Substitution of high monounsaturated fatty acid avocado for mixed dietary fats during an energy-restricted diet: effects on weight loss, serum lipids, fibrinogen, and vascular function

Effect of daily avocado consumption for 6 mo compared with habitual diet on red blood cell fatty acid profiles and association with cardiometabolic risk factors in individuals with abdominal obesity: a randomized trial

BACKGROUND

Avocado intake improves dietary fat quality, but the subsequent impact on red blood cell (RBC) saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA), and trans-fatty acid (TFA) composition and association with cardiometabolic health, has not been elucidated.

OBJECTIVES

To compare the effect of consuming 1 avocado/d relative to habitual diet (HAB) on RBC-FA profiles, and their association with visceral adiposity and cardiometabolic risk factors (CMRFs) in individuals with abdominal obesity.

METHODS

RBC-FA profiling at baseline, 3- and 6 mo was conducted in participants (n = 994) from the Habitual Diet and Avocado Trial (HAT). HAT was a multisite, free-living, parallel-arm intervention study in which participants were randomly assigned to either the avocado-supplemented group (AVO, usual diet with 1 avocado/d) or the HAB group (usual diet with limited avocado intake) for 6 mo. Changes in RBC-FA profiles, a secondary outcome measure, were determined within and between groups using linear regression and mixed effect models, adjusting for age, sex, BMI, clinical site, smoking status, and percentage of energy intake from fat at baseline. The association between changes in RBC-FAs with visceral adiposity measures and CMRFs was assessed after covariate and False Discovery Rate (FDR <0.05) adjustment.

RESULTS

No major differences in RBC-FA profiles were observed between groups, with the exception of MUFA cis-vaccenic [18:1n-7c], which was significantly higher in AVO (β: 0.11 [0.05, 0.17]) compared with the HAB (β: 0.03 [-0.03, 0.08]) participants. In the HAB but not AVO group, increases in MUFA cis (18:1n-7c, oleic [18;1n-9c], erucic [22:1n-9c]) and MUFA trans (palmitelaidic [16:1n-7t], vaccenic [18:1n-7t], elaidic [18:1n-9t], and petroselaidic [18;1n-10-12t), as well as PUFA γ-linolenic [18:3n-6], dihomo-γ-linolenic [20:3n-6], arachidonic [20:4n-6], and α-linolenic [18:3n-3] were associated with unfavorable changes in visceral adiposity measures, lipid profiles, glucose, insulin and high sensitivity C-reactive protein concentrations.

CONCLUSIONS

Daily avocado intake over 6-mo modified RBC-MUFA composition, notably 18:1n-7c, and potentially mitigated some of the unfavorable individual RBC-FA-CMRF associations observed over time in the HAB group. This trial was registered at https://clinicaltrials.gov/study as NCT03528031.

Individual and interaction effects of monounsaturated fatty acids on their associations with hypertension in Chinese residents

Currently, associations between dietary intakes of individual monounsaturated fatty acids (MUFAs) and hypertension were not well disclosed, and the interaction effects of MUFAs on their associations with hypertension were unknown. Obesity was correlated with both MUFAs and hypertension, while if anthropometric obesity indices performed mediating roles in associations between MUFAs and hypertension remained underdetermined. In our study, 8509 Chinese adults investigated from 2004 to 2011 were included. Dietary information collection and physical examinations were performed at baseline and each timepoint of follow-up. As we found, inverse associations of MUFA17, MUFA18 and MUFA20 with hypertension were statistically significant after adjustments, hazard ratios (HRs) were 0.87, 0.90 and 0.91, respectively. MUFA15 was positively associated with hypertension, with an HR of 1.07 (95% confidence interval: 1.01, 1.12). By performing principal component analysis (PCA) to estimate the joint effects of MUFAs on hypertension, the PCA score of MUFAs was only inversely associated with blood pressure. No joint effect was observed in g-computation analyses. Both linear and nonlinear interactions of MUFAs on their associations with hypertension were estimated using restricted cubic spline analysis. The association between MUFA15 and hypertension was interacted by MUFA17, and the association between MUFA20 and hypertension was interacted by MUFA18. The mediation effects of body mass index and waist circumference were found on associations of hypertension with MUFA15, MUFA17 and MUFA20. Our findings suggested that associations with hypertension were different among individual MUFAs, and mutual interactions existed, implying that the utility of individual MUFAs might be recommended for estimating relationships between MUFAs and diseases. Moreover, fat accumulation might potentially underlie associations between MUFAs and hypertension.

