91av

In 1968, 91av identified an unusual solution to the world’s supposed protein shortage

IN THE 1960s, . People’s diets, especially in developing countries, were dangerously low in protein, they said. Ways to address the issue were anxiously being sought.

91av took the problem seriously, and with an international conference to discuss it in The Hague, in the Netherlands, we dedicated five pages of the 21 November 1968 magazine to the subject. We focused on an as-yet-untapped source of protein: “trees and bushes”.

After listing many existing benefits of trees, we suggested “it may be wise to consider whether forested land could be used more effectively as a source of… edible protein”. Forests were a huge potential larder. “A large tree carries many tons of leaf and the leaves on an acre of forest can contain one to three tons of protein.”

Three barriers were mentioned. One was the difficulty of harvesting leaves cheaply in sufficient quantity. Perhaps more significantly, “the case for protein production from coppices depends on the expectation that more protein can be produced in this way than by arable farming”.

But the third barrier had already been overcome. People cannot digest plant matter as effectively as, say, cattle can, so it needed processing. “Protein can be prepared from the leaves of many species by pulping, pressing, coagulating the juice and filtering. It is as useful as animal proteins… and better than seed proteins,” we reported.

Eventually, though, these efforts proved to be of little use as it became clear that the main deficiency in the world wasn’t protein. A paper published in The Lancet in 1974 by Donald McLaren, a professor of clinical nutrition, described the episode as ““. Soon after that, research found that protein deficiency was in fact quite rare, and could be solved simply, .

Leaf protein never took off, perhaps for a reason alluded to in the story. “The product has no immediate appeal,” we said of its flavour, adding rather weakly, “but those who are accustomed to it find it palatable.”