The effects of fruit consumption in patients with hyperuricaemia or gout

Xanthoceras sorbifolium leaves alleviate hyperuricemic nephropathy by inhibiting the PI3K/AKT signaling pathway to regulate uric acid transport

ETHNOPHARMACOLOGICAL RELEVANCE

In China, Xanthoceras sorbifolium Bunge was first documented as "Wen Guan Hua" in the "Jiu Huang Ben Cao" in 1406 A.D. According to the "National Compilation of Chinese Herbal Medicine," X. sorbifolium leaves are sweet and flat in nature and can dispel wind and dampness, suggesting that their extract can be used to treat rheumatoid arthritis. X. sorbifolium Bunge has also been used to treat arteriosclerosis, hyperlipidemia, hypertension, chronic hepatitis, and rheumatism, complications associated with hyperuricemic nephropathy (HN), a condition characterized by kidney damage resulting from high levels of uric acid (UA) in the blood.

AIM OF THE STUDY

The purpose of this study was to investigate the effects and underlying mechanisms of a 70% ethanol extract from X. sorbifolium leaves (EX) in alleviating HN.

MATERIALS AND METHODS

A mouse model of hyperuricemia was established to initially evaluate the hypouricemic effects and determine the effective dose of EX. Phytochemical analyses were conducted using ultra high-performance liquid chromatography and liquid chromatography-mass spectroscopy. The potential key pathways of EX in the alleviation of HN were inferred using network pharmacology and bioinformatics. An HN rat model was then established, and experiments including biomarker detection, western blotting, reverse transcription quantitative polymerase chain reaction, immunohistochemical and Masson's trichrome staining, and transmission electron microscopy were conducted to evaluate the effect of EX on UA transporter expression in vitro.

RESULTS

Network pharmacology and bioinformatics analyses revealed that the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway was the key pathway for the alleviation of HN progression by EX. EX treatment reduced serum biomarkers in HN rats, downregulated the expression of p-PI3K, p-AKT, glucose transporter 9 (GLUT9), urate transporter 1 (URAT1), Collagen I, matrix metalloproteinase (MMP)-2, and MMP-9, and upregulated the expression of ATP binding cassette subfamily G member 2 (ABCG2) to improve renal interstitial fibrosis in HN rats. A high content of both quercitrin and cynaroside were identified in EX; their administration inhibited the increased expression of GLUT9 and URAT1 in damaged HK-2 cells.

CONCLUSION

Our study provides evidence that EX alleviates HN. The potential mechanism underlying this effect may be the regulation of UA transporters, such as GLUT9 and URAT1, by limiting the activation of the PI3K/AKT signaling pathway to improve renal injury.

Association between serum uric acid levels and dietary fiber intake in adults: the Korea national health and nutrition examination survey (KNHANES VII, 2016-2018)

BACKGROUND

Hyperuricemia could be a risk for various chronic diseases, and it could be largely corrected by diet control. This study was a nationwide cross-sectional study to investigate the association between serum uric acid level and dietary fiber intake.

METHODS

This study analyzed data based on the Korean National Health and Nutrition Examination Survey conducted from 2016 to 2018. Adults over 20 years of age with normal renal function, defined as an estimated glomerular filtration rate (eGFR) over 30mL/min/1.73m2, were included. The criteria for hyperuricemia were ≥ 7 mg/dL in men and ≥ 6 mg/dL in women. Data regarding dietary intake were obtained using the 24-hour recall method.

RESULTS

A total of 15,278 subjects (6,455 males/8,823 females) were analyzed. The prevalence of hyperuricemia was 19.3% in men and 6.8% in women. There were significant, negative associations between serum uric acid and total fiber intake in both men and women. Consuming more than 27.9 g of dietary fiber in men and 20.7 g in women reduced the risk of hyperuricemia by approximately 30% with odds ratios of 0.72 (0.62-0.83) and 0.71 (0.56-0.88) in men and women, respectively. With regard to the risk reduction by the type of dietary fiber, cereal fiber was significantly identified in both men and women, while fruit fiber was only significant in men. In the subgroup analysis, this association remained significantly in young and metabolically healthy populations with normal weight.

CONCLUSIONS

Dietary fiber intake was inversely associated with serum uric acid levels. This relationship was particularly significant in metabolically healthy young adults.

Higher intakes of fiber, total vegetables, and fruits may attenuate the risk of all-cause and cause-specific mortality: findings from a large prospective cohort study

BACKGROUND

Although studies have reported an inverse association between fruits, vegetables, and fiber consumption and all-cause and cause-specific mortality, the issue remains incompletely defined in the Middle Eastern population.

AIMS

The current study aimed to investigate the association between dietary fiber, fruit, and vegetable intake and all-cause and cause-specific mortality.

METHODS

A total of 48632 participants (mean age = 52years), 57.5% (n = 27974) women and 42.5% (n = 20658) men, were recruited from an ongoing large-scale prospective cohort study (the Golestan Cohort Study (GCS)), in the north of Iran. Using a validated semi-quantitative 116-item food questionnaire, dietary intakes were collected. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) of all-cause and cause-specific mortality were reported.

RESULTS

After approximately 14 years of follow-up, 10,774 deaths were recorded. In the fully adjusted model, compared to those in the lowest quintile of intake, those in the second and third quintiles of dietary fiber intake had a 7%-10% reduction in risk of all-cause mortality, and a 15%-17% reduction in the risk of mortality from other causes. Increasing consumption of fruits was also associated with a decreased risk of mortality for all-cause mortality by 9%-11%, and all cancer by 15-20%. Further, those in the third and fourth quintiles of vegetables intake had 11%-12% lower risk for CVD mortality.

DISCUSSION

The results from the GCS further support the current recommendations on following a healthy diet containing proper amounts of fiber, vegetables, and fruits, as health-protective dietary items.

CONCLUSIONS

Higher intake of dietary fiber, fruits, and vegetables has the potential to reduce both overall and cause-specific mortality rates. However, additional cohort studies with larger sample size and long-term follow-up durations are required to establish these findings.

High-fructose corn syrup aggravates colitis via microbiota dysbiosis-mediated Th17/Treg imbalance

Dietary fructose is widely used in beverages, processed foods, and Western diets as food additives, and is closely related to the increased prevalence of multiple diseases, including inflammatory bowel disease (IBD). However, the detailed mechanism by which high fructose disrupts intestinal homeostasis remains elusive. The present study showed that high-fructose corn syrup (HFCS) administration exacerbated intestinal inflammation and deteriorated barrier integrity. Several in vivo experimental models were utilized to verify the importance of gut microbiota and immune cells in HFCS-mediated dextran sulfate sodium (DSS)-induced colitis. In addition, untargeted metabolomics analysis revealed the imbalance between primary bile acids (PBAs) and secondary bile acids (SBAs) in feces. Hence, high fructose was speculated to modulate gut microbiota community and reduced the relative abundance of Clostridium and Clostridium scindens at genus and species level respectively, followed by a decrease in SBAs, especially isoalloLCA, thereby affecting Th17/Treg cells equilibrium and promoting intestinal inflammation. These findings provide novel insights into the crosstalk between gut flora, bile acids, and mucosal immunity, and highlight potential strategies for precise treatment of IBD.

