[content warning: moralizing about food]

A lot of people I know argue that the ideal diet for animal rights supporters is veganism– not consuming any animal products. Most of them do consume honey, because of the minimal harm honey causes to bees. I would like, in this post, to argue that we should instead be aiming for lacto bivalvegetarianism.

Bivalveganism– eating bivalves like oysters, clams, mussels, and scallops– has already become quite popular among effective altruist vegans. Because they are sedentary, the bivalve nervous system is extraordinarily simple, much simpler than an insect’s; unlike most animals, they do not have a central nervous system. As far as we know, bivalves do not have any form of nociception. While it is controversial whether creatures capable of nociception feel pain (and thus whether we need to worry about the suffering of insects), as far as I know there is not serious debate about the fact that creatures that do not have nociception do not. Bivalves are considered animals because they don’t photosynthesize or have rigid cell walls; however, these are clearly not morally relevant traits. On everything morally relevant, bivalves are essentially a form of plant.

My support of dairy consumption is more controversial.

According to Brian Tomasik’s How Much Direct Suffering Is Caused By Various Animal Foods?, a kilogram of milk produces the equivalent amount of suffering to 1.68 hours of a beef cow’s life. A kilogram of milk is equivalent to about a quart of milk, three cups of ice cream, or a fifth of a pound of cheese.

Tomasick’s essay did not weight his assessments based on how morally relevant the animal is, presumably because those are sufficiently complicated that everyone who reads his article would disagree. Nevertheless, I think it is possible that I, a human being, get enough pleasure out of a fifth of a pound of cheese to outweigh less than two hours of a suffering cow, and thus it is the correct decision from a utilitarian perspective for me to eat cheese. Depending on how much you value cows and, of course, how much you enjoy cheese, similar calculations may be true for you.

This is particularly true when you consider health benefits. All vegans need to supplement with vitamin B12; most should also supplement with vitamin D and iodine, and some should supplement calcium and iron. With the exception of iron, Vitamin-D-fortified milk is a good source of all those nutrients. (In comparison, bivalves provide only B12.) For this reason, the mostly vegan person can gain significantly more benefits from milk than an omnivore would, which makes the case for consuming dairy considerably stronger for people who are otherwise vegan.

I’ve heard some people object that veganism is much easier to explain than lacto bivalvegetarianism, so being vegan is better for PR. However, I actually think consuming some animal products might be better PR, because lacto bivalvegetarianism isn’t a very common choice. When someone asks “why do you drink milk but not eat eggs?”, that’s an opportunity to bring up the fact that different animal products cause wildly different amounts of suffering, and that by eliminating chicken they can prevent a lot of animal suffering. When someone asks “I thought you were a vegetarian, why are you eating clams?”, that’s an opportunity to talk about the evidence that various animals feel pain.

In conclusion: I think the case for eating bivalves is very strong, and the case for consuming dairy products is strong enough that I currently eat as much cheese as I want, although reasonable people can disagree about how much to weight cows.