Potential Renal Acid Load Values Research Articles

Evaluation of the relationship between dietary acid load and cardiovascular risk factors in patients with type 2 diabetes: a case-control study.

Diets high in dietary acid load are thought to be associated with metabolic diseases. However, the number of studies examining the relationship between dietary acid load and metabolic diseases in Turkey is insufficient. The aim of this study was to investigate the relationship between cardiovascular disease risk factors and dietary acid load in individuals with type 2 diabetes. In this case-control study, 51 participants aged 30-65 years with type 2 diabetes and 59 participants in the control group were included. Blood pressure and biochemical findings were measured. Anthropometric measurements and body composition measurements were made. Dietary intake was assessed using a 3-day (1 day on weekends, 2 days on weekdays) food consumption record. Dietary acid load scores, including potential renal acid load (PRAL) and net endogenous acid production (NEAP), were calculated based on dietary intake. NEAP and PRAL scores were categorized as low and high according to the median value. Smoking status, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), trigylceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL), waist-hip ratio (WHR), waist-to- height ratio (WtHR), hemoglobin and fat mass (%) were evaluated as cardiovascular risk factors. The cut-off values of PRAL and NEAP were 3.61 and 44.78 mEq/d, respectively. After adjustment for various covariates, a significant positive association between PRAL and TG levels was observed in the diabetic group [odds ratio (OR), 5.98; 95% CI, 1.45-24.67; p = 0.013]. In contrast, a negative association was found between PRAL and SBP in the control group [odds ratio (OR), 0.21; 95% CI, 0.05-0.83; p = 0.026]. However, these associations were not observed for NEAP values in either group. A higher PRAL value was consistently associated with higher TG level, but other cardiovascular risk factors were not. More longitudinal and interventional studies are needed to better establish a causal effect between dietary acid load and cardiovascular risk factors in individuals with diabetes.

Macroalgae as Alkalizing Marine Drugs with a Low Potential Renal Acid Load

A growing interest in more sustainable and alternative food sources has brought seaweed and macroalgae to the spotlight for the general worldwide cuisine. Algae are often praised for their high nutritional value and are rich in potassium, calcium, and magnesium. Abundant in base precursors, algae are particularly interesting from an acid-base perspective. Their unique biochemical composition suggests a low potential renal acid load (PRAL), which is a commonly used estimate for the amount of acid or base a certain food produces in humans. Here, we analyzed the PRAL value of n = 106 macroalgae. Results suggested a strong alkalizing potential, with a mean PRAL value of −86.76 mEq/100 g. The lowest PRAL values were found for Laminaria ochroleuca (−286.78 mEq/100 g), Gelidium micropterum (−268.46 mEq/100 g), and Palmaria palmata (−259.16 mEq/100 g). We observed a strong inverse relationship of PRAL with algae’s potassium content (Spearman’s rho = −0.79, p<0.001) and a moderate relationship with algae’s calcium content (Spearmen’s rho: −0.34, p<0.001). Our data point at a potential role for several macroalgae as potent alkalizing marine drugs and suggest that a 10 g edible portion of some algae alone could contribute to a substantial PRAL reduction of up to −28.68 mEq. This might be of particular importance for individuals who benefit from a more alkaline diet and warrants further investigation in future studies.

The potential renal acid load of plant-based meat alternatives

Plant-based meat alternatives (PBMAs) are food products derived from plants and designed to mimic the preparation methods, nutritional profile, and sensorial qualities of meat. PBMAs are currently subject to a controversial debate concerning their health value. Here, we reviewed PBMAs’ potential renal acid load (PRAL). The PRAL is an estimate for the amount of acid or base a certain food produces in the human body, and was associated with tissue damage and acid stress. PRAL values varied substantially across the examined foods, and differences were as large as 19.73 mEq per 100 g of PBMA. Mycoprotein- and wheat-based PBMAs were more acidic than conventional meats. The majority of items, however, exerted a lower PRAL to the human kidneys when compared to their meat-based counterparts. Our findings reiterate that not all PBMAs are created equal, and suggest that PBMAs are generally not suitable to substantially alkalize an individual’s diet.