Associations between vitamin C intake and serum uric acid in US adults: Findings from National Health and Nutrition Examination Survey 2011-2016

BACKGROUNDS

Dietary factors has been found to influence serum uric acid (SUA) levels. We further explored the associations between dietary and supplemental vitamin C intake and SUA in a large population-based study.

METHODS

The cross-sectional study included 6308 participants (3146 males and 3162 females) aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES) 2011-2016 in the United States. The dietary vitamin C was log-transformed for statistical analysis. Hyperuricemia was defined as SUA concentrations >420 umol/L in males or >360 umol/L in females. The associations of dietary vitamin C and supplemental vitamin C with SUA levels and hyperuricemia risk were evaluated using weighted linear regression models and weighted multivariate logistic regression models, and a subgroup analysis stratified by gender was also conducted.

RESULTS

In this large-scale database study, there was a negative association between dietary vitamin C (log transformed) and SUA levels in US adults (β = -7.27, 95% CI: -11.58, -2.97). The inverse relationship existed among males but not females (P for interaction = 0.02). There was inverse correlation between dietary vitamin C (log transformed) and hyperuricemia risk (OR = 0.68, 95% CI: 0.57, 0.81), especially in males compared to females determined through an interaction test (P = 0.04). There were no associations between supplemental vitamin C and SUA levels (β = 1.00 (95% CI: -4.44, 6.44) or hyperuricemia risk (OR = 0.98 (95% CI: 0.78, 1.24). High-dosage supplemental vitamin C (>300 mg) and hyperuricemia risk were not associated (OR = 1.04, 95% CI: 0.69, 1.56).

CONCLUSIONS

This study demonstrated that there were negative associations between dietary vitamin C and SUA levels and hyperuricemia risk among US adults. The inverse correlations between dietary vitamin C and hyperuricemia risk were more significant in males compared to females. There were no associations between supplemental vitamin C and SUA levels or hyperuricemia risk.

Association between vegetarian diet and gouty arthritis: A retrospective cohort study

BACKGROUND AND AIMS

A vegetarian diet is rich in vegetables, fruits, and soy products. Although vegetarian diet is beneficial for improving the health outcomes such as body mass index, metabolic syndrome, cardiovascular disease, and mortality rate, the association between a vegetarian diet and gout incidence is not well known.

METHODS AND RESULTS

We linked the MJ Health Survey Data and MJ Biodata 2000 with the National Health Insurance Research Database (NHIRD) and the National Registration of Death (2000-2018). Information on the diet was collected from the MJ Health Survey Data, and the incidence of gouty arthritis was confirmed using the NHIRD. The Kaplan-Meier survival curve and log-rank test were used to compare the differences between vegetarian and non-vegetarian participants. Cox regression models were used to estimate the risk of the incidence of gouty arthritis. Among 76,972 participants, 37,297 (48.46%) were men, 2488 (3.23%) were vegetarians and the mean age was 41.65 ± 14.13 years. The mean baseline uric acid level was 6.14 ± 1.65 mg/dL. A total of 16,897 participants developed gouty arthritis, including 16,447 (22.08%) non-vegetarians and 450 (18.9%) vegetarians over a mean follow-up of 19 years. Significant differences were observed in the Kaplan-Meier survival curves between vegetarians and non-vegetarians (log-rank p < 0.001). Vegetarians had a significantly decreased incidence of gouty arthritis compared with non-vegetarians (hazard ratio = 0.87, 95% confidence interval = 0.78-0.98, p = 0.02) after adjusting for potential confounders.

CONCLUSION

People with a vegetarian diet had a significantly decreased risk of developing gouty arthritis compared with non-vegetarians in Taiwan.

Composite Dietary Antioxidant Index Is Negatively Associated with Hyperuricemia in US Adults: An Analysis of NHANES 2007-2018

Hyperuricemia and its complications are severe risks to human health. Dietary intervention is considered an essential part of the management of hyperuricemia. Studies have reported that the intake of antioxidants has a positive effect on hyperuricemia. Here, we collected data from 8761 participants of the National Health and Nutrition Examination Survey for this analysis. Daily intakes of vitamins A, C, and E; manganese; selenium; and zinc were calculated as the composite dietary antioxidant index (CDAI). The participants were divided into four groups (Q1, Q2, Q3, and Q4) according to the CDAI. Univariate analysis was used to assess the association of covariates with hyperuricemia. The association between the CDAI and hyperuricemia was evaluated using multinomial logistic regression, and its stability was determined by stratified analysis. Our results revealed that the CDAI has a significant negative association with hyperuricemia (Q2: 0.81 (0.69, 0.95); Q3: 0.75 (0.62, 0.90); Q4: 0.65 (0.51, 0.82); P < 0.01). The results of stratified analysis emphasize that this association between CDAI and hyperuricemia is stable. In conclusion, this study suggested a negative association between the CDAI and hyperuricemia.

Sugar, salt, immunity and the cause of primary hypertension

Despite its discovery more than 150 years ago, the cause of primary hypertension remains unknown. Most studies suggest that hypertension involves genetic, congenital or acquired risk factors that result in a relative inability of the kidney to excrete salt (sodium chloride) in the kidneys. Here we review recent studies that suggest there may be two phases, with an initial phase driven by renal vasoconstriction that causes low-grade ischemia to the kidney, followed by the infiltration of immune cells that leads to a local autoimmune reaction that maintains the renal vasoconstriction. Evidence suggests that multiple mechanisms could trigger the initial renal vasoconstriction, but one way may involve fructose that is provided in the diet (such as from table sugar or high fructose corn syrup) or produced endogenously. The fructose metabolism increases intracellular uric acid, which recruits NADPH oxidase to the mitochondria while inhibiting AMP-activated protein kinase. A drop in intracellular ATP level occurs, triggering a survival response. Leptin levels rise, triggering activation of the sympathetic central nervous system, while vasopressin levels rise, causing vasoconstriction in its own right and stimulating aldosterone production via the vasopressin 1b receptor. Low-grade renal injury and autoimmune-mediated inflammation occur. High-salt diets can amplify this process by raising osmolality and triggering more fructose production. Thus, primary hypertension may result from the overactivation of a survival response triggered by fructose metabolism. Restricting salt and sugar and hydrating with ample water may be helpful in the prevention of primary hypertension.

