Dietary Intake of Carotenoid-Rich Vegetables Reduces Visceral Adiposity in Obese Japanese men-A Randomized, Double-Blind Trial

An overview of the nutritional quality and health benefits linked to the world diversity of citrus fruits/juices

Citrus juices represent a nutrient-dense beverage due to the remarkable balance in their bioactive compounds (vitamins, minerals, dietary fibers, and phytochemicals such as flavonoids and carotenoids). This review aims to examine the nutritional quality and the health benefits of citrus juice consumption linked to the world diversity of citrus fruits. This work provides heterogenous data found on the main citrus bioactive compounds, especially carotenoids and flavonoids, which are difficult to correlate to particular geographic areas. Through an example of study, this work addresses the question of how and to what extent the content of citrus bioactive compounds is linked to the health benefits observed in humans. We explore through the more recent human clinical trials, the health effects of consuming citrus fruit or taking dietary supplements of bioactive compounds to prevent the exponential increase of world chronic diseases (type 2 diabetes, cardiovascular diseases, and obesity) and discuss the effects of dose. Finally, even if the data highlight the importance of geographical origin in accumulation of carotenoids or flavonoids from different Citrus species, the difference of content in front of the complex human metabolism of their absorption has lesser consequences for health than the fact of consuming citrus or not. The citrus health effect results in a synergistic action of numerous phytochemicals whose targeted health benefits vary depending more on the diversity of Citrus species than their geographic origin. Therefore, the use of the diversity of Citrus species could be an interesting approach to providing functional food.

An Overview on the Effects of Some Carotenoids on Health: Lutein and Zeaxanthin

PURPOSE OF REVIEW

In this review, the chemical properties, nutritional sources, absorption mechanisms, metabolism, biosynthesis and promising health-related benefits of lutein and zeaxanthin were emphasized and some recommendations for the future studies are suggested.

RECENT FINDINGS

Lutein and zeaxanthin are phytochemical compounds in the carotenoid group and are synthesised only by plants. All mammals get lutein and zeaxanthin into their bodies by consuming plant-based foods. Especially leafy green vegetables, broccoli, pumpkin, cabbage, spinach and egg yolk are rich in lutein and zeaxanthin. Lutein and zeaxanthin have potential health effects by preventing free radical formation, exhibiting protective properties against oxidative damage and reducing oxidative stress. These compounds have neuroprotective, cardioprotective, ophthalmological, antioxidant, anti-inflammatory, anti-cancer, anti-osteoporosis, anti-diabetic, anti-obesity, and antimicrobial effects. The preventive properties of lutein and zeaxanthin against numerous diseases have attracted attention recently. Further clinical trials with large samples are needed to make generalisations in the prevention and treatment of diseases and to determine the appropriate doses and forms of lutein and zeaxanthin.

Carotenoids Intake and Cardiovascular Prevention: A Systematic Review

Background: Cardiovascular diseases (CVDs) encompass a variety of conditions that affect the heart and blood vessels. Carotenoids, a group of fat-soluble organic pigments synthesized by plants, fungi, algae, and some bacteria, may have a beneficial effect in reducing cardiovascular disease (CVD) risk. This study aims to examine and synthesize current research on the relationship between carotenoids and CVDs. Methods: A systematic review was conducted using MEDLINE and the Cochrane Library to identify relevant studies on the efficacy of carotenoid supplementation for CVD prevention. Interventional analytical studies (randomized and non-randomized clinical trials) published in English from January 2011 to February 2024 were included. Results: A total of 38 studies were included in the qualitative analysis. Of these, 17 epidemiological studies assessed the relationship between carotenoids and CVDs, 9 examined the effect of carotenoid supplementation, and 12 evaluated dietary interventions. Conclusions: Elevated serum carotenoid levels are associated with reduced CVD risk factors and inflammatory markers. Increasing the consumption of carotenoid-rich foods appears to be more effective than supplementation, though the specific effects of individual carotenoids on CVD risk remain uncertain.