Edible insects exert a high potential renal acid load to the human kidneys

ABSTRACTThe potential renal acid load (PRAL) describes the capacity of a food to produce acid or base in the human body. The long-term consumption of high-PRAL diets induces a chronic low-grade metabolic acidosis state that has been associated with inflammation and impaired kidney function. PRAL tables are available to help individuals in selecting low-PRAL foods. However, these tables do not cover novel or uncommon foods in Western societies. Entomophagy – the practice of eating insects is an emerging trend in the Western world with unclear health consequences from an acid-base perspective. Here, we hypothesized that the consumption of insects is associated with a high PRAL, and analyzed the PRAL values of n = 39 commonly consumed edible insects. Our results suggest that the majority of edible insects have very high PRAL values (of up to 43.62 mEq/100 g), indicating strong acidifying properties and likely resulting in acid retention. PRAL values of edible insects rank well above the PRAL values of other high-protein foods, including legumes, pork and beef. PRAL was moderately correlated with the protein content (r = 0.42) and phosphorus content (r = 0.50) of the examined edible insects. Our data point to a potential health concern when regularly consuming edible insects.

Potential renal acid load of non-dairy plant-based milk alternatives

ABSTRACT The market for plant-based milk alternatives has been growing continuously within the last years, and numerous new food items including almond, oat, and soy milk are nowadays commercially available. The impact of said foods on the acid-base balance in humans has been rarely assessed but is of great importance for individuals who adopt an alkaline diet for health reasons. Using the Potential Renal Acid Load (PRAL) score as a measurement of the amount of acid or base a certain food produces in the human body, we analyzed n = 39 plant-based milk items available on the German market. For this cross-sectional study, we used manufacturer-derived data and aimed to compare the PRAL values of different plant-based milks. The median PRAL score for all plant-based milk alternatives was −0.23 (2.14) mEq/100 ml, and indicated a slightly alkalizing potential. Soy milks yielded, on average, the lowest PRAL score (−1.11 ± 1.14 mEq/100 ml), whereas mixed milks were slightly acidifying (mean PRAL score: 0.19 ± 0.39 mEq/100 ml). When compared to the PRAL value of cow’s milk, plant-based milk alternatives were slightly more alkaline. Our results allow for a better characterization of plant-based milk alternatives and are useful for individuals and researchers that aim to estimate the potential renal acid load from a growing group of food items.

The 1995 potential renal acid load (PRAL) values may no longer adequately reflect the actual acid-base impact of certain foods: A hypothesis.

Background: In 1995, Remer and Manz reported potential renal acid load (PRAL) values of various foods, quantifying their estimated impact on acid-base balance. Their estimation considered ionic dissociation, sulphur metabolism and intestinal absorption rates for several micronutrients and proteins. Notably, PRAL values are based on food content data from the early 1990s and may nowadays no longer adequately reflect accurate estimates. Some foods' macronutrient and mineral content has declined over the past three decades due to changes in soil mineral health. Aim: We hypothesize that the 1995 PRAL values no longer adequately reflect reliable estimates of the current acid-base impact of some foods. Methods: Based on specific examples, we argue that these values overestimate the alkalizing effects of various fruits and vegetables. Conclusion: Discussing evidence in favour of (and against) our hypothesis, we conclude that the 1995 PRAL estimates should nowadays rather be used as a relative guidance and reviewed carefully.

Dietary acid load and mortality from all causes, CVD and cancer: results from the Golestan Cohort Study.

Given the limited studies and controversial results on association between dietary acid load and mortality from CVD and cancers, we aimed to investigate this association in a large population cohort study in Middle East, with a wide range of dietary acid load. The study was conducted on the platform of the Golestan Cohort Study (GCS), which enrolled 50045 participants in 2004-2008. Dietary intake was assessed using a validated FFQ. Dietary potential renal acid load (PRAL) score was calculated from nutrient intake. Death and its causes were identified and confirmed by two or three physicians. Cox proportional hazards regression was used to estimate hazard ratio (HR) and 95 % CI for total and cause-specific mortalities. Then, the associations were modelled using restricted cubic splines. PRAL range was -57·36 to +53·81 mEq/d for men and -76·70 to +49·08 for women. During 555142 person-years of follow-up, we documented 6830 deaths, including 3070 cardiovascular deaths, 1502 cancer deaths and 2258 deaths from other causes. For overall deaths, in final model after adjustment for confounders, participants in the first and fifth quintiles of PRAL had a higher risk of mortality compared with the second quintile of PRAL (HR: 1·08; 95 % CI1·01, 1·16 and HR: 1·07; 95 % CI 1·01, 1·15, respectively); Pfor trend < 0·05). Participants in the first and fifth quintiles of PRAL had a 12 % higher risk of CVD mortality compared with the Q2 of PRAL (HR: 1·12; 95 % CI 1·01-1·25 and HR: 1·12; 95 % CI 1·01, 1·26, respectively; Pfor trend < 0·05). We found that all-cause and CVD mortality rates were higher in the lowest and highest PRAL values, in an approximately U-shaped relation (P-values for the overall association and the non-linear association of energy-adjusted PRAL with total mortality were < 0·001 and < 0·001, and with CVD mortality were 0·008 and 0·003, respectively). Our results highlight unfavourable associations of high acidity and alkalinity of diet with the increased total and CVD mortality risk. It may be important to consider a balanced acid-base diet as a protective strategy to prevent pre-mature death, especially from CVD.