The Association of Food Groups and Consumption Time with Hyperuricemia: The U.S. National Health and Nutrition Examination Survey, 2005-2018

Hyperuricemia (HUA) is associated with a wide range of diseases and increases the public health burden on society as a whole. In addition to genetic variation, diet plays a crucial role in the prevention and treatment of HUA as an important modifiable behavior. The purpose of this study is to investigate whether food groups and consumption time are associated with HUA. A total of 41,230 participants from the National Health and Nutrition Examination Survey between 2005 and 2018 were included in the study. All meals, including breakfast, lunch, and dinner, were obtained according to their corresponding Food Patterns Equivalents Database dietary data. The binary logistic regression model was used to analyze the relationship between food groups, food consumption time and HUA. We found that the intake of fruit (mixed in various forms) (OR = 0.942, 95% CI: 0.909-0.976) or freshly squeezed juices (OR = 0.915, 95% CI: 0.859-0.975), milk (OR = 0.839, 95% CI: 0.808-0.872), and eggs (OR = 0.881, 95% CI: 0.839-0.924), poultry (OR = 1.055, 95% CI: 1.033-1.077) and seafood high in n-3 fatty acids (OR = 1.068, 95% CI: 0.1.018-1.120) at dinner, eating refined grains at breakfast (OR = 0.954, 95% CI: 0.924-0.985) and dinner (OR = 0.962, 95% CI: 0.944-0.980), eating whole grains (OR = 0.908, 95% CI: 0.845-0.976) at lunch, consuming alcoholic beverages or foods at breakfast (OR = 0.748, 95% CI: 0.564-0.990)/lunch (OR = 1.118, 95% CI: 1.008-1.240)/dinner (OR = 1.127, 95% CI: 1.073-1.185) were associated with HUA. Eating particular meals at particular times of the day was related to a lower risk of HUA.

High-Fructose Diet-Induced Hyperuricemia Accompanying Metabolic Syndrome-Mechanisms and Dietary Therapy Proposals

Fructose is often used as a food ingredient due to its low production costs and sweetening power. In recent years, it has been noticed that people on a Western diet high in fructose have high levels of uric acid in their blood. It was recognized that the specific metabolism of fructose in the body might cause increased production of uric acid, which then may affect the intensification of lipogenesis and the development of metabolic syndrome (MetS), insulin resistance, gout, cardiovascular diseases, leptin resistance, or non-alcoholic fatty liver disease. So far, to treat hyperuricemia, it has been recommended to use a low-purine diet characterized by limiting protein-containing products. However, this recommendation often leads to an increased intake of carbohydrate-rich foods that may contain fructose. Increased fructose consumption may enhance the secretion of uric acid again and, consequently, does not have therapeutic effects. Therefore, instead of a low-purine diet, using healthy diets, such as DASH or the Mediterranean diet, which can benefit metabolic parameters, could be a better proposal. This article provides an overview of this approach, focusing on MetS and hyperuricemia among high-fructose dieters.

Trends in risk factor control in patients with gout: data from the National Health and Nutrition Examination Survey, 2007-2018

OBJECTIVES

To explore trends in risk factor control (hypertension, diabetes mellitus, hyperlipidaemia) in patients with gout and medication use among those whose risk factor control targets were not achieved.

METHODS

We used the data from National Health and Nutrition Examination Survey (NHANES) between 2007-2008 and 2017-2018 for analyses. The study samples were weighted so that they could be representative of the non-institutionalized US population. We conducted a cross-sectional analysis to assess trends in risk factor control and medication use, and employed logistic regression analyses to explore patient characteristics associated with risk factor control.

RESULTS

The prevalence of participants in whom blood pressure control target was achieved decreased from 64.6% in 2007-2008 to 55.3% in 2017-2018 (P-value for trend = 0.03). The percentage of participants whose glycaemic, lipid or all three risk factor control targets were achieved remained stable temporally (P > 0.05). Some patient characteristics were significantly related to risk factor control, including age 45-64, age ≥65, Asian Americans, non-Hispanic Blacks, higher family income, and being overweight and obese. A trend towards increased use of glucose-lowering medication was found (from 71.0% in 2007-2008 to 94.7% in 2017-2018, P < 0.01), while the prevalence of taking blood pressure-lowering and lipid-lowering medications remained stable (P > 0.05).

CONCLUSION

Based on NHANES data, a significant trend towards decreased blood pressure control was observed in patients with gout, while glycaemic and lipid control levelled off. These findings emphasize that more endeavours are needed to improve management of cardiovascular risk factors in patients with gout.

Dietary intake of fructose increases purine de novo synthesis: A crucial mechanism for hyperuricemia

Background

Fructose consumption is a potential risk factor for hyperuricemia because uric acid (UA) is a byproduct of fructose metabolism caused by the rapid consumption of adenosine triphosphate and accumulation of adenosine monophosphate (AMP) and other purine nucleotides. Additionally, a clinical experiment with four gout patients demonstrated that intravenous infusion of fructose increased the purine de novo synthesis rate, which implied fructose-induced hyperuricemia might be related to purine nucleotide synthesis. Moreover, the mechanistic (mammalian) target of rapamycin (mTOR) is a key protein both involved in fructose metabolism and purine de novo synthesis. The present study was conducted to elucidate how fructose influences mTOR and purine de novo synthesis in a hepatic cell line and livers of mice.

Materials and methods

RNA-sequencing in NCTC 1469 cells treated with 0- and 25-mM fructose for 24 h and metabolomics analysis on the livers of mice fed with 0- and 30-g/kg fructose for 2 weeks were assessed. Gene and protein expression of phosphoribosyl pyrophosphate synthase (PRPSAP1), Glutamine PRPP aminotransferase (PPAT), adenyl succinate lyase (ADSL), adenyl succinate synthetase isozyme-1 (Adss1), inosine-5'-monophosphate dehydrogenase (IMPDH), and guanine monophosphate synthetase (GMPS) was measured. The location of PRPSAP1 and PPAT in the liver was assessed by an immunofluorescence assay.

Results

Metabolite profiling showed that the level of AMP, adenine, adenosine, hypoxanthine, and guanine was increased significantly. RNA-sequencing showed that gene expression of phosphoribosyl pyrophosphate synthase (PRPS2), phosphoribosyl glycinamide formyl transferase (GART), AICAR transformylase (ATIC), ADSL, Adss1, and IMPDH were raised, and gene expression of adenosine monophosphate deaminase 3 (AMPD3), adenosine deaminase (ADA), 5',3'-nucleotidase, cytosolic (NT5C), and xanthine oxidoreductase (XOR) was also increased significantly. Fructose increased the gene expression, protein expression, and fluorescence intensity of PRPSAP1 and PPAT in mice livers by increasing mTOR expression. Fructose increased the expression and activity of XOR, decreased the expression of uricase, and increased the serum level of UA.

