This week we are continuing to explore the research that compares pasture-raised beef and lamb versus grain-finished livestock, and versus protein alternatives.
On the show I have Dr Lovedeep Kaur from Massey University and the Riddet Institute reviewing the interim results of the second stage of research that explores how the human digestion system responds to these alternatives and how their nutrients are then absorbed by the body.
The researchers found the protein from both the pasture-raised and grain-finished cuts of beef digested in a similar way, but significant differences were observed for fat or lipid digestion. Digestion of meat from pasture-raised animals released greater levels of "good" fats, relative to the generally considered “bad” fats.
Dietary intake of long-chain omega-3 PUFAs has been recommended as these fatty acids have been reported to promote lowering of total cholesterol and fats in the blood stream of people with high blood cholesterol. This suggests potential health benefits of consuming pasture-raised beef. The plant-based alternative tested in this study had no long chain omega-3 PUFAs.
Kaur says the research highlighted that meat protein is generally highly digestible and meat with higher digestibility is better for your body. As plant proteins are generally known to be less digestible than meat proteins, the plant-based meat substitute showed relatively lower protein digestibility.
Differences in processing and other non-protein ingredients could also be responsible for the observed differences in protein digestibility, she says. “Scientists generally agree that higher rates of release of amino acids [protein building blocks] during the digestion of meat leads to beneficial effects in muscle, such as maintenance or gain in muscle mass. This is particularly important for the elderly in managing sarcopenia [muscle wasting] and for athletes who want to increase muscle mass, for example. What was interesting to see in our research was that while an animal’s protein composition is largely determined by its genetics, and the samples we tested contained highly digestible proteins, the composition of the fat in an animal, particularly the long-chain PUFAs, is largely affected by what it has been eating,” Kaur says.
What is particularly interesting is that the findings are showing that meat digested from pasture-raised New Zealand beef showed higher total amounts of free long-chain omega-3 polyunsaturated fatty acids, and lower amounts of free, long chain saturated fatty acids, than meat from grain-finished cattle. In simple terms, long chain saturated fatty acids increase the risk of cardiovascular disease.
Although the research is not complete, these initial finding highlight the nutritional benefits of pasture-raised red meat that we produce in New Zealand, over grain-raised red meat.
Dietary intake of long-chain omega-3 polyunsaturated fatty acids has been recommended in dietary guidelines worldwide (UN-Food & Agriculture Organization, United States Department of Health, as well as dietary guidelines from the Ministry of Health, Health Navigator and the Nutrition Foundation). As far as protein alternatives go, well given the highly processed nature of these, you would be forgiven for staying well clear.
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Angus Kebbell is the Producer at Tailwind Media. You can contact him here.