Comparing an olive oil-enriched diet to a standard lower-fat diet for weight loss in breast cancer survivors: a pilot study

Is Extra Virgin Olive Oil the Critical Ingredient Driving the Health Benefits of a Mediterranean Diet? A Narrative Review

Most chronic diseases are preventable with a healthy diet, although there is debate about the optimal dietary approach. Increasingly more countries are focusing on food-based guidelines rather than the traditional nutrient-based approach. Although there is good agreement on plant foods, controversy remains about the types and amounts of fats and oils. This narrative review aims to systematically summarize and evaluate the latest evidence on the protective effects of extra virgin olive oil (EVOO) on disease risk factors. A systematic search of the relevant literature using PubMed, Cochrane Library, and Embase databases was conducted for the years 2000 through December 2022. A narrative synthesis was then undertaken. Of 281 retrieved articles, 34 articles fulfilled our inclusion criteria and were included. Compared with other dietary fats and low-fat diets, EVOO is superior in the management of clinical biomarkers including lowering blood pressure and LDL-c, increasing protective HDL-c, improving glycemic control, and weight management. The protective effects of EVOO are likely due to its polyphenol content rather than the monounsaturated fat content. It is therefore important to promote the regular use of EVOO in the context of healthy dietary patterns such as the Mediterranean diet for maximal health benefit.

Benefits of Dietary Management in Breast Cancer Patients: A Systematic Review and Meta-Analysis

The World Cancer Research Fund/American Institute of Cancer Research recommendations include guidance on diet, nutrition, and weight management for people with cancer. However, for women diagnosed with breast cancer there is a lack of comprehensive analyses on the effects of dietary interventions. The purpose of this study was to investigate the impact of changes in dietary behavior and body composition on breast cancer development. A comprehensive and systematic literature search of 12 electronic databases was undertaken on January 27, 2021 to identify randomized controlled trials (RCTs) of dietary interventions for breast cancer. The Cochrane risk bias assessment tool was used to evaluate the quality of the trials identified with the data analyzed by Review Manager 5.3 software. The results showed that dietary interventions probably did not modify servings of fruit (P = 0.08), fat intake (P = 0.10), total cholesterol level (P = 0.82), body weight (P = 0.08), waist circumference (P = 0.15), or waist-to-hip ratio (P = 0.32). However, a significant reduction in body mass index (P = 0.03), and hip circumference (P = 0.03), and improvement in energy intake (P = 0.02), vegetable servings (P < 0.0001), and fiber intake (P < 0.00001) were observed. Future studies should investigate the benefits of exercise in combination with dietary interventions in breast cancer patients.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1957129.

The effect of extra virgin olive oil on anthropometric indices, lipid profile, and markers of oxidative stress and inflammation in patients with depression, a double-blind randomised controlled trial

BACKGROUND

Epidemiological evidence suggests a mutual association between depression and obesity and also an anti-obesity effect for olive oil. We examined the effect of extra virgin olive oil (EVOO) on weight, waist circumference, and a number of cardiovascular risk factors in patients with depression.

METHODS

The randomised double-blind controlled trial was conducted on 62 patients with depression. Patients were randomly allocated to EVOO and sunflower oil groups (n = 31 for each) that consumed 25 mL/day of the corresponding oils for 52 days. An isocaloric diet was prescribed to each patient according to his/her previous energy intake with considering the energy provided by the administered oils. Weight, body mass index (BMI), waist circumference, blood lipids, malondialdehyde, and hs-C reactive protein (CRP) analysis were performed using the intention-to-treat approach.

RESULTS

BMI was significantly decreased in sunflower oil group (-0.20 ± 0.53 kg/m² , P = .047) and waist circumference was significantly decreased in EVOO group (-2.15 ± 2.09 cm, P < .001); however, only reduction of waist circumference was significantly different between groups (P < .001). High-density lipoprotein (HDL) cholesterol was significantly increased in EVOO group (3.02 ± 6.79 mg/dL, P = .03), without showing a significant between-group difference. Other lipids, malondialdehyde, and hs-CRP did not change.

CONCLUSION

Overall, the results suggest that both EVOO and sunflower oil may benefit overweight patients with depression, as they respectively decreased waist circumference and BMI without need for administration of a low-calorie diet.

Optimising weight-loss interventions in cancer patients-A systematic review and network meta-analysis

Background

Excess weight has been associated with increased morbidity and a worse prognosis in adult patients with early-stage cancer. The optimal lifestyle interventions to optimize anthropometric measures amongst cancer patients and survivors remain inconsistent.