Conclusion

This study demonstrated that the increased purine de novo synthesis may be a crucial mechanism for fructose-induced hyperuricemia.

Effect of Important Food Sources of Fructose-Containing Sugars on Inflammatory Biomarkers: A Systematic Review and Meta-Analysis of Controlled Feeding Trials

Background: Fructose-containing sugars as sugar-sweetened beverages (SSBs) may increase inflammatory biomarkers. Whether this effect is mediated by the food matrix at different levels of energy is unknown. To investigate the role of food source and energy, we conducted a systematic review and meta-analysis of controlled trials on the effect of different food sources of fructose-containing sugars on inflammatory markers at different levels of energy control. Methods: MEDLINE, Embase, and the Cochrane Library were searched through March 2022 for controlled feeding trials ≥ 7 days. Four trial designs were prespecified by energy control: substitution (energy matched replacement of sugars); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced). The primary outcome was C-reactive protein (CRP). Secondary outcomes were tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Independent reviewers extracted data and assessed risk of bias. GRADE assessed certainty of evidence. Results: We identified 64 controlled trials (91 trial comparisons, n = 4094) assessing 12 food sources (SSB; sweetened dairy; sweetened dairy alternative [soy]; 100% fruit juice; fruit; dried fruit; mixed fruit forms; sweetened cereal grains and bars; sweets and desserts; added nutritive [caloric] sweetener; mixed sources [with SSBs]; and mixed sources [without SSBs]) at 4 levels of energy control over a median 6-weeks in predominantly healthy mixed weight or overweight/obese adults. Total fructose-containing sugars decreased CRP in addition trials and had no effect in substitution, subtraction or ad libitum trials. No effect was observed on other outcomes at any level of energy control. There was evidence of interaction/influence by food source: substitution trials (sweetened dairy alternative (soy) and 100% fruit juice decreased, and mixed sources (with SSBs) increased CRP); and addition trials (fruit decreased CRP and TNF-α; sweets and desserts (dark chocolate) decreased IL-6). The certainty of evidence was moderate-to-low for the majority of analyses. Conclusions: Food source appears to mediate the effect of fructose-containing sugars on inflammatory markers over the short-to-medium term. The evidence provides good indication that mixed sources that contain SSBs increase CRP, while most other food sources have no effect with some sources (fruit, 100% fruit juice, sweetened soy beverage or dark chocolate) showing decreases, which may be dependent on energy control. Clinicaltrials.gov: (NCT02716870).

Are Nutraceuticals Effective in COVID-19 and Post-COVID Prevention and Treatment?

The beginning of the end or the end of the beginning? After two years mastered by coronavirus disease 19 (COVID-19) pandemic, we are now witnessing a turnaround. The reduction of severe cases and deaths from COVID-19 led to increasing importance of a new disease called post-COVID syndrome. The term post-COVID is used to indicate permanency of symptoms in patients who have recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Immune, antiviral, antimicrobial therapies, as well as ozone therapy have been used to treat COVID-19 disease. Vaccines have then become available and administered worldwide to prevent the insurgence of the disease. However, the pandemic is not over yet at all given the emergence of new omicron variants. New therapeutic strategies are urgently needed. In this view, great interest was found in nutraceutical products, including vitamins (C, D, and E), minerals (zinc), melatonin, probiotics, flavonoids (quercetin), and curcumin. This review summarizes the role of nutraceuticals in the prevention and/or treatment of COVID-19 disease and post-COVID syndrome.

Higher HEI-2015 scores are associated with lower risk of gout and hyperuricemia: Results from the national health and nutrition examination survey 2007-2016

Gout, the most prevalent inflammatory arthritis, is becoming increasingly prevalent in the United States and across the world, and it adversely impacts people’s quality of life and their health. Few studies have focused on the relationship between daily dietary quality and gout, so the topic requires further exploration. Data were derived from the National Health and Nutrition Examination Survey 2007–2016, and the inclusion criteria of the analytic sample were (1) adults, age ≥20 years, with complete information about HEI-2015, gout, and uric acid; (2) complete information of demographics, lifestyle (BMI, smoking, drinking), and disease history [hypertension, chronic kidney disease (CKD), diabetes]. The quality of the daily diet was reflected using the Healthy Eating Index 2015 (HEI-2015). The baseline features of different groups were examined using the Scott-Rao chi-square tests, and the association between the HEI-2015 score and the risk of gout/hyperuricemia (HUA) was investigated using weighted logistic regression models. The effects of different dietary components in the HEI-2015 on reducing the risk of gout/HUA were evaluated by weighted quantile sum (WQS) regression models. After adjusting for demographic characteristics, behavioral covariates, and disease history, higher HEI-2015 scores were associated with a significantly lower risk of gout (OR: 0.878, 95% CI: 0.876–0.880) and HUA (OR: 0.978, 95% CI: 0.976–0.979) in weighted logistic regression. Dairy, whole grains, plant proteins, and added sugar contributed greatly in HEI-2015 to reducing gout risk (weights of WQS index: 42, 17.18, 16.13, and 7.93%, respectively). Dairy, total fruits, greens and beans, and plant proteins contributed greatly in HEI-2015 to reducing HUA risk (weights of WQS index: 28.9, 17.13, 16.84, and 11.39%, respectively). As the result, adherence to the American Dietary Guidelines may assist to decrease the risk of gout/HUA in American adults, and greater emphasis should be placed on dairy products, whole grains, fruits, legumes, and added sugars.

Gut microbiota remodeling: A promising therapeutic strategy to confront hyperuricemia and gout

The incidence of hyperuricemia (HUA) and gout continuously increases and has become a major public health problem. The gut microbiota, which colonizes the human intestine, has a mutually beneficial and symbiotic relationship with the host and plays a vital role in the host’s metabolism and immune regulation. Structural changes or imbalance in the gut microbiota could cause metabolic disorders and participate in the synthesis of purine-metabolizing enzymes and the release of inflammatory cytokines, which is closely related to the occurrence and development of the metabolic immune disease HUA and gout. The gut microbiota as an entry point to explore the pathogenesis of HUA and gout has become a new research hotspot. This review summarizes the characteristics of the gut microbiota in patients with HUA and gout. Meanwhile, the influence of different dietary structures on the gut microbiota, the effect of the gut microbiota on purine and uric acid metabolism, and the internal relationship between the gut microbiota and metabolic endotoxemia/inflammatory factors are explored. Moreover, the intervention effects of probiotics, prebiotics, and fecal microbial transplantation on HUA and gout are also systematically reviewed to provide a gut flora solution for the prevention and treatment of related diseases.