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.

Effect of Avocado Consumption on Risk Factors of Cardiovascular Diseases: A Systematic Review and Meta-Analysis

High cholesterol levels are a significant risk factor for heart disease, the leading cause of death worldwide. Lowering cholesterol plays a crucial role in maintaining good health. One approach to reducing cholesterol is through dietary modifications, and avocados have been recognized as a potential food choice for this purpose. Avocados are rich in monounsaturated fatty acids (MUFAs), fiber, and plant sterols, which have cholesterol-lowering effects. Incorporating avocados into a low-fat diet can be beneficial. This study design followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and conducted databases in Cochrane, SCOPUS, PubMed, and Web of Science up until May 2023, combining keywords related to avocados and cardiovascular diseases (CVDs). The study focused on randomized clinical trials (RCTs) and excluded observational studies, meta-analyses, surveys, abstracts, and reviews. Seven RCTs were included in the study, all reporting total cholesterol (TC) levels. The findings of the study showed that individuals who followed an avocado diet experienced reduced TC levels compared to those who followed a habitual diet or a low-fat diet. The avocado group exhibited lower TC levels compared to the control group in both the habitual diet and low-fat diet subgroups. When considering high-density lipoprotein (HDL) levels, the control group had higher HDL levels than the avocado group in the habitual diet subgroup, while the avocado group had higher HDL levels than the control group in the low-fat diet subgroup. In both the habitual diet and low-fat diet subgroups, the avocado group had lower levels of low-density lipoprotein (LDL) compared to the control group. The study concluded that incorporating avocados into the diet can be a beneficial dietary strategy for individuals aiming to lower their cholesterol levels and promote heart health. The avocado diet was associated with decreased LDL levels, but it did not significantly impact triglyceride (TG) levels or fasting glucose levels. Systolic blood pressure values showed minimal changes with the avocado diet.

Avocado consumption and markers of inflammation: results from the Multi-Ethnic Study of Atherosclerosis (MESA)

PURPOSE

Since avocado consumption has been linked to a possible reduction in inflammation, we investigated associations between avocado consumption and markers of inflammation in a population-based multi-ethnic cohort [Multi-Ethnic Study of Atherosclerosis (MESA)].

METHODS

We used a food frequency questionnaire (FFQ) at MESA exam 1 to capture avocado/guacamole consumption. To calculate daily servings of avocado/guacamole, we used both frequency and serving size data from the FFQ. We classified participants into three consumer groups: rare or never (daily serving ≤ 0.03), medium (0.03 < daily serving < 0.1), and heavy (0.1 ≤ daily serving). Inflammation was estimated by natural log-transformed inflammatory biomarkers (CRP, IL-2, IL-6, homocysteine, fibrinogen, TNF-a soluble receptors). We used multivariate general linear regression models to assess associations accounting for age, sex, race/ethnicity, educational level, income, energy intake, smoking status, physical activity, diet quality, body mass index, and diabetes type.

RESULTS

Among 5794 MESA participants, the average age and BMI were 62.25 y ± 10.26 and 28.28 ± 5.41 kg/m², respectively, and 48% of the sample were men. Participants self-reported as Hispanic (22.30%), Caucasian (39.92%), African-American (25.39%), and Chinese (12.39%). Over 60% had higher than a high school education and 40% made $50,000 or more a year. Regarding avocado/guacamole consumption, 79% were categorized as rare or never, 12% as medium, and 9% as heavy. When adjusted for relevant confounders, there were no significant differences among the three consumer groups for any inflammatory marker.

CONCLUSION

In this cross-sectional study, we did not find that consumption of avocado/guacamole was associated with levels of inflammatory markers.

The Effect of MUFA-Rich Food on Lipid Profile: A Meta-Analysis of Randomized and Controlled-Feeding Trials

Since the effects of mono-unsaturated fatty acids (MUFA) on lipid profile are still controversial, a meta-analysis of randomized controlled trials was conducted in the present study to assess the effect of MUFA-rich food on lipid profiles. The study was designed, conducted, and reported according to the guidelines of the 2020 preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement. A systematic and comprehensive search was performed in several databases from inception up to 30 January 2022. The results showed that the intake of edible oil-derived MUFA (EDM) could increase the blood HDL-C level (mean difference = 0.08; 95%CI: -0.01, 0.17, p = 0.03), but did not affect the level of TC, TG, or LDL-C. Moreover, the consumption of other food-derived MUFA (ODM) significantly decreased TG concentration (mean difference = -0.35; 95%CI: -0.61, -0.09, p = 0.01)), but did not affect the level of TC, LDL-C, or HDL-C. Findings from this study suggest that MUFA-rich food might be beneficial to modulate the blood lipid profile.

