Comment by James (MrReductio) on Lifestyle interventions to increase longevity · 2014-12-11T21:56:57.387Z · LW · GW

On this topic, I'm a bit concerned about the argued support for fish eating. RS writes,

'Pescetarians live significantly longer than vegans,[4] lending support to fish consumption.'

But this doesn't follow. Does fish consumption make a difference vs. lacto/ovo vegetarianism? If not, there's no support for fish consumption (but perhaps milk/eggs).

The cited study (from the abstract) seems to rate longevity between each group equally, at least from ischemic heart disease, indicating no effect:

'mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lactoovovegetarians...'

Briefly checking wikipedia and other sites, I can't find significant support for fish-eating vs lacto/ovo vegetarianism, but I'd be interested to hear if I'm missing something.

In addition to pure health issues, I'm also concerned that eating fish will have a high disutility, for you get less kg of meat per death. Brian Tomasik has had a stab at crunching the numbers here: http://reducing-suffering.org/how-much-direct-suffering-is-caused-by-various-animal-foods/.

That treats all animal pain as equal, and finds that farmed salmon results in estimated 200x more suffering than beef per kg. You may want to factor in sentience complexity, indirect effects, pain responsiveness, etc. But the intuitive problem is that it would have to be massively less bad to eat fish vs most mammals to conclude that it's better to eat them, for their relatively lower mass will mean killing many more to achieve the same amount of meat.

Of course, the moral disutility of fish-eating is distinct from its health effects. I only raise it in case people want to consider balancing disutility of production with utility gained from health benefits, if any, from consumption.