Temporal changes in serum uric acid and risk for metabolic syndrome: a longitudinal cohort study

BACKGROUND

Studies suggested elevated serum uric acid (SUA) levels are associated with metabolic syndrome (MetS). However, it remains unclear whether baseline SUA and temporal changes predict MetS. The study aimed to investigate the association of baseline SUA and its temporal longitudinal changes with subsequent risk of MetS.

METHODS

We conducted a retrospective longitudinal cohort study among 44,176 healthy participants aged 18 years and older without MetS at enrollment. The baseline levels and longitudinal changes of SUA were categorized by gender-specific quintiles. Participants were followed to identify newly developed MetS. We employed Cox model to investigate the relationship between SUA and MetS in men and women separately.

RESULTS

During a median follow-up of 2.4 years, 5461 (12.36%) participants developed MetS. After adjustment of demographic, major clinical factors, a higher level of baseline SUA was associated with a significant higher risk of MetS. The corresponding HRs (95% CIs) comparing participants at extreme quintiles were 2.59 (2.32, 2.88) in men and 2.87 (2.41, 3.43) in women. Larger longitudinal absolute increase in SUA was also related to an increases risk of MetS (top vs bottom quintile, 1.70 [1.53, 1.89] in men and 1.94 [1.65, 2.28] in women), regardless the level of baseline SUA. Similarly, the HRs about SUA longitudinal percentage changes were 1.74 (1.56, 1.94) in men and 2.01 (1.69, 2.39) in women, respectively. Moreover, we observed the highest risk of MetS among participants with both higher baseline SUA and larger longitudinal increase in SUA.

CONCLUSION

Higher baseline SUA and larger temporal increase in SUA independently predicted risk of MetS, highlighting the importance of longitudinal SUA monitoring and management for primary prevention of MetS in the general population.

The Interaction Between Dietary Fructose and Gut Microbiota in Hyperuricemia and Gout

With the worldwide epidemics of hyperuricemia and associated gout, the diseases with purine metabolic disorders have become a serious threat to human public health. Accumulating evidence has shown that they have been linked to increased consumption of fructose in humans, we hereby made a timely review on the roles of fructose intake and the gut microbiota in regulating purine metabolism, together with the potential mechanisms by which excessive fructose intake contributes to hyperuricemia and gout. To this end, we focus on the understanding of the interaction between a fructose-rich diet and the gut microbiota in hyperuricemia and gout to seek for safe, cheap, and side-effect-free clinical interventions. Furthermore, fructose intake recommendations for hyperuricemia and gout patients, as well as the variety of probiotics and prebiotics with uric acid-lowering effects targeting the intestinal tract are also summarized to provide reference and guidance for the further research.

Hyperuricemia: Features of the Diet

The association of hyperuricemia (HU) with cardiovascular disease (CVD), diabetes, metabolic syndrome, and kidney disease has been demonstrated in numerous studies. НU is the main pathogenetic factor in the development of gout and is associated with an increase in overall and cardiovascular mortality. НU is included in the list of factors determining cardiovascular risk. According to epidemiological studies, there is a high prevalence of HU in the world and its increase in recent decades. A number of factors have been identified that contribute to the increased risk of НU. Non-modifiable factors include gender, age, genetic factors, and modifiable factors include diet and lifestyle. Nutritional unbalances, increased life expectancy, increased prevalence of obesity, and increased use of drugs (especially diuretics) are seen as contributing factors to the rise in НU. The review was carried out to summarize the available information on the effect of dietary habits, individual foods and nutrients on serum uric acid (SUA) levels and the risk of developing HU. The review presents the results of scientific studies demonstrating the relationship of НU with the consumption of foods rich in purines (offal, red meat, fish, seafood, legumes), alcohol consumption, drinks sweetened with fructose, coffee, dairy products, vegetables and fruits. Diet correction is an important and necessary step in the prevention and treatment of НU. The article reviews the basic principles of dietary management in HU and provides dietary recommendations for patients. For effective prevention and treatment of НU, a mandatory correction of the diet is required.

Renal Tubular Handling of Glucose and Fructose in Health and Disease

The proximal tubule of the kidney is programmed to reabsorb all filtered glucose and fructose. Glucose is taken up by apical sodium-glucose cotransporters SGLT2 and SGLT1 whereas SGLT5 and potentially SGLT4 and GLUT5 have been implicated in apical fructose uptake. The glucose taken up by the proximal tubule is typically not metabolized but leaves via the basolateral facilitative glucose transporter GLUT2 and is returned to the systemic circulation or used as an energy source by distal tubular segments after basolateral uptake via GLUT1. The proximal tubule generates new glucose in metabolic acidosis and the postabsorptive phase, and fructose serves as an important substrate. In fact, under physiological conditions and intake, fructose taken up by proximal tubules is primarily utilized for gluconeogenesis. In the diabetic kidney, glucose is retained and gluconeogenesis enhanced, the latter in part driven by fructose. This is maladaptive as it sustains hyperglycemia. Moreover, renal glucose retention is coupled to sodium retention through SGLT2 and SGLT1, which induces secondary deleterious effects. SGLT2 inhibitors are new anti-hyperglycemic drugs that can protect the kidneys and heart from failing independent of kidney function and diabetes. Dietary excess of fructose also induces tubular injury. This can be magnified by kidney formation of fructose under pathological conditions. Fructose metabolism is linked to urate formation, which partially accounts for fructose-induced tubular injury, inflammation, and hemodynamic alterations. Fructose metabolism favors glycolysis over mitochondrial respiration as urate suppresses aconitase in the tricarboxylic acid cycle, and has been linked to potentially detrimental aerobic glycolysis (Warburg effect). © 2022 American Physiological Society. Compr Physiol 12:2995-3044, 2022.

