Article

Influence of grapefruit-, orange- and apple-juice consumption on urinary variables and risk of crystallization

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Abstract

Alkalizing beverages are highly effective in preventing the recurrence of calcium oxalate (Ox), uric acid and cystine lithiasis. The aim of the present study was to evaluate the influence of grapefruit-juice and apple-juice consumption on the excretion of urinary variables and the risk of crystallization in comparison with orange juice. All investigations were carried out on nine healthy female subjects without any history of stone formation and aged 26-35 years. Each juice was tested in a 5 d study. During the study, the subjects received a standardized diet. Fluid intake of 2.75 litres was composed of 2.25 litres neutral mineral water, 0.4 litre coffee and 0.1 litre milk. On the fourth and fifth day 0.5 litre mineral water was partly substituted by 0.5 or 1.0 litre juice under investigation respectively. The influence on urinary variables was evaluated in 24 h urine samples. In addition, the BONN risk index of CaOx, relative supersaturation (RS)CaOx crystallization was determined. Due to an increased pH value and an increased citric acid excretion after consumption of each juice, the RSCaOx decreased statistically significantly (P<0.05) for grapefruit juice, but not significantly for orange and apple juice. The BONN risk index yielded a distinct decrease in the crystallization risk. We showed that both grapefruit juice and apple juice reduce the risk of CaOx stone formation at a magnitude comparable with the effects obtained from orange juice.

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... While physiologically, orange juice (OJ) has been shown in short-term metabolic studies to promote alkaline urine and a citraturic response [27,39], the recommendation for lemonade therapy remains prevalent among practitioners. OJ was directly compared to lemonade therapy in two metabolic studies (Table 1) [31,37]. ...
... Other fruit juices were also explored with regard to their effect on stone formation. Grapefruit juice was shown in several short-term metabolic studies to promote a number of favorable changes in urinary parameters, including an increase in urinary citrate [39,41,42]. However, one study additionally demonstrated an increase in urinary oxalate such that the net effect was no change in urinary saturation of calcium oxalate [41]. ...
... Studies of other juices are limited. Metabolic studies in women found that daily consumption of 0.5-1 L of apple juice significantly increased urinary citrate without a significant impact on the supersaturation of CaOx, calcium phosphate, or UA [39]. However, pooled analysis of the NHS I, NHS II, and HPFS did not demonstrate a benefit of apple juice with respect to the risk of incident stone formation [40]. ...
Article
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Diet plays a central role in the development and prevention of nephrolithiasis. Although pharmacologic treatment may be required for some patients who are resistant to dietary measures alone, dietary modification may be sufficient to modulate stone risk for many patients. While there is no single specialized diet for stone prevention, several dietary principles and recommendations for stone prevention are supported by practice guidelines, including adequate fluid intake, modest calcium intake, low dietary sodium, and limited animal protein. In this review, we summarized the evidence supporting these dietary recommendations and reviewed the current literature regarding specific dietary components and comprehensive diets for stone prevention.
... Four cross-sectional studies [17][18][19][20] looked at a range of fluids: oligomineral water and bicarbonate-alkaline mineral water, [17] blackcurrant, cranberry, and plum, [18] and grapefruit, orange, and apple juices. [19] All four studies were conducted in European countries and all arms within each study were completed within 1 month. ...
... Four cross-sectional studies [17][18][19][20] looked at a range of fluids: oligomineral water and bicarbonate-alkaline mineral water, [17] blackcurrant, cranberry, and plum, [18] and grapefruit, orange, and apple juices. [19] All four studies were conducted in European countries and all arms within each study were completed within 1 month. Urinary parameters were analyzed to look for biochemical changes between beverages via 24-h urine collections and relative supersaturation values were calculated to assess the risk of future stone formation. ...
... All four cross-sectional studies [17][18][19][20] were conducted on healthy participants with no previous history of KSD. Sample sizes varied between all four studies (range: 9-48 participants) [17][18][19][20] with majority between 20 and 40 years of age, of which two studies focused solely on either males or females. ...
Article
Objective: The incidence of kidney stone disease (KSD) is rising worldwide; hence, more focus must be directed toward its etiology and risk factors. Increasing fluid intake is recommended as the most ideal prevention; yet, there is inconsistent evidence surrounding optimum volumes and types of fluid that affect stone formation. This review aimed to analyze the published literature on fluid intake and types of fluid consumed and their impact on KSD prevention. Material and methods: Papers were acquired from databases: MEDLINE, EMBASE, PubMed, CINAHL, and Cochrane Library. Included English language studies that involved adults consuming beverages along with a standardized diet in relation to KSD. Those failing to control dietary factors were excluded. Results: After an initial search of 1099 papers, 9 (541 participants) were included in the final review. Six varieties of water and ten different types of juices were investigated. Higher fluid intake was associated with increased urine output and reduced stone formation. Water with high calcium content seemingly increased the rate of calcium oxalate (CaOx) stone formation. The relative supersaturation of CaOx in urine was decreased with grapefruit, apple, orange juices, and sodas, whereas cranberry juice increased it. Plum juice and the energy drink Gatorade had no effect on stone formation. Conclusion: Fluids low in calcium seem to reduce the risk of KSD. Certain varieties of fluid, such as grapefruit, apple, and orange juices reduce urine CaOx saturation, with a subsequent reduction in stone formation. Findings from this review could contribute to primary prevention for those at risk of KSD.
... Although orange juice has been demonstrated to increase urinary pH and citrate excretion, no significant decline in the relative supersaturation for calcium oxalate was observed in interventional studies [31,32]. In accordance with these results, no association between the consumption of orange juice and the risk of stone formation was found in prospective cohort studies in men and women [33,34]. ...
... Whereas epidemiological studies by Curhan et al. revealed a positive association between grapefruit juice and risk of stone formation in men and women, no changes in lithogenicity were observed by Goldfarb and Asplin in healthy men and women [33,34,36]. On the contrary, Hönow et al. were able to demonstrate a significant reduction in the relative supersaturation with calcium oxalate [31]. ...
... Data from a prospective cohort study over 12 years suggested a positive association between the intake of orange juice and the risk of gout in men [42]. However, interventional trials revealed a significant decrease in urinary undissociated uric acid levels and the relative supersaturation for uric acid [31,32]. ...
Article
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The formation of various types of stones in the urinary tract is strongly influenced by urinary pH. An acidic urinary pH promotes the crystallization of uric acid and cystine, respectively. Moreover, changes in systemic acid-base homeostasis alter urinary excretion of citrate, an important inhibitor of calcium oxalate stone formation. The effect of beverages on urinary pH and citrate excretion is mainly determined by the presence of bicarbonate and citrate. The bicarbonate content of mineral water can replace alkalization therapy with potassium citrate and contribute to urine inhibitory power by increasing urinary pH and citrate excretion. Citrus juices are rich sources of citrate. Oral citrate is absorbed in the intestine and nearly completely metabolized to bicarbonate, providing an alkali load, which in turn increases urinary pH and citrate excretion. However, data from observational and interventional studies on the effect of different types of citrus juices on the risk of urinary stone formation are conflicting. In conclusion, favourable changes in urinary pH and citrate excretion can be attained by various beverages. However, the long-term efficacy of certain beverages for the recurrence prevention of different types of stones has yet to be determined.
... Small prospective clinical studies found that orange, melon, grapefruit, and lemon juices increased urinary citrate levels [13][14][15][16][17][18][19][20][21]. Baia et al., for example, showed that citrate increased after 4 h of ingestion to 0.35 ± 0.15 vs. baseline of 0.22 ± 0.10 mg/mg creatinine in the melon group, 0.32 ± 0.17 vs. baseline of 0.14 ± 0.09 mg/mg creatinine in the orange group, and to 0.29 ± 0.21 vs. baseline of 0.15 ± 0.12 mg/mg creatinine in the lime group. ...
... Lemonade consumption was not evaluated in these large cohort studies. Smaller prospective clinical studies did not demonstrate the increased risk for grapefruit juice [14,19,20] and showed the protective effects on urinary parameters for orange juice [13][14][15]17,18], while the results for lemon juice were mixed [13,16,21,22]. ...
... Lemonade consumption was not evaluated in these large cohort studies. Smaller prospective clinical studies did not demonstrate the increased risk for grapefruit juice [14,19,20] and showed the protective effects on urinary parameters for orange juice [13][14][15]17,18], while the results for lemon juice were mixed [13,16,21,22]. ...
