Which milk should I drink?

Since 2017, 22 August  has been dubbed ‘World Plant Milk Day’ and this year there have been more calls for people to abandon dairy milk and switch to plant ‘milk’ alternatives. We recognise and respect that many people have deep and legitimate ethical, environmental and health concerns about dairy farming and other intensive livestock production. We share those concerns and respect their right to choose. So why is the Sustainable Food Trust interested in the current public discussion about whether to continue to consume dairy products or switch to plant-based alternatives? SFT policy director, Richard Young, explains and also responds to some of the criticism we have received on this issue.

In a press release covered by The Times on 24 August, the organisation Plant Based Health Professionals called for the provision of free milk in schools to be ended. They said, ‘Over 450 health professionals state dairy is unnecessary, and call for plant milks to be offered in schools instead’. This is just one of many initiatives to get people to stop drinking dairy milk and switch to alternatives.

As an organisation, the SFT is totally opposed to intensive livestock production in all its forms. We are also very concerned about the production of soya and its use in livestock farming, as is clear from a press release we issued recently. This focused on the problems associated with the use of soya on intensive livestock farms and the damaging environmental impact this is having. It then highlighted research showing that dairy farmers could switch away from soya to alternative sources of protein produced in the UK, in order to reduce damage to rainforests and other virgin land. We also pointed out that, in the UK, because so much of the milk is produced from grass, a lot more soya is needed to produce a litre of soya milk than a litre of dairy milk.

Only this latter point was picked up by the media and this has had an unfortunate polarising effect. This has, nevertheless, triggered an important discussion: if everyone in the UK gave up dairy, would we have a more sustainable and healthy food system, or might it be even worse than it is at present?

In the UK, more than 80% of the soya used in livestock production goes to pigs and poultry. We see this as an even bigger problem than its use in dairy farming because pigs and poultry depend entirely on grain, whereas dairy cattle get a high proportion of their diet from grass and other non-human edible feed. The review article I co-authored, on which the press release was based, also featured research showing how we could reduce the use of palm kernel meal (another rainforest product) as well as the use of soya in pig and poultry production.

Soya milk only makes up a small part of the UK market, and if the beans it is made from are organically grown in Europe, then the environmental impact is obviously quite small. However, UK plant ‘milk’ sales are increasing rapidly. Almost a quarter of all households and a third of millennials are now drinking plant ‘milk’ alternatives, though not all of them are only drinking plant ‘milks’. They are also eating very little lamb. They are, however, still consuming large amounts of chicken. If these trends continue, we will end up with a population rejecting the dietary proteins and fats that can be largely produced on UK grasslands and depending instead on imported food, much of it produced on former rainforest land, or in other very unsustainable ways.

Comparing dairy and plant milks

A quick look at studies which compare the environmental impact of dairy milk and plant-based alternatives, gives the impression that plant ‘milks’ come out miles on top, yet none I have seen are based on UK data or include the latest research findings. However, anyone who is lactose intolerant and those who avoid dairy produce for ethical reasons will clearly not be able to drink cows’ milk. Before considering the alternatives, let’s look more closely at dairy farming.

Welfare issues

The Sustainable Food Trust has long opposed the increasing intensification of dairy farming. We have been advocating lower protein diets and grass-based systems for many years. Most dairy farms are, however, associated with a practice which understandably some people find unacceptable.

On the vast majority of dairy farms calves are taken away from their mothers at a very young age. This is distressing, though in my experience, less so if it is done quickly before the cow and calf have bonded. I grew up on a dairy farm and milked cows regularly until I was 24. I found that giving extra attention and affection to both the cow and the calf for a few days until they showed signs of being contented can also help make the practice more compassionate. A few farms have gone much further than that and modelled themselves on the first calf-at-foot dairy, while others multiple-suckle each orphaned calf on nurse cows.

Even bigger concerns for me are the way modern dairy cow breeding has produced high yielders that give more milk than they can easily produce without losing weight. Due to commercial pressure and the falling price of milk in real terms, dairy farms also have to keep getting larger to stay in business, resulting in more and more herds being kept indoors full-time.

The reasons for both these trends are rooted in modern society and the cut-throat competition between supermarkets which drove doorstep milk deliveries from local dairies out of business. This also caused the transition from reusable glass to plastic bottles, the huge environmental cost of which should even now be levied on those companies that brought this about.

For me, the biggest driver of problems linked to dairy farming isn’t drinking milk, it is the belief that productivity should continually be increased, and the lack of support to allow dairy farmers to survive economically without having to push their cows to the limit.  This will only change with support from both politicians and consumers.

