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Sustainable Protein Powders | Whey vs Plant-Based Protein Supplements

Whether for health reasons or to improve athletic performance, many people turn to protein supplements as a quick and easy way to boost their protein intake. But there are many different kinds of protein powder, so which is the most sustainable protein powder option?

What is a protein supplement?

Protein supplements are made of protein-rich foods (like milk, soy, oats or insects) that have been dried and crushed, pressed or otherwise processed into forms that make it easier for those looking to boost their protein intake. Two of the most popular forms are protein powders and protein bars, where raw protein is often mixed with flavourings, as well as additional vitamins and minerals to boost its nutritional profile.1 

Traditionally, the most common source of protein used in protein powders and supplements is whey protein. Whey is a protein-rich liquid isolated from cows’ milk – so if dairy products are one of the major drivers of land use, water use and greenhouse gas emissions worldwide2,7, does that mean whey protein powders and supplements have a large environmental footprint, too?

Read more about the true cost of milk production.

Image of cheesemaking - separating the curds from the whey.
Whey is most commonly created during the cheesemaking process. It is what’s leftover after curdling milk and separating out the ‘curds’ (milk solids that can be turned into cheese), making ‘whey’ the liquid left behind.

Whey protein is made from waste products

Whey is often a waste product, most commonly created during the cheesemaking process. It is what’s left after curdling milk and separating the ‘curds’ (milk solids that can be turned into cheese), making ‘whey’ the liquid left behind. 

There are many different uses for whey and traditionally, farmers did their best to find a use for this protein-rich by-product – for example, by turning it into whey-based 'cheeses' like ricotta or simply using it to enrich their animal feed. However, in many cases, excess whey was simply dumped into sewers or waterways or spread onto agricultural land. These methods of disposing of whey came with environmentally devastating consequences, as whey’s high sugar and protein content led to the contamination of soils and nearby waterways. Some estimates show that dumping whey is 175 times more damaging to the environment than dumping raw, untreated human sewage.2,4  

Dumping whey into the environment was eventually banned in both the US and Europe, the world’s two largest cheesemakers5 - though some other countries still permit the dumping of whey. This legislation eventually led to a new approach: filtering, concentrating and drying leftover whey to turn it into new products, including the ‘whey protein’ powders and supplements we know today.2,4

Read more about how cheese is made

Is eating whey protein good for the planet?

The invention and popularisation of whey-protein powders and supplements turned leftover whey from waste products into a highly valuable by-product, creating an incentive to use (rather than discard) it. This helped support legal changes to prevent the dumping of whey into the environment - meaning each product sold represented a little more whey that wasn’t polluting our planet.

Illegal dumping aside, whey’s status as a ‘by-product’ means whey protein qualifies as a sustainable and planet-friendly protein source in its own right - even if its origins are in cows’ milk. Since whey protein is mostly made from the by-products of other industries like cheesemaking, very little of the massive carbon footprint associated with producing milk can be attributed to it. Instead, these emissions should be placed at the feet of the product that is the primary driver for dairy farmers to produce the milk - in this case, cheese.4

This means that in life-cycle assessments, raw whey that would otherwise go to waste has a carbon footprint of almost zero. In fact, the only emissions associated with whey protein powders and supplements are those generated in transporting, processing and packaging them, which gives these products a very small carbon footprint. Some studies have even shown that when the cost of producing milk is not considered, whey protein has a smaller greenhouse gas footprint than most alternative and plant-based protein sources, including peas, lentils, chickpeas and grasshoppers.4,6 

Whey protein’s carbon credentials are currently considered so good that if you’re using whey protein to replace some of your usual protein intake from other foods, it’s likely that you’re reducing the carbon footprint of your diet in the process. Coupled with the damage that eating whey helps prevent by leaving less to be disposed of in other ways, even those using whey protein as a supplement to their normal diet might be doing the planet a favour.6 

Whey protein supplements aren’t future-proof

Despite being a huge environmental success story so far, whey protein may not be the best sustainable protein source for protein supplements of the future. For starters, the processing required to refine and dry whey into a protein supplement is energy-intensive, contributing to the environmental footprint of whey protein powders when compared on a level playing field with other dairy products.7