Article
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To explore the relationship between citrus fruit juices (oranges, grapefruits, and lemonades) and kidney stone disease (KSD). Methods: A systematic review was performed using the Medline, EMBASE, and Scopus databases, in concordance with the PRISMA checklist for all English, French, and Spanish language studies regarding the consumption of citrus fruit juices and the relationship to urinary stone disease. The main outcome of interest was the association of citrus fruit juices with KSD. Results: Thirteen articles met the criteria for inclusion in the final review. Three large epidemiological studies found that grapefruit juice was a risk factor for stone formation, while orange juice did not increase the risk for KSD. Ten small prospective clinical studies found that orange, grapefruit, and lemon juices all increased urinary citrate levels. Only orange and grapefruit juices had an alkalinizing effect and while lemon juice has a protective effect by raising urinary citrate levels, it lacked a significant alkalinizing effect on urine pH. Orange juice and grapefruit juices significantly increased urinary oxalate levels, while orange juice also had a high carbohydrate content. Conclusion: While orange juice seems to play a protective role against stone formation, grapefruit was found to raise the risk of KSD in epidemiological studies but had a protective role in smaller clinical studies. Lemon juice had a smaller protective role than orange juice. Larger amounts of, as well as more accurate, data is needed before recommendations can be made and a high carbohydrate content in these juices needs to be taken into consideration.
... Numerous short-term studies of urinary chemistry measures have demonstrated that urinary citrate levels increased after consumption of either grapefruit 60,61 or orange juice [61][62][63] or lemonade 64-67 whereas a few yielded no improvements in citraturia with lemonade. 63,68 Citrate in orange and grapefruit juices is complexed mainly by potassium, thus also increasing urinary pH. ...
... Numerous short-term studies of urinary chemistry measures have demonstrated that urinary citrate levels increased after consumption of either grapefruit 60,61 or orange juice [61][62][63] or lemonade 64-67 whereas a few yielded no improvements in citraturia with lemonade. 63,68 Citrate in orange and grapefruit juices is complexed mainly by potassium, thus also increasing urinary pH. ...
... 77,78 In one observational study, the risk of stones increased by 35% with apple juice consumption 77 despite its effect to increase urinary citrate excretion. 61 On the other hand, observational studies show that higher potassium intake is inversely associated with incident kidney stones in men and older women, with the exception of younger women. 13,15,17 The effect of higher potassium intake would mostly relate to the cation being accompanied by an organic anion, such as citrate and malate, representing an alkaline load. ...
Article
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We summarize the data regarding the associations of individual dietary components with kidney stones and the effects on 24-hour urinary profiles. The therapeutic recommendations for stone prevention that result from these studies are applied where possible to stones of specific composition. Idiopathic calcium oxalate stone-formers are advised to reduce ingestion of animal protein, oxalate, and sodium while maintaining intake of 800 to 1200 mg of calcium and increasing consumption of citrate and potassium. There are few data regarding dietary therapy of calcium phosphate stones. Whether the inhibitory effect of citrate sufficiently counteracts increasing urine pH to justify more intake of potassium and citrate is not clear. Reduction of sodium intake to decrease urinary calcium excretion would also be expected to decrease calcium phosphate stone recurrence. Conversely, the most important urine variable in the causation of uric acid stones is low urine pH, linked to insulin resistance as a component of obesity and the metabolic syndrome. The mainstay of therapy is weight loss and urinary alkalinization provided by a more vegetarian diet. Reduction in animal protein intake will reduce purine ingestion and uric acid excretion. For cystine stones, restriction of animal protein is associated with reduction in intake of the cystine precursor methionine as well as cystine. Reduction of urine sodium results in less urine cystine. Ingestion of vegetables high in organic anion content, such as citrate and malate, should be associated with higher urine pH and fewer stones because the amino acid cystine is soluble in more alkaline urine. Because of their infectious origin, diet has no definitive role for struvite stones except for avoiding urinary alkalinization, which may worsen their development.
... Three cohort studies reported that the intake of orange juice is associated with a reduced risk of kidney stone formation [51]. Interventional studies under a controlled dietary regimen showed that orange juice provided an alkali load that increased urine pH and citrate excretion [52][53][54]. Despite the alkalizing effect, orange juice did not change the calculated risk for calcium oxalate in the majority of studies. ...
... Studies of other fruit juices, such as grapefruit, apple, cranberry, and blackcurrant juice, have also provided inconsistent results. The findings of two studies of healthy subjects on the impact of grapefruit juice yielded no or only a partial effect on the risk of calcium oxalate stone formation (500 mL/day: p < 0.05; 720 mL/day: n.s.; 1000 mL/day: n.s.), although urinary citrate excretion increased significantly [53,69]. The administration of 0.5 or 1.0 L/day of apple juice likewise increased urinary citrate excretion but did not change the relative supersaturation of calcium oxalate [53]. ...
... The findings of two studies of healthy subjects on the impact of grapefruit juice yielded no or only a partial effect on the risk of calcium oxalate stone formation (500 mL/day: p < 0.05; 720 mL/day: n.s.; 1000 mL/day: n.s.), although urinary citrate excretion increased significantly [53,69]. The administration of 0.5 or 1.0 L/day of apple juice likewise increased urinary citrate excretion but did not change the relative supersaturation of calcium oxalate [53]. In healthy volunteers, the consumption of 330 mL/day of blackcurrant juice significantly increased urine pH and citrate excretion [70]. ...
Article
Full-text available
The prevalence of kidney stone disease is increasing worldwide. The recurrence rate of urinary stones is estimated to be up to 50%. Nephrolithiasis is associated with increased risk of chronic and end stage kidney disease. Diet composition is considered to play a crucial role in urinary stone formation. There is strong evidence that an inadequate fluid intake is the major dietary risk factor for urolithiasis. While the benefit of high fluid intake has been confirmed, the effect of different beverages, such as tap water, mineral water, fruit juices, soft drinks, tea and coffee, are debated. Other nutritional factors, including dietary protein, carbohydrates, oxalate, calcium and sodium chloride can also modulate the urinary risk profile and contribute to the risk of kidney stone formation. The assessment of nutritional risk factors is an essential component in the specific dietary therapy of kidney stone patients. An appropriate dietary intervention can contribute to the effective prevention of recurrent stones and reduce the burden of invasive surgical procedures for the treatment of urinary stone disease. This narrative review has intended to provide a comprehensive and updated overview on the role of nutrition and diet in kidney stone disease.
... Consumption of these fruits also positively affects important biomarkers and contributes to a fit physical condition, such as measured in cholesterol parameters [8,9], bone health [10], intestinal microbiota [11], antioxidant status [12] and anthropometrics [13,14]. Furthermore, citrus fruits are beneficial in preventing illnesses, such as cancer [15][16][17], dementia [18], diabetes [19,20], metabolic syndrome [21], and cardiovascular, kidney and dental diseases [17,22,23]. ...
... It is worth noting that, even though grapefruits are ranked fifth among the most preferred fruits, their mean score is far lower than the previous four fruits. The low preferences Nutrients 2020, 12, 979 7 of 10 assigned by interviewees for grapefruit strongly contrasts with the fact that it seems to be, along with oranges, the most investigated citrus fruit by scholars, thereby highlighting its positive health impacts [5,13,17,19,22,23]. ...
Article
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While the medical community supports the growth of citrus consumption as part of a healthy diet, there is limited knowledge about consumer preferences for these fruits. The current study analyzed the purchasing patterns and drivers of fresh citrus fruits from a convenience sample of 346 Italian food shoppers. Results revealed that clementines were the citrus fruit purchased most, followed by oranges and tangerines. Sweetness and smell were important product attributes for respondents. Different drivers affect the purchasing frequencies of various citrus fruits. Taste motivation, with a specific preference for acidity, impacts orange purchasing. Similarly, clementines are purchased primarily for taste motivation, however, the core sensory attribute for respondents in this case was sweetness. Meanwhile, for tangerines, the taste motivation is less important than the energy motivation, and the size together with the color are the core purchasing drivers. These outcomes provide food scientists, agronomists and market practitioners with new insights into Italian consumers’ preferences for citrus fruits, thus contributing to a potential expansion of this market.
... Grapefruits increase excretion of both citrate and oxalate [37]. The lithogenic effects of grapefruit juice and apple juice are controversial [38,39]. ...
... A study of 42,859 adults showed that high coffee and tea intake decreased the risk of symptomatic stone formation [39]. A more recent study of 6033 adults suggested that coffee intake decreased urine oxalate and uric acid, increased urine calcium and potassium, and also decreased the supersaturation of calcium oxalate by increasing urine volume [42]. ...
... All require the input of several urinary parameters. However, a survey of the literature shows that the number of input parameters used by researchers has varied between 5 and 13 (including pH and volume), which they have deemed in each case as being crucial [3][4][5]9,12,13,15,16,[21][22][23][24][25][26][27]. ...
... Finally, we have noted that in most studies involving urine saturation in the context of calcium kidney stone disease, SS values for calcium oxalate monohydrate (COM) and calcium hydrogen phosphate dihydrate (brushite, Bru) are commonly reported but the value for hydroxyapatite (HAP), a fairly frequent component of renal stones, is not [3,5,8,10,13,15,19,21,23,25]. In our survey, which we do not claim to be exhaustive, we found only one study in which SS (HAP) had been reported in addition to SS (COM) and SS (Bru) [5]. ...