Dietary Acid Load and Blood Pressure in Healthy Adults

Mild metabolic acidosis, as influenced by dietary intake, has been the topic of many epidemiological studies as a contributing factor to developing high blood pressure (BP). Diets that include an abundance of fruits and vegetables are marked by a high potassium intake that contributes to a decreased renal acid load. In contrast, a Western diet, which is typically deficient in potassium and higher in protein and phosphorus, is characterized by a higher acid load that may negatively alter acid-base balance and contribute to future cardiovascular events. The purpose of this study was to investigate the relation between dietary acid load and BP in healthy adults. Healthy adults aged 18-79 years old were included in this retrospective analysis. Dietary acid load was approximated using the Potential Renal Acid Load (PRAL), which is strongly influenced by dietary intake of protein, phosphorus and potassium assessed from a 3-day diet record. The average of three seated BP measurements was used for our analysis. Associations between PRAL and BP were determined using bivariate and partial Pearson correlations. One hundred and fifty-four subjects (78M/76W; 39 ± 2 yrs; BMI 25 ± 0.3 kg/m²) were included in this study. Men had a higher BMI (26 ± 1 kg/m² vs. 25 ± 1 kg/m²; p=0.03) and BP (119 ± 1/70 ± 1 vs. 111 ± 2/67 ± 1 mmHg; p<0.05) than women. Average PRAL was 13.4 ± 1.6 mEq/day and is consistent with a high protein and low potassium diet. PRAL values were also greater in men than women (18.6 ± 2.6 mEq/day vs. 8.1 ± 1.8 mEq/day; p<0.05). Total energy intake was 2089 ± 48 kcals/day, with men consuming more energy than women (2340 ± 70 kcals/day vs. 1835 ± 51 kcals/day; p<0.001). PRAL was positively associated with systolic BP (SBP) and pulse pressure (PP) (SBP: r=0.171, p=0.034; PP: r=0.261, p=0.001) but not with diastolic BP (DBP: r=-0.050, p=0.539). When sex and age were included as covariates, PRAL was positively correlated with both SBP and PP (SBP: r=0.205, p=0.011; PP: r=0.234, p=0.004) but not DBP (DBP: r=0.007, p=0.936). In conclusion, these findings indicate that a higher dietary acid load, correlates with a higher SBP and PP. This relation remains even after accounting for age and sex.

Diet-dependent acid load and the risk of colorectal cancer and adenoma: a case-control study.

Colorectal cancer (CRC) is the third and second most prevalent cancer in men and women, respectively. Various epidemiological studies indicated that dietary factors are implicated in the aetiology of CRC and its precursor, colorectal adenomas (CRA). Recently, much attention has been given to the role of acid-base balance in the development of chronic diseases including cancers. Therefore, the aim of the current study is to examine the association of diet-dependent acid load and the risk of CRC and CRA. In this case-control study, potential renal acid load (PRAL) was computed based on dietary intake of participants assessed via a validated FFQ. Negative PRAL values indicated a base-forming potential, while positive values of PRAL implied acid-forming potential of diet. Logistic regression was used to derive OR and 95 % CI after adjusting for confounders. Tehran, Iran. A total of 499 participants aged 30-70 years were included in the study (240 hospital controls, 129 newly diagnosed CRC and 130 newly diagnosed CRA). The current study was conducted between December 2016 and September 2018. After adjusting for potential confounders, a higher PRAL was associated with increased odds of CRC and CRA. The highest v. the lowest tertile of PRAL for CRC and CRA was OR 4·82 (95 % CI 2·51-9·25) and OR 2·47 (95 % CI 1·38-4·42), respectively. The findings of the current study suggested that higher diet-dependent acid load is associated with higher risk of CRC and CRA.