Objective

To conduct a systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing the effects of exercise and dietary interventions alone or in combination on anthropometric measures of adult cancer patients and survivors.

Methods

A systematic search of Medline, Embase and the Cochrane Trials Registry was performed. Outcomes of interest included changes in weight, body mass index (BMI), and waist circumference. Screening and data collection were performed by two reviewers. Bayesian NMAs were performed.

Results

Overall, 98 RCTs were included; 75 were incorporated in NMAs (n = 12,199). Groups of intervention strategies included: 3 exercise interventions, 8 dietary interventions, 7 combination interventions of diet and exercise and standard care. Median intervention duration was 26 weeks. NMA suggested that diet alone (mean difference [MD] -2.25kg, 95% CrI -3.43 to -0.91kg) and combination strategies (MD -2.52kg, 95% CrI -3.54 to -1.62kg) were associated with more weight loss compared to standard care. All dietary interventions achieved a similar magnitude of weight loss (MD range from -2.03kg to -2.52kg). Both diet alone and combination strategies demonstrated greater BMI reductions versus standard care, and each of diet alone, exercise alone and combination strategies demonstrated greater reductions in waist circumference than standard care.

Conclusion

Diet and exercise alone or in combination are effective lifestyle interventions to improve anthropometric measures in cancer patients and survivors. All reputable diets appear to be similarly effective to achieve weight loss.

Dietary interventions for adult cancer survivors

BACKGROUND

International dietary recommendations include guidance on healthy eating and weight management for people who have survived cancer; however dietary interventions are not provided routinely for people living beyond cancer.

OBJECTIVES

To assess the effects of dietary interventions for adult cancer survivors on morbidity and mortality, changes in dietary behaviour, body composition, health-related quality of life, and clinical measurements.

SEARCH METHODS

We ran searches on 18 September 2019 and searched the Cochrane Central Register of Controlled trials (CENTRAL), in the Cochrane Library; MEDLINE via Ovid; Embase via Ovid; the Allied and Complementary Medicine Database (AMED); the Cumulative Index to Nursing and Allied Health Literature (CINAHL); and the Database of Abstracts of Reviews of Effects (DARE). We searched other resources including reference lists of retrieved articles, other reviews on the topic, the International Trials Registry for ongoing trials, metaRegister, Physicians Data Query, and appropriate websites for ongoing trials. We searched conference abstracts and WorldCat for dissertations.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that recruited people following a cancer diagnosis. The intervention was any dietary advice provided by any method including group sessions, telephone instruction, written materials, or a web-based approach. We included comparisons that could be usual care or written information, and outcomes measured included overall survival, morbidities, secondary malignancies, dietary changes, anthropometry, quality of life (QoL), and biochemistry.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Two people independently assessed titles and full-text articles, extracted data, and assessed risk of bias. For analysis, we used a random-effects statistical model for all meta-analyses, and the GRADE approach to rate the certainty of evidence, considering limitations, indirectness, inconsistencies, imprecision, and bias.

MAIN RESULTS

We included 25 RCTs involving 7259 participants including 977 (13.5%) men and 6282 (86.5%) women. Mean age reported ranged from 52.6 to 71 years, and range of age of included participants was 23 to 85 years. The trials reported 27 comparisons and included participants who had survived breast cancer (17 trials), colorectal cancer (2 trials), gynaecological cancer (1 trial), and cancer at mixed sites (5 trials). For overall survival, dietary intervention and control groups showed little or no difference in risk of mortality (hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.77 to 1.23; 1 study; 3107 participants; low-certainty evidence). For secondary malignancies, dietary interventions versus control trials reported little or no difference (risk ratio (RR) 0.99, 95% CI 0.84 to 1.15; 1 study; 3107 participants; low-certainty evidence). Co-morbidities were not measured in any included trials. Subsequent outcomes reported after 12 months found that dietary interventions versus control probably make little or no difference in energy intake at 12 months (mean difference (MD) -59.13 kcal, 95% CI -159.05 to 37.79; 5 studies; 3283 participants; moderate-certainty evidence). Dietary interventions versus control probably led to slight increases in fruit and vegetable servings (MD 0.41 servings, 95% CI 0.10 to 0.71; 5 studies; 834 participants; moderate-certainty evidence); mixed results for fibre intake overall (MD 5.12 g, 95% CI 0.66 to 10.9; 2 studies; 3127 participants; very low-certainty evidence); and likely improvement in Diet Quality Index (MD 3.46, 95% CI 1.54 to 5.38; 747 participants; moderate-certainty evidence). For anthropometry, dietary intervention versus control probably led to a slightly decreased body mass index (BMI) (MD -0.79 kg/m², 95% CI -1.50 to -0.07; 4 studies; 777 participants; moderate-certainty evidence). Dietary interventions versus control probably had little or no effect on waist-to-hip ratio (MD -0.01, 95% CI -0.04 to 0.02; 2 studies; 106 participants; low-certainty evidence). For QoL, there were mixed results; several different quality assessment tools were used and evidence was of low to very low-certainty. No adverse events were reported in any of the included studies.

