8 minute read
Plants and animals, NOT plants or animals
Forum
Dr Nick Smith from the Riddet Institute’s Sustainable Nutrition Initiative TM programme, talking about global food systems and their impact on availability and affordability of nutrients
Dr Nick Smith of the Riddet Institute’s Sustainable Nutrition Initiative, and science writer, Glenda Lewis
There were some surprising findings and a few reality checks at the Riddet Institute Feed our Future dialogue in Wellington, 9 June.
It's AND, nor OR
All the delicious data from international and local speakers seemed to converge on one bottom line. We need plants AND animals to feed the world properly – that is, not just give the expected 10 plus billion people enough to eat in terms of energy and protein, but all the nutrients for optimum health and development. The evidence strongly points to the right balance of plant and animal food being more sustainable, more affordable, and least disruptive to our economies and cultural traditions.
Our food production system is currently plant based, with plants making up 86% of food biomass leaving the farm gate. As speaker Associate Professor Hannah van Zanten (Wageningen University) pointed out, the right combination of plant and animal production allows for a circular food production system – plant food waste and plant matter that humans can’t eat can be used as animal feed. Conversely plants are fertilised with animal waste and animals utilise land unfit for crops.
The forum was by no means reactionary, but a scientific moderation of the drive towards plant-based diets. Everyone accepts that many people in the western world eat more than their fair share, especially of meat, and could benefit from eating a wider range of fruit, vegetables and wholegrains.
The DELTA model
Riddet Institute Director, Distinguished Professor Harjinder Singh, made no bones about the fact that food technology is the next frontier for disruptive innovation – and that feeding an extra 2 billion, as well as the 2 billion who are currently malnourished (includes those who eat too much), will be a huge challenge for food scientists and technologists.
He says a dichotomy between nutrition and environmental sustainability is widening. Worried that nutrition is coming a poor second, the Riddet Institute started a computer-based project called DELTA – as part of its Sustainable Nutrition Initiative™ – to model ways of feeding the world well, and then test different scenarios (e.g. reducing sugar production to free land for more nutritious crops, or reducing household waste) to fit sustainability boundaries. The model does not compromise on human nutrition. Dr Nick Smith is a researcher on the project and recently presented some of its fascinating insights and trade-offs at the NZIFST conference. The model is designed to be user friendly - you can go in and experiment yourself with changing the settings, and see the outcome for global nutrition.
Costs of eschewing animal nutrients
At Feed our Future, Smith presented the rather astounding results of another Riddet Institute research project.
Dr Sylvia Chungchunglam and Distinguished Professor Paul Moughan have compared the lowest possible cost of a vegan diet, and one containing animal sourced foods – both complete in terms of energy and nutrients – using actual prices and availability in the US (the eagerly-awaited New Zealand version is currently under peer review). The plant-only diet came out at almost twice as much at US$3.61 per day, compared to US$1.98 for the one with animal sourced foods. The latter was able to stand considerable increases in meat, seafood and dairy prices without exceeding the price of the vegan diet.
It’s all about nutrient density, or bang for buck.
Despite the fact that we are food rich, many New Zealanders lack calcium, iron, folate, vitamins C and E. One third of adolescent females are deficient in iron, reflecting either dietary choices or lack of them. Calcium deficits in youth cannot be made up for later. One "Feed our Future" delegate commented that the costs of feeding “the bottom 20%” (of the New Zealand population) well would be less than the costs of them not eating properly.
Fonterra-Riddet Chair of Consumer Science at Massey University, Professor Joanne Hort, explained that consumer choice of foods is largely unconscious
Alternative proteins
It would not have been a future food forum without attention to synthetic meat and alternative proteins. There was a harsh reality check by Professor Paul Wood from Monash University on the feasibility of scaling up cellular agriculture to make meat. He reeled off some stupendous numbers for the amount of plant, energy, feedstock, additives, and human resources required if you were to replace all naturally grown meat. There are “limits to biology”, he said – meaning the rate of, and complex nutrient requirements for, cell growth.