However, by far the greatest impact on the sustainability of whey protein powders and supplements comes from how much of the environmental footprint of milk production can be allocated to these products.2 Huge quantities of whey (and therefore dairy milk) are needed to produce whey protein on an industrial scale. With demand for whey-based protein supplements growing rapidly (~10% per year),8 there is a risk that at some stage in the future demand for whey protein products could outstrip the amount of leftover whey the cheesemaking industry can supply. In this scenario, demand for whey protein could drive increased milk production (with cheese becoming the leftover by-product).

Learn more about the factors that set the price of milk.

So, while whey products are not currently a key driver of milk production, they could become a driver if dairy cheese falls in popularity in the future (or if the growth in demand for whey protein dramatically outstrips the growth in demand for cheese for years to come.) Were this to happen, far more of the environmental costs of raising cattle and producing milk would need to be allocated to whey protein products produced rather than to the cheese left behind, which would dramatically increase whey protein’s environmental footprint and make it a wholeheartedly unsustainable source of protein compared with plant-based alternatives.7 

“Thanks to the way many life cycle assessments assign environmental burdens to different dairy products, whey protein is often determined to have a relatively low environmental impact comparable with some plant-based proteins,” notes Dr Andrew Berardy, Environmental Nutrition, Loma Linda University. “However, future changes in industry practices or rises in consumer demand that increase whey’s economic value would also increase its share of the burdens of milk production, making whey protein a less sustainable choice.”

Alternative protein supplements have a brighter future 

So, for the foreseeable future, we can safely consider whey protein supplements an environmentally friendly option - but things might not stay that way forever. Luckily, today’s world offers plenty of alternative protein supplements from other ingredients. For example, plant-based protein powders exist, using sources such as peas, beans, hemp and soy. Gram for gram, these currently have a similar environmental footprint to whey protein,11 but since they can be produced without needing cows’ milk as a raw ingredient, it’s likely they will prove to be more sustainable in the long run – especially if demand for cheese and other dairy products should fall.

“The lower overall environmental impact of plant-based production systems means that the environmental footprint of plant-based proteins is less sensitive to changes over time than that of whey protein. This means plant-based protein supplements are likely to be the more sustainable choice in the long term.”

 - Dr Andrew Berardy, Environmental Nutrition, Loma Linda University

More recently, insect-derived protein supplements which contain dried, ground whole insects have arrived on the scene. Less is known about the environmental impact of insect-based protein supplements, but initial assessments suggest that they can be more sustainable than whey protein supplements – though this depends largely on how insect farms are set up and what feed the insects are raised on.10

Read more about insect farming and how it can help combat food waste.

Close up photo of crickets
More recently, insect-derived protein supplements have arrived on the scene, which for the most part contain dried, ground whole insects, such as the crickets.

Whey protein is a sustainable protein powder for now, but consider switching 

Right now, whey protein supplements have a very low environmental impact, so you can tuck into your post-workout shake guilt-free. However, you might want to consider switching away from whey protein to a plant-based alternative. In the long term, these are more sustainable protein sources, and so are future-proofed options. Being an early adopter of plant-based protein supplements will also help support this new market and drive the development and improvement of plant-based protein supplements. 

Pea protein is estimated to be between 4x and 7x less greenhouse gas-emitting than milk protein when the production of raw ingredients is compared side-by-side. This clearly shows that if dairy farmers were to start producing milk just to make whey protein products, plant-based products like pea protein would be a far more sustainable choice.

Of course, protein supplements made from dairy alternatives are ]accessible to more people – for example, whey protein may not be suitable for vegans or those who are particularly sensitive to lactose. So, if you’re looking to avoid dairy for health, ethical, religious or personal reasons, plant-based alternatives are highly sustainable alternative protein sources.

Finally, a quick note of caution: don’t go overboard with boosting your protein intake. Eating too much protein can be just as harmful as eating too little, as it can put the health of your bones and kidneys at risk.1

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