The idea that “we are what we are eaten” has been widespread for hundreds of years, and the relationship between body composition and food consumption has been investigated for a long time. The synthesis and decomposition of body protein (protein kinetics throughout the body) in response to dietary consumption has been studied for almost a century. However, controversies persist with respect to the optimal approach to determine protein kinetics throughout the body.
Here, scientists at the University of Arkansas: Professor Robert Wolfe, Professor Arny Ferrand New Zealand). A critical review of the most used approaches to determine the response of the protein kinetics throughout the body to the consumption of dietary proteins, which is published in the newspaper of Open Science Clinical Nutrition 36 (2021): 78-90. https://doi.org/10.1016/j.nutos.2021.02.006
According to the review of Professor Wolfe and his colleagues, the general principles of protein models throughout the body focus on the general processes of synthesis and decomposition of proteins instead of components and several groups. Basically, the marked molecules are used as tracers, which allows the quantification of the appearance of the endogenous tracee from the decomposition of the body protein and the absorption rate of the tracheo in the process of protein synthesis. Tracers are generally administered intravenously but also orally in some cases. The estimate of the balance of net proteins throughout the body (that is, the anabolic response) is equal to the synthesis of protein except the decomposition. The main author, Professor Wolfe said: “Quantify the anabolic response to dietary protein intake is an essential application. There are different models to achieve this goal, each with advantages and limitations. “
The nitrogen flow method (n) has an excellent advantage of requiring only the oral administration of the tracer, so the method is not invasive. In addition, the model allows the calculation of all aspects of protein kinetics throughout the body with minimal assumptions. However, it is difficult to quantify the changes in response to a single meal with this approach. Professor Wolfe emphasizes that despite the advantages of this method when used for a prolonged period of time, “rapid changes in protein kinetics, as produced after a single dietary protein meal, cannot be determined reliably with the N-Flux method. “
The constant infusion of an essential amino acid marker can be used to quantify the rapid changes of the basal state in protein kinetics throughout the body that occurs after the ingestion of a single meal that contains dietary protein. Professor Wolfe mentioned the science that presented that expressing the data as the response of the basal state has the clear advantage of taking into account the differences in the basal rates of protein kinetics between individual subjects. The fast time frame in which a model can be used based on an intravenously infused infused amino acid marker is also an important advantage. The main challenge with the models based on essential amino acid trace after a meal is to distinguish how much of the unbelieving tracee in the blood has emerged from the release of protein decomposition in the body instead of the absorption of the dietary protein digested The consumption of an intrinsically marked protein helps to distinguish whether the tracee observed in the blood has emerged from the ingested protein or the decomposition of the body protein. However, the lack of intrinsically marked protein availability is a limitation of this approach. More fundamentally, the dilution not measured intrinsically marked protein can lead to a significant substation of the absorption rate of dietary protein, with the consequence of an overestimation of the decomposition rate of body protein.
An alternative approach to the use of an intrinsically marked protein is called a “bioavailability” approach, whereby the absorption of tracee’s essential amino acid is calculated from the known amount of ingested protein, the amount of the amino acid traces Protein, and the true ileal digestibility of the protein. “An advantage of the bioavailability approach is that the response to a combination of a variety of proteins that will probably be included in a normal meal can be quantified. In addition, a stable physiological state is not required, which means that the method is adequate to quantify the response to a meal, ”said Professor Wolfe. He added: “On the other hand, only the total anabolic response can be determined because only the total contribution of exogenous phenylalanine to peripheral circulation can be estimated, not the speed at which it is absorbed. In addition, the method must often depend on the values of true ileal digestibility literature, which can be inaccurate in some cases. ” On the other hand, the previous figure demonstrates that the use of the upper or lower limits of the probable true ileal digestibility often does not significantly affect the conclusions.
In summary, the most appropriate method to quantify the protein kinetics throughout the body depends on the degree of uncertainty in the requirements required in a given situation. In this review, all approaches to obtain total body proteins have been shown to have some limits. Professor Wolfe and his colleagues recommend all methods, the upper and lower limits for protein kinetics throughout the body are calculated using maximum and minimal realistic values for supposed parameters. The simultaneous use of two models that require different assumptions can also help validate the calculated results.
Image magazine and credits:
Wolfe, Robert R., Il-Young Kim, David D. Church, Paul J. Moghan, Sanghee Park, and Arny A. Ferrando. “Cinetic models of proteins throughout the body to quantify the anabolic response to the consumption of dietary proteins.” Open Science Clinical Nutrition 36 (2021): 78-90. https://doi.org/10.1016/j.nutos.2021.02.006
About the author
Robert R. Wolfe, Ph.D., professor
Dr. Wolfe is Jane and Edward Warmack’s chair in nutritional longevity, University of Arkansas for Medical Sciences, Little Rock, AR. Dr. Wolfe previously celebrated the distinguished chair of John Sealy in clinical research in the medical branch of the University of Texas in Galveston, Tx. Dr. Wolfe is a world leader in the fields of human metabolism and the stable isotope layout methodology, with more than 600 publications, five books and nine patents in his credit. According to Google Scholar, its documents have been cited more than 77,000 times (H Factor = 137). The NIH has financed it throughout its 40 years of career. He has served as a member of several government and industrial committees responsible for determining dietary protein requirements and has received numerous honors and awards for his work. Disseminations: Dr. Wolfe is a shareholder of Essential Blends, LLC, and the A amino company, Inc. Dr, Wolfe has received research and honorary subsidies from the National Association of Beefleman’s Beef. There are no other revelations.
#Measurement #effects #consumption #dietary #proteins #cytetic #models #protein #body
