Making eco-conscious choices at the shops can be tricky when we’re presented with so many options, especially when it comes to milk. Should we buy plant-based milk, or dairy? We’ve looked at the evidence to help you choose.
Dairy has the biggest environmental footprint, by far
Any plant-based milk, be it made from beans, nuts or seeds, has a lighter impact than dairy when it comes to greenhouse gas emissions, as well as the use of water and land. All available studies, including systematic reviews, categorically point this out.
A 2018 study estimates dairy to be around three times more greenhouse gas emission-intensive than plant-based milks.
In the case of cow’s milk, its global warming potential — measured as kilogram of carbon dioxide equivalent per litre of milk — varies between 1.14 in Australia and New Zealand to 2.50 in Africa. Compare this to the global warming potential of plant-based milks, which, on average, is just 0.42 for almond and coconut milk and 0.75 for soy milk.
What’s more, dairy generally requires nine times more land than any of the plant-based alternatives. Every litre of cow’s milk uses 8.9 square metres per year, compared to 0.8 for oat, 0.7 for soy, 0.5 for almond and 0.3 for rice milk.
Water use is similarly higher for cow’s milk: 628 litres of water for every litre of dairy, compared to 371 for almond, 270 for rice, 48 for oat and 28 for soy milk.
Milks from nuts
Milk can be made from almost any nuts, but almond, hazelnut and coconut are proving popular. Not only do nut milks generally require smaller land areas, the trees they grow on absorb carbon and, at the end of their life, produce useful woody biomass.
Still, there are vast differences in the geographical conditions where various nut trees are grown.
California is the largest producer of almond milk in the world, followed by Australia.
Compared to other plant-based milk options, its water use is much higher and largely depends on freshwater irrigation. One kernel of California almond requires 12 litres of water, which raises questions about the industrial production of these nuts in water-scarce areas.
However the biggest environmental concern with almond production in the US is the high mortality of bees, used for tree cross-pollination. This might be because the bees are exposed to pesticides, including glyphosate, and the intensive industrial agriculture which drastically transforms nature’s fragile ecosystems.
In Australia, where almond orchards are smaller-scale and less industrialised, beekeepers do not experience such problems. Still, millions of bees are needed, and fires, drought, floods, smoke and heat damage can threaten their health.
Generally, the environmental performance of coconut milk is good – coconut trees use small amounts of water and absorb carbon dioxide.
Yet as coconuts are grown only in tropical areas, the industrial production of this milk can destroy wildlife habitat. Increasing global demand for coconut milk is likely to put further pressure on the environment and wildlife, and deepen these conflicts.
Hazelnut is a better option for the environment as the trees are cross-pollinated by wind which carries airborne dry pollen between neighbouring plants, not bees.
Hazelnuts also grow in areas with higher rainfall around the Black Sea, Southern Europe and in North America, demanding much less water than almond trees.
Hazelnut milk is already commercially available and although its demand and production are rising, the cultivation of the bush trees is not yet subjected to intensive large-scale operations.
Milks from legumes
Soy milk has been used for millennia in China and has already an established presence in the West, but the hemp alternative is relatively new.
All legumes are nitrogen fixing. This means the bacteria in plant tissue produce nitrogen, which improves soil fertility and reduces the need for fertilisers. Legumes are also water-efficient, particularly when compared with almonds and dairy.
Soy milk has a very good environmental performance in terms of water, global warming potential and land-use.
The US and Brazil are the biggest suppliers of soybeans, and the plant is very versatile when it comes to its commercial uses, with a large share of the beans used as livestock feed.
However, a major environmental concern is the need to clear and convert large swathes of native vegetation to grow soybeans. An overall reduction in the demand for meat and animal-based foods could potentially decrease the need to produce large amounts of soybeans for animal feed, but we’re yet to witness such changes.
The environmental benefits of hemp milk make it a game-changer.
Its seeds are processed for oil and milk, but the plant itself is very versatile — all its parts can be used as construction material, textile fibres, pulp and paper or hemp-based plastics.
Its roots grow deep, which improves the soil structure and reduces the presence of fungi. It’s also resistant to diseases, and it produces a lot of shade, which supresses the growth of weeds. This, in turn, cuts down the need for herbicides and pesticides.
Hemp requires more water than soy, but less than almond and dairy. Despite being one of the oldest crops used, particularly in Europe, hemp is produced in very low quantities.
Milks from grains
We can produce plant-based milk from almost any grains, but rice and oat are proving popular. However, they require more land compared with nut milks.
Rice milk has a big water footprint. More notably, it’s associated with higher greenhouse gas emissions compared to the other plant-based options because methane-producing bacteria develop in the rice paddies.
In some cases, rice milk may contain unacceptable levels of arsenic. And applying fertilisers to boost yields can pollute nearby waterways.
Oat milk has been becoming increasingly popular around the world because of its overall environmental benefits.
But similar to soy, the bulk of oat production is used for livestock feed and any reduction in the demand for animal-based foods would decrease the pressure on this plant.
Currently grown in Canada and the US, most oat operations are large-scale monoculture, which means it’s the only type of crop grown in a large area. This practice depletes the soil’s fertility, limits the diversity of insects and increases the risk of diseases and pest infection.
