100 % Fruit juice and measures of glucose control and insulin sensitivity: a systematic review and meta-analysis of randomised controlled trials

Whole Fruits Versus 100% Fruit Juice: Revisiting the Evidence and Its Implications for US Healthy Dietary Recommendations

Scientific literature remains inconsistent on whether and to what extent 100% fruit juice should be recommended in the diet. Specifically, the current Dietary Guidelines for Americans (DGA) do not specifically refer to free sugars in fruit juice, and further clarification to provide more explicit guidance may be needed in the 2025-2030 version. We compared evidence on whole fruit and 100% fruit juice regarding its nutrient composition, impact on hunger and satiety, and association with chronic health conditions while highlighting the potential public health perspectives and implications for healthy dietary recommendations. Processing and/or storing 100% fruit juice reduces its fibre, vitamins and other antioxidant contents and transforms intrinsic sugars in the whole fruit into free sugars. Fruit consumed in solid form provides greater satiety due to delayed gastric emptying and related physiological reactions. The synergistic effects of polyphenols and fibre in whole fruit benefit the gut microbiome by acting as prebiotics and producing short-chain fatty acids that reduce inflammation. Although the evidence surrounding 100% fruit juice on chronic conditions remains inconsistent, accumulating studies indicate a more consistently beneficial role of whole fruits. The research evidence reviewed highlights the need for the DGA to update the recommendations on fruit juice, including emphasising the health benefits of whole fruit over fruit juice, providing a clear guideline on the daily fruit juice allowance, defining "free sugars" in fruit juice, and clarifying the distinction between 100% fruit juice and fruit drinks.

Comparative effects of different beverages on weight loss in adults: a systematic review and network meta-analysis of randomized trials

BACKGROUND

There is a lack of clarity on the comparative effects of different beverages on weight loss in adults.

OBJECTIVE

This study aimed at quantifying and ranking the effects of different beverages on weight loss.

METHODS

We searched PubMed, Scopus, and Web of Science up to January 2023. We included randomized trials evaluating the comparative effects of two or more beverages, or compared a beverage against a control group (water, no intervention), for weight loss in adults. We conducted a random-effects network meta-analysis (NMA) with a Bayesian framework to estimate mean difference [MD] and 95% credible interval [CrI].

RESULTS

In total, 78 randomized trials with 4168 participants were eligible. Low/no-calorie sweetened beverages (LNCSB) was effective for weight loss compared with water (MD: -0.79 kg, 95% CrI: -1.35, -0.18), milk (MD: -0.80 kg, 95% CrI: -1.59, -0.01), fruit juice (MD: -0.83 kg, 95% CrI: -1.47, -0.13), sugar-sweetened beverages (SSB) (MD: -1.08 kg, 95% CrI: -1.65, -0.50), and no intervention (MD: -1.19 kg, 95% CrI: -1.93, -0.41). However, in sensitivity analyses, no significant effect was seen in trials with a low risk of bias and those that implemented calorie restriction. LNCSB drinking was effective for waist circumference reduction compared with water (MD: -1.85 cm, 95% CrI: -3.47, -0.22). The certainty of evidence from most comparisons was rated low.

CONCLUSIONS

This study suggested evidence of low certainty that intake of LNCSBs can result in a small weight loss when used as a substitute for other beverages. Considering the low certainty of evidence, more research is needed to compare the effects of different beverages on body weight.

TRIAL REGISTRATION

Not applicable, but the protocol of this systematic review was registered at PROSPERO (registration number: CRD42023407937).

Health effects of drinking 100% juice: an umbrella review of systematic reviews with meta-analyses

CONTEXT

Low fruit and vegetable intakes are major modifiable determinants of disease. One hundred percent juice may facilitate intake and deliver essential nutrients and bioactive compounds. However, the position of 100% juice in healthy eating guidelines remains controversial due to its lower dietary fiber and higher free-sugar contents compared with whole fruits and vegetables.

OBJECTIVE

To conduct an umbrella review of systematic literature reviews with meta-analyses (MAs) to summarize the health benefits of drinking 100% fruit and/or vegetable juice.

DATA SOURCES

Four databases (Medline, The Cochrane Library, EMBASE, and CINAHL) were systematically searched for MAs of 100% juice and any health outcomes.

DATA ANALYSIS

Screening, quality, risk of bias, and content overlap tools were applied, and extracted data were narratively synthesized. No eligible studies for vegetable juice were found. Fifteen systematic literature reviews (51 primary MAs, 6 dose-response, and 87 subanalyses; 50-1200 mL/day; hours to years of duration) were included. Ten MAs (19.6%) reported health benefits (4 for blood pressure, 2 for vascular function, 3 for inflammation, 1 for stroke mortality), 3 MAs (5.9%) reported adverse risks (1 each for cardiovascular disease mortality, prostate cancer, type 2 diabetes risk), while most (74.5%) reported no effect (blood lipids, body composition, liver function, metabolic health, cancers, and inflammation). Risks were limited to cohort studies and benefits were found in both cohort and intervention studies.

CONCLUSION

The findings collate evidence showing some potential health benefits associated with 100% juice consumption, with fewer potential risks. The balance of evidence does not support the exclusion of 100% juice from food-based guides to healthy eating, although caution may be warranted in certain groups or individuals, and the body of evidence is not yet conclusive.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022380588.