AUTHORS' CONCLUSIONS

Evidence demonstrated little effects of dietary interventions on overall mortality and secondary cancers. For comorbidities, no evidence was identified. For nutritional outcomes, there was probably little or no effect on energy intake, although probably a slight increase in fruit and vegetable intake and Diet Quality Index. Results were mixed for fibre. For anthropometry, there was probably a slight decrease in body mass index (BMI) but probably little or no effect on waist-to-hip ratio. For QoL, results were highly varied. Additional high-quality research is needed to examine the effects of dietary interventions for different cancer sites, and to evaluate important outcomes including comorbidities and body composition. Evidence on new technologies used to deliver dietary interventions was limited.

Preparation of a Natural Candy from Date (Phoenix dactyliferaL.), Olive (Olea europaeaL.), and Carob (Ceratonia siliquaL.) Fruits

Until the early 1960s, the traditional recipe “Arkouy” from the mixture of carob (Ceratonia siliquaL.) powder and olive (Olea europaeaL.) oil represented a sought-after food product in some localities of the Kabylian region (Northeastern Algeria). The present work attempted to improve this traditional recipe to obtain a natural candy from date (Phoenix dactyliferaL.), olive (Olea europaeaL.), and carob (Ceratonia siliquaL.) fruits. For this, different formulations with various proportions of the date paste, olive paste, and carob powder were obtained using a constrained mixture design (proportion of date paste ≥ 0.7). The hardness and total color difference in the CIELab system were adopted as dependent variables. For comparison purpose, the local commercial candy “Caprice” was taken as reference. In addition, the two formulations containing the three basic ingredients were analyzed for the overall acceptability, reducing power, and thermal analysis. At first approximation, it can be said that the formulation containing 75% date paste, 20% carob powder, and 5% olive paste ensures a balance between the target values of texture and color. The obtained candy can be used as a dietary supplement for all categories of consumers, especially patients with swallowing difficulties.

Olive oil lessened fatty liver severity independent of cardiometabolic correction in patients with non-alcoholic fatty liver disease: A randomized clinical trial

OBJECTIVES

Olive oil has health benefits for the correction of metabolic diseases. We aimed to evaluate the effect of olive oil consumption on the severity of fatty liver and cardiometabolic markers in patients with non-alcoholic fatty liver disease.

METHODS

This randomized, double-blind, clinical trial was conducted on 66 patients with non-alcoholic fatty liver disease. Patients were divided to receive either olive or sunflower oil, each 20 g/d for 12 wk. A hypocaloric diet (-500 kcal/d) was recommended to all participants. Fatty liver grade, liver enzymes, anthropometric parameters, blood pressure, serum lipid profile, glucose, insulin, malondialdehyde, total antioxidant capacity, and interleukin-6 were assessed pre- and postintervention.

RESULTS

Fatty liver grade, weight, waist circumference, and blood pressure significantly decreased in both groups. Sunflower oil significantly reduced serum aspartate and alanine aminotransferases and olive oil only decreased serum aspartate aminotransferase. Fat-free mass and skeletal muscle mass significantly reduced after the consumption of sunflower oil and serum triacylglycerols and fat mass significantly declined after the ingestion of olive oil. Among these variables, only changes in fatty liver grade (-0.29 ± 0.46 in sunflower oil versus -0.75 ± 0.45 in olive oil; P < 0.001), skeletal muscle mass (-0.71 ± 1.36 in sunflower oil versus +0.45 ± 2.8 in olive oil; P = 0.04), and body fat percentage (+0.38 ± 5.2% in sunflower oil versus -3.4 ± 5.5% in olive oil; P = 0.04) were significantly different between the groups.

CONCLUSIONS

Olive oil may alleviate the severity of fatty liver independent of correcting cardiometabolic risk factors. Low-calorie diets may benefit patients with non-alcoholic fatty liver disease additionally through mitigation of obesity, blood pressure, and liver enzymes.