Article
Background Supersaturation (SS) of urinary salts has been extensively invoked for assessing the risk of renal stone formation, but precursors have often been ignored. Our objectives were to establish by computer modeling, which urinary components are essential for calculating reliable SS values, to investigate whether unique equilibrium processes occur in the urine of stone formers (SF) which might account for their higher SS levels relative to healthy controls (N), to determine the relative efficacies of three different, widely-used protocols for lowering urinary SS of calcium salts and to examine the influence of precursors.
... C. sinensis has been used for ages for its healing properties traditionally (Don, 2010). C. sinensis peel has various properties to cure diseases and is widely used against various ailments, such as colic,upset stomach, cancer, diuretic, carminative, immune-enhancing, stomachic, tonic to digestivesystem, immune system and skin (Faturi et al., 2010a and b;Guarnieri et al., 2007;Honow et al., 2003;Kurowska, 2004;Parmar, 2008;Sharma, 2008;Tanaka et al., 1997a and b;and Tripoli et al., 2007). It is also used to treat and prevent colds, cough, vitamindeficiencies and scurvy and fight against bacterial, fungal and viral infections (Ashok, 2011;Honow et al., 2003;Julius et al., 2009;Strange, 1993;Vivek, 2010 andWiesmanand Chapagain, 2005). ...
... C. sinensis peel has various properties to cure diseases and is widely used against various ailments, such as colic,upset stomach, cancer, diuretic, carminative, immune-enhancing, stomachic, tonic to digestivesystem, immune system and skin (Faturi et al., 2010a and b;Guarnieri et al., 2007;Honow et al., 2003;Kurowska, 2004;Parmar, 2008;Sharma, 2008;Tanaka et al., 1997a and b;and Tripoli et al., 2007). It is also used to treat and prevent colds, cough, vitamindeficiencies and scurvy and fight against bacterial, fungal and viral infections (Ashok, 2011;Honow et al., 2003;Julius et al., 2009;Strange, 1993;Vivek, 2010 andWiesmanand Chapagain, 2005). In this study, the common bacteria which are responsible for gastrointestinal infections were taken into account and the antibacterial activity of C. sinensis was studied on them. ...
Article
Full-text available
Citrus sinensis (C. sinensis), a member of the Rutaceae (citrus family) has been traditionally used for various ailments such as asthma, hypertension, microbial infections, diabetes, tuberculosis, etc. It is rich in many phytochemicals which include flavonoids, saponins, tannins, glycosides, limonene, citral, neohesperidin, naringin, rutin, rhamnose, eriocitrin, and vitamin C. In this study the antibacterial activity of the methanolic extract of C. sinensis was investigated on some bacterial strains like Pseudomonas aeruginosa, Bacillus cereus and Klebsiella sp that are responsible for gastrointestinal disorder. The different concentrations (5 mg/mL, 10 mg/mL, 15 mg/mL, 20mg/mL and 25 mg/mL) of the sample have been used to evaluate the antimicrobial activity and increment in the antimicrobial activity was found with the increasing concentration of the sample. In the investigation of the thrombolytic activity of the C. sinensis methanolic peel extract, weak thrombolytic activity (26%) was found.
... The potential capacity of causing sensitization and irritation effects is very weak. Human patch tests with orange essential oil eight per cent in petrolatum had no irritant reaction after 48 hours, no sensitization, and no phototoxic effects (232) . ...
... A study conducted by Wabner and Pak (1993) in normal subjects and hypocitraturic stone patients found a significant increase in urinary oxalate excretion during consumption of 1.2 l of orange juice, while a study by Goldfarb and Asplin (2001) revealed an increased oxalate excretion during consumption of 240 ml of grapefruit juice. However, in a study under controlled conditions Hö now et al. (2003) failed to detect significant changes in urinary oxalate excretion during consumption of 0.5 and 1.0 l, respectively, of orange and grapefruit juice, respectively. Moreover, Hö now et al. ...
Article
Fruit and vegetable juices are recommended for the treatment of hypocitraturia in calcium oxalate stone disease as alternatives to drugs containing alkaline citrate. Since dietary oxalate can contribute considerably to urinary oxalate excretion, the oxalate content of vegetable and fruit juices, nectars and drinks was analyzed using a validated HPLC-enzyme-reactor method. The highest oxalate concentrations were found in rhubarb nectar (198.3. mg/100. ml) and beetroot juices (60.1-70.0. mg/100. ml). The oxalate levels of all other beverages were below 10. mg/100. ml. Interestingly, except for carrot juice, the oxalate content of juices containing vegetables from organic farming was higher than from conventional farming. The consumption of even 500. ml/d of certain vegetable juices can contribute to a considerable extent to the daily oxalate intake. Calcium oxalate stone formers should therefore pay attention not only to the oxalate content but also to the ingested amount of these beverages.
... It was observed in previous studies, that the extent of damage varied from 29.9 to 43.8% in sweet orange and 25.5 to 36.8% in acid lime (Reddy et al., 2008). Studies have shown that oranges have been found to protect the moderate consumer against cardiovascular diseases (Milind and Diev, 2012), possess anti-carcinogenic properties (Tanaka et al., 1997), reduce the risk of kidney stones (Honow et al., 2003), possess anti-ulcer properties (Simon et al., 2003), antianxiety effect (Fsaturi et al., 2010), anti-typhoid activity (Vivek et al., 2010), antibacterial activity (Milind and Diev, 2012) and antifungal activities (Neeta and Abhishek, 2008) amongst the many medicinal uses. ...
Article
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Citrus sinensis also known as sweet orange is the most popular of the citrus fruits. It is widely cultivated in most regions of the world possessing a rich source of vitamin C, flavonoids, phenolic compounds and pectin. This research was conducted to investigate the assessments of fungal pathogens associated with orange fruit spoilage sold in five markets in Benin metropolis and the possible public health implications. Some pathogenic fungal species were isolated from all five markets used in this study. Aspergillus species had the highest frequency and distribution from all sampling points (80%). Alternaria and Saccharomyces cerevisiae had the least occurrence from all sampling points (40% apiece). Candida, Mucor, Penicillium and Rhizopus had 60% occurrences, respectively. Candida tropicalis and species of Rhizopus, Penicillium, Aspergillus, Alternaria, and Mucor produced same symptoms and signs as observed in the original spoilt orange fruits before isolation. All fungal isolates were able to re-infect the healthy orange fruits with the exception of Alternaria species and Saccharomyces cerevisiae which were not able to grow and produce spoilage condition on the inoculated healthy orange fruits after five days. Aspergillus spp. are known to produce several toxic metabolites, like aflatoxins and ochratoxins, which are very important toxins worldwide because of the hazard it poses to human and animal health. Key word: Pathogenicity test, Aspergillus sp., Alternaria sp., pathogens.
... Dietary citrate is absorbed in the intestine and nearly completely metabolized to bicarbonate, which in turn increases urinary pH [34]. Accordingly, the intake of 0.5 or 1.0 L/day orange juice under controlled conditions led to a significant increase in 24-h urinary pH in healthy adults, reflecting the alkalizing effect of orange juice [35]. However, due to the high energy, sugar and potassium content, the consumption of fruit juices should be limited. ...
Article
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Chronic kidney disease and reduced glomerular filtration rate are risk factors for the development of chronic metabolic acidosis. The prevention or correction of chronic metabolic acidosis has been found to slow progression of chronic kidney disease. Dietary composition can strongly affect acid⁻base balance. Major determinants of net endogenous acid production are the generation of large amounts of hydrogen ions, mostly by animal-derived protein, which is counterbalanced by the metabolism of base-producing foods like fruits and vegetables. Alkali therapy of chronic metabolic acidosis can be achieved by providing an alkali-rich diet or oral administration of alkali salts. The primary goal of dietary treatment should be to increase the proportion of fruits and vegetables and to reduce the daily protein intake to 0.8⁻1.0 g per kg body weight. Diet modifications should begin early, i.e., even in patients with moderate kidney impairment, because usual dietary habits of many developed societies contribute an increased proportion of acid equivalents due to the high intake of protein from animal sources.
... Urine volume, urine analysis, serum analysis were used to assess the efficacy of test drug. The results revealed that the extract possessed good diuretic property [86]. ...
Article
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Antiurolithiatic drugs are the drugs which dissolve or prevent the formation of urinary calculi, while diuretics are drugs which increase the volume of urine excreted. Several medicinal plants can inhibit urolithiasis by many mechanisms: maintains crystalloid-colloid balance by decreasing excretion of urinary calcium, oxalate, uric acid, phosphorus and protein in urolithiasis, improves the renal function by increasing the excretion of urea and creatinine, diuretic and ACE inhibition activity. On the other hand many drugs can produce diuretic effect via their effects on renal water channels, on renal carriers, on nitric oxide-cGMP pathway, on prostaglandin-cAMP pathway, on the renin-angiotensin-aldosterone system (RAAS), on the kinin-kallikrein system (KKS), s on carbonic anhydrase and osmotic effects on kidneys. The current review will discuss the medicinal plants with antiurolithiatic and diuretic effects and their potential in the treatment of urinary stone.
