scholarly journals Inhibitory effect of high protein intake on nephrocalcinogenesis in female rats

1992 ◽  
Vol 67 (2) ◽  
pp. 223-233 ◽  
Author(s):  
J. G. H. Sterck ◽  
J. Ritskes-Hoitinga ◽  
A. C. Beynen

Increased intakes of protein have been shown to reduce kidney calcification (nephrocalcinosis) in female rats. Two questions were addressed in the present study. First, can protein-induced inhibition of nephrocalcinosis be demonstrated when the diets used are balanced for calcium, magnesium and phosphorus in the added protein? Second, can the protein effect be explained by the frequently observed magnesiuria after giving high-protein diets? Nephrocalcinosis was induced in female rats by giving purified diets containing 151 g casein/kg and either an increased concentration of P (6 v. 2 g/kg) or a decreased concentration of Mg (0·1 v. 0·4 g/kg). To these diets 151 g ovalbumin/kg was added at the expense of glucose, and the diets were balanced for Ca, Mg and P in ovalbumin. The diets were given for 29 d. In rats fed on the diet containing 151 g protein/kg, an increased intake of P or a decreased intake of Mg caused nephrocalcinosis as measured chemically by analysis of kidney Ca as well as histologically by scoring kidney sections stained according to Von Kossa's method. The addition of ovalbumin to the diet prevented the induction of nephrocalcinosis. High P intake and low Mg intake with the low-protein diets induced enhanced loss of albumin in urine, suggesting that nephrocalcinosis caused kidney damage. Increased protein intake with a non-calcinogenic diet also caused increased albumin excretion in urine. Irrespective of the composition of the background diet, increased protein intake caused increased urinary excretion of Mg. When all dietary groups were considered, differences in nephrocalcinosis and urinary Mg output were not proportionally related.Nephrocalcinosis: Phosphorus: Magnesium: Protein: Rat

2011 ◽  
Vol 70 (2) ◽  
pp. 205-214 ◽  
Author(s):  
Kevin D. Tipton

Athletes and exercisers have utilised high-protein diets for centuries. The objective of this review is to examine the evidence for the efficacy and potential dangers of high-protein diets. One important factor to consider is the definition of a ‘high-protein diet’. There are several ways to consider protein content of a diet. The composition of the diet can be determined as the absolute amount of the protein (or other nutrient of interest), the % of total energy (calories) as protein and the amount of protein ingested per kg of body weight. Many athletes consume very high amounts of protein. High-protein diets most often are associated with muscle hypertrophy and strength, but now also are advocated for weight loss and recovery from intense exercise or injuries. Prolonged intake of a large amount of protein has been associated with potential dangers, such as bone mineral loss and kidney damage. In otherwise healthy individuals, there is little evidence that high protein intake is dangerous. However, kidney damage may be an issue for individuals with already existing kidney dysfunction. Increased protein intake necessarily means that overall energy intake must increase or consumption of either carbohydrate or fat must decrease. In conclusion, high protein intake may be appropriate for some athletes, but there are potential negative consequences that must be carefully considered before adopting such a diet. In particular, care must be taken to ensure that there is sufficient intake of other nutrients to support the training load.


2015 ◽  
Vol 114 (8) ◽  
pp. 1132-1142 ◽  
Author(s):  
Catherine Chaumontet ◽  
Patrick C. Even ◽  
Jessica Schwarz ◽  
Angélique Simonin-Foucault ◽  
Julien Piedcoq ◽  
...  

AbstractHigh-protein diets are known to reduce adiposity in the context of high carbohydrate and Western diets. However, few studies have investigated the specific high-protein effect on lipogenesis induced by a high-sucrose (HS) diet or fat deposition induced by high-fat feeding. We aimed to determine the effects of high protein intake on the development of fat deposition and partitioning in response to high-fat and/or HS feeding. A total of thirty adult male Wistar rats were assigned to one of the six dietary regimens with low and high protein, sucrose and fat contents for 5 weeks. Body weight (BW) and food intake were measured weekly. Oral glucose tolerance tests and meal tolerance tests were performed after 4th and 5th weeks of the regimen, respectively. At the end of the study, the rats were killed 2 h after ingestion of a calibrated meal. Blood, tissues and organs were collected for analysis of circulating metabolites and hormones, body composition and mRNA expression in the liver and adipose tissues. No changes were observed in cumulative energy intake and BW gain after 5 weeks of dietary treatment. However, high-protein diets reduced by 20 % the adiposity gain induced by HS and high-sucrose high-fat (HS-HF) diets. Gene expression and transcriptomic analysis suggested that high protein intake reduced liver capacity for lipogenesis by reducing mRNA expressions of fatty acid synthase (fasn), acetyl-CoA carboxylase a and b (Acaca and Acacb) and sterol regulatory element binding transcription factor 1c (Srebf-1c). Moreover, ketogenesis, as indicated by plasma β-hydroxybutyrate levels, was higher in HS-HF-fed mice that were also fed high protein levels. Taken together, these results suggest that high-protein diets may reduce adiposity by inhibiting lipogenesis and stimulating ketogenesis in the liver.