Quality Characteristics and Inhibitory Xanthine Oxidase Potential of 21 Sour Cherry (Prunus Cerasus L.) Varieties Cultivated in China

This study aims to analyze the physicochemical characteristics and activities of 21 sour cherry cultivars in China. The evaluated accessions differ in several quality traits including weight, moisture, color, total soluble solids, and total acids. Glucose and malic acid were the predominant individual sugar and organic acid in all accessions. The potassium (K) and iron (Fe) were of the highest contents in Érid jubileum (453.887 mg/100 g FW) and Meili (2.988 mg/100 g FW), respectively. The contents of total phenolics (TP) were from 9.309 to 24.118 mg GAE/g DW, and total flavonoids (TF) were 8.935–27.198 mg RE/g DW, which were highly positively correlated (r = 0.892, p < 0.001). M-15, Érdi fubileum, and Érid jubileum showed the highest inhibitory effects on xanthine oxidase, and the IC₅₀ inhibitory were 2.619, 3.117, and 3.940 mg/ml, respectively. This work evaluated the quality and nutritional characteristics of 21 sour cherry cultivars grown in China and explored their potential as an innovative food ingredient for hyperuricemia by evaluating the inhibitory effects of xanthine oxidase. And these results provide valuable data and new ideas for the future sour cherry breeding program as well as a processing guide.

Fructose in the kidney: from physiology to pathology

The Warburg effect is a unique property of cancer cells, in which glycolysis is activated instead of mitochondrial respiration despite oxygen availability. However, recent studies found that the Warburg effect also mediates non-cancer disorders, including kidney disease. Currently, diabetes or glucose has been postulated to mediate the Warburg effect in the kidney, but it is of importance that the Warburg effect can be induced under nondiabetic conditions. Fructose is endogenously produced in several organs, including the kidney, under both physiological and pathological conditions. In the kidney, fructose is predominantly metabolized in the proximal tubules; under normal physiologic conditions, fructose is utilized as a substrate for gluconeogenesis and contributes to maintain systemic glucose concentration under starvation conditions. However, when present in excess, fructose likely becomes deleterious, possibly due in part to excessive uric acid, which is a by-product of fructose metabolism. A potential mechanism is that uric acid suppresses aconitase in the Krebs cycle and therefore reduces mitochondrial oxidation. Consequently, fructose favors glycolysis over mitochondrial respiration, a process that is similar to the Warburg effect in cancer cells. Activation of glycolysis also links to several side pathways, including the pentose phosphate pathway, hexosamine pathway, and lipid synthesis, to provide biosynthetic precursors as fuel for renal inflammation and fibrosis. We now hypothesize that fructose could be the mediator for the Warburg effect in the kidney and a potential mechanism for chronic kidney disease.

Russian Society for the Prevention of Noncommunicable Diseases (ROPNIZ). Alimentary-dependent risk factors for chronic non-communicable diseases and eating habits: dietary correction within the framework of preventive counseling. Methodological Guidelines

The methodological guidelines are developed as a practical document for medical specialists working in the field of preventive medicine, in order to expand and improve the provision of this type of medical service to the adult population. The methodological guidelines include an informational and informative part for medical specialists and a practical part for patients, presented in the format of memos, contain the main sections-healthy nutrition, correction of eating habits, issues of modifying the diet for the main alimentary-dependent risk factors for chronic non-communicable diseases, such as arterial hypertension, obesity, disorders of lipid, carbohydrate and purine metabolism, a decrease in bone mineral density. They are intended for medical specialists working in the field of prevention, for doctors and secondary medical personnel of offices and departments of medical prevention, public health and medical prevention centers, healthy lifestyle specialists, teachers of medical educational institutions, for specialists who develop and implement educational programs for patients, as well as for medical specialists of a therapeutic profile.

A review on the fruit components affecting uric acid level and their underlying mechanisms

Uric acid (UA) is produced in the liver and excreted through the kidneys and intestines. If UA is overproduced or its excretion reduces, the concentration of UA increases, leading to hyperuricemia and gout. The high concentration of UA is also related to cardiovascular disease, hypertension, obesity, and other diseases. Fruits are healthy foods. However, fruits contain fructose and small amounts of purine, and the product of their metabolism is UA. Therefore, theoretically, eating fruits will increase the concentration of serum UA. Fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In addition to the UA synthesized by fructose and purine metabolism, the mechanisms by which other components affect the concentration of serum UA can be summarized as follows: (a) inhibiting xanthine oxidase; (b) reducing reabsorption of UA; and (c) improving the excretion of UA. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations, and explained their mechanisms for the first time, which references for patients with hyperuricemia to take fruits. PRACTICAL APPLICATIONS: With the rising prevalence, hyperuricemia and gout have become public health problems that endanger our daily life. The key to the treatment of hyperuricemia is to control the level of serum UA within the normal range. Fruits are healthy foods. However, fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations. We also explained their mechanisms, which references for patients with hyperuricemia to take fruits.

The Relationship Between Dietary Choices and Health and Premature Vascular Ageing

The paper aims to review the available data about the main mechanisms enabling improvement or accelerating vascular ageing due to food choices, considering recent experimental and clinical data, and emphasising potential implications for clinical practice and therapy. The main food choices which will be discussed are diets rich in fruits and vegetables, the Mediterranean diet, polyunsaturated fatty acids, cocoa, caffeine, tea, meat, dairy products, sodium, and potassium intake.

MicroRNAs Involved in the Therapeutic Functions of Noni (Morinda citrifolia L.) Fruit Juice in the Treatment of Acute Gouty Arthritis in Mice Induced with Monosodium Urate

We investigated the functions of microRNAs in the therapeutic effects of noni (Morinda citrifolia L.) fruit juice on mouse models of acute gouty arthritis induced with monosodium urate (MSU). Compared with the model group (treated with MSU), mice in both the positive control group (treated with both MSU and colchicine) and noni fruit juice group (treated with MSU and noni fruit juice) showed a significantly decreased degree of paw swelling in 5 days, as well as the contents of two types of proinflammatory cytokines (i.e., NALP3 and TNF-α). Based on the next-generation sequencing technology, a total of 3896 microRNAs (234 known and 3662 novel) were identified in mice treated with noni fruit juice. A large amount of differentially expressed miRNAs were identified in the noni fruit juice group, suggesting the significant effects of noni fruit juice on the mice with acute gouty arthritis, while the different patterns of change in the numbers of both upregulated and downregulated miRNAs in both noni fruit juice and positive control groups indicated that the mice of acute gouty arthritis may be regulated by differential mechanisms between the treatments of noni fruit juice and colchicine. The target genes of microRNAs involved in the pathogenesis and pathology of acute gouty arthritis in mice were identified and further annotated by both Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Our results revealed the therapeutic effects of noni fruit juice on acute gouty arthritis in mice with a group of microRNAs involved in the pharmacological mechanisms of noni fruit juice, providing scientific evidence to support both the agricultural cultivation and pharmacological significance of noni plants.