... Fruits and vegetables increase urinary citrate because of their high alkali content, but not all fruits and juices have the same citraturic effect. Orange juice has shown the most consistent benefit because it has a high content of potassium citrate that confers an alkali load [33,71,72]. Lemonade, which is high in citric acid, does not affect urine pH and has less citraturic effect. ...
Article
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The prevalence of nephrolithiasis is increasing worldwide. Understanding and implementing medical therapies for kidney stone prevention are critical to prevent recurrences and decrease the economic burden of this condition. Dietary and pharmacologic therapies require understanding on the part of the patient and the prescribing practitioner in order to promote compliance. Insights into occupational exposures and antibiotic use may help uncover individual risk factors. Follow-up is essential to assess response to treatment and to modify treatment plans to maximize therapeutic benefit.
... Trinchieri et al., (2002) showed that grapefruit juice increased urinary excretion of citrate and calcium, magnesium in healthy subjects. Honow et al., (2003) reported that both grapefruit and apple juices reduced the risk of calcium oxalate stone formation. Values denote arithmetic means  standard deviation of the mean. ...
Research
The present work aimed to evaluate the effect of Almond nut, Sambucus herbs, Juniperus seeds, Grapefruit albedo& the combination of all (as 5 %) on reinopathic rats. For this purpose the study included about 35 rats about 150/ 200 (g) weight. Biological& chemical analysis of serum and histopathological investigation of internal organs were carried out. The experiment lasted for 4 weeks and eventually urine samples were collected for each rat for 24 hours and size measwredand estimated (creatThe present work aimed to evaluate the effect of Almond nut, Sambucusinine-urea-uric acid-protein-sodium-potassium). The weight of the rats and collect blood samples after collected fasting 12 hours and then serum separated to estimation of (creatinine-urea-uric acid-lipid profile-sodium-potassium-GPT-ALP-GOT). The weight of the internal organs (liver-kidney-heart-spleen-lung) determined and fixed in 10 % formalin for histopathological examinations. Finally a statistical analysis of all the data and was done. Introduction:
... It is also reported that daily consumption of one liter of orange juice increases citraturia and pH and prevents stone formation and reduces crystallization risk factors for calcium phosphate (8,22,23). Although grapefruit juice has been shown to have higher citrate content, it has not been possible to demonstrate that it reduces urinary risk factors (24,25). In addition, grapefruit juice may affect metabolism of commonly used drugs by inhibiting the cytochrome P-450 (24). ...
Article
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Citrate, potassium, and calcium levels in Viburnum opulus (V. opulus) and lemon juice were compared to evaluate the usability of V. opulus in mild to moderate level hypocitraturic stone disease. V. opulus and lemon fruits were squeezed in a blender and 10 samples of each of 100 ml were prepared. Citrate, calcium, sodium, potassium, magnesium, and pH levels in these samples were examined. Potassium was found to be statistically significantly higher in V. opulus than that in lemon juice (p = 0.006) whereas sodium (p = 0.004) and calcium (p = 0.008) were found to be lower. There was no difference between them in terms of the amount of magnesium and citrate. Concusions: Because V. opulus contains citrate as high as lemon juice does and it is a potassium-rich and calciumand sodium-poor fluid, it can be an alternative to pharmaceutical treatment in mild-to-moderate degree hypocitraturic stone patients. These findings should be supported with clinical studies.
... Maize (Zea Mays L), if harvested, need be stored under hot and humid conditions, most farmers lack proper knowledge, and equipment methods of drying grains. Exposure to moist and humid conditions during storage will cause the kennel to absorb water from the surroundings,[9]. ...
... In addition, the type of fluid consumed by individuals should also have received attention (5)(6)(7)(8)(9)(10). The required water of body could be supplied with various beverages including water, milk, tea, fruit juices, coffee, and soft drinks. ...
Article
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Background: Insufficient and inappropriate daily fluid intake in a long period may have adverse effect on human's health. Therefore, the present study evaluated the amounts and sources of fluids consumed by university students to determine whether these amounts and sources of fluid were enough and appropriate. Methods: In this descriptive study, 245 (142 females and 103 males) volunteer students of Tabriz University of Medical Sciences in 2009 were recruited. Food and fluid intake of subjects were as-sessed by 24-hour recall method of 3 days (two week days and one week- end included). Dietary intake of subjects was analyzed by Nutritionist III software program. The mean total fluid intake (drinking fluid values merged with data on the water content of foods) and the rate of metabolic water were figured out. Comparisons of the results with recommended dietary values were made using student's t-test.. Data of dietary intakes for two under-reporter female subjects were not included in the statistical analysis. Results: Daily total mean of fluid intake for girls (1598±40ml) and boys (1861±59ml) reflect the sum of beverages (Girls, 818±29ml; boys, 1147±57ml) and food water (Girls, 780±47ml; boys, 714±86m). The most consumed beverage for girls and boys were water (40%) and tea (49%) respectively. Daily mean intake of milk for girls and boys were 106.31±10ml (13%) and 57.30±11ml (5%), respectively. Conclusion: The mean daily fluid intake of subjects, specially water, and milk was lower than rec-ommended values. Therefore, there is an urgent need for tailored nutrition intervention targeting the young adults to improve their beverage choices.
... Maize, like other stored products is hygroscopic in nature and tends to absorb or release moisture. Even if properly dried, after harvest, exposure to moist and humid conditions during storage will cause the kennel to absorb water from the surroundings, leading to increase in maize moisture content, which resulted in enhanced deterioration, [10]. In tropical and sub tropical countries, a large proportion of the grain, (such as maize) is harvested and stored under hot and humid conditions, and most farmers lack proper knowledge, equipment methods of drying grains, [11]. ...
Article
Urolithiasis is a relatively common disorder with a high recurrence rate. Medical, metabolic, and nutritional factors contribute to or cause stone formation, particularly idiopathic calcium oxalate urolithiasis. Medical factors include bowel disorders, family history of kidney stones, insulin resistance, gout, excessive bone resorption, primary hyperparathyroidism, renal tubular acidosis, and chronic urinary tract infections. Metabolic factors include low urinary pH, hypercalciuria, hypocitraturia, hyperoxaluria, and hyperuricosuria, which may exist alone or in various combinations within individual patients. Nutritional factors include a high intake of animal protein, oxalate, and sodium and a low intake of fluids, calcium, and fruits and vegetables. Nutrition therapy, to be applied in all patients with stones, includes a high fluid intake, low sodium intake, a moderate animal protein intake, and ample fruits and vegetables, especially those rich in potassium, magnesium, and citric acid. When indicated by biochemical and medical data, an oxalate restriction may be required. As nutrition therapy may not sufficiently control stone formation in the presence of severe metabolic abnormalities, pharmacologic intervention is warranted.
Chapter
Citrus juices and some other beverages are widely available, nonpharmacologic sources of citrate, a naturally occurring inhibitor of urinary stone formation. The mechanisms of citrate supplementation are complex, as urinary citrate levels are dependent not only on the citrate content of a given beverage, but also on the patient's systemic acid-base status. Moreover, delivering an appropriate amount of citrate by juice or other beverage may be accompanied by a caloric intake that would make such a prescription inadvisable. Herein, we summarize all available English-language PUBMED-indexed literature on beverages and 24-h urine composition, as well as epidemiologic data on beverage intake and kidney stone risk with special emphasis on calcium urolithiasis. © Springer Science+Business Media New York 2014. All rights are reserved.
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Purpose – The purpose of this paper is to develop a structural model of factors determining quality of juices and to indicate major variables that are significant for further product development. Design/methodology/approach – Juices of apples, oranges, grapefruits, black currants and mixed fruits were subjected to testing in order to determine the qualitative structure of fruit juices. The following determinations were carried out in all fruit‐juice samples: total solids (Brix), Brix other than sucrose, total acidity, pH, vitamin C content, total sugars, direct‐reducing‐sugar content, saccharose content and volatile acidity. In addition, a sensory assessment in a 5‐grade score scale was carried out, covering the sensory characteristics of taste, flavour and colour. Based on the results of sensory analysis, a total sensory quality index (TSQI) was calculated. Findings – Values of the linear correlation coefficient were calculated, and force and direction of the interdependence between the measured juice quality factors were determined. Analysis of major components was applied to develop a model of the structure of quality characteristics of fruit juices and to disclose latent variables. It enabled disclosure of four independent (orthogonal) areas, which determine the quality of fruit juices, and explain 70 per cent of the total juice quality area. They are represented by: total sugars, total solids (Brix), sensory quality and total acidity. Originality/value – The research enabled identification of factors determining the fruit juice quality. It may prove very useful for R&D departments, as it informs an enterprise of which areas to focus their product development efforts on. Reducing the number of the major factors to four reduces costs and shortens the time necessary for product design and development.