Nutritional Management of Dyslipidemia in Pakistan: A Systematic Review of International Guidelines and Practices

Objectives

Dyslipidemia and atherosclerotic cardiovascular events are highly prevalent in Pakistan, which could be attributed to a lack of education, poverty, unhealthy dietary habits, and the absence of local guidelines. Our main goal was to develop a comprehensive comparison of the existing international dyslipidemia guidelines, highlighting the different nutritional recommendations proposed by each. A secondary objective was to establish local food sources beneficial for dyslipidemia coexistent with other morbidities.

Methods

We conducted a systematic review of three databases Pubmed, Scopus, and International Guidelines Library to acquire guidelines for the management of dyslipidemia. The guidelines fulfilling the criteria of the Clinical Practice Guidelines developed by the Institute of Medicine in 2011 were selected for data extraction and their quality was assessed by the Mini-Checklist (MiChe) tool. Using the Harvard Healthy Eating Plate, a modified MyPlate describing portion of each macronutrient was established. Dietary recommendations for dyslipidemia and other comorbidity conditions were developed based on the review of guidelines and data from randomized control trials.

Results

A total of 23 guidelines were selected based on our inclusion criteria. Final guidelines presented dietary patterns beneficial for the management of dyslipidemia, which differed due to the availability and cost-effectiveness of nutritional sources in Pakistan. After developing a modified MyPlate better suited to the dietary intakes of the population of Pakistan, nutritional recommendations for dyslipidemia with other comorbids were developed using local sources suggested by practicing dietitians.

Conclusions

Dietary modification is the cornerstone of managing dyslipidemia. Due to Pakistan's unique dietary patterns and the economic condition, a multidisciplinary approach with physicians and dietitians is required to develop easily applicable dietary regimes for dyslipidemia.

Composite Dietary Antioxidant Index is inversely associated with visceral adipose tissue area among U.S. adults: A cross-sectional study

Obesity is becoming a global health problem. Visceral adiposity is the main cause of metabolic and cardiovascular diseases. Dietary improvement is the key to controlling obesity. We hypothesized that a higher Composite Dietary Antioxidant Index (CDAI) was associated with a lower visceral adipose tissue (VAT) area. In this cross-sectional study, 10,389 adults were selected from the National Health and Nutrition Examination Survey 2011-2018. CDAI was calculated based on 6 micronutrients: zinc, selenium, total carotenoids, vitamin A, vitamin C, and vitamin E. VAT area was determined by the dual-energy X-ray absorptiometry scan. Linear regression models were constructed to evaluate the association between CDAI and VAT area. Subgroup analyses were also performed. The mean age of participants was 39.68 years, 5240 were male, and 3841 of those were non-Hispanic White. The inverse associations were observed in all models. In model 3, CDAI was inversely associated with VAT area as a continuous variable, β (95% confidence interval), -0.56 (-0.85 to -0.27). When compared with the first tertile, the third tertile of CDAI was also inversely associated with VAT area, β (95% confidence interval), -6.72 (-10.44 to -2.99). No interactions were found in the subgroup analyses. In conclusion, an inverse association between CDAI and VAT area was found among U.S. adults aged 20 to 59 years. These results suggest the possible benefit of an antioxidant diet in relieving visceral obesity. More prospective studies are needed to identify this dietary benefit.

Associations of serum carotenoids with visceral adiposity index and lipid accumulation product: a cross-sectional study based on NHANES 2001-2006

BACKGROUND

Visceral adiposity index (VAI) and lipid accumulation product (LAP) are comprehensive indicators to evaluate visceral fat and determine the metabolic health of individuals. Carotenoids are a group of naturally occurring antioxidants associated with several diseases. The purpose of this investigation was to explore the association between serum carotenoid concentration and VAI or LAP.

METHODS

The data were obtained from the National Health and Nutrition Examination Survey between 2001 and 2006. The levels of serum carotenoids were evaluated using high-performance liquid chromatography. Multivariate linear regression models were employed to investigate the relationship between levels of serum carotenoids and VAI or LAP. The potential non-linear relationship was determined using threshold effect analysis and fitted smoothing curves. Stratification analysis was performed to investigate the potential modifying factors.