Health effects of 100% fruit and vegetable juices: evidence from human subject intervention studies

The health effects of 100% fruit and vegetable juices (FVJ) represent a controversial topic. FVJ contain notable amounts of free sugars, but also vitamins, minerals, and secondary compounds with proven biological activities like (poly)phenols and carotenoids. The review aimed to shed light on the potential impact of 100% FVJ on human subject health, comprehensively assessing the role each type of juice may have in specific health outcomes for a particular target population, as reported in dietary interventions. The effects of a wide range of FVJ (orange, grapefruit, mandarin, lemon, apple, white, red, and Concord grapes, pomegranate, cranberry, chokeberry, blueberry, other minor berries, sweet and tart cherry, plum, tomato, carrot, beetroot, and watermelon, among others) were evaluated on a series of outcomes (anthropometric parameters, body composition, blood pressure and vascular function, lipid profile, glucose homeostasis, biomarkers of inflammation and oxidative stress, cognitive function, exercise performance, gut microbiota composition and bacterial infections), providing a thorough picture of the contribution of each FVJ to a health outcome. Some juices demonstrated their ability to exert potential preventive effects on some outcomes while others on other health outcomes, emphasising how the differential composition in bioactive compounds defines juice effects. Research gaps and future prospects were discussed. Although 100% FVJ appear to have beneficial effects on some cardiometabolic health outcomes, cognition and exercise performance, or neutral effects on anthropometric parameters and body composition, further efforts are needed to better understand the impact of 100% FVJ on human subject health.

Mapping the landscape of research on insulin resistance: a visualization analysis of randomized clinical trials

BACKGROUND

Insulin resistance, a condition in which cells do not respond adequately to insulin, plays a crucial role in diabetes and related metabolic disorders. Randomized clinical trials (RCTs) explore interventions to manage insulin resistance, contributing to evidence-based medical progress. The current study aimed to analyze the global research landscape and trends in RCTs targeting insulin resistance.

METHODS

This study used bibliometric analysis and data visualization to examine RCT publications on insulin resistance from 2003 to 2022. The Scopus database was used due to its comprehensive coverage. The search strategy involved combining terms related to insulin resistance with RCT-related terms. The search query was validated, and core bibliometric indicators were used to analyze publication growth, origin, productivity, quality, and citations.

RESULTS

Between 2003 and 2022, 1077 RCT-focused publications on insulin resistance were identified from a pool of 24,932 related articles. The growth followed two phases, with a significant increase after 2008. The USA (n = 308; 28.60%), Iran (n = 165; 15.32%), China (n = 110; 10.21%), and the UK (n = 92; 8.54%) were the main contributors. The active institutions included Tehran University of Medical Sciences (n = 38; 3.53%) and Harvard Medical School (n = 31; 2.88%). Prominent funding agencies include the National Institutes of Health (n = 88; 8.17%) and the National Institute of Diabetes and Digestive and Kidney Diseases (n = 86; 7.99%). The top journals included the American Journal of Clinical Nutrition (n = 44; 4.09%) and Diabetes Care (n = 35; 3.25%). Co-occurrence analysis revealed three clusters addressing "utilizing lipid panels as indicators of insulin resistance," "analyzing the impact of diet composition and physical activity on insulin sensitivity among obese individuals," and "exploring insulin resistance in cases of polycystic ovary syndrome."

CONCLUSIONS

This comprehensive bibliometric analysis highlights the global research landscape and trends in RCTs targeting insulin resistance. Research on lipid panels, diet impact, and insulin resistance in patients with polycystic ovary syndrome will continue to be a hotspot. The findings offer valuable information on research priorities, international collaborations, and impactful publications. This study provides a foundation for future directorial investigations in this critical area of metabolic health.

Effects of short-term sugary beverage consumption on glucose control and cardiovascular disease risk factors: A randomized controlled parallel-arm trial

OBJECTIVE

To determine differences in glucose control and cardiovascular disease risk factors following three weeks of added soda, 100% fruit juice, or water in apparently healthy, college-aged adults.

PARTICIPANTS

Thirty-six adults (18 males; 18 females) between the ages of 18 and 30 years of age.

METHODS

A 3-arm randomized controlled parallel-arm trial; at baseline and after three weeks consuming the assigned beverage, participants completed glucose control and cardiovascular disease risk factor assessments.

RESULTS

There were no significant differences between beverage conditions for glucose control or cardiovascular disease risk factors (ps > 0.05). There were no significant changes in caloric intake or differences in caloric intake between conditions, p = 0.17.

CONCLUSIONS

In healthy, young adults, under free-living conditions, short-term consumption of two commercially packaged servings of SBs did not lead to significant glucose control or cardiovascular disease risk factor changes, indicating potential compensation and/or resilience to negative short-term effects.