2020 ◽  
Vol 31 (8) ◽  
pp. 1667-1679 ◽  
Author(s):  
Gang-Jee Ko ◽  
Connie M. Rhee ◽  
Kamyar Kalantar-Zadeh ◽  
Shivam Joshi

Although high-protein diets continue to be popular for weight loss and type 2 diabetes, evidence suggests that worsening renal function may occur in individuals with—and perhaps without—impaired kidney function. High dietary protein intake can cause intraglomerular hypertension, which may result in kidney hyperfiltration, glomerular injury, and proteinuria. It is possible that long-term high protein intake may lead to de novo CKD. The quality of dietary protein may also play a role in kidney health. Compared with protein from plant sources, animal protein has been associated with an increased risk of ESKD in several observational studies, including the Singapore Chinese Health Study. Potential mediators of kidney damage from animal protein include dietary acid load, phosphate content, gut microbiome dysbiosis, and resultant inflammation. In light of such findings, adopting current dietary approaches that include a high proportion of protein for weight reduction or glycemic control should be considered with care in those at high risk for kidney disease. Given the possibility of residual confounding within some observational studies and the conflicting evidence from previous trials, long-term studies including those with large sample sizes are warranted to better ascertain the effects of high protein intake on kidney health.


Critical Care ◽  
2022 ◽  
Vol 26 (1) ◽  
Author(s):  
Wolfgang H. Hartl ◽  
Philipp Kopper ◽  
Andreas Bender ◽  
Fabian Scheipl ◽  
Andrew G. Day ◽  
...  

Abstract Background Proteins are an essential part of medical nutrition therapy in critically ill patients. Guidelines almost universally recommend a high protein intake without robust evidence supporting its use. Methods Using a large international database, we modelled associations between the hazard rate of in-hospital death and live hospital discharge (competing risks) and three categories of protein intake (low: < 0.8 g/kg per day, standard: 0.8–1.2 g/kg per day, high: > 1.2 g/kg per day) during the first 11 days after ICU admission (acute phase). Time-varying cause-specific hazard ratios (HR) were calculated from piece-wise exponential additive mixed models. We used the estimated model to compare five different hypothetical protein diets (an exclusively low protein diet, a standard protein diet administered early (day 1 to 4) or late (day 5 to 11) after ICU admission, and an early or late high protein diet). Results Of 21,100 critically ill patients in the database, 16,489 fulfilled inclusion criteria for the analysis. By day 60, 11,360 (68.9%) patients had been discharged from hospital, 4,192 patients (25.4%) had died in hospital, and 937 patients (5.7%) were still hospitalized. Median daily low protein intake was 0.49 g/kg [IQR 0.27–0.66], standard intake 0.99 g/kg [IQR 0.89– 1.09], and high intake 1.41 g/kg [IQR 1.29–1.60]. In comparison with an exclusively low protein diet, a late standard protein diet was associated with a lower hazard of in-hospital death: minimum 0.75 (95% CI 0.64, 0.87), and a higher hazard of live hospital discharge: maximum HR 1.98 (95% CI 1.72, 2.28). Results on hospital discharge, however, were qualitatively changed by a sensitivity analysis. There was no evidence that an early standard or a high protein intake during the acute phase was associated with a further improvement of outcome. Conclusions Provision of a standard protein intake during the late acute phase may improve outcome compared to an exclusively low protein diet. In unselected critically ill patients, clinical outcome may not be improved by a high protein intake during the acute phase. Study registration ID number ISRCTN17829198


Reproduction ◽  
2011 ◽  
Vol 141 (5) ◽  
pp. 697-706 ◽  
Author(s):  
Gina C Micke ◽  
Tracy M Sullivan ◽  
I Caroline McMillen ◽  
Sheridan Gentili ◽  
Vivienne E A Perry