RESULTS

In total, 5,084 participants were included in this population-based investigation. In the multivariate linear regressions, compared to the lowest quartiles of serum carotenoids, the highest quartiles were significantly associated with VAI, and the effect size (β) and 95% CI was - 0.98 (- 1.34, - 0.62) for α-carotene, - 1.39 (- 1.77, - 1.00) for β-carotene, - 0.79 (- 1.18, - 0.41) for β-cryptoxanthin, - 0.68 (- 0.96, - 0.39) for lutein/zeaxanthin, and - 0.88 (- 1.50, - 0.27) for trans-lycopene. Using piece-wise linear regression models, non-linear relationships were found between β-carotene and trans-lycopene and VAI with an inflection point of 2.44 (log2-transformed, ug/dL) and 3.80 (log2-transformed, ug/dL), respectively. The results indicated that α-carotene, β-cryptoxanthin, and lutein/zeaxanthin were linearly associated with VAI. An inverse association was also found between serum carotenoids and LAP after complete adjustments.

CONCLUSION

This study revealed that several serum carotenoids were associated with VAI or LAP among the general American population. Further large prospective investigations are warranted to support this finding.

Review of Phytochemical Potency as a Natural Anti-Helicobacter pylori and Neuroprotective Agent

Phytochemicals are plant secondary metabolites that show health benefits for humans due to their bioactivity. There is a huge variety of phytochemicals that have already been identified, and these compounds can act as antimicrobial and neuroprotection agents. Due to their anti-microbial activity and neuroprotection, several phytochemicals might have the potency to be used as natural therapeutic agents, especially for Helicobacter pylori infection and neurodegenerative disease, which have become a global health concern nowadays. According to previous research, there are some connections between H. pylori infection and neurodegenerative diseases, especially Alzheimer's disease. Hence, this comprehensive review examines different kinds of phytochemicals from natural sources as potential therapeutic agents to reduce H. pylori infection and improve neurodegenerative disease. An additional large-scale study is needed to establish the connection between H. pylori infection and neurodegenerative disease and how phytochemicals could improve this condition.

Longitudinal Associations of Healthy Dietary Pattern Scores with Coronary Artery Calcification and Pericardial Adiposity in United States Adults with and without Type 1 Diabetes

BACKGROUND

Pericardial adipose tissue volume (PAT) and coronary artery calcification (CAC) are prognostic indicators for future cardiovascular events; however, no studies have assessed the long-term associations of adherence to dietary patterns (DPs) with PAT and CAC in adults with and without type 1 diabetes (T1D).

OBJECTIVES

We investigated the longitudinal associations of the Mediterranean Diet (MedDiet) and Dietary Approaches to Stop Hypertension (DASH) diet with PAT and CAC progression in adults with and without T1D.

METHODS

The Coronary Artery Calcification in Type 1 Diabetes (CACTI) study is a population-based, prospective study of 652 T1D and 764 nondiabetic mellitus (nonDM) (19-56 y) participants that began in 2000-2002 with follow-up visits in 2003-2004 and 2006-2007. At each visit, food frequency questionnaires were collected and used to develop adherence scores for the MedDiet and DASH diets. PAT and CAC were measured at each visit using electron beam computed tomography. CAC progression was defined as a ≥2.5 mm square root-transformed volume. Mixed effect models were used to conduct statistical analyses.

RESULTS

Combined models found a significant-0.09 cm3 (95% CI: -0.14, -0.03; P = 0.0027) inverse association in PAT for every 1-point increase in the MedDiet score and a significant-0.26 cm3 (95% CI: -0.38, -0.14; P < 0.0001) inverse association in PAT for every 1-point increase in the DASH score. In combined models, the DPs were not significantly associated with lower odds of CAC progression; however, both DPs had significant interactions by diabetes status for CAC. Only the DASH diet was associated with lower odds of CAC progression in the nonDM group (OR: 0.96; 95% CI: 0.93, 0.99; P = 0.0224).