The relationship between serum uric acid concentration and cardiovascular risk factors in normotensivepostmenopausal women with dyslipidemia.

According to the latest recommendation for patients with hyperuricemia and high cardiovascular risk, the serum uric acid (SUA) concentration should be lower than 5 mg/dL (<298 &mu;mol/L). Additionally, studies have shown that SUA concentration in participants with hyperuricemia correlates with some dietary factors. The aim of this study was to assess the relationship between SUA concentration and some cardiovascular risk factors. Fifty-six postmenopausal women with dyslipidemia and without hypertension were assigned to 2 groups based on SUA concentration. The first group consisted of women with a SUA concentration &ge;5 mg/dL and without gout, and the second group comprised women with a SUA concentration <5 mg/dL. Anthropometric parameters, nutrition, structure of consumption, dietary potential renal acid load (PRAL), lipid profile parameters and blood pressure were evaluated. Postmenopausal women with a SUA &ge;5 mg/dL had statistically significant higher values of serum triglyceride (TG) concentration, waist-to-hip ratio (WHR) and diastolic blood pressure than women with a SUA concentration <5 mg/dL. Analysis of nutrition showed statistically significant differences between the groups in the intake of starch, saturated and polyunsaturated fatty acids, cholesterol and vitamin E. Additionally, we observed a correlation between PRAL value and SUA. The structure of consumption between the groups was varied. SUA concentration &ge;5 mg/dL may increase the cardiovascular risk. The association observed between PRAL and SUA can be used to evaluate diet.

Effects of mineral waters on acid-base status in healthy adults: results of a randomized trial.

BackgroundThe ‘Western diet’ typically consumed in industrialized countries is characterized by high amounts of processed cereal grains and animal products while being low in vegetables, tubers, and fruits. This dietary behavior leads to imbalances of acid–base status in favor of the acids and may cause low-grade metabolic acidosis (LGMA) that is associated with negative effects on health in the long run, including urolithiasis, bone loss, and even cardiometabolic diseases. Therefore, it has become of great interest to find dietary strategies that can be used to neutralize the acid load associated with Western diets.ObjectiveThe aim of this study was to investigate whether the diet-dependent net acid load can be reduced by the daily consumption of mineral waters with different bicarbonate content and different potential renal acid load (PRAL).MethodsA single-centered, randomized trial including 129 healthy men and women aged from 18 to 75 years was conducted. Participants consumed 1,500–2,000 mL of one of four mineral waters with different bicarbonate content and different PRAL values daily for 4 weeks: low bicarbonate, high PRAL (LBHP, HCO3−: 403.0 mg/L, PRAL: 10.7); medium-high bicarbonate, medium PRAL (MBMP, HCO3− : 1816.0 mg/L, PRAL: −10.8); high bicarbonate, low PRAL (HBLP, HCO3−: 2451.0 mg/L, PRAL: −19.3); medium-high bicarbonate, low PRAL (MBLP, HCO3−: 1846.0 mg/L, PRAL: −22.1). Throughout the study, participants were asked to maintain their usual dietary habits. The primary outcome was the net acid excretion (NAE) measured in the 24-h urine output.ResultsConsumption of the three mineral waters: MBMP, HBLP, and MBLP led to a significant decrease in NAE values. Within the MBMP group, the NAE could be reduced by 48% (P = 0.001), while consumption of HBLP led to a reduction of 68% (P < 0.001) and MBLP to a reduction of 53% (P = 0.001). Moreover, a slight increase in serum bicarbonate could also be observed in the groups that drank HBLP (P = 0.057) and MBLP (P = 0.001).ConclusionDaily consumption of at least 1,500–2,000 mL of mineral water rich in bicarbonate (>1800.0 mg/L) with medium or low PRAL (<−11 mEq/L) can effectively reduce the NAE level by reducing the dietary acid load under free-living conditions in healthy adults.