A review of citrus plants as functional foods and dietary supplements for human health, with an emphasis on meta-analyses, clinical trials, and their chemical composition

Fruits, flowers, leaves, essential oils, hydrosols, and juices of citrus spp. Are utilized to prepare various forms of food products. Along with their nutritional values, in the health industry, different parts of the plants of the citrus genus have been used as supplements or remedies to prevent or control diseases. This review focused on reported meta-analyses and clinical trials on the health benefits of citrus plants as functional foods. Also, chemical compounds of various citrus species were reviewed. The following information sources were used for data collection: Google Scholar, the Web of Science, Scopus, and PubMed. Various keywords, including "citrus AND chemical compounds," "citrus AND phytochemicals," "citrus species," "citrus AND meta-analysis," "nutritional and therapeutical values of citrus spp.," "clinical trials AND citrus," "clinical trials AND Rutaceae," "health benefits of citrus spp.," "citrus edible or non-edible applications," and scientific names of the citrus plants were utilized to collect data for the review. The scientific name and common name of all twenty-eight citrus species, along with any of the above keywords, were also searched in the mentioned databases. Scientific papers and data sources were sought to review and discuss the citrus plant's nutritional and therapeutic importance. Several meta-analyses and clinical trials have reported beneficial effects of citrus spices on a variety of cancer risks, cardiovascular risk factors, neurologic disorders, urinary tract conditions, and gastrointestinal tract conditions. They have shown anxiolytic, antimicrobial, and pain-alleviating effects. Some of them can be helpful in managing obesity and cardiovascular risk factors.

The Association between Unhealthy Food Consumption and Impaired Glucose Metabolism among Adults with Overweight or Obesity: A Cross-Sectional Analysis of the Indonesian Population

BACKGROUND

It has been shown that dietary patterns are associated with glucose control. However, the association between the types of food consumed and blood glucose in overweight or obese individuals is still unclear. The present study aimed to determine the association between unhealthy food consumption and impaired glucose metabolism in adults with overweight or obesity.

METHODS

The analysis presented in this study was based on the data from a population-based, cross-sectional, nationally representative survey (Indonesian Basic Health Research 2018/RISKESDAS 2018). The body mass index (BMI) was calculated as weight (kg)/height squared (m²) and was determined based on the World Health Organization (WHO) criteria for the Asian population. A validated questionnaire and food card were used to assess the diet. Fasting plasma glucose and 2-hpost-prandial glucose were employed to determine blood glucose markers.

RESULTS

In total, 8752 adults with overweight or obesity were included in this analysis. We found that consumption of sweet, grilled, and processed foods was associated with impaired fasting plasma glucose (IFG) before and after adjustment (p < 0.05). Consumption of high-fat foods was also associated with impaired glucose tolerance (IGT) for all models tested (p < 0.05). Furthermore, all models showed a link between processed food consumption and combined glucose intolerance (CGI) (p ≤ 0.001).

CONCLUSIONS

Differential food group consumption was associated with IFG, IGT, and CGI in Indonesian adults who were overweight or obese.

Associations Between Fruit Intake and Risk of Diabetes in the AusDiab Cohort

CONTEXT

Fruit, but not fruit juice, intake is inversely associated with type 2 diabetes mellitus (T2DM). However, questions remain about the mechanisms by which fruits may confer protection.

OBJECTIVE

The aims of this work were to examine associations between intake of fruit types and 1) measures of glucose tolerance and insulin sensitivity and 2) diabetes at follow-up.

METHODS

Among participants of the Australian Diabetes, Obesity and Lifestyle Study, fruit and fruit juice intake was assessed by food frequency questionnaire at baseline. Associations between fruit and fruit juice intake and 1) fasting plasma glucose, 2-hour postload plasma glucose, updated homeostasis model assessment of insulin resistance of β-cell function (HOMA2-%β), HOMA2 of insulin sensitivity (HOMA2-%S), and fasting insulin levels at baseline and 2) the presence of diabetes at follow-up (5 and 12 years) were assessed using restricted cubic splines in logistic and linear regression models.

RESULTS

This population of 7675 Australians (45% males) had a mean ± SD age of 54 ± 12 years at baseline. Total fruit intake was inversely associated with serum insulin and HOMA2-%β, and positively associated with HOMA2-%S at baseline. Compared to participants with the lowest intakes (quartile 1), participants with moderate total fruit intakes (quartile 3) had 36% lower odds of having diabetes at 5 years (odds ratio, 0.64; 95% CI, 0.44-0.92), after adjusting for dietary and lifestyle confounders. Associations with 12-year outcomes were not statistically significant.

CONCLUSION

A healthy diet including whole fruits, but not fruit juice, may play a role in mitigating T2DM risk.

100% Fruit juice intake and cardiovascular risk: a systematic review and meta-analysis of prospective and randomised controlled studies

PURPOSE

The relationship between 100% fruit juice (100%FJ) consumption and cardiovascular risk is object of debate: indeed, recently published investigations provided new but discrepant evidence on this important question and International dietary guidelines are not in agreement on recommendations about fruit juice consumption. Therefore, we performed a meta-analysis of the prospective studies and the randomised controlled trials (RCTs) that explored the relationship between 100%FJ intake, cardiovascular risk profile and risk of cardiovascular events.

METHODS

We performed a systematic search of publications up to August 2019. Summary relative risks and exploration of linearity of the association were estimated for prospective studies and summary mean differences (MDs) calculated for RCTs.

RESULTS

A total of 21 prospective studies and 35 RCTs met the inclusion criteria. Dose-response analysis detected a significant inverse association between low-moderate 100%FJ consumption and risk of stroke (up to 200 ml/day) or total CV events (up to 170 ml/day) compared with no consumption, with a non-linear relationship (p for non-linearity < 0.05). No significant association was found for coronary heart disease and diabetes risk. In RCTs, a favorable and significant effect of 100%FJ intake was detected on blood pressure (systolic, MD: - 3.14 mmHg; diastolic, MD: - 1.68 mmHg), arterial compliance (carotid-femoral pulse wave velocity, - 0.38 m/s) and endothelial function (flow-mediated dilation, 2.10%). Neutral effects were found on body weight, blood lipids and glucose metabolism.