Environmental issues

On the most intensive dairy farms the high levels of nitrogen fertiliser used to grow grass and other crops results in both ammonia and nitrous oxide emissions. Ammonia from housed dairy cows in the UK is a significant cause of air pollution. Most nitrous oxide is associated with crop production, but livestock are also a significant source. The increasing size of herds also results in too much effluent in a single location, with the essential nutrients in animal waste not replenishing all the soils on which the feed crops were grown. Much of the SFT’s work is to promote more sustainable alternatives to reduce these problems.

Cows grazing grass, however, produce much less ammonia than cows housed indoors and, where forage legumes like clover are used to fix nitrogen naturally, the use of nitrogen fertilisers can be reduced or avoided completely. This reduces ammonia emissions still further because it avoids the ammonia lost when nitrogen fertiliser is applied to land, and can also reduce nitrous oxide emissions by over 40%, as trials by Rothamsted Research in beef cattle have recently established. Grassland, when properly managed, is also extremely important as a carbon store, for river catchment management (i.e. flood prevention), for drinking water quality and for the significant range of birds and invertebrates that have co-evolved with grazing animals. That said, grassland on most dairy farms is far from the diverse and species-rich habitat it could be.

At this point you may well be wondering how I can possibly advocate cows’ milk, given the welfare and environmental issues I’ve just acknowledged. I should first make clear that my case relates specifically to the UK. There is no one perfect sustainable approach that fits all countries because soils, climates and the most appropriate ways to produce food vary greatly. I also do not have specific data for other countries and using global averages can result in very false conclusions.

Before explaining why getting ‘milk’ from plants is not a long-term sustainable use of land, we need to look next at research which provides a fresh perspective on what is generally seen as the biggest environmental weakness of cattle farming – methane emissions.

Methane

Methane emissions from cattle remain one of the key environmental reasons many people mention for avoiding dairy produce, and global increases in methane are a huge concern. However, recent analysis by scientists at Oxford University shows that where you have a stable population of cattle, as in the UK, the true impact of their methane emissions is about 75% lower than currently used calculations suggest. This may sound odd, but it isn’t based on some biased study by the dairy industry. Professor Myles Allen, the senior scientist behind the research, is a lead author of two IPCC reports and was a key figure behind the work which explained to the world that just reducing fossil fuel use moderately won’t prevent runaway climate change – instead we have to reduce use dramatically and move quickly to a point where every kilo of CO₂ we continue to emit in future is balanced by a kilo taken out of the atmosphere. He explained this when he was interviewed by Jim Al-Khalili for an episode of ‘The Life Scientific’ on Radio 4 earlier this year.

The science behind this – the fact that CO₂ is an extremely persistent greenhouse gas that accumulates in the atmosphere – is, in a way, the same science behind why methane from ruminants in particular is less of a problem than previously believed. In contrast to CO₂, methane is a very short-lived greenhouse gas and breaks down to CO₂ and water within about a decade. In addition, the methane that is lost when fossil fuels are extracted, stored and distributed (and that is more than is produced by all ruminants) leaves additional, fossil CO₂ in the atmosphere at the end of the process. Ruminants, however, simply recycle atmospheric CO₂ – what’s left at the end is the same CO₂ that was taken out of the atmosphere through photosynthesis by the plants they ate.

The method currently used (GWP¹⁰⁰) to compare the warming impact of greenhouse gases with CO₂, works well for long-lived gases like nitrous oxide, but doesn’t for methane because it fails to account fully for the fact that each emission of methane doesn’t persist in the atmosphere like CO₂.

The authors of the study use the analogy that a herd of cows is like a closed power station. A power station that closed in say 1960, is still warming the planet as much today as in its last year of operation because all the carbon emitted during its lifetime (with the exception of that taken up by oceans, which is causing acidification) is still in the atmosphere, and will still be there in hundreds, if not thousands of years. The closed power station and a stable population of cows continue to have a warming effect but do not increase global warming. They don’t take us any closer to the 1.5 degrees C temperature rise we need to avoid, unlike all the additional carbon we are still putting into the atmosphere. This is a difficult concept to grasp. There is an excellent and more detailed explanation of this on the Food Climate Research Network (FCRN) website written by John Lynch, Tara Garnett and others.