Dietary acid load and risk of hypertension: A systematic review and dose-response meta-analysis of observational studies

Background and aimPrevious studies have assessed diet-induced mild metabolic acidosis in relation to blood pressure, however, data are conflicting. Current systematic review and dose-response meta-analysis aimed to summarize earlier findings from observational studies on the association between dietary acid load and hypertension. Methods and resultsWe searched the online databases for relevant publications up to Feb 2019, using relevant keywords. Overall, 14 studies (3 prospective and 11 cross-sectional studies) that included 306,183 individuals and 62,264 cases of hypertension were included in the current meta-analysis. Combining effect sizes from both prospective and cross-sectional studies revealed no significant non-linear association between dietary acid load (based on net endogenous acid production (NEAP) method) and hypertension. However, stratified analysis based on study design showed a significant non-linear association between dietary acid load and hypertension in prospective studies (P = 0.006), but not cross-sectional ones. According to linear dose-response analysis, no significant association was found between dietary acid load (based on NEAP) and hypertension (combined effect size: 1.01, 95% CI: 0.97–1.06, P = 0.51). In terms of dietary acid load based on potential renal acid load (PRAL) method, no significant non-linear association was seen with hypertension (P = 0.52). However, in linear dose-response analysis, a-20 unit increase in PRAL values was associated with 3% increased risk of hypertension (combined effect size: 1.03, 95% CI: 1.00–1.06, P = 0.03). ConclusionWe found a significant positive association between dietary acid load and hypertension. Further studies, particularly those with prospective nature, are needed to confirm our findings.

Dietary acid load and cardiometabolic risk in the Polish adult population.

The potential influence of disorders of acid/base homeostasis on cardiovascular risk factors has been suggested. The aim of the study was to estimate the relationship between dietary acid load and the prevalence of cardiovascular disease and the prevalence and intensity of cardiovascular risk factors (i.e., hypertension, diabetes, overweight and obesity, dyslipidemia) in the Polish adult population. Data was derived from a cross-sectional survey of a random sample of 6,170 Polish residents aged 20+ (Multi-Center National Population Health Examination Survey, WOBASZ II study), including anthropometric and laboratory measurements, and estimates of nutrient intakes by 24-h recall. Dietary acid/ base load was assessed as potential renal acid load (PRAL) and net endogenous acid production (NEAP). The median PRAL and NEAP values for the whole study population were: PRAL -3.85 mEq/day and NEAP 39.79 mEq/day. The prevalence of overweight and obesity, both in males and females, tended to decrease across tertiles of PRAL and to increase across tertiles of NEAP. In females, the values of several metabolic characteristics differed across tertiles of NEAP. After adjustment for age and waist circumference, these relationships did not persist, but the prevalence of diabetes was found to increase across tertiles of PRAL (p for trend <0.05) in females. The dietary acid load in the Polish adult population was relatively low. There was no independent relationship between dietary acid load and cardiovascular disease and its risk factors in the population under study, except for the positive association between the PRAL value and diabetes prevalence in females.

Dietary Potential Renal Acid Load Is Positively Associated with Serum Uric Acid and Odds of Hyperuricemia in the German Adult Population

Initial interventional data indicate that a reduction in dietary acid load (e.g., by an increased consumption of alkalizing fruit and vegetables) can increase renal uric acid excretion and decrease serum uric acid (SUA). Against this background, we examined the association between dietary potential renal acid load (PRAL) and SUA in a representative population sample. Cross-sectional analyses were performed in 6894 participants (aged 18-79 y) of the German Health Interview and Examination Survey for Adults (DEGS1). Dietary intake was assessed with a food-frequency questionnaire. Nutritive acid load and the intake of uric acid equivalents (UAEs) were characterized by assigning PRAL and UAE values to reported food consumption. In multiple linear regression models, the associations of PRAL, UAEs, and relevant food groups with SUA were analyzed. Multiple logistic regressions were used to calculate ORs for hyperuricemia comparing lower and upper tertiles of the predictors. After adjustment for relevant confounders, PRAL (P = 0.003), alcohol (P < 0.0001), and UAE (P = 0.03) intakes were positively associated with SUA, whereas the intake of dairy products and fruit and vegetables was inversely associated (both P < 0.0001). Subgroup analyses among participants without interacting medication use confirmed these results. In addition, participants with lower PRAL had lower odds for hyperuricemia (OR: 0.60; 95% CI: 0.43, 0.83). Apart from observing known dietary influences on SUA, we found in this population-based, cross-sectional study in adults that low PRAL may represent a potentially SUA-reducing dietary pattern. This highlights dietary alkalization as a possible nonpharmacologic option to influence elevated SUA concentrations.