Oats are also typically grown with glyphosate-based pesticides, which tarnishes its environmental credentials because it can cause glyphosate-resistant plant, animal and insect pathogens to proliferate.
The final message: diversify your choices
Organic versions of all these plant-based milks are better for the environment because they use, for example, fewer chemical fertilisers, they’re free from pesticides and herbicides, and they put less pressure on the soils. Any additives, be it fortifiers, such as calcium or vitamins, flavours or additional ingredients, such as sugar, coffee or chocolate, should be taken into account separately.
Packaging is also very important to consider. Packaging contributes 45% of the global warming potential of California’s almond milk. And it’s worth keeping in mind that wasting milk has a much bigger environmental footprint, and questions the ethics of how humans exploit the animal world.
If, as a consumer you are trying to reduce the environmental footprint of the milk you drink, the first message is you should avoid dairy and replace it with plant-based options.
The second message is it’s better to diversify the plant-based milks we use. Shifting to only one option, even if it’s the most environmentally friendly one for the time being, means the market demand may potentially become overexploited.
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According to the United Nations, food shortages are a threat due to climate change. Are food shortages a major threat to New Zealand due to climate change?
Climate change is altering conditions that sustain food production, with cascading consequences for food security and global economies. Recent research evaluated the simultaneous impacts of climate change on agriculture and marine fisheries globally.
Modelling of those impacts under a business-as-usual carbon emission scenario suggested about 90% of the world’s population – most of whom live in the least developed countries – will experience reductions in food production this century.
New Zealanders are fortunate to live in a part of the world blessed with relatively fertile soils, adequate water supplies and mild temperatures. This gives us a comparative advantage for agriculture and horticulture over many other countries, including our main trading partner, Australia.
New Zealand produces more than enough food for its population. Exports exceed local consumption, and climate-change induced food shortages should not be an imminent risk for New Zealand. But behind every general statement like this lies some rather more troubling detail.
Overcoming domestic challenges
As residents of a developed country, we are accustomed to accessing the world’s resources through supermarkets. New Zealanders take for granted that most foods (even those we do not produce, like rice or bananas) will be available all year round.
Asparagus, new potatoes and strawberries are examples of foods New Zealanders may expect to see only at particular times of the year, but if apples or kiwifruit are out of stock, people usually complain. Our expectations are based on imports of products when they are out of season in New Zealand. The availability of those imports may be seriously compromised by climate change.
A recent Ministry for the Environment report describes climate impacts, including detailed projections of the average temperature increase and changes in rainfall patterns across New Zealand. The consistent trends are towards wetter conditions in the west, drier in the east and the largest average temperature rises in the north.
Implications for agriculture are manifold. For example, many temperate crops require cool autumn or winter temperatures to initiate flowering or fruit ripening. Orchards may need to be relocated further south, or novel low-chill varieties may need to be bred, as is already happening around the world.
Insect pests and diseases are normally controlled by our low winter temperatures, but they may become more of a problem in the future. Introduced pests and diseases include fruit flies that have a major impact in Australia and other more tropical countries, but struggle to establish breeding colonies in New Zealand. Strong biosecurity controls are our best bet for reducing this risk.
What matters more than the gradual increase in temperature predicted by climate change models, is the greater frequency of extreme weather events. These include droughts, floods and hail, which can lead to total crop losses in particular regions. One obvious mitigation strategy is to expand the provision of irrigation in our drier eastern regions, but concerns over water quality in our rivers mean this is not a popular option with the public – for example on the Heretaunga Plains or in Canterbury.
Risks to imported products
New Zealand is a net exporter of dairy, beef, lamb and many fruit and vegetables, but for some products, we depend heavily on imports. Figures from the US Department of Agriculture are not perfect, but they highlight trade imbalances for major commodities.
New Zealand imports all rice and most of its wheat. It is a net importer of pork products. Horticultural data released annually in Fresh Facts show New Zealand’s major horticultural imports are (in order of value) wine, nuts, processed vegetables, coffee, bananas and table grapes. These imported products come primarily from Australia, China, the US and Ecuador – all countries that may be less resilient to climate change than New Zealand.
As a recent report by the UN Food and Agriculture Organisation (FAO) explains, rising temperatures, rising seas and the increasing frequency of adverse weather events will interact to reduce agricultural and horticultural productivity in many regions around the world. While New Zealand is unlikely to experience food shortages in the near future as a direct result of climate change, the price and availability of imported products may increase significantly.
Unfortunately, there is another important consideration. Some New Zealanders already experience food insecurity. The 2008/9 Adult Nutrition Survey found 14% of New Zealand households reported running out of food often or sometimes due to lack of money.
Perhaps rather than worrying about the future impact of climate change on the price or availability of imported rice or bananas, we should be paying more attention to this social inequity.
As a wealthy agricultural nation and a net exporter of food, it does not seem right that one sector of our society is already regularly experiencing food shortages.
Our diets can have a big environmental impact. The greenhouse gas emissions involved in producing and transporting various foods has been well researched, but have you ever thought about the water-scarcity impacts of producing your favourite foods? The answers may surprise you.
In research recently published in the journal Nutrients, we looked at the water scarcity footprints of the diets of 9,341 adult Australians, involving more than 5,000 foods. We measured both the amount of water used to produce a food, and whether water was scarce or abundant at the location it was drawn from.