CONCLUSIONS

The results of these analyses indicate that 100%FJ consumption is not associated with higher CV risk. A non-linear inverse dose-response relationship occurs between 100%FJ consumption and CV disease, in particular for risk of stroke, probably mediated by the decrease in blood pressure.

TRIAL REGISTRATION

PROSPERO registration number (CRD42019135577).

Fruit Juices: Are They Helpful or Harmful? An Evidence Review

Dietary guidelines often deal with 100% fruit juice (FJ) inconsistently because it represents a source of free sugars. However, FJ also provides bioavailable micronutrients and plant bioactives at levels similar to those found in whole fruits. The present review weighs up the evidence from high-quality studies investigating a potential health harm for FJ against evidence from studies which indicate a potential health benefit. The findings reveal that FJ consumption, at moderate intakes consistent with the dietary guidelines for the US and some European countries (75-224 mL daily), does not increase the risk of obesity, type 2 diabetes, cardiovascular disease or poor glycaemic control. In contrast, regular consumption of FJ-even up to 500 mL per day in short-to-medium-term studies-appears to confer a health benefit in terms of vascular function and reduced blood pressure. Emerging evidence for cognitive health benefits requires further investigation in human trials. Observational studies report associations between FJ and nutrient adequacy and suggest that FJ consumption is associated with reduced risk of stroke. In conclusion, FJ appears to offer more benefit than risk and there appears to be no justification for discouraging FJ within a balanced diet for children and adults.

Is sugar extracted from plants less healthy than sugar consumed within plant tissues? The sugar anomaly

There are dilemmas in the minds of consumers with respect to sugar consumption - they would like to consume sugars for sweetness, but in a healthy (and perhaps guilt free!) way. In a sense, consumers believe that if sugar does not appear as an ingredient on the product label, but is intrinsic in the food (and will appear as a nutrient), it is 'good'. As an ingredient, however, it is viewed as a 'bad chemical' associated with tooth decay and obesity. The reality is that unless processing induced modifications have occurred, the sugar molecule within a plant tissue is the same molecule structure as present in purified sugar. The same calorific value. However, there is an argument that humans eat too refined food and that if sugars were eaten in their natural context (e.g. within a fruit), their presence and concentration would be in harmony (where different nutrients complement and balance the sugar concentration) with the human body. This reflects the process of eating, satiety, presence of other nutrients (including water) and the associated impact of the indigestible components of plant foods on the transit/nutrient bioavailability control and thus benefits through the gut. The authors explore these issues in this article and seek to provide a scientific basis to different sides of the argument - sugar is good or bad depending on how (in which format and how much/how concentrated) it is consumed. More importantly perhaps, how should sugar consumption - an important nutrient - be managed to optimize the benefits but reduce the disadvantages? © 2020 Society of Chemical Industry.

Stratification of Volunteers According to Flavanone Metabolite Excretion and Phase II Metabolism Profile after Single Doses of 'Pera' Orange and 'Moro' Blood Orange Juices

Large interindividual variations in the biological response to citrus flavanones have been observed, and this could be associated with high variations in their bioavailability. The aim of this study was to identify the main determinants underlying interindividual differences in citrus flavanone metabolism and excretion. In a randomized cross-over study, non-obese and obese volunteers, aged 19-40 years, ingested single doses of Pera and Moro orange juices, and urine was collected for 24 h. A large difference in the recovery of the urinary flavanone phase II metabolites was observed, with hesperetin-sulfate and hesperetin-sulfo-O-glucuronide being the major metabolites. Subjects were stratified according to their total excretion of flavanone metabolites as high, medium, and low excretors, but the expected correlation with the microbiome was not observed at the genus level. A second stratification was proposed according to phase II flavanone metabolism, whereby participants were divided into two excretion groups: Profiles A and B. Profile B individuals showed greater biotransformation of hesperetin-sulfate to hesperetin-sulfo-O-glucuronide, as well as transformation of flavanone-monoglucuronide to the respective diglucuronides, suggestive of an influence of polymorphisms on UDP-glucuronosyltransferase. In conclusion, this study proposes a new stratification of volunteers based on their metabolic profiles. Gut microbiota composition and polymorphisms of phase II enzymes may be related to the interindividual variability of metabolism.

Role of fruit juice in achieving the 5-a-day recommendation for fruit and vegetable intake

Although there is strong evidence that consumption of fruit and vegetables is associated with a reduced rate of all-cause mortality, only a minority of the population consumes 5 servings a day, and campaigns to increase intake have had limited success. This review examines whether encouraging the consumption of fruit juice might offer a step toward the 5-a-day target. Reasons given for not consuming whole fruit involve practicalities, inconvenience, and the effort required. Psychologically, what is important is not only basic information about health, but how individuals interpret their ability to implement that information. It has been argued that fruit juice avoids the problems that commonly prevent fruit consumption and thus provides a practical means of increasing intake and benefitting health through an approach with which the population can readily engage. Those arguing against consuming fruit juice emphasize that it is a source of sugar lacking fiber, yet juice provides nutrients such as vitamin C, carotenoids, and polyphenols that offer health-related benefits. Actively encouraging the daily consumption of fruit juice in public health policy could help populations achieve the 5-a-day recommendation for fruit and vegetable intake.

