Ethics of Whey Protein: Net Negative or Justifiable for Environmental Vegans?

I personally do not consume any animal products (including whey protein powder), but wanted to share some points from a discussion I recently had.

(I know whey protein is technically not vegan, as it’s an animal product, but there’s an argument that it might be animal-welfare neutral or even environmentally beneficial.)

Here are the key points:

So, on one hand, buying whey protein creates demand for whey processing, which could be environmentally positive. Without this market, more whey would likely be wasted, causing significant environmental harm.

On the other hand, the money ultimately supports the cheesemaking industry, which profits from animal exploitation. Even if buying whey doesn’t directly increase suffering in the short term, it helps sustain an industry that does.

Is it obvious that whey is a net negative? Could someone who’s vegan for environmental reasons justify consuming whey protein? I haven’t found any solid estimates comparing the environmental damage averted by consuming whey to the social cost of indirectly supporting cheesemaking.

Would love to hear some thoughts on this!