Fish has been an important source of protein for humans throughout recorded history.
Fish, meat and vegetariansMeat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat, but it may also describe other edible organs and tissues. The term "meat" is used by the meat packing industry in a more restrictive sense—the flesh of mammalian species (pigs, cattle, etc.) raised and prepared for human consumption, to the exclusion of fish and poultry.
Vegetarians don't eat fish, and consider that fish is meat, since it is the flesh of an animal. Vegans or strict vegetarians refrain from consuming any animal products, not only meat and fish but, in contrast to ovo-lacto vegetarians, eggs, dairy products and all other animal-derived substances.
However, pescetarians eat fish and other seafood, but not mammals and birds. The Merriam-Webster dictionary dates the origin of the term "pescetarian" to 1993 and defines it to mean: "one whose diet includes fish but no meat." Pescatarians may consume fish based solely upon the idea that the fish are not factory farmed as land animals are (i.e., their problem is with the capitalist-industrial production of meat, not with the consumption of animal foods themselves). However, this is an incorrect assumption, as fish are often raised in artificial environments, with the same types of cramped, unnatural, and often unsanitary conditions that land animals are raised in. Some eat fish with the justification that fish have less sophisticated nervous systems than land-dwelling animals. Others may choose to consume only wild fish based upon the lack of confinement, while choosing to not consume fish that have been farmed.
A 1999 metastudy combined data from five studies from western countries. The metastudy reported mortality ratios, where lower numbers indicated fewer deaths, for pescetarians (fish eaters) to be 0.82, vegetarians to be 0.84, occasional meat eaters to be 0.84. Regular meat eaters and vegans shared the highest mortality ratio of 1.00. The study reported the numbers of deaths in each category, and expected error ranges for each ratio, and adjustments made to the data. However, the "lower mortality was due largely to the relatively low prevalence of smoking in these [vegetarian] cohorts".