Article
Background and purpose: Raising urinary pH and citrate excretion with alkali citrate therapy has been a widely used treatment in calcium nephrolithiasis. Citrate lowers ionized Ca(+2) concentrations and inhibits calcium salt precipitation. Conservative alternatives containing citrate such as fruit juices have been investigated and recommended. Any compound that induces systemic alkalosis will increase citraturia. Malate, a polycarboxylic anion like citrate, is a potential candidate for chelating Ca(+2) and for inducing systemic alkalinization. We undertook to investigate these possibilities. Materials and methods: Theoretical modeling of malic acid's effects on urinary Ca(+2) concentration and supersaturation (SS) of calcium salts was achieved using the speciation program JESS. Malic acid (1200 mg/day) was ingested for 7 days by eight healthy subjects. Urines (24 hours) were collected at baseline and on day 7. They were analyzed for routine lithogenic components, including pH and citrate. Chemical speciation and SS were calculated in both urines. Results: Modeling showed that complexation between calcium and malate at physiological concentrations of the latter would have no effect on SS. Administration of the supplement induced statistically significant increases in pH and citraturia. The calculated concentration of Ca(+2) and concomitant SS calcium oxalate (CaOx) decreased after supplementation, but these were not statistically significant. SS for the calcium phosphate salts hydroxyapatite and tricalcium phosphate increased significantly as a consequence of the elevation in pH, but values for brushite and octacalcium phosphate did not change significantly. Conclusions: We speculate that consumption of malic acid induced systemic alkalinization leading to reduced renal tubular reabsorption and metabolism of citrate, and an increase in excretion of the latter. The decrease in SS(CaOx) was caused by enhanced complexation of Ca(+2) by citrate. We conclude that malic acid supplementation may be useful for conservative treatment of calcium renal stone disease by virtue of its capacity to induce these effects.
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Diet modification plays an important role in nephrolithiasis. Development of an easy, ready-to-use beverage such as a commercial juice drink to use as a preventive treatment for renal calculi formation would be widely welcomed. We previously developed a novel Drosophila model for the study of nephrolithiasis. It provides a new well-established drug discovery platform for this common disease. In our current study, we used the Drosophila model to investigate the preventive effects of various commercial juices as potential treatments for nephrolithiasis. Our results showed that apple, cranberry, orange, and pomegranate juices failed to reduce calcium oxalate (CaOx) crystal formation, whereas our positive control-potassium citrate (K-citrate)-significantly prevented CaOx crystal formation. Unlike the commercial fruit juices that were tested, the administration of K-citrate significantly ameliorated the ethylene glycol (EG)-induced life-span reduction in treated flies. These results indicate that EG-induced CaOx nephrolithiasis in Drosophila can be prevented by K-citrate, but not by commercial citrate-containing juices. However, the inhibitory capability of citrate-containing juices to reduce renal stone formation in humans requires further elucidation.
Article
OBJECTIVES Potassium citrate is prescribed to patients with calcium oxalate (CaOx) stone formation to increase urinary citrate and pH, thus reducing CaOx crystal formation. Lemonade therapy (LT) might also increase urinary citrate and the total urine volume. We compared the effects of LT alone (group 1, n 63) and potassium citrate plus LT (group 2, n 37) in patients with CaOx stone formation on the urinary citrate and total urine volume to determine the efficacy of LT. METHODS Adult patients with CaOx stone formation and three or more clinic visits from 1996 to 2005 and three or more UroRisk profiles were included in our retrospective analysis. RESULTS Urinary citrate increased maximally by 203 and 346 mg/day for groups 1 and 2, respectively. The maximal total urine volume increase was 763 and 860 mL/day for groups 1 and 2, respectively. The urinary citrate and total urine volume increased sooner during follow-up for group 1. By the last clinic visit, the urinary citrate and total urine volume had decreased in both groups. However, group 1 sustained a greater total urine volume than did group 2 (2.35 0.10 standard error versus 2.17 0.12 L/day). Urinary citrate was greater in group 1 (765 56 standard error versus 548 56 mg/day for group 2), but the change from baseline to the last visit was significant (P 0.008) only in group 2. CONCLUSIONS LT resulted in favorable changes in urinary citrate and total urine volume in our series. Potassium citrate with LT was more effective than LT alone at increasing urinary citrate. Because maximal changes for urinary citrate and total urine volume were achieved earlier in follow-up, individualized encouragement and motivation should be provided to patients at each visit for sustained prevention. UROLOGY 70: 856 – 860, 2007.
Chapter
Inappropriate dietary habits and overweight are suggested to promote the worldwide increasing incidence and prevalence of urolithiasis. Nutrition plays an important role in urinary stone formation, especially in calcium oxalate, uric acid, calcium phosphate, and cystine urolithiasis. Specific dietary factors can alter urinary composition and supersaturation, which can affect the process of crystallization and stone formation. Adequate dietary treatment can contribute to an effective prevention or reduction of stone recurrences and decrease the burden of invasive measures in patients with recurrent stone disease. The current knowledge of the impact of dietary factors on the risk of stone formation is presented.
Article
Fragestellung: Das Harnsteinleiden gilt in der Bundesrepublik mit einer Häufigkeit von 5 % und stetiger Zunahme der Inzidenz als eine Volkskrankheit. Wachsende sozio-ökonomische Belastungen rücken zunehmend in den Vordergrund der öffentlichen Diskussion. Die bisherigen Therapiestrategien helfen dem Arzt nur unzureichend bei der Erfassung der oftmals komplexen Ursachen des Harnsteinleidens und der Erfolgskontrolle seiner eingeschlagenen Therapie. Für eine erfolgreiche Behandlung bei möglichst geringem Aufwand ist daher eine generelle Verbesserung der Möglichkeiten der bestehenden Harnsteinprophylaxe und -metaphylaxe notwendig. Dabei ist es unerlässlich, eine detaillierte Untersuchung und Interpretation der Urinzusammensetzung beim Steinpatienten vorzunehmen. Material und Methoden: Zwei neue aussagekräftige Diagnoseverfahren werden vorgestellt. 1. Die einfache und genaue Bestimmung des Calciumoxalat-Kristallisationsrisikos in einer Urinprobe mithilfe des BONN-Risk-Index (BRI), mit dem die mit 75 % am häufigsten auftretende Steinart erfasst wird. 2. Die Berücksichtigung der Abreicherung der Urinprobe an lithogenen Substanzen, durch im Körper wachsende Harnsteine. Das als „depletion effect” bezeichnete Phänomen kann durch die Verursachung falsch-normaler Urinparameter erhebliche klinische Relevanz haben. Ein neuentwickeltes Programm berücksichtigt diesen Effekt und gibt die korrigierten Werte aus. Ergebnisse: Anhand eines Reviewartikels wird der theoretische Hintergrund dieser Methoden dargelegt und die vielfältigen Einsatzmöglichkeiten der neuen Methoden in der Praxis aufgezeigt. Schlussfolgerungen: Neue Strategien der Harnsteinprävention können helfen, das Ausmaß des Steinleidens für den einzelnen Patienten zu reduzieren. Der Arzt hat mit dem BRI erstmals die Möglichkeit, mit geringem Aufwand die Therapie für seinen Patienten zu optimieren. Die Berücksichtigung der steinwachstumsbedingten Alteration einer Urinprobe verbessert die Interpretation der chemischen Urinanalyse.
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Introduction: Kidney stone is a major public health problem. Over 5% of the population is affected by kidney stones, with causes a lifetime risk of transmitting renal lithiasis of about 8 to 10%. Objective: The goal of our study is the attitude and awareness of lithiasis patients regarding the use of medicinal plants in eastern Morocco. Methods: We carried out a study on lithiasis patients to retrospectively identify medicinal plants used in this disease, using a pre-established questionnaire. The study was carried out from 10 December 2017 to 28 February 2018. Results: Our survey describes several medicinal plants used to treat renal lithiasis in eastern Morocco. Most patients used Herniaria hirsuta L., Zea mays L., Urtica dioica L., and Petroselinum crispum (Mill.) Fuss. This preliminary study showed that the first reason to use medicinal plants in half of lithiasis patients is to calm the pain and expel the stones. The primary source of plant use information is oral tradition. However 67% of lithiasis patients are unaware of the harmful and toxic effects that can appear. Conclusion: Medicinal plants must, like medicines, comply with strict requirements and standard rules of use to which only the specialist in herbal medicine can respond and sensitize people to the dangers of irrational consumption of medicinal plants.
Chapter
Nephrolithiasis is a common urological disease that will affect 5–10 % of adults during their lifetime. The natural history of nephrolithiasis is characterized by recurrence, with almost 50 % of patients recurring within 5 years of their initial stone event. Each stone episode can cause significant pain, decreases productivity, and, if not treated appropriately, may lead to renal dysfunction. Medical therapy has been used for many years in the prevention of stone growth/recurrence. Potassium citrate is an oral alkalizing agent that has been used as the mainstay of medical nephrolithiasis management in the last three decades. With the recent increase in calcium-phosphate stone formation, concern has been raised that potassium citrate may be contributing to this finding. In this chapter, we will highlight the contemporary use of potassium citrate in the clinical management of nephrolithiasis. The mechanisms of action and physicochemical changes that can be achieved by potassium citrate will be elaborated. Clinical trials demonstrating the efficacy of potassium citrate will be reviewed. Overall benefits and possible risks of potassium-citrate treatment will be provided.