A polyphenol-rich dietary pattern improves intestinal permeability, evaluated as serum zonulin levels, in older subjects: The MaPLE randomised controlled trial

BACKGROUND & AIM

Increased intestinal permeability (IP) can occur in older people and contribute to the activation of the immune system and inflammation. Dietary interventions may represent a potential strategy to reduce IP. In this regard, specific food bioactives such as polyphenols have been proposed as potential IP modulator due to their ability to affect several critical targets and pathways that control IP. The trial aimed to test the hypothesis that a polyphenol-rich dietary pattern can decrease serum zonulin levels, an IP surrogate marker involved in tight junction modulation, and can beneficially alter the intestinal microbiota, and IP-associated biochemical and clinical markers in older subjects.

METHODS

A randomised, controlled, cross-over intervention trial was performed. Sixty-six subjects (aged ≥ 60 y) with increased IP based on serum zonulin levels, were randomly allocated to one of the two arms of the intervention consisting of a control diet (C-diet) vs. a polyphenol-rich diet (PR-diet). Each intervention was 8-week long and separated by an 8-week wash out period. At the beginning and at the end of each intervention period, serum samples were collected for the quantification of zonulin and other biological markers. Faecal samples were also collected to investigate the intestinal microbial ecosystem. In addition, anthropometrical/physical/biochemical parameters and food intake were evaluated.

RESULTS

Fifty-one subjects successfully completed the intervention and a high compliance to the dietary protocols was demonstrated. Overall, polyphenol intake significantly increased from a mean of 812 mg/day in the C diet to 1391 mg/day in the PR-diet. Two-way analysis of variance showed a significant effect of treatment (p = 0.008) and treatment × time interaction (p = 0.025) on serum zonulin levels, which decreased after the 8-week PR-diet. In addition, a treatment × time interaction was observed showing a reduction of diastolic blood pressure (p = 0.028) following the PR-diet, which was strongest in those not using antihypertensive drugs. A decrease in both diastolic (p = 0.043) and systolic blood pressure (p = 0.042) was observed in women. Interestingly, a significant increase in fibre-fermenting and butyrate-producing bacteria such as the family Ruminococcaceae and members of the genus Faecalibacterium was observed following the PR intervention. The efficacy of this dietary intervention was greater in subjects with higher serum zonulin at baseline, who showed more pronounced alterations in the markers under study. Furthermore, zonulin reduction was also stronger among subjects with higher body mass index and with insulin resistance at baseline, thus demonstrating the close interplay between IP and metabolic features.

CONCLUSIONS

These data show, for the first time, that a PR-diet can reduce serum zonulin levels, an indirect marker of IP. In addition, PR-diet reduced blood pressure and increased fibre-fermenting and butyrate-producing bacteria. These findings may represent an initial breakthrough for further intervention studies evaluating possible dietary treatments for the management of IP, inflammation and gut function in different target populations. THIS STUDY WAS REGISTERED AT WWW.ISRCTN.

ORG AS

ISRCTN10214981.

Anti-diabetic, anti-cholinesterase, and antioxidant potential, chemical composition and sensory evaluation of novel sea buckthorn-based smoothies

Sea buckthorn berries fit into the strategy of seeking natural factors in the non-communicable diseases prevention, but their sensory qualities are a challenge for consumers and food industry. The study aimed to evaluate anti-cholinesterase (anti-acetylcholinesterase and -butylcholinesterase), anti-diabetic (anti-α-amylase, -α-glucosidase, -pancreatic lipase) and antioxidant potential (FRAP, ORAC), phenolic compounds (UPLC-PDA-FL), basic chemical composition, and sensory quality of sea buckthorn-based smoothies. Eighteen novel products containing sea buckthorn (25-50%) with other fruits and vegetables were analyzed. Sea buckthorn enriched the smoothies in flavonols (25.46-95.13 mg/100 g), and fruits and vegetables provided phenolic acids and procyanidins. The anti-BuChE effect was higher than anti-AChE, while products with apricot, orange, grape and parsley root were strong inhibitors of carbohydrates digesting enzymes. Lipase inhibition by all smoothies was over 50%. Products with 75% fruits or 50% vegetables were the most sensory attractive. The results will be valuable in designing innovative food with rarely used berries.

How a Spanish Group of Millennial Generation Perceives the Commercial Novel Smoothies?

The World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO) constantly emphasize the importance of increasing fruit and vegetable consumption; these natural products help in the prevention of major diseases. Smoothies are a simple and convenient way of doing so; thus, their demand is constantly growing and their market is becoming important for the food industry. Therefore, the objective of this research was to determine Millennial consumer opinion towards novel fruit- and vegetable-smoothies available on the retail market. Napping^®, descriptive sensory analysis, and consumer studies were conducted. Napping^® results group samples into four clusters of smoothies; the main grouping factor was the type of fruit and the percentage of vegetables. Penalty analysis showed that smoothies need improvement mainly dealing with sweetness, bitterness, and vegetable flavors. Millennial consumers formed a homogeneous sensory group in which the overall liking was negatively correlated with the level of sweetness, and earthy, carrot, beetroot, and pear flavors. The key liking drivers were sourness and notes of mango, banana, and peach flavors. This research is a new insight into the perception of smoothies, provides comprehensive knowledge for the food industry, and can guide the design of new healthy smoothies.

