Protein Intake and Bone Health

Adequate nutrition plays an important role in the development and maintenance of bone structures resistant to usual mechanical stresses. In addition to calcium in the presence of an adequate supply of vitamin D, dietary proteins represent key nutrients for bone health and thereby function in the prevention of osteoporosis. Several studies point to a positive effect of high protein intake on bone mineral density or content. This fact is associated with a significant reduction in hip fracture incidence, as recorded in a large prospective study carried out in a homogeneous cohort of postmenopausal women. Low protein intake (< 0.8 g/kg body weight/day) is often observed in patients with hip fractures and an intervention study indicates that following orthopedic management, protein supplementation attenuates post-fracture bone loss, tends to increase muscle strength, and reduces medical complications and rehabilitation hospital stay. There is no evidence that high protein intake per se would be detrimental for bone mass and strength. Nevertheless, it appears reasonable to avoid very high protein diets (i. e. more than 2.0 g/kg body weight/day) when associated with low calcium intake (i. e. less than 600 mg/day). In the elderly, taking into account the attenuated anabolic response to dietary protein with ageing, there is concern that the current dietary protein recommended allowance (RDA), as set at 0.8 g/kg body weight/day, might be too low for the primary and secondary prevention of fragility fractures.

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High Protein Intake during Continuous Hemodiafiltration: Impact on Amino Acids and Nitrogen Balance

The International Journal of Artificial Organs ◽

10.1177/039139880202500403 ◽

2002 ◽

Vol 25 (4) ◽

pp. 261-268 ◽

Cited By ~ 72

Author(s):

R. Bellomo ◽

H. K. Tan ◽

S. Bhonagiri ◽

I. Gopal ◽

J. Seacombe ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Nitrogen Balance ◽

Protein Intake ◽

Protein Supplementation ◽

High Protein ◽

Total Serum ◽

Amino Acid Supplementation ◽

Continuous Hemodiafiltration ◽

High Protein Intake

Aims To study the effect of combined continuous veno-venous hemodiafiltration (CVVHDF) and high (2.5 g/kg/day) parenteral amino acid supplementation on nitrogen balance, amino acid losses and azotemic control in a cohort of patients with severe acute renal failure (ARF). Methods We administered 2.5 grams/kg/day of amino acids intravenously to seven critically ill patients with ARF. We obtained paired blood and ultrafiltrate (UF) samples (n=20) and calculated amino acid clearances and losses, nitrogen balance, protein catabolic rate and total nitrogen losses. Results The median total serum amino acid concentration was high at 5.2 mmol/L with particularly high concentrations of ornithine, lysine, and phenylalanine, but a low level of histidine. The median overall amino acid clearance was 18.6 ml/min (range: 12 to 29 ml/min). UF losses as percentage of administered dose were high for tyrosine (53.6 %) but low for methionine (3.0 %) and arginine (2.3 %). A positive nitrogen balance was achieved in 7 (35%) of the 20 study days with an overall median nitrogen balance of -1.8 g/day. Urea levels were maintained at a median of 26.6 mmol/L. Conclusions High protein intake increases the serum concentrations of most amino acids. Such protein supplementation, when coupled with CVVHDF, achieves a slightly negative overall nitrogen balance in extremely catabolic patients while still allowing adequate azotemic control.

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High protein intake stimulates glomerular prostaglandin formation in remnant kidneys

AJP Renal Physiology ◽

10.1152/ajprenal.1987.252.6.f1088 ◽

1987 ◽

Vol 252 (6) ◽

pp. F1088-F1094 ◽

Cited By ~ 1

Author(s):

R. A. Stahl ◽

S. Kudelka ◽

U. Helmchen

Keyword(s):

Dietary Protein ◽

Protein Intake ◽

Renal Mass ◽

Filtration Rate ◽

High Protein ◽

Bolus Administration ◽

Cyclooxygenase Inhibitor ◽

Synthesis Inhibitor ◽

High Protein Intake ◽

Low Protein

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.

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Effects of high-protein intake on bone turnover in long-term bed rest in women

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2016-0292 ◽

2017 ◽

Vol 42 (5) ◽

pp. 537-546 ◽

Cited By ~ 8

Author(s):

Martina Heer ◽

Natalie Baecker ◽

Petra Frings-Meuthen ◽

Sonja Graf ◽

Sara R. Zwart ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Bone Turnover ◽