CONCLUSIONS

These data suggest that the DPs are associated with lower PAT, which may reduce future cardiovascular events. The DASH diet may be beneficial for lower odds of CAC progression in those without T1D.

Effect of Lycopene Intake on the Fasting Blood Glucose Level: A Systematic Review with Meta-Analysis

Lycopene is a lipophilic unsaturated carotenoid exhibiting a strong singlet oxygen-quenching ability. Herein, we investigated the effect of lycopene intake on the fasting blood glucose (FBG) level by conducting a systematic review and meta-analyses. We searched 15 databases (from the earliest date to June 2022 for PubMed or to August or September 2018 for the other databases) and included human interventional studies that assessed the effects of oral lycopene intake on FBG levels of participants ≥ 18 years of age. Three authors independently selected applicable studies and then assessed the study quality. Data were pooled as standardized mean difference (SMD) and analyzed by the random-effects model. Heterogeneity was assessed by I² statistics. A meta-analysis including 11 trial arms (n = 750) revealed a tendency towards a significant decrease in FBG level with not-important heterogeneity [SMD = -0.15 (95% CI: -0.31, 0.00), p = 0.05, I² = 9%]. Subgroup meta-analysis including two studies (n = 152) in type 2 diabetes patients revealed significantly decreased FBG levels with not-important heterogeneity [SMD = -0.37 (95% CI: -0.69, -0.05), p = 0.02, I² = 0%]. Most studies meeting the eligibility criteria had a moderate risk of bias. The funnel plot for FBG suggested an absence of publication bias. In conclusion, this systematic review and meta-analyses suggested that lycopene intake exerted an FBG-decreasing effect.

Carotenoids in orange carrots mitigate non-alcoholic fatty liver disease progression

Background

Carotenoids are abundant in colored fruits and vegetables. Non-alcoholic fatty liver disease (NAFLD) is a global burden and risk factor for end-stage hepatic diseases. This study aims to compare the anti-NAFLD efficacy between carotenoid-rich and carotenoid-deficient vegetables.

Materials and methods

Male C57BL/6J mice were randomized to one of four experimental diets for 15 weeks (n = 12 animals/group): Low-fat diet (LFD, 10% calories from fat), high-fat diet (HFD, 60% calories from fat), HFD with 20% white carrot powders (HFD + WC), or with 20% orange carrot powders (HFD + OC).

Results

We observed that carotenoids in the orange carrots reduced HFD-induced weight gain, better than white carrots. Histological and triglyceride (TG) analyses revealed significantly decreased HFD-induced hepatic lipid deposition and TG content in the HFD + WC group, which was further reduced in the HFD + OC group. Western blot analysis demonstrated inconsistent changes of fatty acid synthesis-related proteins but significantly improved ACOX-1 and CPT-II, indicating that orange carrot carotenoids had the potential to inhibit NAFLD by improving β-oxidation. Further investigation showed significantly higher mRNA and protein levels of PPARα and its transcription factor activity.

Conclusion

Carotenoid-rich foods may display more potent efficacy in mitigating NAFLD than those with low carotenoid levels.

Carotenoid fates in plant foods: Chemical changes from farm to table and nutrition

Carotenoids in plant foods are sources of pro-vitamin A and nutrients with several health benefits, including antioxidant and anticancer activities. However, humans cannot synthesize carotenoids de novo and must obtain them from the diet, typically via plant foods. We review the chemical changes of carotenoids in plant foods from farm to table and nutrition, including nutrient release and degradation during processing and metabolism in vivo. We also describe the influencing factors and proposals corresponding to enhancing the release, retention and utilization of carotenoids, thus benefiting human health. Processing methods influence the release and degradation of carotenoids, and nonthermal processing may optimize processing effects. The carotenoid profile, food matrix, and body status influence the digestion, absorption, and biotransformation of carotenoids in vivo; food design (diet and carotenoid delivery systems) can increase the bioavailability levels of carotenoids in the human body. In this review, the dynamic fate of carotenoids in plant foods is summarized systematically and deeply, focusing on changes in their chemical structure; identifying critical control points and influencing factors to facilitate carotenoid regulation; and suggesting multi-dimensional strategies based on the current state of food processing industries to achieve health benefits for consumers.