Draining and salting as responsible key steps in the generation of the acid-forming potential of cheese: Application to a soft blue-veined cheese

A disregarded nutritional feature of cheeses is their high acid-forming potential when ingested, which is associated with deleterious effects on consumers’ health. This work aimed to characterize the acid-forming potential of a blue-veined cheese during manufacturing to identify the main steps of the process involved in this phenomenon. Sampling was performed on 3 batches at 10 steps of the cheese-making process: reception of raw milk, pasteurization, maturation of milk, coagulation, stirring, draining of the curds, and 4 ripening stages: 21, 28, 42, and 56d. The acid-forming potential of each sample was evaluated by (1) the calculation of the potential renal acid load (PRAL) index (considering protein, Cl, P, Na, K, Mg, and Ca contents), and (2) its organic anion content (lactate and citrate), considered as alkalinizing elements. Draining and salting were identified as the main steps responsible for generation of the acid-forming potential of cheese. The draining process induced an increase in the PRAL index from 1.2mEq/100g in milk to 10.4mEq/100g in drained curds due to the increase in dry matter and the loss of alkaline minerals into the whey. The increase in PRAL value (20.3mEq/100g at d 56) following salting resulted from an imbalance between the strong acidogenic elements (Cl, P, and proteins) and the main alkalinizing ones (Na and Ca). Particularly, Cl had a major effect on the PRAL value. Regarding organic anions, draining induced a loss of 93% of the citrate content in initial milk. The lactate content increased as fermentation occurred (1,297.9mg/100g in drained curds), and then decreased during ripening (519.3mg/100g at d 56). This lactate level probably helps moderate the acidifying potential of end products. Technological strategies aimed at limiting the acid-forming potential of cheeses are proposed and deserve further research to evaluate their nutritional relevance.

Exploratory study of acid-forming potential of commercial cheeses: impact of cheese type

Due to their composition, cheeses are suspected to induce an acid load to the body. To better understand this nutritional feature, the acid-forming potential of five cheeses from different cheese-making technologies and two milk was evaluated on the basis of their potential renal acid load (PRAL) index (considering protein, P, Cl, Na, K, Mg and Ca contents) and organic anions contents. PRAL index ranged from −0.8 mEq/100 g edible portion for fresh cheese to 25.3 mEq/100 g for hard cheese Cantal and 28 mEq/100 g for blue-veined cheese Fourme d’Ambert. PRAL values were greatly subjected to interbatch fluctuations. This work emphasized a great imbalance between acidifying elements of PRAL calculation (Cl, P and proteins elements) and alkalinizing ones (Na and Ca). Particularly, Cl followed by P elements had a strong impact on the PRAL value. Hard cheeses were rich in lactate, thus, might be less acidifying than suspected by their PRAL values only.

Avaliação do potencial alcalinizante das águas minerais comercialmente disponíveis em território brasileiro

Objective: To characterize the profile of commercially available mineral waters in Brazil (from national and international sources) by calculating the potential renal acid load (PRAL). Methods: We evaluated 308 commercially available mineral waters in the five Brazilian macroregions. The content of sulfate, chloride, sodium, potassium, magnesium and calcium from mineral waters were obtained to calculate the PRAL, using Remers & Manz formula, adapted for mineral waters. Results: From the 308 mineral waters collected, 256 were included in this analysis. We found a great variability in the composition of mineral waters according to the source and country of origin. All the components analyzed were present in greater quantities in the mineral waters from international sources and differed significantly from the values found in the mineral waters from Brazilian sources, with the exception of potassium and sodium (Mg: 1,9 vs 6,8, p=0,0008; Ca: 5,78 vs 32,9, p=0,001; SO4: 0,9 vs 13, p<0,0001; Cl: 1,49 vs 12, p=0,0019, mineral waters from Brazilian sources versus international sources, respectively). The PRAL value of mineral waters from Brazilian sources was also statistically different (-0,39 vs -1,39; p=0,0025). The potential basifying / acidifying effects of the mineral water evaluated by PRAL did not correlate with the pH value. The magnesium and bicarbonate content were the major predictors of a negative PRAL - the higher the content thereof, lower the PRAL. Conclusion: The mineral waters from Brazilian sources have a low grade of mineralization and the vast majority (n=201) have a PRAL value considered neutral