The food system accounts for around 70% of global freshwater use. This means a concerted effort to minimise the water used to produce our food – while ensuring our diets remained healthy – would have a big impact in Australia, the driest inhabited continent on Earth.
Biscuits, beer or beef: which takes the most water to produce?
We found the average Australian’s diet had a water-scarcity footprint of 362 litres per day. It was slightly lower for women and lower for adults over 71 years of age.
A water-scarcity footprint consists of two elements: the litres of water used, multiplied by a weighting depending on whether water scarcity at the source is higher or lower than the global average.
Foods with some of the highest water-scarcity footprints were almonds (3,448 litres/kg), dried apricots (3,363 litres/kg) and breakfast cereal made from puffed rice (1,464 litres/kg).
In contrast, foods with some of the smallest water-scarcity footprint included wholemeal bread (11.3 litres/kg), oats (23.4 litres/kg), and soaked chickpeas (5.9 litres/kg).
It may surprise you that of the 9,000 diets studied, 25% of the water scarcity footprint came from discretionary foods and beverages such as cakes, biscuits, sugar-sweetened drinks and alcohol. They included a glass of wine (41 litres), a single serve of potato crisps (23 litres), and a small bar of milk chocolate (21 litres).
These foods don’t only add to our waistlines, but also our water-scarcity footprint. Previous studies have also shown these foods contribute around 30% of dietary greenhouse gas emissions in Australia.
The second highest food group in terms of contributing to water-scarcity was fruit, at 19%. This includes whole fruit and fresh (not sugar-sweetened) juices. It should be remembered that fruit is an essential part of a healthy diet, and generally Australians need to consume more fruit to meet recommendations.
Dairy products and alternatives (including non-dairy beverages made from soy, rice and nuts) came in third and bread and cereals ranked fourth.
The consumption of red meat – beef and lamb – contributed only 3.7% of the total dietary water-scarcity footprint. These results suggest that eating fresh meat is less important to water scarcity than most other food
groups, even cereals.
How to reduce water use in your diet
Not surprisingly, cutting out discretionary foods would be number one priority if you wanted to lower the water footprint of the food you eat, as well as the greenhouse gas emissions of production.
Over-consumption of discretionary foods is also closely linked to weight gain and obesity. Eating a variety of healthy foods, according to energy needs, is a helpful motto.
Aside from this, it is difficult to give recommendations that are relevant to consumers. We found that the variation in water-scarcity footprint of different foods within a food group was very high compared to the variation between food groups.
For example, a medium sized apple was found to contribute a water-scarcity footprint of three litres compared with more than 100 litres for a 250 ml glass of fresh orange juice. This reflects the relative use of irrigation water and the local water scarcity where these crops are grown. It also takes more fruit to produce juice than when fruit is consumed whole.
Two slices of wholegrain bread had a much lower water-scarcity footprint than a
cup of cooked rice (0.9 litres compared with 124 litres). Of the main protein sources, lamb had the lowest water-scarcity footprint per serve (5.5 litres). Lambs are rarely raised on irrigated pastures and when crops are used for feeding, these are similarly rarely irrigated.
Consumers generally lack the information they would need to choose core foods with a lower water-scarcity footprint. Added to this, diversity is an important principle of good nutrition and dissuading consumption of particular core foods could have adverse consequences for health.
Perhaps the best opportunities to reduce water scarcity impacts in the Australian food system lie in food production. There is often very large variation between producers in water scarcity footprint of the same farm commodity.
For example, a study of the water scarcity footprint of tomatoes grown for the Sydney market reported results ranging from 5.0 to 52.8 litres per kg. Variation in the water-scarcity footprint of milk produced in Victoria was reported to range from 0.7 to 262 litres. This mainly reflects differences in farming methods, with variation in the use of irrigation and also the local water scarcity level.
Water-scarcity footprint reductions could best be achieved through technological change, product reformulation and procurement strategies in agriculture and food industries.
Not all water is equal
This is the first study of its kind to report the water-scarcity footprint for a large number of individual self-selected diets.
This was no small task, given that 5,645 individual foods were identified. Many were processed foods which needed to be separated into their component ingredients.
It’s hard to say how these results compare to other countries as the same analysis has not been done elsewhere. The study did show a large variation in water-scarcity footprints within Australian diets, reflecting the diversity of our eating habits.
Water scarcity is just one important environmental aspects of food production and consumption. While we don’t suggest that dietary guidelines be amended based on water scarcity footprints, we hope this research will support more sustainable production and consumption of food.
The author originally disclosed that he undertakes research for Meat and Livestock Australia. His disclosure has been updated to specify that the above research is among the projects to which the MLA has contributed funding.
Reducing emissions from deforestation and farming is an urgent global priority if we want to control climate change. However, like many climate change problems, the solution is complicated. Cutting down forests to plant edible crops feeds some of the world’s hungriest people.
More than 820 million people suffer from hunger, and about 2 billion people face moderate food insecurity – meaning they do not always know when their next meal will come.
But villagers in the Himalayas are turning to a traditional practice that can slow land clearing and feed people: growing and collecting food from the forests.
Food in the forest
My research in the Himalayan region, where high population density means farmland is very scarce, investigated how people used their forests as a food source.