Avocado Consumption and Risk of Cardiovascular Disease in US Adults

Background Epidemiologic studies on the relationship between avocado intake and long-term cardiovascular disease (CVD) risk are lacking. Methods and Results This study included 68 786 women from the NHS (Nurses' Health Study) and 41 701 men from the HPFS (Health Professionals Follow-up Study; 1986-2016) who were free of cancer, coronary heart disease, and stroke at baseline. Diet was assessed using validated food frequency questionnaires at baseline and then every 4 years. Cox proportional hazards regressions were used to estimate hazard ratios and 95% CIs. A total of 14 274 incident cases of CVD (9185 coronary heart disease events and 5290 strokes) were documented over 30 years of follow-up. After adjusting for lifestyle and other dietary factors, compared with nonconsumers, those with analysis-specific higher avocado intake (≥2 servings/week) had a 16% lower risk of CVD (pooled hazard ratio, 0.84; 95% CI, 0.75-0.95) and a 21% lower risk of coronary heart disease (pooled hazard ratio, 0.79; 95% CI, 0.68-0.91). No significant associations were observed for stroke. Per each half serving/day increase in avocado intake, the pooled hazard ratio for CVD was 0.80 (95% CI, 0.71-0.91). Replacing half a serving/day of margarine, butter, egg, yogurt, cheese, or processed meats with the equivalent amount of avocado was associated with a 16% to 22% lower risk of CVD. Conclusions Higher avocado intake was associated with lower risk of CVD and coronary heart disease in 2 large prospective cohorts of US men and women. The replacement of certain fat-containing foods with avocado could lead to lower risk of CVD.

Avocado oil: Production and market demand, bioactive components, implications in health, and tendencies and potential uses

Avocado is a subtropical/tropical fruit with creamy texture, peculiar flavor, and high nutritional value. Due to its high oil content, a significant quantity of avocado fruit is used for the production of oil using different methods. Avocado oil is rich in lipid-soluble bioactive compounds, but their content depends on different factors. Several phytochemicals in the oil have been linked to prevention of cancer, age-related macular degeneration, and cardiovascular diseases and therefore have generated an increase in consumer demand for avocado oil. The aim of this review is to critically and systematically analyze the worldwide production and commercialization of avocado oil, its extraction methods, changes in its fat-soluble phytochemical content, health benefits, and new trends and applications. There is a lack of information on the production and commercialization of the different types of avocado oil, but there are abundant data on extraction methods using solvents, centrifugation-assisted aqueous extraction, mechanical extraction by cold pressing (varying concentration and type of enzymes, temperature and time of reaction, and dilution ratio), ultrasound-assisted extraction, and supercritical fluid to enhance the yield and quality of oil. Extensive information is available on the content of fatty acids, although it is limited on carotenoids and chlorophylls. The effect of avocado oil on cancer, diabetes, and cardiovascular diseases has been demonstrated through in vitro and animal studies, but not in humans. Avocado oil continues to be of interest to the food, pharmaceutical, and cosmetic industries and is also generating increased attention in other areas including structured lipids, nanotechnology, and environmental care.

Ripening of avocado fruits studied by spectroscopic techniques

Avocados are considered very healthy due to the high content mono-unsaturated lipid, essential vitamins and minerals, minimal sugar and no cholesterol and are therefore sometimes referred to as "the perfect fruits". Avocados, mainly grown in Latin-America, are harvested unripe and sent overseas. However, the ripening process is very difficult to assess visually and tactilely. A tool for precise noninvasive judgment of the status would be valuable as the fruit is too expensive to be cut open unripe or overdue. A white-light source and a light-emitting diode unit with four excitation wavelengths (365, 385, 395, and 405 nm) were used for reflectance and fluorescence spectroscopy in a fiber-coupled set-up for noninvasive monitoring. Twelve non-ripe avocados, with approximately the same size and appearance, were studied and divided into three groups and kept at three different storage conditions; at room temperature, in a refrigerator and a combination of the two. We showed that fluorescence was useful for following the ripening process. A method, which compensates for the spatial variations in spectral properties around a fruit, is described. Remote fluorescence monitoring, intended for orchard use, was also demonstrated. A low-cost device based on fluorescence for avocado ripeness assessment is proposed.