Noncitrus Alkaline Fruit: A Dietary Alternative for the Treatment of Hypocitraturic Stone Formers

Fruits and vegetables are natural suppliers of potassium, bicarbonate, or bicarbonate precursors such as citrate, malate and others-hence, possessing potential effects on citraturia. We aimed to compare the acute effects of a noncitrus (melon) fruit vs citric ones (orange and lime) on citraturia and other lithogenic parameters. Two-hour urine samples were collected from 30 hypocitraturic stone-forming patients after an overnight fast and 2, 4, and 6 hours after the consumption of 385 mL (13 oz) of either freshly squeezed orange juice (n=10), freshly blended melon juice (n=10), or freshly squeezed lime juice (n=10). Urinary citrate, potassium, pH, and other lithogenic parameters were determined and net gastrointestinal alkali absorption (NGIA) was calculated. Potential renal acid load (PRAL) and pH from juices were determined. Significant and comparable increases of mean urinary citrate were observed in all groups, whereas mean urinary potassium, pH, and NGIA were significantly increased only after consumption of melon and orange juices. The pH of melon juice was higher and the PRAL value was more negative compared with orange juice, indicating a higher alkalinity. These findings suggested that melon, a noncitrus source of potassium, citrate, and malate, yielded an increase in urinary citrate excretion equivalent to that provided by orange, and hence represents another dietary alternative for the treatment of hypocitraturic stone-formers. Despite its low potassium content, lime also produced comparable increases in citraturia possibly because of its high citric acid content.

Dietary Acid-Base Balance in Adolescent Sprint Athletes: A Follow-up Study

Sprinters are advised to include additional protein sources in their diet. Basal metabolism and vigorous physical activities generate hydrogen ions that need to be buffered. The present follow-up study estimates the dietary potential renal acid load (PRAL) and net endogenous acid production (NEAP) in adolescent sprint athletes. Seven-day food diaries and anthropometrics of 60 adolescent sprint athletes (mean age at start 14.7 ± 1.9 years) were collected every six months over a three year period. Comparisons were made between athletes with a negative (PRAL(−)) versus positive PRAL (PRAL(+)). For the entire sample, mean PRAL values of up to 6 mEq/day were slightly positive despite a relatively high protein intake of around 1.5 g/kg. The NEAP ranging between 42 and 46 mEq/day remained stable during the study period. Athletes with a PRAL(−) (−8 to −10 mEq/day) consumed significantly more fruit and fruit juice than athletes with a PRAL(+) (+9 to 14 mEq/day). Athletes with a PRAL(+) did not consume more meat, fish and poultry than athletes with a PRAL(−). Grains and dairy products were only discriminative between the two groups on one measurement occasion. Lowering the PRAL can be obtained by increasing the consumption of potatoes, fruits, vegetables and vegetable soup.

Nutrient Based Estimation of Acid-Base Balance in Vegetarians and Non-vegetarians

A first objective of the present study was to estimate the acid-base balance of the food intake in vegetarians and non-vegetarians. A second objective was to evaluate if additional input of specific food items on the existing potential renal acid load (PRAL) list was necessary for the comparison of the two dietary patterns. Thirty vegetarians between the age of 18 and 30 years were matched for sex, age and BMI with 30 non-vegetarians. Based on the 3-days food diaries the acid-base status of the food intake was estimated using the PRAL method. Mean PRAL values as estimated with the standard table yielded an alkaline load of -5.4 +/- 14.4 mEq/d in the vegetarians compared to an acid load of 10.3 +/- 14.4 mEq/d in the nonvegetarians (p<0.001). Mean PRAL values as estimated with the extended table yielded an alkaline load of -10.9 +/-19.7 mEq/d in the vegetarians compared to an acid load of 13.8 +/- 17.1 mEq/d for the non-vegetarians (p<0.001). The findings of this study indicate that vegetarian food intake produces more alkaline outcomes compared to non-vegetarian diets. The use of the standard PRAL table was sufficient for discrimination between the two diets.