The role of diet in renal cell carcinoma incidence: an umbrella review of meta-analyses of observational studies

BACKGROUND

Evidence associating diet with the incidence of renal cell carcinoma (RCC) is inconclusive. We aimed to summarize evidence associating dietary factors with RCC incidence and assess the strength and validity of this evidence.

METHODS

We conducted an umbrella review of systematic reviews or meta-analyses (SRoMAs) that assessed the association between diet and RCC incidence. Through April 2021, PubMed, Web of Science, Embase, The Cochrane Library, Scopus, and WCRF were searched. Two independent reviewers selected studies, extracted data, and appraised the quality of SRoMAs. According to credibility assessment criteria, evidence can be divided into five categories: convincing (class I), highly suggestive (class II), suggestive (class III), weak (class IV), and nonsignificant (class V).

RESULTS

Twenty-nine meta-analyses were obtained after screening. After excluding 7 overlapping meta-analyses, 22 meta-analyses including 502 individual studies and 64 summary hazard ratios for RCC incidence were included: dietary patterns or dietary quality indices (n = 6), foods (n = 13), beverages (n = 4), alcohol (n = 7), macronutrients (n =15), and micronutrients (n =19). No meta-analyses had high methodological quality. Five meta-analyses exhibited small study effects; one meta-analysis showed evidence of excess significance bias. No dietary factors showed convincing or highly suggestive evidence of association with RCC in the overall analysis. Two protective factors had suggestive evidence (vegetables (0.74, 95% confidence interval 0.63 to 0.86) and vitamin C (0.77, 0.66 to 0.90)) in overall analysis. One protective factor had convincing evidence (moderate drinking (0.77, 0.70 to 0.84)) in Europe and North America and one protective factor had highly suggestive evidence (cruciferous vegetables (0.78, 0.70 to 0.86)) in North America.

CONCLUSIONS

Although many meta-analyses have assessed associations between dietary factors and RCC, no high-quality evidence exists (classes I and II) in the overall analysis. Increased intake of vegetables and vitamin C is negatively associated with RCC risk. Moderate drinking might be beneficial for Europeans and North Americans, and cruciferous vegetables might be beneficial to North Americans, but the results should be interpreted with caution. More researches are needed in the future.

TRIAL REGISTRATION

PROSPERO CRD42021246619.

Preventive Effects of β-Cryptoxanthin, a Potent Antioxidant and Provitamin A Carotenoid, on Lifestyle-Related Diseases-A Central Focus on Its Effects on Non-Alcoholic Fatty Liver Disease (NAFLD)

Humans usually get dietary carotenoids from foods such as green and yellow vegetables and algae. Carotenoids have been reported to effectively reduce the risk of developing lifestyle-related diseases. β-Cryptoxanthin, which is an antioxidative carotenoid and a type of provitamin A, is metabolically converted to vitamin A. β-Cryptoxanthin has recently gained attention for its risk-reducing effects on lifestyle-related diseases, especially on non-alcoholic fatty liver disease (NAFLD), from epidemiological, interventional, and mechanistic studies. Retinoids (vitamin A) have also been reported to be useful as a therapeutic agent for NAFLD. Provitamin A is known to serve as a supply source of retinoids through metabolic conversion by the regulated activity of β-carotene 15,15′-monooxygenase 1 (BCMO1) to the retina only when retinoids are deficient. From mechanistic studies using NAFLD-model mice, β-cryptoxanthin has been shown to contribute to the improvement of NAFLD through a multifaceted approach, including improved insulin resistance, suppression of oxidative stress and inflammation, a reduction of macrophages and a shift of their subsets, and control of lipid metabolism by peroxisome proliferator-activated receptor (PPAR) family activation, which are also expected to have clinical applications. β-Cryptoxanthin has the potential to prevent lifestyle-related diseases from different angles, not only as an antioxidant but also as a retinoid precursor.