Avocado Pear Pulp (Persea americana)-Supplemented Cake Improved Some Serum Lipid Profile and Plasma Protein in Rats

Avocado pear pulp (Persea americana) is indigenous to Mexico. It is widely cultivated and consumed all over the world. Its oil is rich in monounsaturated fatty acids (SFAs) and can be used to replace SFAs in a diet to lower low-density lipoprotein (LDL) and raise high-density lipoprotein (HDL). Consumers seek healthy foods that aid in reducing metabolic syndrome. The aim of this study is to evaluate the effects of the best acceptable cakes supplemented with 0%, 10%, 30%, and 50% avocado on the serum lipid profile and plasma protein in rats. Twenty-five rats separated into five groups of four test groups and one control group were fed individually for 14 days, after which blood samples were withdrawn and subjected to biochemical analysis. Intake of cake supplemented with avocado pear pulp resulted in significant (P < .05) increment in the body weight, total cholesterol, triglycerides and HDL, and serum protein and decrement in LDL of the rats. The group fed 50% supplemented cake showed highest increase in HDL and least decrease in LDL. Cake supplemented with 50% avocado pear pulp proved to be a better supplementation in reducing serum LDL and increasing serum HDL and serum protein in rats, indicating to be a promising nutraceutical for the management of cardiovascular diseases and its associated complications.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

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.

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

Avocados contain nutrients and bioactive compounds that may help reduce the risk of becoming overweight/obese. We prospectively examined the effect of habitual avocado intake on changes in weight and body mass index (BMI). In the Adventist Health Study (AHS-2), a longitudinal cohort (~55,407; mean age ~56 years; U.S. and Canada), avocado intake (standard serving size 32 g/day) was assessed by a food frequency questionnaire (FFQ). Self-reported height and weight were collected at baseline. Self-reported follow-up weight was collected with follow-up questionnaires between four and 11 years after baseline. Using the generalized least squares (GLS) approach, we analyzed repeated measures of weight in relation to avocado intake. Marginal logistic regression analyses were used to calculate the odds of becoming overweight/obese, comparing low (>0 to <32 g/day) and high (≥32 g/day) avocado intake to non-consumers (reference). Avocado consumers who were normal weight at baseline, gained significantly less weight than non-consumers. The odds (OR (95% CI)) of becoming overweight/obese between baseline and follow-up was 0.93 (0.85, 1.01), and 0.85 (0.60, 1.19) for low and high avocado consumers, respectively. Habitual consumption of avocados may reduce adult weight gain, but odds of overweight/obesity are attenuated by differences in initial BMI values.

Influence of Avocado Purée as a Fat Replacer on Nutritional, Fatty Acid, and Organoleptic Properties of Low-Fat Muffins

OBJECTIVE

The feasibility of developing reduced-fat muffins with avocado is investigated by preparing muffins with 25%, 50%, 75%, and 100% avocado purée as a fat (butter) replacer.

METHODOLOGY

The resulting products were compared to the control muffin, which was made with 100% butter. Muffins were analyzed for nutritional content, fatty acid profiles, and sensory acceptability.

RESULT

Muffins incorporated with avocado purée revealed a significant increase (p < 0.05) with respect to moisture, ash, and carbohydrate in comparison with the control sample. However, no significant changes (p > 0.05) were detected in all muffin formulations for protein and dietary fiber content. Both fat content and caloric value of muffins incorporated with avocado purée were significantly decreased (p < 0.05). The fatty acid profile showed that there was an increment in the monounsaturated fatty acids (MUFA) content by 16.51% at full-fat substitution. The sensory evaluation test demonstrated that muffins had acceptability at up to 50% substitution. Fat substitution at higher than 50% lead to undesirable flavor and aftertaste, which was significant (p < 0.05) to the panelists.

CONCLUSION

The findings indicated the feasibility of avocado purée in fat-reduced muffin preparation with an optimal level of 50% avocado purée substitution.

Avocado consumption and risk factors for heart disease: a systematic review and meta-analysis

Background

Nutrients in avocados are associated with cardiovascular benefits.

Objective

The aim of this study was to determine the effect of avocado intake on cardiovascular disease (CVD) risk with the use of a systematic review and meta-analysis.

