scholarly journals Tolerable amounts of amino acids for human supplementation: summary and lessons from published peer-reviewed studies

Amino Acids ◽  
2021 ◽  
Author(s):  
François Blachier ◽  
Anne Blais ◽  
Rajavel Elango ◽  
Kuniaki Saito ◽  
Yoshiharu Shimomura ◽  
...  

AbstractAmino acid supplementation may be indicated to correct for insufficient amino acid intake in healthy individuals, and in specific physiological or pathophysiological situations. However, there is a concern to not supplement beyond the tolerable upper intake level (UL) by determining parameters of no-observed-adverse-effect level (NOAEL) or lowest-observed-adverse-effect level (LOAEL) for each amino acid. Since the NOAEL and LOAEL values are at least one order of magnitude different when comparing the values obtained in rats and humans, the aim of this review is to evaluate to what extent the amino acid UL measured in the rat model, when referenced to the dietary usual consumption (UC) and dietary requirement (RQ) for indispensable amino acids, may be used as an approximation of the UL in humans. This review then compares the ratios of the NOAEL or LOAEL over UC and RQ in the rat model with the same ratios calculated in humans for the nine amino acids (arginine, serine, glycine, histidine, leucine, lysine, methionine, phenylalanine, and tryptophan) for which this comparison can be done. From the calculations made, it appears that for these 9 amino acids, the calculated ratios for rats and humans, although rather different for several amino acids, remains for all of them in the same order of magnitude. For tryptophan, tyrosine, and valine, the ratios calculated in rats are markedly different according to the sex of animals, raising the view that it may be also the case in humans.

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 200-201
Author(s):  
Hyunjun Choi ◽  
Sun Jong You ◽  
Beob Gyun G Kim

Abstract The objective was to determine the influence of amino acid (AA) supplementation during the adaptation period on the ileal digestibility of crude protein and AA in corn and soybean meal (SBM). Six barrows with an initial body weight of 30.9 ± 2.6 kg fitted with a T-cannula in the distal ileum were assigned to a 6 × 6 Latin square design with 6 dietary treatments and 6 periods. Two experimental diets contained corn or SBM as the sole source of AA and an N-free diet was additionally prepared. For AA supplementation groups, an AA mixture consisted of Gly, Lys, Met, Thr, Trp, Ile, Val, His, and Phe was added to the corn diet and the N-free diet at the expense of cornstarch, and an AA mixture of Lys, Met, and Thr was added to the SBM diet. All diets contained 0.5% of chromic oxide. The 6 experimental diets were fed to the pigs for 4 and half days, and the 3 diets containing AA mixture were switched to the respective diets without AA mixture during the following 2 and half days. Ileal digesta were collected during the last 2 days. The addition of AA mixture during the adaptation period caused increased apparent ileal digestibility of Arg and Trp in corn (P < 0.05), but did not affect that in SBM. The addition of AA mixture during the adaptation period caused increased apparent ileal digestibility of Pro and Gly regardless of feed ingredient (P < 0.05), but did not affect that of other AA. All AA except Pro in corn and SBM were unaffected by the addition of AA mixture during the adaptation period. In conclusion, the addition of amino acid during the adaptation period does not affect the standardized ileal digestibility of indispensable amino acids in feed ingredients.


2019 ◽  
Vol 49 (1) ◽  
pp. 312-321 ◽  
Author(s):  
Marion Tharrey ◽  
Francois Mariotti ◽  
Andrew Mashchak ◽  
Pierre Barbillon ◽  
Maud Delattre ◽  
...  

Abstract Background The intake of specific amino acids (AA) has been associated with cardiovascular health, but amino acids are consumed together as dietary protein. Here we investigated the association between identified patterns of amino acid intake and cardiovascular mortality. Methods A total of 2216 cardiovascular deaths among 79 838 men and women from the Adventist Health Study-2 were included in our analysis. Baseline dietary patterns based on the participants' amino acids intakes were derived by factor analysis. Using Cox regression analyses, we estimated multivariate-adjusted hazard ratios (HRs) adjusted for sociodemographic and lifestyle factors and other dietary components. Results Three patterns of amino acids were identified. Factor 1 was positively associated with cardiovascular disease (CVD) mortality [hazard ratio (HR)Q5-Q1: 1.62, 98.75% confidence interval (CI): 1.15, 2.28; P-trend <0.001]; and Factors 2 and 3 were inversely associated with CVD mortality (HR Q5-Q1 Factor 2: 0.74, 98.75% CI: 0.53, 1.04; P-trend <0.01 and HR Q5-Q1 Factor 3: 0.65, 98.75% CI: 0.44, 0.95; P-trend <0.05]. The associations with Factor 1 (with high loadings on indispensable amino acids such as branched chain amino acids, lysine, methionine) and Factor 3 (with high loadings on non-indispensable amino acids, namely arginine, glycine, aspartate+asparagine) remained significant after further adjustment for nutrient intake and for the five protein source patterns identified previously (HR Q5-Q1: 1.56 (0.99, 2.45) and 0.55 (0.35, 0.85); P-trends < 0.01). Conclusions Indispensable AA have a positive and some non-indispensable AA have a negative, independent, strong association with the risk of cardiovascular mortality.


Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1763 ◽  
Author(s):  
Chien-Ning Hsu ◽  
You-Lin Tain

During pregnancy, amino acids are important biomolecules that play essential roles in fetal growth and development. Imbalanced amino acid intake during gestation may produce long-term morphological or functional changes in offspring, for example, developmental programming that increases the risk of developing hypertension in later life. Conversely, supplementation with specific amino acids could reverse the programming processes in early life, which may counteract the rising epidemic of hypertension. This review provides an overview of the evidence supporting the importance of amino acids during pregnancy and fetal development, the impact of amino acids on blood pressure regulation, insight from animal models in which amino acids were used to prevent hypertension of developmental origin, and interactions between amino acids and the common mechanisms underlying development programming of hypertension. A better understanding of the pathophysiological roles of specific amino acids and their interactions in developmental programming of hypertension is essential so that pregnant mothers are able to benefit from accurate amino acid supplementation during pregnancy in order to prevent hypertension development in their children.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Andrew Matchado ◽  
Kathryn Dewey ◽  
Christine Stewart ◽  
Per Ashorn ◽  
Ulla Ashorn ◽  
...  

Abstract Objectives 1) to estimate the probability of inadequate amino acid intake among infants 9–10 months of age in rural Malawi 2) to evaluate whether dietary amino acid intake or protein quality are associated with length gain from 6 to 12 months of age Methods We assessed total amino acid intake from breast milk and complementary foods in 285 infants. Breast milk intake and complementary foods were estimated using dose-to-mother deuterium oxide dilution method and repeat 4-pass interactive 24-hour recall interviews, respectively. Amino acid composition values were taken from FAO human milk profile, Tanzania Food Composition table and International Minilist. Protein quality was estimated using Digestible Indispensable Amino Acid Score (DIAAS). Probability of intake below Estimated Average Requirement (EAR) for each amino acid was estimated using National Cancer Institute (NCI) method. We estimated protein quality of complementary food using median DIAAS. We assumed a DIAAS of ≥0.75 to represent a diet or food with good protein quality. Relationships between amino acid intake or protein quality with length gain were assessed using regression models. Length was measured at 6 and 12 months of age and length for age z-score (LAZ) velocity was calculated (ΔLAZ/months). Results The probability of inadequate amino acid intake from breast milk and complementary food that included a lipid-based nutrient supplement (LNS) was 3% for lysine, 0% for tryptophan, threonine, valine, histidine, isoleucine, leucine, sulfur containing amino acids (SAA), and aromatic amino acids (AAA). Without LNS, the probability was 7% for lysine and 0–2% for the other amino acids. The median (interquartile range) DIAAS for complementary food with and without LNS was 0.70 (0.28) and 0.64 (0.32), respectively. Dietary amino acid intake and protein quality were not significantly associated with length gain velocity from 6 to 12 months even after adjusting for confounding factors. Conclusions The prevalence of inadequate amino acid intake in 9–10 months old infants in rural Malawi is very low. However, in conditions of frequent clinical or sub-clinical infections this situation may be different. Linear growth at 6–12 months does not appear to be limited by dietary amino acid intake or protein quality in this setting. Funding Sources The Bill & Melinda Gates Foundation.