Muscle Mass ◽

Protein Intake ◽

Bed Rest ◽

High Protein ◽

Mineral Density ◽

High Protein Intake ◽

Potassium Intake

Bed rest (BR) causes bone loss, even in otherwise healthy subjects. Several studies suggest that ambulatory subjects may benefit from high-protein intake to stimulate protein synthesis and to maintain muscle mass. However, increasing protein intake above the recommended daily intake without adequate calcium and potassium intake may increase bone resorption. We hypothesized that a regimen of high-protein intake (HiPROT), applied in an isocaloric manner during BR, with calcium and potassium intake meeting recommended values, would prevent any effect of BR on bone turnover. After a 20-day ambulatory adaptation to a controlled environment, 16 women participated in a 60-day, 6° head-down-tilt (HDT) BR and were assigned randomly to 1 of 2 groups. Control (CON) subjects (n = 8) received 1 g/(kg body mass·day)−1 dietary protein. HiPROT subjects (n = 8) received 1.45 g protein/(kg body mass·day)−1 plus an additional 0.72 g branched-chain amino acids per day during BR. All subjects received an individually tailored diet (before HDTBR: 1888 ± 98 kcal/day; during HDTBR: 1604 ± 125 kcal/day; after HDTBR: 1900 ± 262 kcal/day), with the CON group’s diet being higher in fat and carbohydrate intake. High-protein intake exacerbated the BR-induced increase in bone resorption marker C-telopeptide (>30%) (p < 0.001) by the end of BR. Bone formation markers were unaffected by BR and high-protein intake. We conclude that high-protein intake in BR might increase bone loss. Further long-duration studies are mandatory to show how the positive effect of protein on muscle mass can be maintained without the risk of reducing bone mineral density.

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Effect of resistance training exercise combined with high protein diet on body weight and muscle mass in underweight adolescent males

Malaysian Journal of Nutrition ◽

10.31246/mjn-2020-0039 ◽

2021 ◽

Vol 27 (1) ◽

pp. 041-052

Author(s):

Wittawas Sajjapong ◽

◽

Preeya Leelahagul ◽

Sitha Pongphibool ◽

Narupon Thongsuk ◽

...

Keyword(s):

Body Weight ◽

Resistance Training ◽

Protein Intake ◽

High Protein Diet ◽

High Protein ◽

Protein Diet ◽

Protein Supplements ◽

High Protein Intake ◽

Training Exercise ◽

Resistance Training Exercise

Introduction: Many underweight males take commercial protein supplements to increase their body weight and build muscle. Nonetheless, commercial protein supplements may cause adverse effects. This study aimed to determine the effects of resistance training exercise combined with a high protein diet on body weight and muscle mass in underweight adolescent males. Methods: A repeated measures design study was conducted on nine males aged 12-15 years with low body weight. Energy and protein requirements were calculated, and energy and protein consumptions were measured for each meal during the high protein diet without exercise (HP) period and the high protein diet with resistance exercise (HPE) period. Subjects engaged in three resistance training sessions each week during HP-E period, for eight weeks. Dietary intake, body composition, blood biochemistry, physical fitness, and self-esteem were assessed. Results: In HP-E period, resistance training exercise combined with a high protein intake (2.14 g/kg/d) increased body weight and lean tissue mass (LTM) by 0.5 kg and 0.5 kg, respectively. Resistance training during HP-E period increased arm, leg, and trunk muscle strength by 20.2%, 7.2%, and 14.5%, respectively, more than high protein diet alone during HP period. High protein intake in HP-E period did not affect blood urea nitrogen (BUN) and creatinine levels (11.0 mg/dL and 0.70 mg/dL, respectively). Conclusion: Eight weeks of resistance training combined with a high protein diet increased body weight and LTM without adverse effects. In particular, resistance exercise predominantly increased muscle strength. Kidney function was not affected by high protein consumption throughout this study.

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The Effects of High-Protein Diets on Kidney Health and Longevity

Journal of the American Society of Nephrology ◽

10.1681/asn.2020010028 ◽

2020 ◽

Vol 31 (8) ◽

pp. 1667-1679 ◽

Cited By ~ 6

Author(s):

Gang-Jee Ko ◽

Connie M. Rhee ◽

Kamyar Kalantar-Zadeh ◽

Shivam Joshi

Keyword(s):

Dietary Protein ◽

Protein Intake ◽

Observational Studies ◽

Animal Protein ◽

High Protein ◽

High Protein Intake ◽

High Protein Diets ◽

Protein Diets ◽

Kidney Health

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.