Design

MEDLINE, Cochrane Central, and Commonwealth Agricultural Bureau abstracts were searched from 1946 through September 2017 for publications on avocado intake and CVD risk. All designs except for cross-sectional studies that evaluated avocado intake were included. Two investigators independently screened citations and extracted data. Random-effects models meta-analysis was used when ≥3 studies reported the same outcome.

Results

Of 18 eligible studies (481 subjects), 7 studies compared avocado intake with no intake, 3 studies compared avocado plus monounsaturated fat intake with a control, and 8 studies reported data for qualitative synthesis. In 7 studies, avocado intake significantly increased HDL cholesterol (summary net change: 2.84 mg/dL; 95% CI: 0.18, 5.49 mg/dL), with significant heterogeneity. This remained consistent in sensitivity and subgroup analyses. There was no significant difference between avocado intake and the control for the outcomes of serum total cholesterol (TC), LDL cholesterol, triglycerides (TGs), ratios of TC to HDL cholesterol and LDL cholesterol to HDL cholesterol, and body weight. In qualitative synthesis, there was no significant difference between groups for blood glucose (2 studies), homeostasis model assessment (1 of 2 studies), oxidized LDL (2 studies), high-sensitivity C-reactive protein (2 studies), or apolipoprotein B (2 studies) or, in 1 study each, for body mass index, systolic and diastolic blood pressure, arterial compliance, fibrinogen, interleukin 6, tumor necrosis factor α, and serum nitric oxide. No studies reported incident clinical outcomes of CVD, including myocardial infarction, stroke, and other clinical endpoints.

Conclusions

Avocado intake resulted in no difference in serum TC, LDL-cholesterol, and TG concentrations, but it did increase serum HDL-cholesterol concentrations, with significant heterogeneity. The association between avocado intake and CVD risk should be confirmed by well-conducted prospective observational studies or long-term trials.

Effects of Avocado (Persea americana) on Metabolic Syndrome: A Comprehensive Systematic Review

Metabolic syndrome (MetS) is a clustering of risk factors including high blood glucose, dyslipidemia, hypertension, and obesity that lead to the increased risk of type 2 diabetes mellitus and cardiovascular diseases (CVDs), which are among leading causes of death in the world. Metabolic syndrome increases the risk of type 2 diabetes mellitus and CVDs by approximately five and three folds, respectively. Therefore, it is of vital importance to manage such conditions with herbal options which have less undesirable adverse effects and may be more efficacious in comparison with synthetic options. Avocado is a well-known source of carotenoids, minerals, phenolics, vitamins, and fatty acids. The lipid-lowering, antihypertensive, antidiabetic, anti-obesity, antithrombotic, antiatherosclerotic, and cardioprotective effects of avocado have been demonstrated in several studies. In this review, we aimed to find out avocado's pharmacological effects on different components of MetS. Moreover, this review report is performed on the MetS effects of peel, seed, flesh, and leaves of avocado. Copyright © 2017 John Wiley & Sons, Ltd.

Impact of avocado-enriched diets on plasma lipoproteins: A meta-analysis

BACKGROUND

Optimizing plasma lipoproteins is the primary goal of pharmacotherapy and diet interventions in people at risk for cardiovascular diseases. Avocados offer a rich source of monounsaturated fat and may pose beneficial effects on the lipid profile.

OBJECTIVE

We aimed to perform a meta-analysis of randomized clinical trials assessing the impact of avocados on TC, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, and/or triglycerides (TG).

METHODS

We searched PUBMED, Cumulative Index to Nursing and Allied Health Literature, Index to Nursing and Allied Health Literature, and the Cochrane Database of Systemic Reviews from their inception to February 2015. The weighted mean difference from baseline was calculated for all endpoints. Subgroup analyses were performed to assess heterogeneity, and funnel plots inspected to assess publication bias.

RESULTS

Ten unique studies (n = 229) were included. Avocado consumption significantly reduced TC, LDL-C, and TG by -18.80 mg/dL (95% confidence interval [CI], -24.56 to -13.05; I(2), 46.9%), -16.50 mg/dL (95% CI, -22.91 to -10.10; I(2), 72.5%), -27.20 mg/dL (95% CI, -44.41 to -9.99; I(2), 91.1%) respectively. High-density lipoprotein cholesterol decreased nonsignificantly by -0.18 mg/dL (95% CI, -3.23 to 2.88; I(2), 84.8%).

