visits. Diet quality (DQI-I) and avocado intake were calculated from the FFQ; BMI z-scores (BMIz), waist-to-height ratio (WHtR), and fat mass (FM), fat-free mass (FFM), and %body fat (%BF) were determined from the anthropometric data. Compared to non-consumers, avocado consumers had significantly higher covariate-adjusted mean scores on total DQI-I (68.3 vs. 64.6) and energy-adjusted mean scores on variety (18.8 vs. 18.0) and adequacy (36.4 vs. 33.4). Avocado consumption was significantly associated with DQI-I components adequacy (β [SE] = 0.11 [0.03]) and moderation (β [SE] = 0.06 [0.03]) but not with BMIz, WHtR, FM, FFM, and %BF. Mean intakes of fruits, vegetables, and plant protein foods, total and vegetable proteins, dietary fiber, retinol, vitamin C, calcium, magnesium, iron, and potassium were significantly higher for avocado consumers; saturated and trans fats intakes were significantly higher for non-consumers. In our adolescent population, avocado consumption was associated with higher diet quality and intake of plant-based foods and shortfall nutrients, but not with measures of obesity and body composition. Studies are needed to determine the optimal amount of avocado that would confer health benefits during adolescence.

A Comprehensive Review of Hass Avocado Clinical Trials, Observational Studies, and Biological Mechanisms

This first comprehensive review of fresh Hass avocados includes 19 clinical trials, five observational studies, and biological mechanisms. We identified four primary avocado health effects: (1) reducing cardiovascular disease risk in healthy overweight or obese adults with dyslipidemia by lowering non-HDL-C profiles, triglycerides, LDL oxidation, small atherogenic LDL particles and promoting postprandial vascular endothelial health for better peripheral blood flow; (2) lowering the risk of being overweight or obese, supporting weight loss, and reducing visceral fat tissue in overweight or obese women; (3) improving cognitive function in older normal-weight adults and in young to middle age overweight or obese adults especially in frontal cortex executive function; and (4) stimulating improved colonic microbiota health in overweight or obese adults by promoting healthier microflora and fecal metabolites. We also identified a unique combination of four Hass avocado nutritional features that appear to be primarily responsible for these health effects: (1) a 6 to 1 unsaturated (rich in oleic acid) to saturated fat ratio similar to olive oil; (2) a source of multifunctional prebiotic and viscous fiber; (3) a relatively low energy density of 1.6 kcal/g (79% of edible Hass avocado weight consists of water and fiber with a creamy, smooth texture); and (4) its oleic acid and water emulsion increases carotenoid absorption from low-fat fruits and vegetables (e.g., salsa or salad) when consumed with avocados. They are also a good source of micronutrients and polyphenols, and are very low in sodium and available carbohydrates supporting secondary health and wellness benefits. Hass avocado health effects are best demonstrated when consumed in a healthy dietary plan such as the Mediterranean diet. More extensive and longer clinical trials are needed to further enhance our understanding of the Hass avocado’s health effects.

Effects of Different Allotments of Avocados on the Nutritional Status of Families: A Cluster Randomized Controlled Trial

Avocados are a nutrient-dense plant-food, but limited trial-derived evidence exists about the effects of avocado intake on family nutritional status. We investigated the impact of two levels of avocado allotment, plus a standard nutrition education intervention on the nutritional status of Hispanic/Latino families. Seventy-two families consisting of at least three members of ≥5 years of age and residing in the same home, free of severe chronic disease, not on specific diets, and self-identified of Hispanic heritage, were randomized to one of two levels of avocado allotment (low = 3/week/family or high = 14/week/family) for 6 months plus 12 bi-weekly nutrition education sessions. The primary outcomes included change in a family’s total energy and macro- and micronutrient intakes. Primary analysis was intention-to-treat with unpaired, two-sided t-tests to assess mean changes between groups at 6 months. At 6 months, the high avocado allotment group had a significant reduction in energy intake, carbohydrate, animal and vegetable protein, saturated and polyunsaturated fat, calcium, magnesium, sodium, potassium, iron, and vitamin D intakes (all p < 0.05). A high allotment of avocados significantly reduced self-reported energy intake by 29% kcal/family/day, compared to a 3% kcal/family/day reduction in families who received a low allotment. Culturally-appropriate plant-food interventions may alter the nutritional status of at-risk families.

Avocado Consumption, Abdominal Adiposity, and Oral Glucose Tolerance Among Persons with Overweight and Obesity

BACKGROUND

Although intake of Hass avocado has been cross-sectionally linked to lower abdominal obesity, knowledge of the effects of avocado consumption on abdominal adiposity and glycemic outcomes remains limited.

OBJECTIVE

The effects of avocado consumption on abdominal adiposity, insulin resistance, oral-glucose-tolerance test (OGTT), and estimated β-cell function were evaluated.