An “edible forest” is one in which people have planted trees and crops that can produce food in the forest, as well as harvesting what naturally grows. In fact, this is a traditional practice in the Himalayan region. A farmer I interviewed in Siding village, at the base of Mardi Himal – one of the peaks in Annapurna Himalayan range – told me:
I go to [the] forest when food is scarce at home. I collect vegetables, fruits, nuts, medicinal herbs, spices, roots and tubers. Sometimes I also collect wild honey, bamboo shoots and mushroom, which is consumed at home and also sold in the market. Occasionally, we also get wild meat.
Traditionally, these villagers see forest and farms as an extension of each other rather than distinct categories, and manage them so they support each other.
Generally, people plant trees useful for households – for their wood, for example, or fruit – in the forest close to the villages, and preserve those grown naturally.
The community itself protects the forest, in the past even pooling grains and cash to hire a guard if needed.
This forest food is supplementary, becoming more important in scarce times and as a buffer during famine. Taking wood for fuel or timber is strictly regulated, but there are no restrictions on gathering food, to the great benefit of the poorest.
Collecting food is mainly the work of women, who gather a few things whenever they go into the forest for firewood or animal fodder. They have a great deal of knowledge about edible plants. Men take part by hunting for honey and wild animals. Children, too, go to the forest in their free time to gather berries and tubers.
Sometimes villagers collect these foods to sell in nearby markets as a seasonal source of cash.
The centralised forest management and curtailment of traditional rights of the communities that came with modern forest bureaucracy in the Himalayan region distanced people from the forest. This also led to rapid deforestation between the mid-1960s to 1980s.
This trend was reversed in the early 1990s, when community rights came to the forefront and communally managed forestry gained a strong foothold. This helped reduce poverty. Yet it is still hard for locals to grow food in the forests as they once did. One farmer told me,
We do not destroy forest when collecting these things, but conservation regulation is making this collection difficult.
We need power to move from centralised governments to local stewardship and local knowledge. Government oversight would still be required to protect the local interests, but any new mechanism needs to be developed in consultation with local communities. Research institutions could play a role in finding better ways to meet the interest of local communities when they manage their forest.
A new category of land use
Edible forests are a departure from standard schemes to reduce emissions from deforestation and land degradation, in which developed countries pay less developed countries to preserve or replant their forests.
If people are actively planting and harvesting in a forest, it may not qualify as protected or conserved land. Conversely, if a local community depends on their forest for food, they may hesitate to register for a formal scheme, for fear they will lose a valuable resource.
If reforestation schemes can be expanded to take into account planting that doesn’t compromise tree coverage, we can encourage rapid growth of edible forests and speed up our response to climate change. It will help meet goals like food security, mitigation and adaptation to climate change, and reducing desertification and land degradation that the United Nations’ Intergovernmental Panel on Climate Change has recommended for sustainable land management in the light of climate change.
Climate change and food insecurity are the main drivers of migration away from rural areas in developing countries, which brings its own challenges for sustainable land management.
Wages sent home by those who move away is a huge part of food security and reducing poverty for many people. In 2018 about US$530 billion was transferred to low- and middle-income countries between family members, compared with US$162 billion in development aid.
This flow of money means families with marginal land – like farmland on hill slopes in Nepal’s case – can afford to slowly convert it to plantations or forests. Migration and remittances – which contribute some 28% of Nepal’s gross domestic product – helps increase forest coverage, especially in marginal lands vulnerable to erosion and landslides.
There is an opportunity to increase planting in these lands, which have been abandoned for farming. If official reforestation policies can acknowledge and support edible forests, we could see the Himalayan region lead the pack on a new way of thinking about forests and food.
Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.
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I would like to know to what extent regenerative agriculture practices could play a role in reducing carbon emissions and producing food, including meat, in the future. From what I have read it seems to offer much, but I am curious about how much difference it would make if all of our farmers moved to this kind of land management practice. Or even most of them. – a question from Virginia
To identify and quantify the potential of regenerative agriculture to reduce greenhouse gas emissions, we first have to define what it means. If regenerative practices maintain or improve production, and reduce wasteful losses on the farm, then the answer tends to be yes. But to what degree is it better, and can we verify this yet?
Let’s first define how regenerative farming differs from other ways of farming. For example, North Americans listening to environmentally conscious media would be likely to define most of New Zealand pastoral agriculture systems as regenerative, when compared to the tilled fields of crops they see across most of their continent.
If milk and meat-producing animals are not farmed on pasture, farmers have to grow grains to feed them and transport the fodder to the animals, often over long distances. It’s hard to miss that the transport is inefficient, but easier to miss that nutrients excreted by the animals as manure or urine can’t go back to the land that fed them.
Returning nutrients to the land really matters because these build up soil, and grow more plants. We can’t sequester carbon in soil without returning nutrients to the soil.
New Zealand’s style of pastoral agricultural does this well, and we’re still improving as we focus on reducing nutrient losses to water.
First, the animals that efficiently digest tough plants – including cows, sheep, and goats – all belch the greenhouse gas methane. This is a direct result of their special stomachs, and chewing their cud. Therefore, farms will continue to have high greenhouse gas emissions per unit of meat and milk they produce. The recent Intergovernmental Panel on Climate Change (IPCC) report emphasised this, noting that changing diets can reduce emissions.
