A new study has found red meat is a better source of protein than a processed plant-based alternative.
The human clinical trial undertaken for the Pasture Raised Advantage research programme, discovered that meat delivers more of the essential protein building blocks.
The four-stage multidisciplinary project is exploring the health and wellbeing benefits of eating pasture-raised beef and lamb as part of a balanced diet, compared to grain-finished beef or a plant-based alternative.
The study is a collaboration between researchers at AgResearch, the University of Auckland, Massey University and the Riddet Institute.
In this first of two clinical trials, thirty participants aged 20-34 years were fed breakfast on four different days and their blood, digestive symptoms and mood were monitored for four hours immediately following the meal.
Breakfast was a burrito that contained a single serving of a different protein each day; pasture-raised beef, grain-finished beef, lamb and a plant-based alternative - served in random order to each participant across the four days.
Dr Andrea Braakhuis from the University of Auckland headed up the team of nutrition scientists responsible for the study.
"We measured the nutrients in the blood of the participants and saw a significant difference in the type and amounts of amino acids that come from the digestion of the protein of red meat compared to the protein of the processed meat alternative," she said.
"Amino acids from red meat were of greater biological value and better absorbed by the body."
Braakhuis said these clinical outcomes reflected the results of laboratory experiments carried out on the same foods by Massey University (led by Dr Lovedeep Kaur), where red meat was better digested in laboratory simulator conditions than the plant-based alternative.
"Our project is showing that red meat is probably a better source of protein for the body than highly processed plant-based products promoted as meat alternatives," Braakhuis said.
AgResearch senior scientist Dr Scott Knowles said: "The new generation of plant-based meat analogues are formulated to mimic the taste and basic nutrient composition of meat. But very little is known yet about their nutritional quality and health benefits".
Plant-based alternatives were produced very differently from pasture-raised livestock and marketed as having advantages in environmental footprint and sustainability - credentials that were still being scrutinised, Knowles said.
"However, we know for certain that New Zealand farmers are producing a highly nutritious food in one of the most efficient production systems in the world."
Listen to Jamie Mackay interview Dr Scott Knowles about the study on The Country below:
A second clinical trial, nearing completion, looks at the longer-term impacts of eating a diet that includes moderate amounts of red meat.
Over 10 weeks, 80 participants follow either a flexitarian diet containing pasture-raised beef and lamb or a vegetarian diet that includes various plant-based alternatives.
"This is the first clinical trial of its kind to compare the effects of flexitarian and vegetarian lifestyles on a range of outcomes of people's health and wellbeing," Braakhuis said.
"We're hoping it will fill some gaps in our understanding about the nutritional value of pasture-raised red meat in a balanced diet."
In addition to chemical and blood measurements, researchers use a dietary app to collect food diaries and are monitoring the impact of the diets on physical responses in the body, such as weight, sleep and exercise.
They also monitor psychological and well-being factors, such as mood and satisfaction, to understand the full impact of the diet on individuals' health.
The Pasture-Raised Advantage research programme looks at a modest amount of fresh red meat included as part of a balanced diet, particularly red meat raised in New Zealand, where the animals are free-range, predominantly pasture-based and have zero treatment with antibiotics and hormones.
The research is funded by Meat Industry Association of New Zealand Innovation Ltd, Beef + Lamb New Zealand Ltd, the High-Value Nutrition National Science Challenge, and the Ministry of Business, Innovation and Employment.
Results from the first clinical trial have been published in an international journal, Current Developments in Nutrition.
The results of the current trial will be published next year.
Find out more about the Pasture Raised Advantage research programme here.