CONCLUSION

Avocado-substituted diets significantly decrease TC, LDL-C, and TG levels. Substituting dietary fats with avocados versus adding to the free diet should be the primary recommendation strategy. Larger trials looking at the impact of avocados on major adverse cardiovascular events are warranted.

Functional foods as potential therapeutic options for metabolic syndrome

Obesity as part of metabolic syndrome is a major lifestyle disorder throughout the world. Current drug treatments for obesity produce small and usually unsustainable decreases in body weight with the risk of major adverse effects. Surgery has been the only treatment producing successful long-term weight loss. As a different but complementary approach, lifestyle modification including the use of functional foods could produce a reliable decrease in obesity with decreased comorbidities. Functional foods may include fruits such as berries, vegetables, fibre-enriched grains and beverages such as tea and coffee. Although health improvements continue to be reported for these functional foods in rodent studies, further evidence showing the translation of these results into humans is required. Thus, the concept that these fruits and vegetables will act as functional foods in humans to reduce obesity and thereby improve health remains intuitive and possible rather than proven.

Effect of a moderate fat diet with and without avocados on lipoprotein particle number, size and subclasses in overweight and obese adults: a randomized, controlled trial

BACKGROUND

Avocados are a nutrient-dense source of monounsaturated fatty acids (MUFA) that can be used to replace saturated fatty acids (SFA) in a diet to lower low density lipoprotein cholesterol (LDL-C). Well-controlled studies are lacking on the effect of avocado consumption on cardiovascular disease (CVD) risk factors.

METHODS AND RESULTS

A randomized, crossover, controlled feeding trial was conducted with 45 overweight or obese participants with baseline LDL-C in the 25th to 90th percentile. Three cholesterol-lowering diets (6% to 7% SFA) were fed (5 weeks each): a lower-fat diet (LF: 24% fat); 2 moderate-fat diets (34% fat) provided similar foods and were matched for macronutrients and fatty acids: the avocado diet (AV) included one fresh Hass avocado (136 g) per day, and the moderate-fat diet (MF) mainly used high oleic acid oils to match the fatty acid content of one avocado. Compared with baseline, the reduction in LDL-C and non-high-density lipoprotein (HDL) cholesterol on the AV diet (-13.5 mg/dL, -14.6 mg/dL) was greater (P<0.05) than the MF (-8.3 mg/dL, -8.7 mg/dL) and LF (-7.4 mg/dL, -4.8 mg/dL) diets. Furthermore, only the AV diet significantly decreased LDL particle number (LDL-P, -80.1 nmol/L, P=0.0001), small dense LDL cholesterol (LDL(3+4), -4.1 mg/dL, P=0.04), and the ratio of LDL/HDL (-6.6%, P<0.0001) from baseline.

CONCLUSIONS

Inclusion of one avocado per day as part of a moderate-fat, cholesterol-lowering diet has additional LDL-C, LDL-P, and non-HDL-C lowering effects, especially for small, dense LDL. Our results demonstrate that avocados have beneficial effects on cardio-metabolic risk factors that extend beyond their heart-healthy fatty acid profile.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01235832.

Isolation and chemical identification of lipid derivatives from avocado (Persea americana) pulp with antiplatelet and antithrombotic activities

Bioassay-guided isolation of acetogenins from avocado pulp within vitroantiplatelet aggregation andin vivoantithrombotic effects in CD1 mice.

Potential use of avocado oil on structured lipids MLM-type production catalysed by commercial immobilised lipases

Structured Lipids are generally constituents of functional foods. Growing demands for SL are based on a fuller understanding of nutritional requirements, lipid metabolism, and improved methods to produce them. Specifically, this work was aimed to add value to avocado oil by producing dietary triacylglycerols (TAG) containing medium-chain fatty acids (M) at positions sn-1,3 and long-chain fatty acids (L) at position sn-2. These MLM-type structured lipids (SL) were produced by interesterification of caprylic acid (CA) (C8:0) and avocado oil (content of C18:1). The regiospecific sn-1,3 commercial lipases Lipozyme RM IM and TL IM were used as biocatalysts to probe the potential of avocado oil to produce SL. Reactions were performed at 30–50°C for 24 h in solvent-free media with a substrate molar ratio of 1∶2 (TAG:CA) and 4–10% w/w enzyme content. The lowest incorporation of CA (1.1% mol) resulted from Lipozyme RM IM that was incubated at 50°C. The maximum incorporation of CA into sn-1,3 positions of TAG was 29.2% mol. This result was obtained at 30°C with 10% w/w Lipozyme TL IM, which is the highest values obtained in solvent-free medium until now for structured lipids of low-calories. This strategy opens a new market to added value products based on avocado oil.