The second problem is worst in dairying. When a cow lifts its tail to urinate, litres of urine saturate a small area. The nitrogen content in this patch exceeds what plants and soil can retain, and the excess is lost to water as nitrate and to the air, partly as the powerful, long-lived greenhouse gas nitrous oxide.
Regenerative agriculture lacks a clear definition, but there is an opportunity for innovation around its core concept, which is a more circular economy. This means taking steps to reduce or recover losses, including those of nutrients and greenhouse gases.
Organic agriculture, which prohibits the use of antibiotics and synthetic pesticides and fertilisers, could potentially include regenerative agriculture. Organics once had the same innovative status, but now has a clear business model and supply chain linked to a price premium achieved through certification.
The price premium and regulation linked to certification can limit the redesign of the organic agricultural systems to incremental improvements, limiting the inclusion of regenerative concepts. It also means that emission studies of organic agriculture may not reveal the potential benefits of regenerative agriculture.
Instead, the potential for a redesign of New Zealand’s style of pastoral dairy farming around regenerative principles provides a useful example of how progress might work. Pastures could shift from ryegrass and clover to a more diverse, more deeply rooted mix of alternate species such as chicory, plantains, lupins and other grasses. This system change would have three main benefits.
The first big win in farming is always enhanced production, and this is possible by better matching the ideal diet for cows. High performance ryegrass-clover pastures contain too little energy and too much protein. Diverse pastures fix this, allowing potential increases in production.
A second benefit will result when protein content of pasture doesn’t exceed what cows need to produce milk, reducing or diluting the nitrogen concentrated in the urine patches that are a main source of nitrous oxide emissions and impacts on water.
A third set of gains can result if the new, more diverse pastures are better at capturing and storing nutrients in soil, usually through deeper and more vigorous root growth. These three gains interrelate and create options for redesign of the farm system. This is best done by farmers, although models may help put the three pieces together into a win-win-win.
Whether you’re interested in local beef in Virginia, or the future of New Zealand’s dairy industry, the principles that define regenerative agriculture look promising for redesigning farming to reduce emissions. They may prove simpler than agriculture’s wider search for new ways of reducing greenhouse gas emissions, including genetically engineering ryegrass.
In wealthy societies we’ve become increasingly picky about what we eat. The “wrong” fruits and vegetables, the “wrong” animal parts, and the “wrong” animals inspire varying degrees of “yuck”.
Our repugnance at fruit and vegetables that fail to meet unblemished ideals means up to half of all produce is thrown away. Our distaste at anything other than certain choice cuts from certain animals means the same thing with cows and other livestock slaughtered for food. As for eating things like insects – perfectly good in some cultures – forget about it.
Disgust has its advantages. Its origins likely lie in the basic survival benefit of avoiding anything that smells or tastes bad. But disgust may also be an impediment to many of us adopting more sustainable lifestyles – from eating alternative sources of protein to drinking recycled water.
We set out to answer this by getting a better grip on how disgust works, focusing on disgust in everyday food choices, rather than aversions to the unknown or unfamiliar.
Our research suggests some disgust responses, once set early in childhood, are hard to shift.
But responses involving culturally conditioned ideas of what is “natural” may be modified over time.
Don’t eat that!
Disgust likely began as a powerful “basic” emotional reaction that evolved to steer us away from (and literally eject) potential contaminants – food that smelled and tasted bad. You can think of it as originally being a “don’t eat that” emotion.
The disgust system tends to be “conservative” – rejecting valid sources of possible nutrition that have characteristics implying they might be risky, and guiding us towards food choices that are ostensibly safer. Research by University of British Columbia psychologist Mark Schaller and colleagues suggests people who live in areas with historically high rates of disease not only have stricter food preparation rules but more “conservative” cultural traditions generally.
Is is unclear exactly how or when individual templates for what is disgusting are set, but generally what is seen as “disgusting” is set relatively early in life. Culture, learning and development all help shape disgust.
It’s just not natural!
In our study, we showed 510 adults pairs of “normal” and “alternative” products via an online survey, and asked them how much they would be willing to pay for the alternatives. We also asked them to rate which product was tastier, healthier, more natural, visually appealing and nutritious. Product pairs included:
- shiny and typically shaped fruits and vegetables vs knobbly, blotchy, gnarled and multi-limbed examples.
- plant protein foods vs insect-based foods
- standard drinks vs drinks with ingredients reclaimed from sewage
- standard medicines vs medicines with ingredients extracted from sewage.
Our results show that, even after statistically adjusting for obvious factors like pro-environmental attitudes, those with a greater “disgust propensity” are less willing to consume atypical (weird-looking) products.
This may seem rather obvious but most prior studies have muddled a food’s “novelty” with its possible disgusting properties (by asking people, for example, whether they’d eat bugs). By asking about really common fruits and vegetables, our study shows just how far disgust may reach in influencing what we consume.
As importantly, our results suggest evaluations of a product’s perceived naturalness, taste, health risk, and visual appeal “explains” about half of the disgust effect.
In particular, lack of perceived “naturalness” was a frequently reason for unwillingness to pay for product alternatives. This result was in line with previous studies that have looked attitudes to eating insects or lab-grown meat. This is a promising area for social marketing.
Given evidence about how much of what we consider disgusting is cultural and learned, marketing campaigns could help shift attitudes about what is “natural”. It has been done before. Consider this advertisement to naturalise sugar consumption.