2006 ◽  
Vol 6 (1) ◽  
pp. 47-59
Author(s):  
Nancy Montilla ◽  
◽  
Lolito Bestil ◽  
Sulpecio Bantugan ◽  

A feeding trial with broilers was conducted to evaluate the effects of amino acids (lysine and methionine) supplementation of diets low in protein content on the voluntary intake, feed conversion efficiency, broiler performance, and cost and return of broiler production. Results showed cumulative voluntary feed intake was not significantly affected by lowering the protein content of the diet. Cumulative weight gain of broilers was lower with diet when supplemented iwht lysine and methionine to meet requirements. Birds fed with diets low in protein has less efficient feed converstion, but became comparable with those receiveing diets high in protein when supplemented with amino acids. Feed cost per kilogram broiler produced was not significantly affected by diets used in the study, although the low-protien diet with amino acid supplement had the lowest values. In terms of return above feed and chick cost, broilers fed with high-protein diet had the greatest value, but not significantly different from birds fed with low-protien diet with amino acid supplementation which gave about P10 per bird higher returns than those fed low-protein diet without amino acid supplementation.


1998 ◽  
Vol 78 (1) ◽  
pp. 81-87 ◽  
Author(s):  
S. X. Huang ◽  
W. C. Sauer ◽  
M. Pickard ◽  
S. Li ◽  
R. T. Hardin

Studies were carried out to determine the effect of micronization on energy, starch and amino acid digestibilities in hulless barley. Six pigs (Canabrid × Camborough) were weaned at 21 d of age and fitted with a simple T-cannula at the distal ileum on days 23 or 24. The pigs were fed one of three diets with major constituents of hulless barley and soybean meal (HB + SBM), micronized hulless barley and soybean meal (MHB + SBM) and corn starch and soybean meal (C + SBM) according to a repeated Latin square design. The pigs were fed three times daily, equal amounts at 8-h intervals. The diets were supplied at a rate of 5% (wt/wt) of body weight. The average body weight of the pigs was 9.3 kg at start and 15.9 kg at the conclusion of the experiment at 58 d of age. Faeces were collected for 48 h on days 6 and 7 and ileal digesta for 24 h on days 8 and 9. Chromic oxide was used as digestibility marker. The apparent ileal amino acid digestibilities in HB and MHB were determined by the difference method. The apparent ileal digestibilities of the indispensable amino acids were higher in MHB than in HB and ranged from 5.3 to 10.0 percentage units. Of the indispensable amino acids, the differences were significant (P < 0.05) for arginine, histidine, isoleucine, phenylalanine and valine. Micronization of HB improved (P < 0.05) the ileal digestibility of starch from 79.0 to 97.3%. Micronization resulted in an increase in the digestion of energy in the small intestine and a decrease in microbial fermentation of energy in the large intestine. This shift in the disappearance of energy from the large to the small intestine should also result in an improvement in the efficiency of energy utilization. These studies show a positive effect of micronization on the digestibilities of energy and amino acids in young pigs fed HB. Key words: Micronization, barley, digestibility, pigs


1998 ◽  
Vol 14 (1-2) ◽  
pp. 311-323 ◽  
Author(s):  
Antonio Mutti ◽  
Audrey Smargiassi

Increased serum prolactin (PRL) is a common finding among subjects exposed to styrene, perchloroethylene, lead (Pb), and manganese (Mn) at levels below the current threshold limit values. On a group basis, abnormally high basal PRL shows a dose-related distribution among workers exposed to styrene, Pb, and Mn. On the basis of dose-response relationships, the benchmark doses (BMD) for styrene metabolites in urine, lead in blood (Pb-B), and Mn in urine (Mn-U), are 4 mg/g creatinine, 112 μg/L, and 0.3 μg/L, respectively. Noteworthy, the BMD for Mn-U and Pb-B is well below the upper reference limit. A shift in the distribution but not in the prevalence of abnormally high values of serum PRL was observed among perchloroethylene-exposed dry cleaners, which makes interpretation in terms of risk difficult. The measurement of PRL thus provides opportunities for early identification of excess exposure to neurotoxic chemicals affecting dopaminergic control of pituitary secretion. For styrene, Pb, and Mn the BMD provides an objective and statistically determined threshold, which seems to be in good agreement with the estimated no-observed-adverse-effect-level (NOAEL). The NOAEL, however, is based on traditional approaches that require the application of uncertainty factors, e.g., a default factor of 10 when extrapolating the NOAEL from the lowest-observed- adverse-effect-level (LOAEL). Due to its sensitivity to a number of potential confounders, caution must be exercised when using PRL as a screening test at the individual level. Also, age and sex dependent variations in susceptibility may hamper extrapolations from the occupational settings to the general population.


2002 ◽  
Vol 25 (4) ◽  
pp. 261-268 ◽  
Author(s):  
R. Bellomo ◽  
H. K. Tan ◽  
S. Bhonagiri ◽  
I. Gopal ◽  
J. Seacombe ◽  
...  

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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