Reduced-calorie avocado paste attenuates metabolic factors associated with a hypercholesterolemic-high fructose diet in rats

The objective of this study was to evaluate the effect of reduced-calorie avocado paste on lipid serum profile, insulin sensitivity, and hepatic steatosis in rats fed a hypercholesterolemic-high fructose diet. Thirty five male Wistar rats were randomly separated in five groups: Control group (ground commercial diet); hypercholesterolemic diet plus 60% fructose solution (HHF group); hypercholesterolemic diet plus 60% fructose solution supplemented with avocado pulp (HHF+A group); hypercholesterolemic diet plus 60% fructose solution supplemented with reduced-calorie avocado paste (HHF+P group); and hypercholesterolemic diet plus 60% fructose solution supplemented with a reduced-calorie avocado paste plus fiber (HHF+FP group). The A, P, and FP were supplemented at 2 g/kg/d. The study was carried out for seven weeks. Rats belonging to the HHF group exhibited significantly (P ≤ 0.05) higher total cholesterol, triglycerides, and insulin levels in serum as well as lower insulin sensitivity than the control group. Supplementation with reduced-calorie avocado paste showed a significant (P ≤ 0.05) decrease in total cholesterol (43.1%), low-density lipoprotein (45.4%), and triglycerides (32.8%) in plasma as well as elevated insulin sensitivity compared to the HHF group. Additionally, the liver enzymes alanine aminotransferase and aspartate aminotransferase decreased significantly in the HHF-P group (39.8 and 35.1%, respectively). These results are likely due to biocompounds present in the reduced-calorie avocado paste, such as polyphenols, carotenoids, chlorophylls, and dietary fibre, which are capable of reducing oxidative stress. Therefore, reduced-calorie avocado paste attenuates the effects of a hypercholesterolemic-high fructose diet in rats.

Avocado consumption is associated with better diet quality and nutrient intake, and lower metabolic syndrome risk in US adults: results from the National Health and Nutrition Examination Survey (NHANES) 2001-2008

BACKGROUND

Avocados contain monounsaturated fatty acids (MUFA) dietary fiber, essential nutrients and phytochemicals. However, no epidemiologic data exist on their effects on diet quality, weight management and other metabolic disease risk factors. The objective of this research was to investigate the relationships between avocado consumption and overall diet quality, energy and nutrient intakes, physiological indicators of health, and risk of metabolic syndrome.

METHODS

Avocado consumption and nutrition data were based on 24-hour dietary recalls collected by trained NHANES interviewers using the USDA Automated Multiple Pass Method (AMPM). Physiological data were collected from physical examinations conducted in NHANES Mobile Examination Centers. Diet quality was calculated using the USDA's Healthy Eating Index-2005. Subjects included 17,567 US adults ≥ 19 years of age (49% female), including 347 avocado consumers (50% female), examined in NHANES 2001-2008. Least square means, standard errors, and ANOVA were determined using appropriate sample weights, with adjustments for age, gender, ethnicity, and other covariates depending on dependent variable of interest.

RESULTS

Avocado consumers had significantly higher intakes of vegetables (p<0.05); fruit, diet quality, total fat, monounsaturated and polyunsaturated fats, dietary fiber, vitamins E, K, magnesium, and potassium (p<0.0001); vitamin K (p=0.0013); and lower intakes of added sugars (p<0.0001). No significant differences were seen in calorie or sodium intakes. Body weight, BMI, and waist circumference were significantly lower (p<0.01), and HDL-C was higher (p<0.01) in avocado consumers. The odds ratio for metabolic syndrome was 50% (95th CI: 0.32-0.72) lower in avocado consumers vs. non-consumers.

CONCLUSIONS

Avocado consumption is associated with improved overall diet quality, nutrient intake, and reduced risk of metabolic syndrome. Dietitians should be aware of the beneficial associations between avocado intake, diet and health when making dietary recommendations.