Thinking differently about emotion-eliciting stimuli is termed “reappraisal”. Reappraisal has been shown to reduce disgust effects among those with obsessive compulsive disorder. Desensitisation (repeated exposures) seems less effective in reducing disgust (versus fear) among people with diagnosed phobias, but it may work better among the general population.
Of course, such speculations remain untested and their ultimate success remains unclear.
But it wasn’t so long ago that Western consumers turned their noses up at fermented foods, and the notion of “friendly bacteria” made as much sense as “friendly fire”. More than a decade ago the residents of a drought-stricken Australian town voted against recycling sewage for drinking water. Now the residents of an Australian city accept recycled sewage being pumped back into the city’s groundwater.
Given time, circumstance and a little nudging, a future meal at your favourite Thai restaurant may well involve ordering a plate of insects.
Glyphosate is back in the news again. The common weed killer, which has previously attracted controversy for its possible link to cancer, has been found in beer and wine.
Researchers in the US tested 15 different types of beer and five different types of wine, finding traces of the pesticide in 19 out of the 20 beverages.
So how much should we be worried? Hint: not at all. The amount detected was well below a level which could cause harm. And there are insufficient details in the methods section to feel confident about the results.
How was this study conducted?
One of the first things I do when evaluating a piece of research is to check the methods – so how the researchers went about collecting the data. What I found didn’t fill me with confidence.
The authors say they set up their experiment based on a technique called a mass spectroscopy method. This methodology has been used to measure the quantities of glyphosate in milk (but not alcoholic drinks). Mass spectroscopy is a very sensitive and specific method, and the authors quote the concentrations that can be reliably detected in milk with this approach.
But the method they actually used is called enzyme linked immunosorbent assay (ELISA). Importantly, you can’t use the concentrations that can be reliably detected with the mass spectroscopy to describe ELISA sensitivity. They’re not compatible.
ELISA is sensitive, but typically not as sensitive as mass spectroscopy, which uses an entirely different physical method to measure glyphosate.
ELISA also has issues of cross contamination. Biological samples for glyphosate measurement, whether ELISA or mass spectroscopy, need careful sample preparation to avoid cross-reaction with any other materials in the sample such as the common amino acid glycine, which looks quite similar to glyphosate and is present in much higher quantities. But the authors didn’t give any detail about the sample preparation used.
These issues make it difficult to be confident in the results.
We’ve seen this before with claims of detection of glyphosate in breast milk, which could not be duplicated. So given the lack of detail around the methodologies used, we should be cautious about taking these figures at face value.
What did they find?
For the sake of argument, let’s accept the researchers’ values and take a look at what they mean.
The highest level of glyphosate they measured was 51.4 parts per billion in one wine (in most of the beverages they found much less). That’s equivalent to 0.0514 miligrams per litre (mg/L).
The authors cite California’s Office of Environmental Health Hazard’s proposed “No Significant Risk Level” for glyphosate consumption of 0.02 mg/kg body weight/day. The limits are based on body weight, so a heavier person can be exposed to more than a person who weighs less, taking into account body volume and metabolism.
This is much lower than the EU Food Safety Authorities’ and Australia’s regulatory allowable daily intake of 0.3 mg/kg body weight/day.
But again, for argument’s sake, let’s use the Californian proposed limits and look at the wine in which the researchers measured the highest amount of glyphosate. With those limits, an average Australian male weighing 86kg would need to drink 33 litres of this wine every day to reach the risk threshold. A 60kg person would need to drink 23 litres of this wine each day.
If you’re drinking 33 litres of wine a day you have much, much bigger problems than glyphosate.
Alcohol is a class 1 carcinogen. Those levels of alcohol consumption would give you a five times greater risk of head, neck and oesophageal cancer (and an increased risk of other cancers). The risk of glyphosate causing cancer is nowhere near these levels. The irony is palpable.
This isn’t even taking into account the likelihood of dying of alcohol poisoning by drinking at this level – which will get you well before any cancer.
And that’s using the highly conservative Californian limits. Using the internationally accepted limits, an average adult male would have to drink over 1,000 litres of wine a day to reach any level of risk.
So how should we interpret the results?
The report does not contain a balanced representation of the risks of glyphosate.
They cite the International Agency for Research on Cancer’s finding of glyphosate as class 2 (probably) carcinogenic (alcohol is class 1, a known carcinogen).
But they don’t mention the European Food Safety authority finding that glyphosate posed no risk of cancer, or the WHO Joint Meeting on Pesticide Residues report showing no significant cancer risk to consumers under normal exposure.
They don’t cite the most important study of human exposure, the Agricultural Health Study which is the largest and longest study of the effect of glyphosate use. This study found no significant increase in cancer in highly exposed users.
The “report” claiming that there is glyphosate in wine and beer provides inadequate information to judge the accuracy of the claimed detection, and does not put the findings in context of exposure and risk.
Even taking their reported levels at face value, the risk from alcohol consumption vastly outweighs any theoretical risk from glyphosate. Their discussion does not fairly consider the evidence and is weighted towards casting doubt over the safety of glyphosate.
So you may enjoy your beer and wine (in moderation), without fear of glyphosate.