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Introduction Production, Varieties, and Harvesting Consumption Trend, Significance to Human Health Postharvest Physiology and Storage Technologies Fresh-Cut and Minimally Processed Products Processing and Processed Products Nutritional Profile and Health Benefits References
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The present work aimed to evaluate the effect of Almond nut, Sambucus herbs, Juniperus seeds, Grapefruit albedo & the combination of all(as5%) on reinopathic rats. For this purpose , the study included about 35 rats about 150/200(g) weight. Biological & chemical analysis of serum and histopathological investigation of internal organs were carried out. The experiment lasted for 4 weeks and eventually urine samples were collected for each rat for 24 hours and size measwredand estimated (creatinine - urea - uric acid - protein - sodium - potassium). The weight of the rats and collect blood samples after collected fasting 12 hours and then serum separated to estimation of (creatinine - urea - uric acid – lipid profile - sodium - potassium - GPT-ALP-GOT). The weight of the internal organs (liver - kidney - heart - spleen - lung) determined and fixed in 10% formalin for histopathological examinations. finally a statistical analysis of all the data and was done.
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Fresh oranges juice is an excellent source of vitamin C and contains powerful natural antioxidant, folate, dietary fibre and other bioactive components. The effects of fresh orange juice on the microflora, haematology and histopathology of selected organs of albino rats was evaluated using standard methods. Different volumes of the juice were fed to the rats daily for 8 weeks. Their weight was taken every other day and a comprehensive assessment of their hematology, gastrointestinal flora and histopathology of selected organs done. The juice did not cause any pathological degeneration of the tissue or organs assessed. It caused increased in Packed Cell Volume (PCV) of the rats with the highest increase observed in the rats given 1.0 ml of the juice daily. The PCV was 51.22 ± 1.24% for the group given 1.0 ml daily while the control group was 41.33 ± 0.67%. All the results for the PCV were significantly different at P ≤ 0.05. None of the rats gut was sterile with 7 bacteria identified. The bacteria load ranges from 1.3 × 102 cfu/ml to 1.9 × 104 cfu/ml. The group fed with 0.5 ml of the juice had the highest weight gain. The results obtained has proof the effect of fresh orange juice as a source of vitamin. The histopathological results of the selected organs showed that they are pathologically fine without any degeneration of tissues thereby providing evidence that fresh orange juice has prophylactic and therapeutic values. Conclusively, fresh orange juice has medicinal values, boost immunity, increase blood volume, and restore normal gastrointestinal microflora.
Article
Among the prerenal risk factors of stone disease, diet plays an important role. Various interventional studies have provided evidence that appropriate dietary modifications can reduce the risk of stone formation and recurrence rate. Individualized dietary recommendations should be offered to patients according to their stone type, specific metabolic, and dietary risk profile. The reduction of overweight, risk-adapted dietary modifications based on a comprehensive dietary assessment as well as appropriate changes in lifestyle are the basis of a successful metaphylaxis in urinary stone disease.
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Background . Urolithiasis is a disease with high recurrence rate, 30-50% within 5 years. The aim of the present study was to learn the effects of citrus-based products on the urine profile in healthy persons and people with urolithiasis compared to control diet and potassium citrate. Methods. A systematic review was performed, which included interventional, prospective observational and retrospective studies, comparing citrus-based therapy with standard diet therapy, mineral water, or potassium citrate. A literature search was conducted using PUBMED, COCHRANE, and Google Scholar with "citrus or lemonade or orange or grapefruit or lime or juice" and "urolithiasis" as search terms. For statistical analysis, a fixed-effects model was conducted when p > 0.05, and random-effects model was conducted when p < 0.05. Results. In total, 135 citations were found through database searching with 10 studies found to be consistent with our selection criteria. However, only 8 studies were included in quantitative analysis, due to data availability. The present study showed a higher increased in urine pH for citrus-based products (mean difference, 0.16; 95% CI 0.01-0.32) and urinary citrate (mean difference, 124.49; 95% CI 80.24-168.74) compared with a control group. However, no differences were found in urine volume, urinary calcium, urinary oxalate, and urinary uric acid. From subgroup analysis, we found that citrus-based products consistently increased urinary citrate level higher than controls in both healthy and urolithiasis populations. Furthermore, there was lower urinary calcium level among people with urolithiasis. Conclusions. Citrus-based products could increase urinary citrate level significantly higher than control. These results should encourage further research to explore citrus-based products as a urolithiasis treatment.
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The action of various beverages and foods on the composition of the urine in the circadian rhythm and in the 24-hour urine has been investigated under standardized conditions. Orange juice leads to a significant increase of urinary pH and citric acid excretion. Black tea leads to a raised excretion of oxalic acid by only 7.9%. In the short term, beer increases diuresis, but afterwards leads to a compensatory antidiuresis with increased risk of stone formation. Depending on their composition, mineral waters have very different effects on the urinary constituents. Milk as well as cocoa beverage significantly increase calcium excretion; moreover, cocoa causes an increase in the oxalic acid excretion. The leafy vegetable foods containing oxalate, e.g., spinach and rhubarb, lead to peaks of oxalate excretion of 300-400% in the circadian excretion curve. Cheese leads to a significant rise of calcium excretion with acidification of the urine and lowering of citrate excretion. Calcium excretion is increased by 30% by sodium chloride. Foods containing purine result in an increased uric acid excretion over several days. Depending on their phytic acid content, brans bind calcium, but lead to an increased oxalic acid excretion. Analysis of the urine indicates that average diet in Germany entails a high risk of urinary stone formation. As a result of the change to a balanced mixed or vegetarian diet, according to the requirements, significant alterations in urinary pH, calcium, magnesium, uric acid, citric acid, cystine, and glycosaminoglycan excretion are measured, resulting in a drastic reduction in the risk of urinary stone formation.
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Some drugs demonstrate a significantly greater (up to 3-fold) mean oral bioavailability on coadministration with grapefruit juice. With some calcium antagonists, the benzodiazepines midazolam and triazolam and the antihistamine terfenadine, changes in bioavailability are accompanied by altered drug action. Study design factors possibly contribute to the magnitude of changes in drug bioavailability; they include the source of the citrus, its intake schedule, drug formulations and individual metabolising capacity. The components of citrus juice that are responsible for clinical drug interactions have yet to be fully determined. Based on the flavonoid naringin’s unique distribution in the plant kingdom, abundance in grapefruit and ability to inhibit metabolic enzymes, naringin is likely to be one of the grapefruit components influencing drug metabolism. Other components present in citrus fruit, such as furanocoumarins, may be more potent inhibitors than flavonoids and are under investigation. Conclusions drawn from clinical drug interaction studies should be considered specific to the citrus fruit products evaluated because of the variation in their natural product content. The predominant mechanism for enhanced bioavailability is presumably the inhibition of oxidative drug metabolism in the small intestine. The consistent findings across studies of diverse cytochrome P450 (CYP) 3A substrates support the mechanistic hypothesis that 1 or more grapefruit juice components inhibit CYP3A enzymes in the gastrointestinal tract. The evaluation of the need to avoid the concomitant intake of grapefruit products with drugs is best done on an individual drug basis rather than collectively by drug class. Based on the narrow therapeutic range of cyclosporin and research experience in organ transplant recipients, its interaction with grapefruit juice is likely to be clinically significant.
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Although methods of urinary stone removal are becoming evermore effective, the prevalence of urolithiasis is continuously increasing. Epidemiological studies show that 5-10% of the population suffer from urinary stones. Stone removal alone is not a curative measure. Depending on the stone composition, a recurrence rate of 60-100% must be expected. Hence, analysis of the stone material and basic diagnosis of the metabolic origins of urolithiasis are imperative, as well as consistent recurrence prevention in high-risk patients. This revised and updated handbook meets these requirements. It is designed to assist clinicians and healthcare professionals by guiding them through the appropriate diagnostic examinations and the development of effective and safe plans for treatment and prevention. It takes the newest international and European guidelines for urinary stone therapy into account, and includes the latest findings in clinical and laboratory diagnosis, dietary therapy and medication. Furthermore, it offers specific solutions for the treatment of children. Its clear organization makes it a valuable and indispensable reference book, especially for urologists, nephrologists and pediatricians.
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A BASIC computer program for the calculation of urinary supersaturation with respect to the common kidney stone components is described. In vitro and in vivo tests show that the program described accurately calculates supersaturation. The application of this computer program to urolithiasis research is discussed.