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Low carbohydrate intake only shows a larger decrease in body weight and fat percentage in the presence of high protein intake

Appetite ◽

10.1016/j.appet.2009.04.183 ◽

2009 ◽

Vol 52 (3) ◽

pp. 859

Author(s):

S. Soenen ◽

M.S. Westerterp-Plantenga

Keyword(s):

Body Weight ◽

Protein Intake ◽

High Protein ◽

Carbohydrate Intake ◽

Fat Percentage ◽

High Protein Intake ◽

Low Carbohydrate

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Dietary protein and bone health

Proceedings of The Nutrition Society ◽

10.1079/pns2003307 ◽

2003 ◽

Vol 62 (4) ◽

pp. 867-876 ◽

Cited By ~ 51

Author(s):

Fiona Ginty

Keyword(s):

Bone Health ◽

Dietary Protein ◽

Protein Intake ◽

Protein Quality ◽

Skeletal Development ◽

Positive Association ◽

The Elderly ◽

Dietary Factors ◽

Low Protein ◽

The Usa

The effects of dietary protein on bone health are paradoxical and need to be considered in context of the age, health status and usual diet of the population. Over the last 80 years numerous studies have demonstrated that a high protein intake increases urinary Ca excretion and that on average 1 mg Ca is lost in urine for every 1 g rise in dietary protein. This relationship is primarily attributable to metabolism of S amino acids present in animal and some vegetable proteins, resulting in a greater acid load and buffering response by the skeleton. However, many of these early studies that demonstrated the calciuric effects of protein were limited by low subject numbers, methodological errors and the use of high doses of purified forms of protein. Furthermore, the cross-cultural and population studies that showed a positive association between animal-protein intake and hip fracture risk did not consider other lifestyle or dietary factors that may protect or increase the risk of fracture. The effects of protein on bone appear to be biphasic and may also depend on intake of Ca- and alkali-rich foods, such as fruit and vegetables. At low protein intakes insulin-like growth factor production is reduced, which in turn has a negative effect on Ca and phosphate metabolism, bone formation and muscle cell synthesis. Although growth and skeletal development is impaired at very low protein intakes, it is not known whether variations in protein quality affect the achievement of optimal peak bone mass in adolescents and young adults. Prospective studies in the elderly in the USA have shown that the greatest bone losses occur in elderly men and women with an average protein intake of 16–50 g/d. Although a low protein intake may be indicative of a generally poorer diet and state of health, there is a need to evaluate whether there is a lower threshold for protein intake in the elderly in Europe that may result in increased bone loss and risk of osteoporotic fracture.

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Old Question Revisited: Are High-Protein Diets Safe in Pregnancy?

Nutrients ◽

10.3390/nu13020440 ◽

2021 ◽

Vol 13 (2) ◽

pp. 440

Author(s):

Thorhallur I. Halldorsson ◽

Bryndis E. Birgisdottir ◽

Anne L. Brantsæter ◽

Helle Margrete Meltzer ◽

Margaretha Haugen ◽

...

Keyword(s):

Birth Weight ◽

Low Birth Weight ◽

Preterm Delivery ◽

Fetal Growth ◽

Protein Intake ◽

Protein Supplementation ◽

High Protein ◽

High Protein Intake ◽

Neonatal Deaths ◽

Combining Data

Background: A previous randomized dietary intervention in pregnant women from the 1970s, the Harlem Trial, reported retarded fetal growth and excesses of very early preterm births and neonatal deaths among those receiving high-protein supplementation. Due to ethical challenges, these findings have not been addressed in intervention settings. Exploring these findings in an observational setting requires large statistical power due to the low prevalence of these outcomes. The aim of this study was to investigate if the findings on high protein intake could be replicated in an observational setting by combining data from two large birth cohorts. Methods: Individual participant data on singleton pregnancies from the Danish National Birth Cohort (DNBC) (n = 60,141) and the Norwegian Mother, Father and Child Cohort Study (MoBa) (n = 66,302) were merged after a thorough harmonization process. Diet was recorded in mid-pregnancy and information on birth outcomes was extracted from national birth registries. Results: The prevalence of preterm delivery, low birth weight and fetal and neonatal deaths was 4.77%, 2.93%, 0.28% and 0.17%, respectively. Mean protein intake (standard deviation) was 89 g/day (23). Overall high protein intake (>100 g/day) was neither associated with low birth weight nor fetal or neonatal death. Mean birth weight was essentially unchanged at high protein intakes. A modest increased risk of preterm delivery [odds ratio (OR): 1.10 (95% confidence interval (CI): 1.01, 1.19)] was observed for high (>100 g/day) compared to moderate protein intake (80–90 g/day). This estimate was driven by late preterm deliveries (weeks 34 to <37) and greater risk was not observed at more extreme intakes. Very low (<60 g/day) compared to moderate protein intake was associated with higher risk of having low-birth weight infants [OR: 1.59 (95%CI: 1.25, 2.03)]. Conclusions: High protein intake was weakly associated with preterm delivery. Contrary to the results from the Harlem Trial, no indications of deleterious effects on fetal growth or perinatal mortality were observed.

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