Blind peer review
This is a fair and accurate assessment of the study and its findings. That said, it is prudent for the scientific community to remain attentive to changes within the food supply and issues of potential risk to public health. Considering the increasing use of glyphosate by the food industry, we need continued diligence in this area. – Ben Desbrow
Research Checks interrogate newly published studies and how they’re reported in the media. The analysis is undertaken by one or more academics not involved with the study, and reviewed by another, to make sure it’s accurate.
If we’re serious about feeding the world’s growing population healthy food, and not ruining the planet, we need to get used to a new style of eating. This includes cutting our Western meat and sugar intakes by around 50%, and doubling the amount of nuts, fruits, vegetables and legumes we consume.
These are the findings our the EAT-Lancet Commission, released today. The Commission brought together 37 leading experts in nutrition, agriculture, ecology, political sciences and environmental sustainability, from 16 countries.
Over two years, we mapped the links between food, health and the environment and formulated global targets for healthy diets and sustainable food production. This includes five specific strategies to achieve them through global cooperation.
Right now, we produce, ship, eat and waste food in a way that is a lose-lose for both people and planet – but we can flip this trend.
What’s going wrong with our food supply?
Almost one billion people lack sufficient food, yet more than two billion suffer from obesity and food-related diseases such as diabetes and heart disease.
The foods causing these health epidemics – combined with the way we produce our food – are pushing our planet to the brink.
One-third of the greenhouse gas emissions that drive climate change come from food production. Our global food system leads to extensive deforestation and species extinction, while depleting our oceans, and fresh water resources.
To make matters worse, we lose or throw away around one-third of all food produced. That’s enough to feed the world’s hungry four times over, every year.
At the same time, our food systems are at risk due to environmental degradation and climate change. These food systems are essential to providing the diverse, high-quality foods we all consume every day.
A radical new approach
To improve the health of people and the planet, we’ve developed a “planetary health diet” which is globally applicable – irrespective of your geographic, economic or cultural background – and locally adaptable.
The diet is a “flexitarian” approach to eating. It’s largely composed of vegetables and fruits, wholegrains, legumes, nuts and unsaturated oils. It includes high-quality meat, dairy and sugar, but in quantities far lower than are consumed in many wealthier societies.
The planetary health diet consists of:
- vegetables and fruit (550g per day per day)
- wholegrains (230 grams per day)
- dairy products such as milk and cheese (250g per day)
- protein sourced from plants, such as lentils, peas, nuts and soy foods (100 grams per day)
- small quantities of fish (28 grams per day), chicken (25 grams per day) and red meat (14 grams per day)
- eggs (1.5 per week)
- small quantities of fats (50g per day) and sugar (30g per day).
Of course, some populations don’t get nearly enough animal-source foods necessary for growth, cognitive development and optimal nutrition. Food systems in these regions need to improve access to healthy, high-quality diets for all.
The shift is radical but achievable – and is possible without any expansion in land use for agriculture. Such a shift will also see us reduce the amount of water used during production, while reducing nitrogen and phosphorous usage and runoff. This is critical to safeguarding land and ocean resources.
By 2040, our food systems should begin soaking up greenhouse emissions – rather than being a net emitter. Carbon dioxide emissions must be down to zero, while methane and nitrous oxide emissions be kept in close check.
How to get there
The commission outlines five implementable strategies for a food transformation:
1. Make healthy diets the new normal – leaving no-one behind
Shift the world to healthy, tasty and sustainable diets by investing in better public health information and implementing supportive policies. Start with kids – much can happen by changing school meals to form healthy and sustainable habits, early on.
Unhealthy food outlets and their marketing must be restricted. Informal markets and street vendors should also be encouraged to sell healthier and more sustainable food.
2. Grow what’s best for both people and planet
Realign food system priorities for people and planet so agriculture becomes a leading contributor to sustainable development rather than the largest driver of environmental change. Examples include:
- incorporating organic farm waste into soils
- drastically reducing tillage where soil is turned and churned to prepare for growing crops
- investing more in agroforestry, where trees or shrubs are grown around or among crops or pastureland to increase biodiversity and reduce erosion
- producing a more diverse range of foods in circular farming systems that protect and enhance biodiversity, rather than farming single crops or livestock.
The measure of success in this area is that agriculture one day becomes a carbon sink, absorbing carbon dioxide from the atmosphere.
3. Produce more of the right food, from less
Move away from producing “more” food towards producing “better food”.
This means using sustainable “agroecological” practices and emerging technologies, such as applying micro doses of fertiliser via GPS-guided tractors, or improving drip irrigation and using drought-resistant food sources to get more “crop per drop” of water.
In animal production, reformulating feed to make it more nutritious would allow us to reduce the amount of grain and therefore land needed for food. Feed additives such as algae are also being developed. Tests show these can reduce methane emissions by up to 30%.
We also need to redirect subsidies and other incentives to currently under-produced crops that underpin healthy diets – notably, fruits, vegetables and nuts – rather than crops whose overconsumption drives poor health.
4. Safeguard our land and oceans
There is essentially no additional land to spare for further agricultural expansion. Degraded land must be restored or reforested. Specific strategies for curbing biodiversity loss include keeping half of the current global land area for nature, while sharing space on cultivated lands.
The same applies for our oceans. We need to protect the marine ecosystems fisheries depend on. Fish stocks must be kept at sustainable levels, while aquaculture – which currently provides more than 40% of all fish consumed – must incorporate “circular production”. This includes strategies such as sourcing protein-rich feeds from insects grown on food waste.