Article
In an effort to develop a simple and reliable method with which to assess the propensity for spontaneous nucleation of calcium oxalate and brushite in urine, the permissible increment of oxalate and calcium was calculated. This represented the additional amount of oxalate or calcium that could be added to urine in three hours before spontaneous precipitation of calcium oxalate or brushite was initiated. The permissible increment of oxalate inversely correlated (P less than 0.001) with the formation-product ratio-activity-product ratio discriminant score of calcium oxalate, which was previously shown to reflect a quantitative measure of the likelihood for spontaneous nucleation. Similarly, the permissible increment of calcium inversely correlated (P less than 0.001) with the formation-product ratio-activity-product ratio discriminant score of brushite. The permissible increments in oxalate and calcium were significantly lower (P less than 0.001) in patients with renal stones than in control subjects. Moreover, treatment with thiazides, allopurinol, sodium cellulose phosphate, orthophosphate, and diphosphonate significantly raised the permissible increment of oxalate in patients with stones. Thus, the permissible increment was reliable in discriminating "stone-forming" from control urine and in assessing response to treatment.
Article
The increase of concentrations observed for many drugs when administered concomitantly with grapefruit juice was attributed to inhibition of cytochrome P450 enzymes by naringenin, the aglycone of the grapefruit flavonoid naringin. However, this explanation is equivocal, and formation of naringenin after ingestion of grapefruit juice has not been proved. We investigated renal excretion of naringin, naringenin, and its glucuronides after administration of 20 ml grapefruit juice (621 mumol/L naringin) per kilogram of body weight to six healthy adults. Urine was collected for 24 hours, and flavonoids were measured by HPLC in aliquots with and without glucuronidase pretreatment. Naringin or naringin glucuronides were not found. Naringenin and its glucuronides appeared in urine after a median lag-time of 2 hours and reached 0.012% to 0.37% and 5.0% to 57%, respectively, of the molar naringin dose. In additional investigations, low concentrations (< 4 mumol/L) of naringenin glucuronides, but neither naringin nor naringenin were found in plasma samples from previous grapefruit juice interaction studies, and metabolization of naringin to naringenin occurred during 24 hours of incubation (37 degrees C) in three of five feces samples tested. The data suggest that cleavage of the sugar moiety, presumably by intestinal bacteria, is the first step of naringin metabolism. Naringenin formation is thought to be the crucial step in determination of bioavailability of the compound, which undergoes rapid glucuronidation. The pronounced interindividual variability of naringin kinetics provides a possible explanation for some of the apparently contradictory results of drug interaction studies with grapefruit and naringin.
Article
The value of orange juice consumption in kidney stone prevention was examined in 8 healthy men and 3 men with documented hypocitraturic nephrolithiasis. They underwent 3 phases of a metabolic study, a placebo phase and 2 treatment phases in which they ingested either 1.2 l. orange juice (containing 60 mEq. potassium and 190 mEq. citrate per day) with meals or potassium citrate tablets (60 mEq. per day) with water and meals. Compared to potassium citrate, orange juice delivered an equivalent alkali load and caused a similar increase in urinary pH (6.48 versus 6.75 from 5.71) and urinary citrate (952 versus 944 from 571 mg. per day). Therefore, orange juice, like potassium citrate, decreased urinary undissociated uric acid levels and increased the inhibitor activity (formation product) of brushite (calcium phosphate). However, orange juice increased urinary oxalate and did not alter calcium excretion, whereas potassium citrate decreased urinary calcium without altering urinary oxalate. Thus, orange juice lacked the ability of potassium citrate to decrease urinary saturation of calcium oxalate. Overall, orange juice should be beneficial in the control of calcareous and uric acid nephrolithiasis.
Article
Patients with kidney stones are routinely advised to increase their fluid intake to decrease the risk of stone recurrence. However, there has been no detailed examination to determine whether the effect on recurrence varies by the type of beverage consumed. The authors conducted a prospective study of the relation between the intake of 21 different beverages and the risk of symptomatic kidney stones in a cohort of 45,289 men, 40-75 years of age, who had no history of kidney stones. Beverage use and other dietary information was measured by means of a semiquantitative food frequency questionnaire in 1986. During 6 years of follow-up (242,100 person-years), 753 incident cases of kidney stones were documented. After adjusting simultaneously for age, dietary intake of calcium, animal protein and potassium, thiazide use, geographic region, profession, and total fluid intake, consumption of specific beverages significantly added to the prediction of kidney stone risk (p < 0.001). After mutually adjusting for the intake of other beverages, the risk of stone formation decreased by the following amount for each 240-ml (8-oz) serving consumed daily: caffeinated coffee, 10% (95% confidence interval 4-15%); decaffeinated coffee, 10% (3-16%); tea, 14% (5-22%); beer, 21% (12-30%); and wine, 39% (10-58%). For each 240-ml serving consumed daily, the risk of stone formation increased by 35% (4-75%) for apple juice and 37% (1-85%) for grapefruit juice. The authors conclude that beverage type may have an effect on stone formation that involves more than additional fluid intake alone.
Article
The effects of grapefruit juice on the bioavailability of 17 alpha-ethinylestradiol (EE2) after a single oral administration of 50 micrograms EE2 have been investigated. The pharmacokinetics of EE2 were studied in an open, randomized, cross-over study in which 13 healthy volunteers were administered the drug with herbal tea or grapefruit juice (naringin, 887 mg/ml). In contrast to herbal tea, grapefruit juice increased the peak plasma concentration (Cmax) significantly to 137% (mean; range 64% to 214%, p = 0.0088) and increased the area under plasma concentration-time curve from 0 to 8 hours (AUC0-8) to 128% (mean; range 81% to 180%, p = 0.0186). This study shows that grapefruit juice increases the bioavailable amount of EE2. A possible explanation may be that grapefruit juice inhibits the metabolic degradation of EE2. Whether the increased bioavailability of EE2 following grapefruit juice administration is of clinical importance should be investigated in long-term studies.
Article
In this paper we present an improved method for the selective and sensitive determination of oxalate in different matrices such as urine, plasma, and food. The method uses ion chromatography for the separation of anions. To overcome problems with interfering matrix-anions, colourings, and macromolecules, we used an inline enzyme-reactor (ER) containing immobilised oxalate oxidase, which converts oxalate to hydrogen peroxide. Hydrogen peroxide was analysed with high sensitivity by amperometric detection. The determination limit for the HPLC-ER method was 1.5 mumol/1, the mean recovery in urine was 102%. The evaluation in a urinary matrix achieved C.V. values from 2.2% to 6.7% for the within-run precision and C.V. values from 3.7% to 8.6% for the between-batch precision. The results of the new method were statistically equivalent to those obtained by enzymatic kits. We present first results of the HPLC-ER method, when applied to body fluids and food analysis.
Article
Current examples for the development of urinary stone disease are discussed by means of data from the literature and our own studies. Urinary stone disease has gained increasing significance due to changes in living conditions, i.e., industrialization and malnutrition. Changes in prevalence and incidence, the occurrence of stone types and stone location, and the manner of stone removal are explained. The importance of nutrition in the prevention of calcium oxalate stone disease is discussed in terms of fluid intake, calcium and oxalate metabolism, and dietary fat intake. The results of a study on a standardized mixed diet or an ovo-lactovegetarian diet show that well-balanced nutrition with consecutive high intake of fluids leads to a significant decrease in the risk for urinary stone formation (calculated as relative supersaturation with calcium oxalate by the computer program EQUIL).
Article
An increase in fluid intake is routinely recommended for patients who have had kidney stones to decrease the likelihood of recurrence. However, data on the effect of particular beverages on stone formation in women are limited. To examine the association between the intake of 17 beverages and risk for kidney stones in women. Prospective cohort study with 8 years of follow-up. United States. 81093 women in the Nurses' Health Study who were 40 to 65 years of age in 1986 and had no history of kidney stones. Beverage use and diet were assessed in 1986 and 1990 with a validated, self-administered food-frequency questionnaire. The main outcome measure was incident symptomatic kidney stones. During 553 081 person-years of follow-up over an 8-year period, 719 cases of kidney stones were documented. After risk factors other than fluid intake were controlled for, the relative risk for stone formation for women in the highest quintile of total fluid intake compared with women in the lowest quintile was 0.62 (95% CI, 0.48 to 0.80). Inclusion of consumption of specific beverages in the multivariate model significantly added to prediction of risk for kidney stones (P < 0.001). In a multivariate model that adjusted simultaneously for the 17 beverages and other possible risk factors, risk for stone formation decreased by the following amount for each 240-mL (8-oz) serving consumed daily: 10% (CI, 5% to 15%) for caffeinated coffee, 9% (CI, 2% to 15%) for decaffeinated coffee, 8% (CI, 1% to 15%) for tea, and 59% (CI, 32% to 75%) for wine. In contrast, a 44% (CI, 9% to 92%) increase in risk was seen for each 240-mL serving of grapefruit juice consumed daily. An increase in total fluid intake can reduce risk for kidney stones, and the choice of beverage may be meaningful.