Hass avocado composition and potential health effects

Hass avocados, the most common commercial avocado cultivars in the world, contain a variety of essential nutrients and important phytochemicals. Although the official avocado serving is one-fifth of a fruit (30 g), according to NHANES analysis the average consumption is one-half an avocado (68 g), which provides a nutrient and phytochemical dense food consisting of the following: dietary fiber (4.6 g), total sugar (0.2 g), potassium (345 mg), sodium (5.5 mg), magnesium (19.5 mg), vitamin A (43 μg), vitamin C (6.0 mg), vitamin E (1.3 mg), vitamin K1 (14 μg), folate (60 mg), vitamin B-6 (0.2 mg), niacin (1.3 mg), pantothenic acid (1.0 mg), riboflavin (0.1 mg), choline (10 mg), lutein/zeaxanthin (185 μg), phytosterols (57 mg), and high-monounsaturated fatty acids (6.7 g) and 114 kcals or 1.7 kcal/g. The avocado oil consists of 71% monounsaturated fatty acids (MUFA), 13% polyunsaturated fatty acids (PUFA), and 16% saturated fatty acids (SFA), which helps to promote healthy blood lipid profiles and enhance the bioavailability of fat soluble vitamins and phytochemicals from the avocado or other fruits and vegetables, naturally low in fat, which are consumed with avocados. There are eight preliminary clinical studies showing that avocado consumption helps support cardiovascular health. Exploratory studies suggest that avocados may support weight management and healthy aging.

Exotic Fruits as Therapeutic Complements for Diabetes, Obesity and Metabolic Syndrome

The prevalence and severity of obesity, type 2-diabetes, and the resultant metabolic syndrome are rapidly increasing. As successful preventive and therapeutic strategies for these life-threatening health ailments often come with adverse side effects, nutritional elements are widely used in many countries as preventive therapies to prevent or manage metabolic syndrome. Fruits are important dietary components, and contain various bioactive constituents. Many of these constituents have been proven to be useful to manage and treat various chronic diseases such as diabetes, obesity, cancer and cardiovascular diseases. Although exotic fruits are understudied throughout the world due to their limited regional presence, many studies reveal their potent ability to ameliorate metabolic derangements and the resultant conditions i.e. diabetes and obesity. The aim of this article is to review the role of exotic fruits and their constituents in the regulation of metabolic functions, which can beneficially alter diabetes and obesity pathophysiology.

Obesity, weight loss and conditional cardiovascular risk factors

Obesity is a pathological condition aggregating a substantial number of proatherogenic factors, such as insulin resistance, type 2 diabetes mellitus, dyslipidaemia and hypertension. In addition to these classic cardiometabolic risk factors, atherosclerosis may be aggravated by other non-classic factors, which are characterized as conditional, including homocysteine, fibrinogen, lipoprotein(a), LDL particle size and high-sensitivity CRP. Some of these biomarkers are disturbed in obesity because of a combination of dietary factors, hypertrophic adipose tissue, low-grade inflammation, insulin resistance and other parameters under investigation. For the reduction of these risk factors, weight loss exceeding 10-20% of the initial body weight is probably necessary, achieved through either conventional lifestyle measures or more drastic interventions such as bariatric surgery. It has been shown that certain well-balanced diets, such as the Mediterranean diet, constitute a means of improving in a concerted manner the levels of CRP, fibrinogen, homocysteine and small dense LDL particles, regardless of weight loss. The significance of considering these factors in weight management intervention is an issue that needs further investigation.

Could the quality of dietary fat, and not just its quantity, be related to risk of obesity?

This review focuses on the possible association between types of fatty acids and weight change. It examines the biological plausibility underlining these associations and the evidence obtained to date from clinical trials and epidemiological studies. Animal studies have shown that dietary short- and medium-chain fatty acids compared to long-chain fatty acids appear to promote weight loss. Similarly, monounsaturated fatty acids (MUFAs) appear to favor weight loss compared to saturated fatty acids (SFAs) in human studies. The structure of fatty acids seems to affect their degree of oxidation and deposition. Although results are conflicting, human studies follow the general trend reported in animal studies. These trials suggest that some fatty acids are prone to oxidation and some others lead to fat storage when comparing isocaloric diets. For instance, n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic and docosahexaenoic acids are preferentially oxidizied to other PUFA but results remain inconsistent. Epidemiological studies concerning this issue reported that total dietary fat, which includes MUFA, PUFA, and SFA could increase the risk of obesity, but results are few and conflicting. The rising biological plausibility linking dietary fat quality and risk of obesity, together with the rather recent addition of fatty acids content in food composition tables, support the need for major epidemiological studies in that area.