Potential health benefits of (poly)phenols derived from fruit and 100% fruit juice

(Poly)phenol-rich diets have been associated with reduced risk of various diseases. Coffee and tea are typically identified as dietary sources of chlorogenic acid and flavan-3-ols; however, 100% fruit juice greatly contributes to anthocyanin, flavonol, flavan-3-ols, and flavanone intake, making them complementary sources of dietary (poly)phenols. Thus, the aim of this narrative review was to provide an overview of fruit (poly)phenols and their potential health benefits. Fruit (poly)phenols have been associated with several health benefits (eg, reduced risk of cardiovascular disease and neurocognitive benefits). Although perspectives on 100% fruit juice consumption are controversial due to the perception of sugar content, growing evidence supports the role of fruit in whole and 100% juice forms to provide consumer benefits in alignment with dietary guidance. However, differences in (poly)phenol profiles and bioavailability likely exist between whole fruit and 100% fruit juice due to processing and the presence/absence of fiber. Ongoing studies are better defining similarities and differences between whole fruit and 100% fruit juice to elucidate protective mechanisms and align with processing and consumer products.

Saccharide Characteristics and Their Potential Health Effects in Perspective

To understand the effects of saccharides on our metabolism and health, we need a clear understanding of what they are, how they differ, and why some types are deemed "less healthy" and others "better for health." There are various ways to look at this topic. Firstly, saccharides can be classified according to their degree of polymerization (DP). This classification is useful when qualitative or quantitative analysis and calculation of intakes are required or for food-labeling definitions. However, it does not account for the fact that saccharides with a similar DP can differ in molecular composition, which will influence digestion, absorption, and metabolism. Secondly, another approach widely used in the biomedical and nutritional sciences is therefore a physiological classification, which addresses the rate and degree of digestibility and absorption, the glycemic response, and the metabolic fate. The individual health status also plays a role in this respect. An active, lean person will have a metabolic response that differs from an inactive person with overweight and insulin resistance. However, this approach will not give a complete answer either because the characteristics of the matrix/meal in which these carbohydrates (CHOs) are present will also influence the responses of our body. Thirdly, one can also rank CHOs by comparing their functional/technological properties, such as relative sweetness, viscosity, and solubility. Understanding CHO characteristics and related physiological responses will help understand health and disease implications. Therefore, a brief outline of different carbohydrate classifications is presented. This outline will be placed in the context of potential overall effects after consumption. The answer to the question whether we should we eat less of certain sugars depends on the angle from which you look at this matter; for example, do you address this question from a single molecular characteristic point of view or from a meal quality perspective? Looking at one particular CHO characteristic will almost always lead to a different conclusion (e.g., the labeling of fructose as toxic) than evaluating from a "total perspective" (fructose has adverse effects in certain conditions). Examples are given to help understand this matter for the benefit of justified dietary/food-based recommendations.

Pure Fruit Juice and Fruit Consumption Are Not Associated with Incidence of Type 2 Diabetes after Adjustment for Overall Dietary Quality in the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) Study

BACKGROUND

Dietary guidelines on pure fruit juice consumption vary from country to country regarding the inclusion of pure fruit juice in the recommendations as an acceptable alternative for fruit. Current epidemiological evidence on the association between pure fruit juice consumption and diabetes risk is scarce.

OBJECTIVE

We studied the association of both pure fruit juice and fruit consumption with diabetes risk and investigated the differences between low and high fruit consumers in the association of pure fruit juice consumption with diabetes risk.

METHODS

This prospective cohort study included 36,147 participants in the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) Study aged 20-69 y at baseline. Fruit juice and fruit consumption were assessed using a validated food-frequency questionnaire; amounts of consumption were divided into 5 categories and quintiles, respectively. Incident type 2 diabetes cases were mainly self-reported and verified against medical records. Cox regression was used to estimate adjusted HRs and 95% CIs.

RESULTS

After an average follow-up of 14.6 y, 1477 verified incident cases of type 2 diabetes were documented. Compared with no consumption, pure fruit juice consumption was not significantly associated with type 2 diabetes, with adjusted HRs ranging from 0.92 (95% CI: 0.79, 1.09) to 1.03 (95% CI: 0.83, 1.26). The associations did not differ between participants with low and high fruit consumption. None of the categories of fruit consumption were associated with type 2 diabetes (lowest quintile as reference). Adjusted HRs ranged between 0.93 (95% CI: 0.78, 1.10) and 1.00 (95% CI: 0.84, 1.19). Adjustment for the Dutch Healthy Diet Index, as an overall measure of dietary quality, strongly attenuated the observed associations of type 2 diabetes with both fruit juice and fruit consumption.

CONCLUSIONS

We found no evidence for associations between pure fruit juice and fruit consumption and diabetes risk after adjustment for overall dietary quality for participants in the EPIC-NL study. This trial was registered at https://www.trialregister.nl/trial/6939 as NL6939.