Changes in maternal nutrient intake during gestation alterIGFreceptor abundance and leptin (LEP) mRNA expression in fetal adipose tissue. It is not known whether such changes persist into adult life and whether they are associated with an effect on phenotype. We investigated the effect of high (240%) and low (70%) levels of recommended daily crude protein intake for beef heifers during the first and second trimesters of gestation on singleton progeny (n=68): subcutaneous (SC) adipose tissue depth at rump (P8) and rib (RF) sites from 65 until 657 days of age; plasma leptin concentrations from birth until 657 days and expression ofIGF1andIGF2, their receptors (IGF1RandIGF2R) andLEPmRNA in perirenal (PR), omental (OM) and SC adipose tissue at 680 days of age. High-protein diets during the first trimester increasedLEPandIGF1mRNA in PR of males and females, respectively, compared with low-protein diets, and decreasedIGF1RmRNA in SC of all progeny but increased RF depth of males between 552 and 657 days. High-protein diets compared with low-protein diets during the second trimester increasedIGF1RmRNA in PR and OM of all progeny;LEPmRNA in PR of males; andIGF2andIGF2RmRNA in OM of all progeny. Conversely,LEPmRNA in OM andIGF2mRNA in PR of all progeny were decreased following exposure to high- compared with low-protein diets during the second trimester. Heifer diet during gestation has permanent sex- and depot-specific effects on the expression of adipogenic and adipocytokine genes and offspring adiposity.


PEDIATRICS ◽  
1962 ◽  
Vol 29 (1) ◽  
pp. 90-96
Author(s):  
Oliver W. Vaughan ◽  
L. J. Filer ◽  
Helen Churella

One-day-old piglets were fed diets of either 50% or 14% protein for 8 weeks; they were given intravenous injections with S35-methionine-labeled plasma protein and were given a nonprotein diet. The plasma protein turnover and the nitrogen excreted were estimated by measuring the S35 activity and the nitrogen in aliquots of blood, urine and feces. During a 102-day period of protein privation, the animals that had received the high-protein diet lost little weight, while pigs previously fed a low level of protein lost 4.4 kg. However the high-protein group had a considerably faster rate of plasma protein turnover, catabolized a much large quantity of protein, and excreted more S35 and nitrogen than did the low-protein group. It is concluded that high-protein diets may make pigs less well able to cope with the stress of sudden protein deprivation.


2002 ◽  
Vol 35 (6) ◽  
pp. 601-607 ◽  
Author(s):  
Janira Lúcia Assumpção Couto ◽  
Haroldo da Silva Ferreira ◽  
Dinalva Bezerra da Rocha ◽  
Maria Eugênia Leite Duarte ◽  
Monica Lopes Assunção ◽  
...  

The effects of high and low-protein diets on the structure of the jejunal mucosa were studied in Schistosoma mansoni infected mice (morphology and histomorphometry). Weaning male albino mice were infected with 80 cercariae, fed with high (20%) or low-protein (5%) diets and compared to uninfected controls under the same conditions. Mice were sacrificed 12 weeks after infection. Animals submitted to a low-protein diet showed lower weight curves, mainly when infected. In the jejunal mucosa, finger-like villi were the predominant pattern among uninfected high-protein fed animals, while the infected ones showed leaf-shaped and flattened villi in most cases. Undernourished infected mice had 65.7% leaf-shaped villi. A significant increase in the number of goblet cells was seen in infected mice. A decrease in the number of absorptive cells was detected in undernourished mice, particularly in infected ones.


1987 ◽  
Vol 252 (6) ◽  
pp. F1088-F1094 ◽  
Author(s):  
R. A. Stahl ◽  
S. Kudelka ◽  
U. Helmchen

Reduction of renal mass in the rat results in an increased glomerular prostaglandin (PG) and thromboxane (TX) formation that modulates renal hemodynamics. To evaluate whether dietary protein intake could exert effects on renal PG and TX formation after reduction of approximately 70% of renal mass, rats with remnant kidneys were placed on either a high-protein (HP) or a low-protein (LP) diet. After 2 wk on the diet, proteinuria, glomerular filtration rate (GFR), urinary PGE2 excretion, and glomerular PGE2, 6-keto PGF1 alpha, and TxB2 biosynthesis were significantly greater in the rats on HP diets. Two-wk administration of the thromboxane synthesis inhibitor UK 38485 reduced renal TxB2 formation by approximately 70%. In addition, chronic UK 38485 treatment significantly inhibited papillary PGE2 production. Neither chronic nor bolus administration of UK 38485 had an effect on proteinuria or GFR in rats on HP diets. Chronic UK 38485 treatment, however, reduced GFR and proteinuria in rats on LP diets. The bolus administration of UK 38485 did not alter GFR in animals receiving a LP diet. The cyclooxygenase inhibitor indomethacin reduced GFR only in rats on HP diets. The data demonstrate that HP intake stimulates renal prostanoid formation. The increased prostaglandin formation on HP intake modulates GFR in these rats.


1941 ◽  
Vol 74 (6) ◽  
pp. 591-600 ◽  
Author(s):  
H. Philipsborn ◽  
L. N. Katz ◽  
S. Rodbard

The effect of high and low protein diets were studied on fourteen dogs in twenty-four different experiments. In only two of these animals, both with moderate renal excretory failure, was a reversible rise in blood pressure elicited by a high protein diet. The possible mechanisms involved in meeting an increased excretory load are discussed.


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