Spinach consumption and nonalcoholic fatty liver disease among adults: a case-control study

BACKGROUND

Spinach has high antioxidants and polyphenols and showed protective effects against liver diseases in experimental studies. We aimed to assess the association between dietary intake of spinach and odds of nonalcoholic fatty liver disease (NAFLD) in a case-control study among Iranian adults.

METHODS

Totally 225 newly diagnosed NAFLD patients and 450 controls, aged 20-60 years, were recruited in this study. Participants' dietary intakes were collected using a valid and reliable 168-item semi-quantitative food frequency questionnaire (FFQ). The logistic regression test was used for assessing the association between total, raw, and boiled dietary spinach with the odds of NAFLD.

RESULTS

The mean (SD) age and BMI of participants (53% male) were 38.1 (8.8) years and 26.8 (4.3) kg/m², respectively. In the final adjusted model for potential confounders, the odds (95% CI) of NAFLD in individuals in the highest tertile of daily total and raw spinach intake was [0.36 (0.19-0.71), P_trend = 0.001] and [0.47 (0.24-0.89), P_trend = 0.008], respectively compared with those in the lowest tertile. Furthermore, in the adjusted analyses, an inverse association was observed between the highest yearly intake versus no raw spinach consumption and odds of NAFLD [(OR 0.41; 95% CI 0.18-0.96), P for trend = 0.013]. However, there was no significant association between higher boiled spinach intake and odds of NAFLD.

CONCLUSIONS

The present study found an inverse association between total and raw spinach intake with the odds of NAFLD.

Association between Serum Concentration of Carotenoid and Visceral Fat

Consumption of fruits and vegetables rich in carotenoids has been widely reported to prevent cardiovascular diseases. However, the relationship between serum carotenoid concentrations and visceral fat area (VFA), which is considered a better predictor of cardiovascular diseases than the body-mass index (BMI) and waist circumference, remains unclear. Therefore, we examined the relationship in healthy individuals in their 20s or older, stratified by sex and age, to compare the relationship between serum carotenoid concentrations and VFA and BMI. The study was conducted on 805 people, the residents in Hirosaki city, Aomori prefecture, who underwent a health checkup. An inverse relationship between serum carotenoid concentrations and VFA and BMI was observed only in women. In addition, the results were independent of the intake of dietary fiber, which is mainly supplied from vegetables as well as carotenoids. This suggests that consumption of a diet rich in carotenoids (especially lutein and beta-carotene) is associated with lower VFA, which is a good predictor of cardiovascular disease, especially in women. This study is the first to comprehensively evaluate the association between serum carotenoid levels and VFA in healthy individuals.

Fruits and Vegetables in the Management of Underlying Conditions for COVID-19 High-Risk Groups

SARS-CoV-2 or COVID-19 is a novel coronavirus, which is the cause of the current pandemic with 107,411,561 infections and 2,351,195 death worldwide so far. There are multiple symptoms that are linked with the infection of COVID-19 such as coughing, shortness of breath, congestion together with fatigue, fever, loss of taste or smell, headaches, diarrhea, vomiting, and loss of appetite. The lack of or early stage of development of a cure for COVID-19 illness, there is need for insuring the best possible position of health to be able to fight the virus naturally through a robust immune system to limit severe complication. In this article, we have discussed the role of fruits and vegetables consumption to boost the immune system and major emphasis has been given to high risk group. We have taken into consideration a number of underlying conditions such as people with cardiovascular diseases, obesity, diabetes, chronic obstructive pulmonary disease, chronic kidney disease, hemoglobin disorder such as sickle cell disease, weakened immune system due to organ transplant. Furthermore, factors to improve the immune system, risks associated with quarantine and lifestyle and food handling during COVID-19 has been discussed.