5. Radically reduce food losses and waste
We need to more than halve our food losses and waste.
Poor harvest scheduling, careless handling of produce and inadequate cooling and storage are some of the reasons why food is lost. Similarly, consumers must start throwing less food away. This means being more conscious about portions, better consumer understanding of “best before” and “use by” labels, and embracing the opportunities that lie in leftovers.
Circular food systems that innovate new ways to reduce or eliminate waste through reuse will also play a significant role and will additionally open new business opportunities.
For significant transformation to happen, all levels of society must be engaged, from individual consumers to policymakers and everybody along the food supply chain. These changes will not happen overnight, and they are not the responsibility of a handful of stakeholders. When it comes to food and sustainability, we are all at the decision dining table.
The EAT-Lancet Commission’s Australian launch is in Melbourne on February 1. Limited free tickets are available.
Alessandro R Demaio, Australian Medical Doctor; Fellow in Global Health & NCDs, University of Copenhagen; Jessica Fanzo, Bloomberg Distinguished Associate Professor of Global Food and Agriculture Policy and Ethics, Johns Hopkins University, and Mario Herrero, Chief Research Scientist, Food Systems and the Environment, CSIRO
What did you have for dinner last night? Might you have made a different choice if you had a simple way to compare the environmental impacts of different foods?
Most people do not recognise the environmental impact of their food choices. Our research, published in Nature Climate Change, shows that even when consumers do stop to think about the greenhouse gas emissions associated with their food, they tend to underestimate it.
Fortunately, our study also points to a potential solution. We found that a simple “carbon label” can nudge consumers in the right direction, just as nutrition information helps to highlight healthier options.
Most food production is highly industrialised, and has environmental impacts that most people do not consider. In many parts of the world, conversion of land for beef and agricultural production is a major cause of deforestation. Natural gas is a key input in the manufacture of fertiliser. Refrigeration and transportation also depend heavily on fossil fuels.
Overall, food production contributes 19-29% of global greenhouse emissions. The biggest contributor is meat, particularly red meat. Cattle raised for beef and dairy products are major sources of methane, a potent greenhouse gas.
Meat production is inherently inefficient: fertiliser is used to grow feedstock, but only a small portion of this feed becomes animal protein. It takes about 38 kilograms of plant-based protein to produce 1kg of beef – an efficiency of just 3%. For comparison, pork has 9% efficiency and poultry has 13%.
We could therefore cut greenhouse emissions from food significantly by opting for more vegetarian or vegan meals.
Food for thought
To find out whether consumers appreciate the environmental impact of their food choices, we asked 512 US volunteers to estimate the greenhouse emissions of 19 common foods and 18 typical household appliances.
We told the respondents that a 100-watt incandescent light bulb turned on for 1 hour produces 100 “greenhouse gas emission units”, and asked them to make estimates about the other items using this reference unit. In these terms, a serving of beef produces 2,481 emission units.
As shown below, participants underestimated the true greenhouse gas emissions of foods and appliances in almost every case. For example, the average estimate for a serving of beef was around 130 emission units – more than an order of magnitude less than the true amount. Crucially, foods were much more underestimated than appliances.
Improving consumers’ knowledge
People often overestimate their understanding of common everyday objects and processes. You might think you have a pretty solid idea of how a toilet works, until you are asked to describe it in exact detail.
Food is a similarly familiar but complex phenomenon. We eat it every day, but its production and distribution processes are largely hidden. Unlike appliances, which have energy labels, are plugged into an electrical outlet, emit heat, and generally have clear indications of when they are using electricity, the release of greenhouse gases in the production and transportation of food is invisible.
One way to influence food choice is through labelling. We designed a new carbon label to communicate information about the total amount of greenhouse emissions involved in the production and transport of food.
Drawing on knowledge from the design of existing labels for nutrition, fuel economy and energy efficiency, we came up with the label shown below. It has two key features.
First, it translates greenhouse emissions into a concrete, familiar unit: equivalent number of light bulb minutes. A serving of beef and vegetable soup, for example, is roughly equivalent to a light bulb turned on for 2,127 minutes – or almost 36 hours.
Second, it displays the food’s relative environmental impact compared with other food, on an 11-point scale from green (low impact) to red (high impact). Our serving of beef and vegetable soup rates at 10 on the scale – deep into the red zone – because beef production is so emissions-intensive.
To test the label, we asked 120 US volunteers to buy cans of soup from a selection of six. Half of the soups contained beef and the other half were vegetarian. Everyone was presented with price and standard nutritional information. Half of the group was also presented with our new carbon labels.
Volunteers who were shown the carbon labels chose significantly fewer beef soup options. Importantly, they also had more accurate perceptions of the relative carbon footprints of the different soups on offer.
Figuring out the carbon footprint of every food item is difficult, expensive, and fraught with uncertainty. But we believe a simplified carbon label – perhaps using a traffic light system or showing relative scores for different foods – can help inform and empower consumers to reduce the environmental impact of their food choices.
Adrian R. Camilleri, Senior Lecturer in Marketing, University of Technology Sydney; Dalia Patino-Echeverri, Associate professor, Duke University, and Rick Larrick, Professor of Management and Organizations, Duke University