Plant-based diet still a long way off say scientists
Switching to a plant-based diet might not be as simple as has often been portrayed, a group of Scottish scientists have concluded - and the capacity to replace meat in the human diet with plant protein alternatives on a global scale is limited.
While the anti-meat lobby has been advocating a move towards such an eventuality, the researchers from some of S cotland’s top institutes said that such a move would require “major changes” to the structure of global agriculture – and they raised fears that such an approach could have considerable environmental impacts.
The study carried out by scientists from Scotland’s Rural College( SR U C ), the James Hut ton Ins titute and the University of Aberdeen’s Rowett Institute found that it would be extremely difficult to meet the world’s require - ment for lysine – an essential amino acid in human nutrition–if a global uptake of plant-based diets was adopted.
Current production of plant-based lysine which could replace its animalderived equivalent comes largely from soy beans, which are grown and imported from a small number of countries.
The study concluded that broadening the supply of plant-based lysine would mean increasing soya production outside its current main growing areas in Brazil, the USA and Argentina, where it has in the past been associated with the clearing of rainforests.
While lysine is available in other crops such as legumes and cereals, the concentration levels are less than a fifth of that found in soya – and well below that required to provide a healthy human diet on a global scale.
“Switching to a plantbased diet may not be as simple as previously thought,” said the study’s lead author, Dr Ilkka Leinonen from SRUC.
He said that the research had looked at options such as increasing the production of legumes other than soya, such as beans and peas, or other lysine -rich crops; obtaining plantbased lysine from sources not currently used for human consumption (such as oilseed); or, manufacturing lysine from non-standard plant-based sources, such as via fermentation.
“All of these options would require major changes in the structure of global agricultural production and address the barriers associated with current a gr i-food systems,” said Leinonen.
“Some of these options may also have consequences on agricultural land use, because alternative crops would need a much bigger land area to produce the same amount of lysine as soya.”
The study which looked at finding a pathway to a sustainable protein economy was funded by the Scottish Government SEFARI Gateway project, and carried out by scientists working for institutes supported by the Scottish Government’s Strategic Research Programme.