But to Dr Laura Domigan, a University of Auckland and Riddet Institute scientist at the meeting who is engaged in research on synthetic meat production, it is happening, it is inevitable, and accelerated by huge investment. She is confident that it will be one component of the feedthe-world equation, though probably no threat to our natural meat in the short term – as far as we can see, which is not very far.
DELTA draws attention to the glaring global deficit in calcium (34%) and Vitamin E (19%) – neither of which can be much improved, even by preventing 100% of food waste. People tend not to throw out milk and oils, and waste of nutrients is not uniform around the world, as emphasised in the talk from Professor Wayne Martindale. To make up for the global deficit in calcium, milk production would have to double by 2050. How is that going to happen within environmental and land competition constraints? Is supplementation the answer? Remedying the shortage of Vitamin E is similarly challenging because the Western diet does not include as much as it should, and simply supplementing diets with more vegetable oils – one of the densest sources of Vitamin E – would lead to undesirable increases in energy intake. There are minor amounts of vitamin E in many foods and getting enough is no problem in a well-balanced diet.
Carbon emissions
Dr Stewart Ledgard from AgResearch presented data familiar to people in the primary sector about our second lowest-in-the-world carbon emissions from meat and dairy production, which he reframed and amplified by comparing CO 2 emissions against nutrient density. He showed that fruit and vegetables can have a high carbon footprint too Hothouse tomatoes, which have become an urban staple, were almost off the graph. Again, the scientific evidence moderates extreme ideas about the need for a wholesale shift to entirely plant-based diets. There was talk of environmental labelling, which will be very scientifically demanding, but create new selling point opportunities for many New Zealand producers. We need to provide scientific proof to consumers, who have an increasing understanding of the nuances of environmental impacts: on land, on water, in the atmosphere and biodiversity.
Professor Thom Huppertz (Wageningen University & Research) focused on bioavailability of nutrients as the proper labelling index, not the nutrient content of a food as a fraction of RDI. In simple terms, the content of calcium or other nutrient in a food product is not the same as what is actually absorbed by the digestive system. Our access to many nutrients is dependent on the food structure they are contained in. The Riddet Institute is helping expand knowledge of bioavailability for a number of foods.
Professor Barbara Burlingame, Massey University (and former Deputy Director of Nutrition at FAO), advocated a less reductive, abstract approach to nutrition. She gave examples of more holistic and locally practical ways of improving overall nutrition and particular nutrient deficits. Children in Micronesia were going blind from lack of betacarotene. Researchers found that the local bananas varied hugely in carotene content. The commercial cultivar they’d been eating had less than 5 micrograms – they could have been substituted for local varieties that were no longer grown but had up to 8500 micrograms. Burlingame said these differences show why losing crop biodiversity is such a worry.
Sociology of food choices
Professor Frédéric Leroy, Vrije Universiteit Brussels, changed scale from micro-nutrients to the broad sweep of the history and philosophy of food, in particular killing and eating animals. He discussed the plant/ animal divide and the mass media portrayal of eating meat – the hyperbole of meat as harmful to humans and the environment. Meat has gone from being seen as “normal, necessary, nice and natural, to disgusting, abnormal and unnecessary”. Leroy quoted the popular saying, “it’s not the cow, but the how”. In his view, self-actualisation and status have become our priorities, and diet an important expression of identity.When it comes to food, ultimately it’s not what scientists think, it’s about what consumers want to eat, and what they can afford to eat. Consumer behaviour expert, Massey University Professor Joanne Hort, impressed on delegates that consumer choice is 95% subconscious. “Price and taste are the key drivers,” she said. Many want sustainable foods, but they have to be tasty, easy to use, and “normalised” to be accepted and purchased longer term.In summing up the forum, Dr John Roche, Chief Science Advisor at MPI, offered a final data morsel: The world needs to produce as much food in the next 30 years as we’ve produced in the last 2000 years. No pressure, food scientists and technologists.