Soya use by dairy cows

In the UK, most imported soya is used in pig and poultry feed, but according to an FOI request, 8-15% is included in dairy rations. Figures from the AHDB in June indicate that annual use of soya for livestock in Great Britain is currently 1,155,500 tonnes, very close to the levels of recent years. On this basis the use by cows is between 92,000 and 173,000 tonnes. Figures for Northern Ireland are not readily available, but full UK figures would obviously be proportionally higher.

There are also no published figures on how much imported soya goes into human food and non- food uses, which is perhaps why so many people assume that almost all of it goes to livestock. Use in food includes noodles, pasta, flour, bread, fillers and much more. Clear information is hard to find but this webpage of a company in Serbia gives an indication of the range. There is evidence that significant amounts are also used in the production of pet food, paint, ink (including toner), pharmaceuticals and cosmetics, plastics, biodiesel and other industrial uses. This doesn’t exonerate the livestock sector, of course, but it does indicate that action is needed across a wider range of sectors than just livestock to reduce our dependence on soya.

The key thing about soya bean meal, however, which is generally overlooked, is that it has already had almost all the oil extracted. It is not the same as soya bean flour which is produced from whole beans. About 99% of the oil is used by humans, either in processed foods or non-food products. After the oil has been extracted, the remaining 85% by weight is meal. Financially, this accounts for about 70% of the value of the crop globally. However, since soya oil has become one of our main dietary fat sources, the question arises, whether human or animal use is the main driver of soya production? The reality is that you can’t get the oil without producing the meal. The answer, of course, is that they are both drivers.

Plant ‘milks’

Looking at dairy alternatives, it is difficult to find one that comes from a genuinely sustainable system. Nutritionally, soya ‘milk’ is lower in fat than dairy milk, but also lower in calcium and vitamins which need to be added artificially. The belief that low-fat milk is a good thing for everyone, is being challenged. A recent extensive review of research on this issue found that children who drink low fat milk are more overweight than those who drink full-cream milk. Likely reasons for this include better appetite satisfaction with full-cream milk and lower desire for other potentially unhealthy foods. Opinion is divided also about soya ‘milk’s potential negative health effects. Scientific reviews allude to possible problems but hold back from advising against use. A major review on the developmental toxicity of soya infant formula in 2011, found modest cause for concern; some panelists felt it should be given a clean bill of health while others wanted their concerns expressed more strongly. In her book, ‘Put Your Heart in Your Mouth’, Dr Natasha Campbell-McBride is more outspoken than most and strongly advises against soya in all forms except as used in traditional Japanese foods. Among her concerns she points to the high level of phytates which reduce mineral absorption and its potential ability to impair thyroid function. She also suggests that aluminium residues from commercial production may be linked to dementia.

Almond milk is one of the most popular ‘milk’ alternatives and appears to be safe for anyone who does not have a nut allergy. However, it is very low in protein and all the minerals have to be added artificially. On the environmental side, 80% of all almonds come from California where there is very high use of pesticides and water. It is claimed that it takes 5 litres of water to produce each individual almond and that this causes significant ecological stress in an increasingly drought-prone region. In addition, 1.5 million colonies of bees have to be trucked in from all over America for 4 weeks to pollinate the crop, because the monoculture conditions under which the crop is grown leave no place for wild pollinators. Large numbers of these bees die every year, but it is unclear exactly why.

There are also significant environmental issues associated with rice production including high water use and greenhouse gas emissions, and the leaching of pesticides into rivers. Rice ‘milk’ also isn’t suitable for children under 5, due to its relatively high arsenic levels. If it is the only ‘milk’ someone can tolerate there is obviously no choice, but there are also socio-economic questions surrounding the rise in demand for rice and rice ‘milk’ in the west. Rice is a staple crop for more than half the world’s population and there has long been concern about the ability to increase production every year sufficiently to meet the needs of expanding populations. At times of shortage rice prices can increase significantly, pricing out the poorest in the poorest countries .

Coconut milk has also become popular, but as the Independent exposed recently, expansion in the production of coconuts for oil and ‘milk’ is associated with significant loss of biodiversity. Whether this is greater or less than for palm oil is hotly disputed. Either way, it is no small player, with about 12 million hectares growing coconuts compared with 18 million hectares producing palm oil. Nutritionally it is high in fat and contains a range of natural vitamins and minerals. Consumers appear willing to pay more for plant ‘milks’ than cows’ milk which is sometimes retailed at a lower price than bottled water. Coconut ‘milk’ is one of the most expensive. But if cows’ milk retailed at the same price, dairy farmers in the UK would be able to make a decent living with a lot less cows and much less intensive methods.