Effects of Olive Oil Phenolic Compounds on Inflammation in the Prevention and Treatment of Coronary Artery Disease

Coronary artery disease (CAD) is responsible for more than 7 million deaths worldwide. In the early stages of the development of atherosclerotic plaques, cardiovascular risk factors stimulate vascular endothelial cells, initiating an inflammatory process, fundamental in the pathogenesis of CAD. The inclusion of potentially cardioprotective foods, such as olive oil, to the diet, may aid in the control of these risk factors, and in the reduction of cytokines and inflammatory markers. The present review aims to address the interaction between phenolic compounds present in olive oil, and inflammation, in the prevention and treatment of CAD. In vitro and in vivo studies suggest that phenolic compounds, such as hydroxytyrosol, tyrosol, and their secoiridoid derivatives, may reduce the expression of adhesion molecules and consequent migration of immune cells, modify the signaling cascade and the transcription network (blocking the signal and expression of the nuclear factor kappa B), inhibit the action of enzymes responsible for the production of eicosanoids, and consequently, decrease circulating levels of inflammatory markers. Daily consumption of olive oil seems to modulate cytokines and inflammatory markers related to CAD in individuals at risk for cardiovascular diseases. However, clinical studies that have evaluated the effects of olive oil and its phenolic compounds on individuals with CAD are still scarce.

Toward the optimal strategy for sustained weight loss in overweight cancer survivors: a systematic review of the literature

PURPOSE

To gain more insight into the optimal strategy to achieve weight loss and weight loss maintenance in overweight and obese cancer survivors after completion of initial treatment, this systematic review aimed to provide an overview of the literature on intervention effects on weight, to describe intervention components used in effective interventions, to identify and synthesize behaviour change techniques (BCTs) and to assess the frequency with which these BCTs were used in effective interventions.

METHODS

Six databases were searched for original research articles describing weight changes in adult overweight cancer survivors after participation in a lifestyle intervention initiated after completion of initial treatment. Two researchers independently screened the retrieved papers and extracted BCTs using the BCT Taxonomy version 1.

RESULTS

Thirty-two papers describing 27 interventions were included. Interventions that were evaluated with a robust study design (n = 8) generally showed <5% weight loss and did not evaluate effects at ≥12 months after intervention completion. Effective interventions promoted both diet and physical activity and used the BCTs 'goal setting (behaviour)', 'action planning', 'social support (unspecified)' and 'instruction on how to perform the behaviour'.

CONCLUSIONS

The results of this first review on intervention components of effective interventions could be used to inform intervention development and showed a need for future publications to report long-term effects, a detailed intervention description and an extensive process evaluation.

IMPLICATIONS FOR CANCER SURVIVORS

This study contributed to increasing knowledge on the optimal strategy to achieve weight loss, which is recommended for overweight cancer survivors to improve health outcomes.

Antiurolithic effect of olive oil in a mouse model of ethylene glycol-induced urolithiasis

Purpose

At present, commercially available antiurolithic drugs have more adverse effects than potential therapeutic or preventive effects with chronic use. With this in mind, the present study was designed to assess the antiurolithic effect of olive oil in a mouse model of ethylene glycol (EG)-induced urolithiasis.

Materials and Methods

Adult albino mice were divided into 6 groups. Group I was fed the vehicle only. Group II was supplemented with 0.75% EG alone in drinking water during the experimental period to initiate deposition of calcium oxalate in kidneys, which leads to urolithiasis in animals. Groups III (olive oil control group) through V were fed olive oil orally at various doses during the experimental period. Group VI received cystone (750 mg/kg). Groups IV–VI additionally received 0.75% EG in drinking water ad libitum. SPSS ver.17.0 was used for statistical analysis.

Results

The study results showed significantly higher levels of serum urea, uric acid, and creatinine (p<0.05) in group II than in groups III–VI and I. Administration of olive oil at different doses restored the elevated serum parameters in groups IV and V compared with group II. Urine and kidney calcium, oxalate, and phosphate levels in groups IV–VI were significantly lower (p<0.05) than in animals with EG-induced urolithiasis (group II). Group V mice showed a significant restoration effect on serum as well as urine and kidney parameters compared with group II.

Conclusions

Supplementation with olive oil (1.7 mL/kg body weight) reduced and prevented the growth of urinary stones, possibly by inhibiting renal tubular membrane damage due to peroxidative stress induced by hyperoxaluria.