Intake of 100% Fruit Juice Is Associated with Improved Diet Quality of Adults: NHANES 2013-2016 Analysis

Fruit intake is generally associated with better diet quality and overall health. This report examined the effect of 100% fruit juice (considered a part of total fruit servings) and its replacement with whole fruits equivalents on nutrient intake and diet quality. National Health and Nutrition Examination Survey 2013-2016 data (24-h dietary recall) from adults 19+ years (n = 10,112) were used to assess the diet quality and nutrient intakes and to isocalorically replace with 100% fruit juice intakes whole fruit equivalents in a modeling analysis. About 15.6% adults were 100% fruit juice consumers. Consumers had higher diet quality (10% higher Healthy Eating Index, HEI 2015 score), and higher intakes of energy, calcium, magnesium, potassium, vitamin C and vitamin D than non-consumers. Consumption of 100% fruit juice was also associated with lower risk of being overweight/obese (-22%) and having metabolic syndrome (-27%). Replacing 100% fruit juice with whole fruits equivalents did not affect nutrient intake except for a modest increase (+6.4%) in dietary fiber. Results show that 100% fruit juice intake was associated with better diet quality and higher nutrient intake. Replacement of 100% fruit juice intake with whole fruits equivalents had no significant effect on nutrients except for dietary fiber.

Consumption of Raw Orange, 100% Fresh Orange Juice, and Nectar- Sweetened Orange Juice-Effects on Blood Glucose and Insulin Levels on Healthy Subjects

Objective: The aim of this study is to investigate the effect of consumption of raw orange (RO), 100% fresh orange juice (FOJ), and nectar-sweetened orange juice (NSOJ) on postprandial glucose and insulin levels in non-diabetic young Emirati women. Research Methods: This is a prospective, three-way, crossover study design. Blood records of thirteen normal weight and seven healthy obese university students were analyzed from Zayed University on three random days with the following three meal samples: 2 ROs, 100% FOJ, and NSOJ. Venous blood was collected at 0, 30, 60, 90, and 120 minutes after the respective meal consumption. Statistical analyses included repeated measures analysis of variance and calculations of the area under the glucose and insulin curves (AUC) for each one of the meal samples. Results: Total fasting glucose and insulin levels did not differ by treatment in the normal versus obese group. All three meals had no significant effects on the plasma glucose levels. However, there was a significant change in plasma insulin concentrations at 120 min compared with that at 0 min for RO: −14 (−27.05, −0.90, P < 0.001); 100% FOJ −13.7 (−28.80, 1.44, P < 0.001); and NSOJ: −9.2 (−28.75, 10.30, P < 0.001). Conclusions: This study shows that whole fresh fruit, 100% fruit juice, and sweetened fruit juice did not have a significant effect on the blood glucose levels in non-diabetic Emirati university students. However, a significant decrease in insulin response and HOMA-IR on all three sample meals was observed.

Frequency of Consumption of Whole Fruit, Not Fruit Juice, Is Associated with Reduced Prevalence of Obesity in Korean Adults

BACKGROUND

Fruit consumption is known to be beneficial to health. However, the health benefits of fruit juice are controversial due to its high sugar content.

OBJECTIVES

To examine the associations of frequency of consumption of whole fruit and fruit juice with obesity and metabolic syndrome.

DESIGN

This cross-sectional study used data from the 2012-2015 Korea National Health and Nutrition Examination Survey.

PARTICIPANTS

A total of 10,460 adults (4,082 men and 6,378 women) aged 19 to 64 years were included in the study.

MAIN OUTCOME MEASURES

Frequency of consumption of whole fruit and fruit juice was evaluated using a food frequency questionnaire, and dietary sugar intake was calculated using a 24-hour recall. Obesity and abdominal obesity were determined using body mass index and waist circumference, respectively. Metabolic syndrome was defined on the basis of the National Cholesterol Education Program Adult Treatment Panel III.

STATISTICAL ANALYSES PERFORMED

Multiple logistic regression analysis was performed to examine the associations between frequency of whole fruit or fruit juice consumption and obesity and metabolic syndrome abnormalities.

RESULTS

The percentage of participants who consumed whole fruit daily was 32.6%, whereas 52.3% consumed fruit juice rarely. The average intake of total sugars was 14.9% of total energy, which was within the recommend range (<20% of total energy) for Koreans. Consuming whole fruit ≥1 time/day was associated with reduced prevalence of obesity, abdominal obesity, and elevated blood pressure compared with consuming whole fruit ≤1 time/wk. However, frequency of fruit juice consumption showed no association with obesity, abdominal obesity, and metabolic syndrome.

CONCLUSIONS

Frequency of whole fruit consumption was associated with reduced prevalence of obesity and metabolic syndrome abnormalities among Korean adults with average total sugar intake within the recommended range.

Pomegranate juice to reduce fecal calprotectin levels in inflammatory bowel disease patients with a high risk of clinical relapse: Study protocol for a randomized controlled trial

Background

Inflammatory bowel disease (IBD) is a chronic condition characterized by recurrent episodes of intestinal inflammation and is thought to be related to an autoimmune reaction to genetic and environmental factors. Although evidence indicates that a polyphenolic-rich diet plays an important role in modulating aspects of chronic inflammation, few studies have focused on the effect of ellagitannin (ET)-rich food consumption on long-term remission maintenance in IBD patients with a high risk of clinical relapse. Therefore, we hypothesize that supplementation with a pomegranate juice, a naturally rich source of ETs, could significantly modulate the markers of mucosal and systemic inflammation relative to a control group receiving a placebo.