Article
This work focuses on the in vitro calcium-oxalate (CaOx) crystallization behaviour of native and synthetic urine samples in order to establish a CaOx crystallization risk index for unprepared native urine. Native 24-h urine samples from healthy persons and from stone-formers were examined. Within a [Ca2+] versus added oxalate (Ox2-) diagram, we observed fields which allow the discrimination of each urine sample in terms of more or less risk. The [Ca2+]/(Ox2-) ratio is calculated and termed the "Bonn-Risk Index" (BRI; per litre). We propose that BRIs > 1/l denote samples "at risk", whereas BRIs < or = 1/l denote those "without risk". Second. the effects of different concentrations of citrate and Mg2+ on BRI were investigated in artificial urine. The transferability of BRI between native and synthetic urine samples is proved. To evaluate the impact of the proposed BRI, it is compared with the more familiar relative urine saturation index calculated for CaOx and brushite. Urine sampled from stone-formers shows risk indexes between 0.278 and 23.0/l (mean 2.87/l), while urine from healthy persons varied between 0.060 and 4.890/l (mean 1.05/l). Comparing the results of healthy volunteers and patients, the significance of BRI and relative urine supersaturation (RS) with respect to CaOx is P < 0.0005 and P = 0.013, respectively. Fast and easy to perform, determination of the risk index is a suitable tool for estimating the actual CaOx formation "status"--"at risk" or "without risk"--from the native urine of any person.
Article
An increased risk of nephrolithiasis has been associated with the ingestion of grapefruit juice in epidemiological studies. To our knowledge the basis of this effect of grapefruit juice has not been studied previously. We studied the effect of grapefruit juice consumption on urinary chemistry and measures of lithogenicity. Ten healthy men and women between ages of 25 and 40 years participated. Each subject drank 240 ml. of tap water at least 3 times daily for 7 days during the control period. This period was followed by a second 7 days experimental period during which they drank 240 ml. of grapefruit juice 3 times daily. In each 7-day period urine was collected for 24 hours during the last 3 days. Urine chemical analysis was performed, supersaturations of calcium oxalate, calcium phosphate and uric acid were calculated and urinary lithogenicity was measured. Urine volume and creatinine excretion were the same during the control and experimental periods. Grapefruit juice ingestion was associated with an increase in mean oxalate excretion plus or minus standard deviation of 41.1 +/- 9.2 to 51.9 +/- 12.0 mg. per 24 hours (p = 0.001) and in mean citrate excretion of 504.8 +/- 226.5 to 591.4 +/- 220.0 mg. per 24 hours (p = 0.01). There was no net change in the supersaturation or upper limit of metastability of calcium oxalate, calcium phosphate or uric acid. Crystal aggregation and growth inhibition by urinary macromolecules was not affected by grapefruit juice ingestion. Offsetting changes in urine chemistry caused by the ingestion of grapefruit juice led to no net change in calculated supersaturation. No changes in lithogenicity were demonstrated. The results do not demonstrate an effect of grapefruit juice for increasing lithogenicity. The basis of the observations of epidemiological studies remain unexplained.
Article
When introducing a new parameter, it is necessary to compare the power of the new measure with already established ones. For a new method it is quite difficult to compete with established methods which have already ascertained sets of data over many years. A formal comparison of the new parameter with the actual "gold-standard" method can be a useful approach to reduce that problem. It cannot be expected that a new measure would reflect the "gold-standard" method in a simple proportionality. Therefore, it is important to find out the accuracy of the prediction of one parameter from the other, based on simple, e.g. linear, functions. A number of methods exist to determine the crystallization risk of calcium oxalate salts from urine. The most established method is the calculation of the relative urinary supersaturations with respect to these salts using the EQUIL-program, a program computing the equilibrium concentrations of complexes of primary cations and anions commonly found in urine. The Bonn-Risk-Index (BRI) is a new strategy for the evaluation of the risk of calcium oxalate formation, by performing crystallization experiments on native unprepared urine samples. Although the analytical and computational efforts of both approaches are quite different (relative supersaturation = high, BRI = low), the measurements revealed a considerable and significant linear relationship between the relative urinary calcium oxalate supersaturation, and BRI. We were, therefore, interested in predicting the relative supersaturation from the BRI and in the accuracy of this prediction.
Article
A variety of equipment is used for the observation of precipitation processes which occur in urinary samples. The Bonn-Risk-Index, a measure of the calcium oxalate crystallization risk of human urine, has been developed with the use of an in-line laser-probe gauge. For basic research or in clinical laboratories, however, this instrument, which fulfills industrial requirements for the evaluation of particle size distributions, is not widely available. The evaluation of an alternative method to determine the Bonn-Risk-Index based on a more commonly available apparatus would therefore be useful. In vitro crystallization experiments with 124 native urine samples from stone-forming and non-stone forming individuals were performed in order to determine their crystallization risk according to the Bonn-Risk-Index approach. The onset of an induced urinary crystallization was detected by simultaneous sample monitoring with an in-line laser-probe and a conventional dip-in photometer. A decrease of the sample's relative light transmissivity from initially 100% to 98% was assumed to be a reliable photometer-based criterion to indicate that crystallization actually began. The laser-probe signal was set as the reference measure. Linear regression analysis of the results of the laser-probe and the photometer-based Bonn-Risk-Index determinations reveals a significant and close correlation between the two measures. Method comparison by statistical evaluation shows i) that no significant deviation from linearity exists and ii) that both methods are statistically identical. The differences in the results are small enough to be confident that the photometer can be used in place of the laser-probe for clinical purposes. The photometer is a reliable, easy-to-use and cost-effective method for the determination of a triggered crystallization event in a urine sample. The assumed 98% criterion allows the determination of the Bonn-Risk-Index with adequate accuracy.
Article
The effect of citrus fruit juice ingestion on the risk of calcium oxalate stone formation is still debated. The present study was undertaken to investigate changes in urinary stone risk factors after administration of a soft drink containing grapefruit juice. Seven healthy subjects, with no history of kidney stones, were submitted to an acute oral load (20 ml/kg body weight over 60 min) of a soft drink containing grapefruit juice diluted (10%) in mineral water. After a 7-day wash-out period, each subject underwent an oral load with mineral water alone under the same conditions. Urine specimens were collected before (for 120 min) and after each oral fluid load (for 180 min). Urinary flow was significantly increased after both grapefruit juice (46+/-26 vs 186+/-109 ml/h, p = 0.01) and mineral water (42+/-16 vs 230+/-72 ml/h, p=0.001) compared to baseline. Compared to mineral water, grapefruit juice significantly (p=0.021) increased urinary excretion of citrate (25.8+/-9.3 vs 18.7+/-6.2 mg/h), calcium (6.7+/-4.3 vs 3.3+/-2.3 mg/h, p=0.015) and magnesium (2.9+/-1.5 vs 1.0+/-0.7 mg/h, p=0.003). Citrus fruit juices could represent a natural alternative to potassium citrate in the management of nephrolithiasis, because they could be better tolerated and cost-effective than pharmacological calcium treatment. However, in order to obtain a beneficial effect in the prevention of calcium renal stones a reduced sugar content is desirable to avoid the increase of urinary calcium due to the effect of sugar supplementation.
Harnsteine, pathochemie und klinische-chemische diagnostik (Urinary stones, pathochemistry and clinical chemical diagnostics)
  • A Hesse
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Hesse A & Bach D (1982) Harnsteine, pathochemie und klinische-chemische diagnostik (Urinary stones, pathochemistry and clinical chemical diagnostics). In Klinische Chemie und Einzeldarstellung V (Clinical Chemistry and Single Cases), pp. 33 -38 [H Breuer, H Büttner and D Stamm, editors].
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Empfehlungen fü die Nä (Recommendations for Nutrient Intakes)
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  • Deutsche Gesellschaft
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Deutsche Gesellschaft für Ernährung (1996) Empfehlungen für die Nährstoffzufuhr (Recommendations for Nutrient Intakes).
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Drug interaction with grapefruit juice
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Ameer B & Weintraub RA (1997) Drug interaction with grapefruit juice. Clin Pharmacokinet 33, 102– 121.
Empfehlungen für die Nährstoffzufuhr (Recommendations for Nutrient Intakes). Frankfurt: Deutsche Gesellschaft für Ernährung
  • Deutsche Gesellschaft Für Ernährung
Deutsche Gesellschaft für Ernährung (1996) Empfehlungen für die Nährstoffzufuhr (Recommendations for Nutrient Intakes). Frankfurt: Deutsche Gesellschaft für Ernährung.
Calcium stones: some physical and clinical aspects
  • B Finlayson
Finlayson B (1977) Calcium stones: some physical and clinical aspects. In Calcium Metabolism in Renal Failure and Nephrolithiasis, pp. 337-382 [DS David, editor]. New York, London, Sydney, Toronto: J Wiley & Sons.
Urinary Stones, Diagnosis, Treatment and Prevention of Recurrence
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  • A Jahnen
Hesse A, Tiselius HG & Jahnen A (1997) Urinary Stones, Diagnosis, Treatment and Prevention of Recurrence. Basel, Freiburg, Paris, London, New York, New Dehli, Bangkok, Singapore, Tokyo, Sydney: Karger.