Effects of Olive Oil on Markers of Inflammation and Endothelial Function-A Systematic Review and Meta-Analysis

The aim of the present systematic review was to synthesize data from randomized controlled trials investigating the effects of olive oil on markers of inflammation or endothelial function. Literature search in electronic databases Cochrane Trial Register, EMBASE, and MEDLINE was performed. Thirty studies enrolling 3106 participants fulfilled the selection criteria. Pooled effects of different interventions were assessed as mean difference using a random effects model. Olive oil interventions (with daily consumption ranging approximately between 1 mg and 50 mg) resulted in a significantly more pronounced decrease in C-reactive protein (mean difference: −0.64 mg/L, (95% confidence interval (CI) −0.96 to −0.31), p < 0.0001, n = 15 trials) and interleukin-6 (mean difference: −0.29 (95% CI −0.7 to −0.02), p < 0.04, n = 7 trials) as compared to controls, respectively. Values of flow-mediated dilatation (given as absolute percentage) were significantly more increased in individuals subjected to olive oil interventions (mean difference: 0.76% (95% CI 0.27 to 1.24), p < 0.002, n = 8 trials). These results provide evidence that olive oil might exert beneficial effects on endothelial function as well as markers of inflammation and endothelial function, thus representing a key ingredient contributing to the cardiovascular-protective effects of a Mediterranean diet. However, due to the heterogeneous study designs (e.g., olive oil given as a supplement or as part of dietary pattern, variations in control diets), a conservative interpretation of the results is necessary.

Effect of Olea oleaster and Juniperus procera leaves extracts on thioacetamide induced hepatic cirrhosis in male albino mice

The effect of Olea oleaster and Juniperus procera leaves extracts and their combination on thioacetamide (TAA)-induced hepatic cirrhosis were investigated in male albino mice. One hundred sixty mice were used in this study and were randomly distributed into eight groups of 20 each. Mice of group 1 served as controls. Mice of group 2 were treated with TAA. Mice of group 3 were exposed to TAA and supplemented with O. oleaster leaves extracts. Mice of group 4 were treated with TAA and supplemented with J. procera leaves extracts. Mice of group 5 were subjected to TAA and supplemented with O. oleaster and J. procera leaves extracts. Mice of groups 6, 7 and 8 were supplemented with O. oleaster, J. procera, and O. oleaster and J. procera leaves extracts respectively. Administration of TAA for six and twelve weeks resulted in a decline in body weight gain and increased the levels of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and total bilirubin. Histopathological evaluations of hepatic sections from mice treated with TAA showed severe alterations including increase of fibrogenesis processes with structural damage. Treatment of mice with these extracts showed a pronounced attenuation in TAA induced hepatic cirrhosis associated with physiological and histopathological alterations. Finally, this study suggests that the supplementation of these extracts may act as antioxidant agents and could be an excellent adjuvant support in the therapy of hepatic cirrhosis.

Weight Loss Intervention for Breast Cancer Survivors: A Systematic Review

To determine the effectiveness of weight loss intervention for breast cancer survivors. From October 2012 until March 2013, Pubmed was searched for weight loss intervention trials that reported body weight or weight loss as a primary outcome. Fifteen of these studies are included in this review. Of the 15 studies included, 14 resulted in statistically significant weight loss and 10 obtained clinically meaningful weight loss of ≥5 % from baseline. Evidence was provided of the feasibility of using several methods of weight loss intervention (telephone, in person, individual, group). Successful intervention used a comprehensive approach, with dietary, physical activity, and behavior modification components. Weight loss improved cardiovascular risk factors and markers of glucose homeostasis. However, there is insufficient evidence to identify the components of this intervention that led to successful weight loss, or to determine the weight loss necessary to affect biomarkers linked to breast cancer prognosis. The small number of randomized controlled trials shared several limitations, including small study sample sizes and lack of follow-up beyond 6 months. Intervention with longer follow-up revealed weight regain, showing the importance of considering strategies to promote long-term weight maintenance. Weight loss intervention for breast cancer survivors can lead to statistically significant and clinically meaningful weight loss, but the limited number of interventional studies, small sample sizes, and short duration of follow-up in many studies limit our ability to draw conclusions regarding the most efficacious weight-loss intervention after a breast cancer diagnosis. The findings to date are encouraging, but research on the effect of weight loss on breast cancer recurrence and mortality, and on prevention of weight gain for women newly diagnosed with breast cancer, is needed.