No Effect of Added Sugars in Soft Drink Compared With Sugars in Fruit on Cardiometabolic Risk Factors: Results From a 4-Week, Randomized Controlled Trial

High intakes of added sugar from soft drinks are associated with negative health outcomes such as the increased risk of gout and type 2 diabetes, weight gain and cardiovascular disease. Fruits are naturally high in sugars but their effect on cardiometabolic risk remains unknown. We examined the effect on cardiometabolic risk factors of consuming natural sugars from fruit or added sugars from sugar-sweetened soft drinks in overweight adults. Forty-eight healthy, overweight (BMI ≥ 28 kg/m²) men (n = 21) and women (n = 20) were randomized to either a fruit (n = 19) or sugar-sweetened soft drink (n = 22) intervention for 4 weeks. The fruit group received 6 items of fresh and dried fruit per day and the sugar-sweetened soft drink group received 955 ml of sugar-sweetened soft drink per day. The interventions were matched for both energy (fruit: 1,800 kJ/d; soft drink: 1,767 kJ/d) and fructose content (fruit: 51.8 g/d; soft drink: 51.7 g/d). The soft drink intervention provided 101 g total sugars, which was all added sugar and the fruit intervention provided 97 g total sugars, which were all natural sugars. Dietary intakes were otherwise ad libitum. Despite being asked to consume additional sugar (up to 1,800 additional kJ/d), there were no changes in weight, blood pressure or other cardiometabolic risk factors, except by uric acid, in any of the intervention groups. In conclusion, our findings do not provide any evidence that short-term regular intake of added sugars is linked to higher cardiometabolic risks, with exception of uric acid in overweight men. Public health interventions to prevent obesity and related diseases should focus on the quality of the whole diet rather than only focusing on reducing sugary drinks or sugar intakes.

Association Between Dietary Intake and Serum Uric Acid Levels in Kidney Transplant Patients

OBJECTIVES

The aim of this study was to evaluate the association between dietary intake and uric acid (UA) levels in kidney transplant patients (KTPs).

METHODS

A cross-sectional study was performed with 113 KTPs. Dietary intake assessment was carried out thorough two 24-hour dietary recalls using the 5-step multiple pass method. We evaluated the intake of energy, carbohydrate, total protein, animal protein, vegetable protein, total fat, saturated fat, trans fat, monounsaturated fat, polyunsaturated fat, omega-3 and omega-6 fatty acids, cholesterol, total sugar, added sugars, total fiber, insoluble fiber, soluble fiber, alcohol, caffeine, fructose, glucose, lactose, sucrose, vitamin A, vitamin C, vitamin E, and calcium. The intake of several food groups (portions) was also evaluated. Hyperuricemia was classified as >7.0 and >6 mg/dL for men and women, respectively.

RESULTS

In odds ratio analyses, the individuals who ingested more vegetable protein (g/kg) and caffeine (mg) presented lower chance to have hyperuricemia. In linear regression, animal protein (g) intake was positively associated (β = 0.011, P = .048), while vegetable protein (g/kg) intake was inversely associated (β = -2.45, P = .047) with serum UA. However, after a multiple linear regression including vegetable and animal protein intakes together, only vegetable protein intake remained associated with UA. The intake of other nutrients and portions of food groups was not associated with UA. All the analyses were adjusted for sex, age, hypertension, body mass index, glomerular filtration rate, use of medicines, and caloric intake misreporting.

CONCLUSIONS

Vegetable protein and caffeine intakes were inversely associated with UA in KTPs.

Role of Vitamin C in Prophylaxis and Treatment of Gout-A Literature Review

Gout, known as “the disease of the kings”, is the most frequent type of arthritis. It results from sustained hyperuricemia that leads to monosodium urate crystal deposition in joint structures and soft tissue. Environmental factors such as diet affect the incidence of gout; there is a known relationship between the occurrence of an acute attack of gout and the consumption of alcohol and meat; and a low purine diet is a widely recognized nonpharmacological method of supplementing the treatment and preventing recurrence of arthritis. This review aims to summarize the current knowledge about the role of vitamin C in prevention and treatment of gout. A PubMed/Medline database search on the role of vitamin C in purine metabolism was done. Reports from in vitro and animal studies seem to be promising and to allow explanation of the physiological relationship between vitamin C and uric acid. Most epidemiological studies indicate a significant correlation between high vitamin C intake and lower serum uric acid levels. Despite promising observations, there are few observational and interventional studies, and their results do not clearly define the benefits of a high daily intake of vitamin C in preventing the development and recurrence of gout.

Effects of quercetin and metabolites on uric acid biosynthesis and consequences for gene expression in the endothelium

BACKGROUND

Uric acid, a metabolic product of purine degradation in humans, is a risk factor for developing gout and type 2 diabetes, and supplementation with quercetin lowers plasma uric acid in mildly hyperuricemic men. Here we examined the mechanism of inhibition of enzymes involved in uric acid metabolism by quercetin, conjugates and microbial catabolites, and measured the effect of lowered circulating uric acid on endothelial cell gene expression.

METHODS

Inhibition of adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP) and xanthine oxidoreductase (XOR) activity by quercetin and metabolites was determined by HPLC. Human umbilical vein endothelial cells (HUVECs) were cultured under conditions mimicking blood flow, treated with uric acid (0, 300 or 500 μmol/L), and changes in gene expression measured using transcriptomics and quantitative droplet digital PCR.

RESULTS

In human plasma, no inhibition of PNP activity was observed, and only quercetin weakly inhibited ADA. XOR was not present at sufficient amount in human plasma to use for testing, but quercetin, quercetin-3'-sulfate and the gut microbial metabolite 3',4'-dihydroxyphenylacetic acid inhibited bovine milk XOR. Several changes were observed in gene expression in HUVECs under flow compared to static conditions, but after uric acid treatment, only very few changes were detected.

CONCLUSIONS

We propose that the main mechanism by which quercetin, as quercetin-3'-sulfate, lowers uric acid in vivo is through inhibition of XOR, and not ADA nor PNP. The pertinent shift in uric acid concentration was not sufficient to produce significant changes in endothelial gene expression in a cell model.

Organismal Fructose Metabolism in Health and Non-Alcoholic Fatty Liver Disease

NAFLD has alarmingly increased, yet FDA-approved drugs are still lacking. An excessive intake of fructose, especially in liquid form, is a dietary risk factor of NAFLD. While fructose metabolism has been studied for decades, it is still controversial how fructose intake can cause NAFLD. It has long been believed that fructose metabolism solely happens in the liver and accordingly, numerous studies have investigated liver fructose metabolism using primary hepatocytes or liver cell lines in culture. While cultured cells are useful for studying detailed signaling pathways and metabolism in a cell-autonomous manner, it is equally important to understand fructose metabolism at the whole-body level in live organisms. In this regard, recent in vivo studies using genetically modified mice and stable isotope tracing have tremendously expanded our understanding of the complex interaction between fructose-catabolizing organs and gut microbiota. Here, we discuss how the aberrant distribution of fructose metabolism between organs and gut microbiota can contribute to NAFLD. We also address potential therapeutic interventions of fructose-elicited NAFLD.

