Findings from a human clinical trial undertaken for the Pasture Advantage research programme found that meat delivers more of the essential protein building blocks compared to a plant-based alternative.
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 research 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 heads 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,” says Dr Braakhuis.
“Amino acids from red meat were of greater biological value and better absorbed by the body.”
Dr Braakhuis says these clinical outcomes reflect the results of laboratory experiments carried out on the same foods by Massey University (led by Dr Lovedeep Kaur). Red meat was better digested in the 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.”
AgResearch senior scientist Dr Scott Knowles says: “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 are produced very differently from pasture-raised livestock and they’re marketed as having advantages in environmental footprint and sustainability. Those credentials are still being scrutinised. 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.”
A second clinical trial, nearing completion, is looking at the longer-term impacts of eating a diet that includes moderate amounts of red meat.
Over 10 weeks, 80 participants are following 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,” says Dr Braakhuis.
“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 are using 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 are also monitoring psychological and well-being factors such as mood and satisfaction to understand the full impact of the diet on individuals’ health.
Much of the global research on the environmental aspects of producing and eating red meat has been based on intensive grain-finished farming systems and often the nutritional and health studies have used meat that is processed or consumed in excess of recommended dietary guidelines.
In contrast, the Pasture-Raised Advantage research programme is looking at 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 the industry partners 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. You can view these here(external link). The results of the current trial will be published next year.
More about the Pasture Raised Advantage research programme can be found here(external link).