New Research Suggests That These Protein Sources Are Not Nutritionally Equivalent

Consuming equal ounce equivalents of animal-based and plant-based protein foods according to American dietary guidelines alters essential amino levels. acid Bioavailability in both young and old.

Proteins derived from 2 ounce equivalents (oz-eq) of animal foods provide higher bioavailability of essential nutrients. amino acid Scientists at Purdue University say it contains less (EAA) than the same amount from plant-based sources.

The protein quality of a food or diet (that is, the dietary EAA content) is a major factor in determining how the body can utilize amino acids for muscle and whole body protein building.

The Dietary Guidelines for Americans (DGA) focuses on consuming a variety of protein foods based on ounce equivalents with similar nutritional content. One ounce equivalent equals 1 ounce of meat, 1 whole egg, 0.25 cups of beans, or 0.5 ounces of nuts.

“The DGA evidence that these protein foods are ‘equivalent’ and have ‘similar nutritional content’ is unclear,” said lead investigator Wayne Campbell, Ph.D., professor of nutritional sciences at Purdue University. suggests.

Protein foods vary in their energy and nutrient content, including protein quantity and quality (See Table 1), he added. In addition, there is limited information about how consuming ounce-equivalent protein foods from various sources as part of a mixed diet affects the body’s ability to digest and utilize protein.

table 1. Energy and macronutrient content of test meals and protein food sources, and essential amino acid content of protein food sources.

Adapted from Connolly et al. (2023); the amount of protein in each study includes protein from the study diet. lean pork (20 g); Whole egg (18.5 g). black beans (13.5 g); almonds (12 g). His EAA total for each trial includes his EAA from the trial diet. lean pork loin (9.45 g). Whole eggs (7.47 g); black beans (5.11 g); almonds (3.94 g). EAA – essential amino acids.

This includes populations that may lack diversity in protein options, such as the young, and high-quality, nutrient-rich diets, despite their need for more nutrients, such as the elderly. Includes populations that may be deficient in protein source intake.

Scientists therefore found that eating two ounce equivalents of animal-based and plant-based protein foods as part of a mixed whole-food diet had differential effects on EAA bioavailability for protein building in these populations. I tried to test if it gives.

Research overview

Two crossover randomized controlled trials were conducted in 30 healthy young people and 25 elderly people. Each study participant completed four separate 300-minute trials, with each trial separated by at least three days.

The researchers were blinded to the order in which participants completed the protein food tasks until all participants had finished testing and the results were analyzed.

For the duration of the study, study participants received a standardized diet containing 2 ounce equivalents of either animal protein foods (e.g., raw lean pork loin, scrambled whole eggs) or vegetable protein foods (black beans, green beans). I reported to the clinic to eat. sliced ​​almonds).

Blood samples were taken at baseline and 30, 60, 120, 180, 240, and 300 minutes postprandial to measure EAA bioavailability, blood glucose levels, and blood glucose levels. insulin level.

Summary of results

“Consistent with our hypothesis prior to initiating this study, consuming a diet containing 2 ounce equivalents of animal protein foods is associated with a diet containing 2 ounce equivalents of plant protein foods in both young and older adults. It increased EAAs in the bloodstream by comparison,” explains Dr. Gavin Connolly, Clinical Trials Project Manager and Research Fellow at Purdue University’s Department of Nutritional Sciences. There was also no difference in EAA bioavailability between young and old people, he added.

This means that animal-sourced protein (from raw lean pork loin or scrambled eggs) provides EAAs more effectively, which helps our body’s ability to build protein and muscle. Dr. Connolly points out that it is related. “This is an important consideration for muscle and general health, as well as lifelong physical function,” he suggests.

Additional findings from this study include:

• Lean pork alone or in combination resulted in better EAA bioavailability than eggs in young adults or the elderly.
• There was no difference in EAA bioavailability between black beans and almonds.
• There was no difference in EAA bioavailability between young and old.

Current research has limitations.

“The amount of protein food in the study likely doesn’t accurately reflect how much young and old people eat each meal or week,” Dr. Connolly said. Furthermore, he explains, they were unable to directly measure changes in muscle protein synthesis or whole-body protein balance in response to diets containing different protein foods.

Additional research is needed to better understand how animal- and plant-based protein foods affect lifelong muscle and general health in order to promote healthy aging. is.

Public Health Nutritional Impact:

The study authors concluded that the results of this study may have implications for public health nutrition guidance and may support future DGA equating different protein sources within protein food groups on a lifelong oz-eq basis. It suggests that it may serve as an important resource for reassessing adequacy.

“These results also relate to DGA recommendations to consume more plant-based foods,” Dr. Campbell added.

Although there are health benefits to consuming more plant-based foods, guidance on the importance of nutritious animal-based protein foods, which are sources of high-quality protein, should be incorporated in dietary recommendations. It’s important information to have, he explains.

Reference: Effect of ounce-equivalent intakes of animal- and plant-based protein foods, as defined by the Dietary Guidelines for Americans, on the bioavailability of essential amino acids in young and old: two Crossover Randomized Controlled Trial, Gavin, Connolly, Joshua L. Hudson, Robert E. Bergia, Eric M. Davis, Austin S. Hartman, Wenbin Zhu, Chad C. Carroll, Wayne W. Campbell , June 25, 2023, nutrients.
DOI: 10.3390/nu15132870

“Dietary Protein Quality Determines Anabolic Response in Older People,” Kim Il-yong, Yoon Ah. Shin, Scott E. Schutzler, Gohar Azhar, Robert R. Wolfe, Arny A. Ferrando, 6 October 2017, clinical nutrition.
DOI: 10.1016/j.clnu.2017.09.025

“Metabolic Assessment of Ounce Equivalents of Dietary Guidelines Protein Food Sources in Young Adults: A Randomized Controlled Trial” Sanghee Park, David D Church, Scott E Schutzler, Gohar Azhar, Il-Young Kim, Arny A Ferrando, Robert R Wolfe , 9 March 2021, nutrition journal.
DOI: 10.1093/jn/nxaa401

“Essential Amino Acids and Protein Synthesis: Insights for Maximizing Muscle and Whole Body Responses to Feeding” David D. Church, Katie R. Hirsch, Sanghee Park, Il-Young Kim, Jess A. Gwin, Stefan M. Pasiakos , Robert R. Wolfe and Ernie A. Ferrand, 2 Dec 2020, Available here. nutrients.
DOI: 10.3390/nu12123717

This study was funded by the National Pork Board and the American Egg Board – Egg Nutrition Center.