Recent advances in fructose intake and risk of hyperuricemia

With the widespread popularity of hyperuricemia, it has become a severe threat to human public health. Accumulating evidence suggests that dietary fructose has a close relationship with hyperuricemia, but the role of fructose intake in hyperuricemia remains unclear. Hyperuricemia is characterized by excessive production and deposition of urate crystals. Metabolism of fructose leads to the increased serum concentration of urate. In this review, we depict an update of fructose consumption worldwide and the epidemiology of hyperuricemia and summarize the progress in studying the relationship between fructose intake and the risk of hyperuricemia. This review highlights the metabolic process of fructose in the liver, small intestine, and kidney. Furthermore, we discuss molecular insights on fructose metabolism to reveal the underlying mechanism of fructose metabolism. Additionally, we elaborate on the effect of fructose metabolism on hyperuricemia to deeply understand the pathogenesis of hyperuricemia caused by fructose intake. Fructose consumption has a close correlation with an enhanced risk of developing hyperuricemia. More prospective studies are inevitable to understand the role of fructose intake in the development of hyperuricemia.

Hyperuricemia and Hypertension: Links and Risks

Hyperuricemia has long been recognized to be associated with increased cardiovascular risk, including risk of developing hypertension. Epidemiological findings suggest that the link with hypertension is stronger in children and adolescents. Uric acid acts as a strong antioxidant compound in the extracellular environment but has pro-inflammatory effects within the intracellular setting. A chronic phase of microvascular injury is known to occur after prolonged periods of hyperuricemia. This is proposed to contribute to afferent arteriolopathy and elevation of blood pressure that may become unresponsive to uric acid-lowering therapies over time. Studies have struggled to infer direct causality of hyperuricemia due to a vast number of confounders including body mass index. The aim of this review is to present the available data and highlight the need for large scale prospective randomized controlled trials in this area. At present, there is limited evidence to support a role for uric acid-lowering therapies in helping mitigate the risk of hypertension.

Effectiveness of Cherries in Reducing Uric Acid and Gout: A Systematic Review

Background

Previous studies have reported the use of complementary therapies to reduce the risk of gout attacks. In this study, we assessed the effectiveness of cherries in reducing uric acid levels associated with gout.

Methods

We searched for relevant studies on PubMed, Embase, and the Cochrane Library without restrictions on language from inception until August 15, 2019. The risk of bias was evaluated using the PRISMA statement and checklist, and the methodological quality was assessed using the Cochrane Collaboration tool.

Results

The six studies included in this systematic review reported decreases in the incidence and severity of gout following the ingestion of cherries. Gout patients regularly ingesting cherry extract/juice reported fewer gout flare ups than those patients who did not supplement their diets with cherry products. Overall, we observed a positive correlation between the consumption of tart cherry juice and a decrease in serum uric acid concentration.

Conclusions

Current evidence supports an association between cherry intake and a reduced risk of gout attacks. Note however that we were unable to conduct effective meta-analysis due to a lack of relevant studies and a high degree of variation in the methodologies and metrics used in previous studies. Further comprehensive trials or long-term follow-up studies will be required to evaluate the efficacy of cherry intake in treating patients with gout or hyperuricemia.

Arterial Stiffness, Sugar-Sweetened Beverages and Fruits Intake in a Rural Population Sample: Data from the Brisighella Heart Study

Introduction: There is conflicting information linking fruit and fructose intake with cardiometabolic disorders. The main objective of our study was to evaluate the association between intake of fruits and sugar-sweetened beverages, and carotid-femoral pulse wave velocity (cfPWV), a non-invasive marker of arterial aging, in a large population sample. Methods: For this study, we selected four age and sex-matched subgroups from the last Brisighella Heart Study population survey, after exclusion of those in secondary prevention for cardiovascular diseases, affected by gout and moderate-to-severe chronic kidney disease (defined as eGFR < 60 mL/min), and/or actively treated with direct vasodilating drugs (calcium-antagonists, alpha-blockers, nitrates). The remaining subjects were classified into four groups: (1) low fruit and low sugar-sweetened beverage intake (LFLB), (2) high fruit and low sugar-sweetened beverage intake (HFLB), (3) low fruit and high sugar-sweetened beverage intake (LFHB), (4) high fruit and high sugar-sweetened beverage intake (HFHB). Results: CfPWV was significantly elevated in subjects consuming a higher fructose load, particularly when it was derived from industrially sweetened beverages (pooled LFHB & HFHB: 9.6 ± 2.3 m/s; pooled LFLB & HFLB: 8.6 ± 2.3 m/s, p < 0.001). Moreover, the main predictors of cfPWV values were serum uric acid (B = 0.391, 95%CI 0.321–0.486, p = 0.001), fructose load from both fruits and sugar-sweetened beverages (B = 0.310, 95%CI 0.099–0.522, p = 0.004), triglycerides (B = 0.228, 95%CI 0.117–0.389, p = 0.018), fasting plasma glucose (B = 0.015, 95%CI 0.008–0.022, p < 0.001) and estimated Glomerular Filtration Rate (B = −0.043, 95%CI −0.052–−0.035, p < 0.001). Conclusion: our data suggest that increased intake of fructose derived from industrial sweetened beverages, though not from fruits, is associated with higher pulse wave velocity.

Uric Acid and Plant-Based Nutrition

Plant-based diets (PBDs) are associated with decreased risk of morbidity and mortality associated with important noncommunicable chronic diseases. Similar to animal-based food sources (e.g., meat, fish, and animal visceral organs), some plant-based food sources (e.g., certain soy legume products, sea vegetables, and brassica vegetables) also contain a high purine load. Suboptimally designed PBDs might consequently be associated with increased uric acid levels and gout development. Here, we review the available data on this topic, with a great majority of studies showing reduced risk of hyperuricemia and gout with vegetarian (especially lacto-vegetarian) PBDs. Additionally, type of ingested purines, fiber, vitamin C, and certain lifestyle factors work in concordance to reduce uric acid generation in PBDs. Recent limited data show that even with an exclusive PBD, uric acid concentrations remain in the normal range in short- and long-term dieters. The reasonable consumption of plant foods with a higher purine content as a part of PBDs may therefore be safely tolerated in normouricemic individuals, but additional data is needed in hyperuricemic individuals, especially those with chronic kidney disease.

Association of dietary fiber intake with hyperuricemia in U.S. adults

Current evidence on the relationship between dietary fiber intake and risk of hyperuricemia is limited.