METHODS

A total of 105 adults aged 25-45 y (61% female) with BMI ≥25 kg/m2 were randomly assigned to an intervention (N = 53) that received a daily meal with 1 fresh Hass avocado or a control (N = 52) that received an isocaloric meal with similar ingredients without avocado for 12 wk. DXA was used to assess the primary outcomes of abdominal adiposity [visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAAT), and the ratio of VAT to SAAT (VS Ratio)]. Fasted glucose and insulin were used to assess the primary outcomes of insulin resistance (HOMA-IR), and insulin sensitivity (Matsuda index) and β-cell function (Insulinogenic index) were estimated using an OGTT. Changes between groups were compared using an ANCOVA. Secondary analyses were conducted based on sex.

RESULTS

The control group exhibited a greater reduction in SAAT [-54.5 ± 155.8 g (control) compared with 17.4 ± 155.1 g (treatment), P = 0.017] and increase in VS Ratio [0.007 ± 0.047 (control) compared with -0.011 ± 0.044 (treatment), P = 0.024]. Among females, the treatment group exhibited a greater reduction in VAT [1.6 ± 89.8 g (control) compared with -32.9 ± 81.6 g (treatment), P = 0.021] and VS Ratio [0.01 ± 0.05 (control) compared with -0.01 ± 0.03 (treatment), P = 0.001]. Among males, there was no significant difference between groups in changes in abdominal adiposity or glycemic outcomes.

CONCLUSIONS

Daily consumption of 1 fresh Hass avocado changed abdominal adiposity distribution among females but did not facilitate improvements in peripheral insulin sensitivity or β-cell function among adults with overweight and obesity.This study was registered at clinicaltrials.gov as NCT02740439.

A Comprehensive Critical Assessment of Increased Fruit and Vegetable Intake on Weight Loss in Women

No previous reviews or meta-analyses have specifically assessed the effects of increased fruit and vegetable (FV) intake on weight loss with a primary focus on women. Several studies show differences between men and women in how increased FV intake affects their weight loss and maintenance, risk of becoming overweight or obese, and the influence of eating speed and frequency on weight control. This analysis provides a comprehensive and visual assessment of the effects of increasing FV intake and long-term weight change from observational studies and weight loss from randomized controlled trials (RCTs) in women. Consistent evidence from prospective studies and RCTs shows that increased intake of FV is a chief contributor to weight loss in women. This effect is enhanced with concurrent dietary restriction of high energy density (ED) or high-fat foods. Yet, the type of FV differentially impacts weight loss in women. Whole FV intake may influence weight through a variety of mechanisms including a reduction in eating rate, providing a satisfying, very-low to low energy density, low glycemic load or low-fat content. Also, FV are the primary source of dietary fiber, which can provide additional support for weight loss in women when consumed at adequate levels.

The Forgotten Fruit: A Case for Consuming Avocado Within the Traditional Mediterranean Diet

The Mediterranean diet is rich in fruits and vegetables and includes an abundant intake of oleic-acid-rich olive oil. People who adhere to a Mediterranean diet have reduced risk for numerous chronic diseases. As obesity rates rise globally, people who choose to follow a traditional Mediterranean diet and/or make improvements in food choices may reduce their risk of metabolic dysfunction and disease. Incorporating non-traditional fruits and vegetables into the Mediterranean diet could provide greater flexibility in suitable food choices for people who struggle to adhere to recommended healthy dietary patterns, and it could also provide greater adaptability for people living outside of the Mediterranean region who are interested in adopting the diet. The avocado fruit thrives in a Mediterranean climate, is produced in the region, and is rich in oleic acid and fiber, yet avocados are not commonly consumed within the traditional Mediterranean diet. Based on the existing research studies on the health benefits of avocado consumption and the continued investigation into the nutritional attributes of the avocado, a case can be made for including avocados as part of the Mediterranean dietary pattern.

The Odyssey of Bioactive Compounds in Avocado (Persea americana) and Their Health Benefits

Persea americana, commonly known as avocado, has recently gained substantial popularity and is often marketed as a “superfood” because of its unique nutritional composition, antioxidant content, and biochemical profile. However, the term “superfood” can be vague and misleading, as it is often associated with unrealistic health claims. This review draws a comprehensive summary and assessment of research performed in the last few decades to understand the nutritional and therapeutic properties of avocado and its bioactive compounds. In particular, studies reporting the major metabolites of avocado, their antioxidant as well as bioavailability and pharmacokinetic properties, are summarized and assessed. Furthermore, the potential of avocado in novel drug discovery for the prevention and treatment of cancer, microbial, inflammatory, diabetes, and cardiovascular diseases is highlighted. This review also proposes several interesting future directions for avocado research.