Veganuary: Is a vegan diet best for the planet?

For anyone who has known me a while, you’ll know that in 2015 I decided to go vegan. I had been thinking about it for a while after seeing the documentary Cowspiracy which explains the impact of animal agriculture on the planet. I was shocked at the statistics about greenhouse gas emissions from ruminating animals and also at the amount of land used to grow crops to feed animals raised for their meat. I hadn’t realised before that a lot of the deforestation in the Amazon is to grow soy and grains to feed these animals and that it takes 7kg grain to produce just 1kg of meat. I’ve always been interested in environmental protection and sustainability so at the time it made total sense to me to switch to a completely vegan diet.

Now 5 years later, I am no longer vegan but this morning I listened to a podcast from the Guardian titled Is veganism the future? which talked about the environmental benefits of switching to a vegan diet. It was originally aired in January 2020 due to the rising popularity of Veganuary, going vegan for the month of January. Last year I finished my Master’s degree in public health nutrition and for my dissertation project I decided to research environmentally sustainable diets. Listening to the podcast this morning it got me thinking again about whether a vegan diet is best for the environment and we should all be going vegan in the future to save our planet. Here I want to share some of the ways that animal agriculture affects the environment and give you some things to think about if you are considering changing your diet.

Environmental impact of animal agriculture at a glance

  • Large amounts of land and water are needed to grow grains to feed animals
  • Often the land used to grow these crops comes from deforestation in places like the amazon rainforest
  • Ruminant animals such as cows and sheep release huge amounts of methane, a greenhouse gas with 21x the global warming potential as carbon dioxide
  • Badly managed farms can cause pollution through run off of animal wastes and chemicals
  • Fertilizers used to maximise production of feed crops emit huge amounts of harmful greenhouse gas emissions such as nitrous oxide
  • Feed crops are often grown on mono-culture farms destroying the natural landscape and biodiversity in these areas

Even though some of the points above also apply to growing of plant-based foods, there’s no denying the evidence that animal products have a significant environmental impact. You can definitely find more sustainable types of animal products, including pasture raised, organic meat and dairy but these products are pretty expensive and not accessible to the majority of people. It is also clear from years of research that, in terms of greenhouse gas emissions, even the most sustainably produced meat still has a higher environmental impact than the majority of plant-based protein sources such as beans, lentils and soy. But does this mean that a vegan diet is best for the planet? Not necessarily.

In my research, I found out that it is not as straight forward as “a vegan diet is better for the planet”. An Italian research study on 2018 compared carbon dioxide emissions, land and water use for the real diets of omnivores, vegetarians and vegans. I say real diets because a lot of studies use computer modelling to compare different diets rather than food diaries showing what people actually eat. The study found that yes, on the whole, vegan diets had the lowest environmental impact in terms of carbon dioxide emissions and land use but the difference between the vegetarian and vegan diets were small and on average the vegetarian diets had the lowest water usage of the three group. And another shocking result was that the two participants with the highest environmental impact in the whole study were vegans whose diet consisted mainly of fruit, eek!

And what about dairy products, how do vegan milks compare to dairy in terms of environmental impact? The graph below is from another study in 2018 which again compared carbon dioxide emissions, land use and water consumption this time for different types of dairy-free alternatives vs. dairy milk.

environmental impact dairy-free milk alternatives

Typically, dairy milk does have a much higher environmental impact than dairy alternatives, even rice and almond milk which are known for the amount of water they consume. But I’m not sure whether these figures account for the global warming impact of deforestation to be able to grow huge amounts of soy and almonds in certain parts of the world. Forests are the lungs of our planet, taking in carbon dioxide and converting it to oxygen. When we cut down trees to plant crops, we not only have increased emissions from agricultural processes but we also lose the protective effect of the forests. I don’t think there is a problem with choosing dairy-free alternatives and they can definitely play a role in a sustainable diet. I drink them personally but I do think we have to choose wisely and mindfully.

I’m going to go into the nutrition aspects of the vegan diet in more detail in another post but I will touch here on the fact that dairy-free milks are not equivalent to dairy in terms of protein, minerals and fat-soluble vitamins which are essential to healthy bones and teeth. That’s not to say that you can’t get these things elsewhere on a vegan diet, there are plenty of sources of calcium in the plant-kingdom but I am just pointing out that substituting rice milk for dairy you could run into nutritional deficiencies down the line. Personally, I am no longer vegan for this reason although I still eat a mostly plant-based diet with plenty of vegan meals.

In reality there are many aspects to a sustainable diet including where the food is grown, how it is transported and packaged, whether it is eaten in season or not and what methods of farming are used. Of course, it’s possible to eat an environmentally sustainable diet if you consume a lot of staple foods such as grains and potatoes that are grown in your region but if you are eating avocados, mangos and almond milk on a daily basis like the typical vegan influencer then you are kidding yourself! This isn’t a criticism to anyone doing this as there have been times when I bought lots of imported fruit and almond milk too, I’m just highlighting that sometimes we need to look at the bigger picture. Another major issue that is often overlooked when we think about sustainable diets is not what we eat but what we don’t eat. No matter what the type of food, vegan or animal products, if it goes into the bin as food waste that has a massive impact on the environment.

So, in summary, no I don’t think that a vegan diet is always best for the environment or the only way to eat sustainably. Although if you do want to adopt a vegan diet you can definitely reduce your environmental footprint by doing so if you do your research beforehand. I do think though that you can make a significant impact by cutting down the amount of animal products you consume, or even adopting a pescatarian or vegetarian diet without having to take “extreme” measure of going 100% vegan. If you’re interested in reading more about sustainable diets and how you can make your diet more environmentally friendly, I’d recommend checking out the British Dietetic Association One Blue Dot project which sets out guidelines for a healthy, environmentally sustainable diet. They do recommend significantly reducing meat consumption as well as eating less foods imported by plane and eating local and seasonal produce.

Over to you…

Thank you for taking the time to read this post, let me know in the comments below if you found this article interesting and whether you have thought about going vegan for environmental reasons. Like this post and follow my blog if you want me to share more about this area of research. It’s not something I usually write about here but it is something I am interested in! If you want to read my research publication on “A cross-sectional survey of the readiness of consumers to adopt an environmentally sustainable diet” you can find the pdf here.

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