Oat milk is probably the best alternative in the UK from an environmental perspective because it can be grown here, and because oats are a relatively low-input crop. Sales have increased rapidly since it was launched. Like rice milk and to some extent soya, it needs to be fortified with calcium and a range of vitamins that are naturally found in dairy milk. The manufacturers also add a small amount of rape oil. During the production process, about 40 % of the calories and a high proportion of the protein are left in the residue sludge. Originally sold to pig farmers to avoid waste, this was stopped after consumer backlash.

Why the SFT supports grazing livestock in the UK

For the SFT, grass, forage legumes and grazing animals are key cornerstones of any truly sustainable food system. There are two main reasons. The first is that continuous crop production without grass and grazing animals in the rotation depletes soil carbon. The lost carbon persists in the atmosphere and the soil becomes less resilient because organic matter, essential for a healthy soil, is 50% carbon. Unpopular as it may sound, we actually need to re-introduce grass and grazing animals into arable rotations. This is the best way to sequester significant amounts of carbon and regenerate the almost 40% of arable soils in England and Wales that are badly degraded. It is also necessary to break the weed, pest and disease cycles that cause such high use of pesticides. The second reason is that grazing animals are the only way to bring in sufficient nitrogen naturally, via clover and other forage legumes, to maintain high productivity, while still continuously producing food. We feel this is essential for food security and because most nitrogen fertiliser is produced from natural gas, which is a finite resource. Its production and use are also associated with a wide range of problems, as detailed by the European Nitrogen Assesment, all of which produce major hidden costs for society, as this study quantifies. In the UK, grazing animals are particularly important because almost two-thirds of all farmland is under grass. In many areas, grass is the only possible or reliable crop due to topography, soil type or climate.

The loss of natural grasslands to produce soya

Many people assume that soya grown in the US or on other non-rainforest land has almost no carbon footprint, because the land on which it is grown has already lost most of its carbon. Yet the carbon lost from decades of continuous cropping is still in the atmosphere contributing to global warming and that should really feature in calculations. Greenpeace and others have drawn attention to the Cerrado in Brazil where half the virgin land has now been converted to soya and other crops, but as WWF’s Plow Print report for 2016 shows, between 2009 and 2016, 53 million acres of the remaining temperate grasslands in the US were ploughed to grow soya, corn and wheat. Since then, a further 2 million acres have gone under the plough. Undoubtedly some of this land will have been over-grazed but such grassland are varied and important habitats. While clearly not on the same scale as rainforest loss, the ploughing of this land will result in greenhouse gas emissions from soil carbon and nitrogen loss that are equivalent to about 1.2 billion tonnes of CO₂from the top 30 centimetres of soil over about 30 years, and probably more from lower depths . This calculation, in what is an under-researched area of science, assumes an initial soil carbon content of 4% and is based on ‘The impact of grassland ploughing on CO2 and N2O emissions in the Netherlands’, this USDA page and long-term studies at Rothamsted Research in the UK.

Conclusion

The issues associated with changing from dairy to plant-based ‘milks’ are more complex than generally realised and even now we need to learn more to plot the most sustainable and beneficial way forward. Stepping back from the published environmental and nutritional evidence allows me to add an historical perspective. Archaeological evidence has indicated that the mutation which first enabled Europeans to produce lactase, the enzyme that allows us to digest the milk sugar, lactose, after weaning, is believed to have arisen in a dairy farming community somewhere between the Central Balkans and Central Europe about 7,500 years ago. It has been suggested that all those of us who can digest milk in Europe may be descended from the individual in whom this mutation occurred. Being able to digest cows’ milk gave a huge boost to childhood survival and human fertility. It is a natural food which has served us Europeans well over millennia. People who originate from other parts of the world where lactose tolerance is lower will have evolved in subtley different ways and are probably better off with the diets traditionally used in those regions.

But, as I acknowledged at the start, there are many issues to resolve with modern dairy farming. What it really needs is much greater consumer understanding of why dairy farmers need to be able to make a living without constantly having to increase herd size and productivity per cow. That requires consumers to pay a fair price for milk and put further pressure on supermarkets to treat dairy farmers fairly, but also to use their power to de-intensify rather than constantly intensify the industry. Increasing sales of dairy alternatives may reduce the amount of cows’ milk produced, but this won’t do anything to ensure the milk that is produced comes from more sustainably managed and happier animals – sadly it will do just the opposite.