Methods/design

This double-blind, randomized controlled trial includes patients with IBD involving the colorectum who have been in stable therapy for at least the three previous months and have a high risk of clinical relapse. Participants are randomly allocated to one of two groups: active supplementation (125 mL of cv. Wonderful pomegranate juice) or placebo (125 mL) taken twice daily for 12 weeks. The primary outcome is changes in the fecal neutrophil-derived protein calprotectin, a surrogate marker of mucosal improvement, between the two groups from baseline to 12 weeks later. The secondary outcomes include transcriptomic changes in peripheral blood mononuclear cells and intestinal biopsies and changes in circulating inflammatory markers and trimethylamine-N-oxide levels. Pomegranate ET-derived metabolites are identified and quantified in plasma and urine samples.

Discussion

The results will provide information on the possible reduction of fecal calprotectin levels following the consumption of pomegranate juice. The findings will also show the in vivo metabolism of pomegranate ETs. Finally, the effect of 12-week pomegranate juice consumption on local and systemic inflammatory markers will be elucidated, which will likely provide additional insights into the maintenance of remission in IBD patients.

Trial registration

ClinicalTrials.gov, NCT03000101. Registered on 21 December 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3321-8) contains supplementary material, which is available to authorized users.

The effect of high compared with low dairy consumption on glucose metabolism, insulin sensitivity, and metabolic flexibility in overweight adults: a randomized crossover trial

BACKGROUND

Dairy products contain many nutritious components that may benefit metabolic health. There are indications that glucose metabolism and insulin sensitivity, which are generally disturbed in overweight and obese individuals, may improve by increased dairy intake. This may also affect one's metabolic flexibility.

OBJECTIVE

The aim of this study was to investigate the effects of high compared with low dairy intake on glucose metabolism, insulin sensitivity, and metabolic flexibility in overweight adults (aged 45-65 y).

METHODS

In this randomized intervention study, subjects consumed a high- and a low-dairy diet [HDD (5-6 dairy portions) and LDD (≤1 dairy portion), respectively] for 6 wk in a crossover design, with a washout period of 4 wk. Dairy portions were 200 g semi-skimmed yoghurt, 30 g reduced-fat (30+) cheese, and 250 mL semiskimmed milk and buttermilk. After 6 wk, a 75-g oral-glucose-tolerance test (13C-labeled) and a subsequent fasting challenge were performed. Metabolic flexibility was studied by determining the respiratory quotient (RQ) using indirect calorimetry. Fasting and postprandial plasma concentrations of glucose and insulin were analyzed. The dual isotope technique enabled calculation of glucose kinetics.

RESULTS

The study was completed by 45 overweight men and postmenopausal women [age 58.9 ± 4.3 y, BMI 27.9 ± 1.9 kg/m2 (mean ± SD)]. Fasting RQ and ΔRQ, reflecting metabolic flexibility, did not differ after both diets. Fasting glucose concentrations were similar, whereas fasting insulin concentrations were lower after the LDD (LDD: 8.1 ± 2.8 mU/L; HDD: 8.9 ± 3.3 mU/L; P = 0.024). This resulted in a higher HOMA-IR after the HDD (P = 0.027). Postprandial glucose and insulin responses as well as glucose kinetics were similar after both diets.

CONCLUSIONS

The amount of dairy intake during a 6-wk period had a neutral effect on metabolic flexibility or postprandial glucose metabolism in middle-aged overweight subjects. More trials are needed to study the effects of specific dairy types and to differentiate between metabolic subgroups. This trial was registered at trialregister.nl as NTR4899.

The effects of whole-grain compared with refined wheat, rice, and rye on the postprandial blood glucose response: a systematic review and meta-analysis of randomized controlled trials

Background

Whole grains are often referred to collectively, despite differences in their composition, physical structure, processing, and potential health benefits.

Objective

The aim of this study was to compare the postprandial blood glucose response of whole-grain with refined wheat, rice, or rye, while controlling for the food delivery matrix and the processing of the grain (e.g., grinding, germination).

Design

Eleven electronic databases were systematically searched to identify studies published up to and including November 2017. Randomized controlled trials comparing the effects of whole-grain wheat, rice, or rye with those of each grain's refined counterpart on postprandial blood glucose area under the curve (AUC) were included. Pooled effect sizes were computed by using the difference in the blood glucose AUC after the consumption of the whole compared with the refined grain.

Results

Twenty publications were included, with 10, 14, and 5 strata (or active-control comparisons) on whole-grain wheat, rice, and rye, respectively. The consumption of ground (wholemeal) wheat, compared with white wheat, was not associated with a significant reduction in blood glucose AUC (-6.7 mmol/L ⋅ min; 95% CI: -25.1, 11.7 mmol/L ⋅ min; P = 0.477). The consumption of wholemeal rye, compared with endosperm rye, was not associated with a significant reduction in blood glucose AUC (-5.5 mmol/L ⋅ min; 95% CI: -24.8, 13.8 mmol/L ⋅ min; P = 0.576). The consumption of intact (whole-grain) rice, compared with white rice, was associated with a significant reduction in blood glucose AUC (-40.5 mmol/L ⋅ min; 95% CI: -59.6, -21.3 mmol/L ⋅ min; P < 0.001).

Conclusions

Compared with white rice, whole-grain rice significantly attenuates the postprandial blood glucose response. In most of the studies on wheat and rye, the postprandial blood glucose responses to foods formulated with wholemeal compared with refined flours were compared. Whether reductions in the blood glucose AUC can be achieved with whole-grain (as opposed to wholemeal) wheat and rye requires further investigation.