pescatarianism, dietary practice based on the consumption of fish and shellfish to the exclusion of land-based meats.
Fishing is an ancient pursuit, and many maritime and riverine cultures have developed culinary traditions relying on fish. Numerous long-lived religious traditions eschew the consumption of beef, pork, and other meats while permitting the use of fish. However, pescatarianism as theory and practice is a newer development, the term first appearing in 1991 and combining the Latin root piscis (“fish”) with the English word vegetarian, which dates to 1839.
Pescatarianism can be seen as an outgrowth of 19th-century ethical vegetarianism, with the Vegetarian Society of the United Kingdom allowing associate membership in 1884 to those who ate fish but no other meat. On its face this would seem a contradiction in terms, unless one considers fish and shellfish to lack sentience or the ability to experience pain, questions that scientists and philosophers continue to debate. Typically, pescatarians follow a mostly vegetarian regime resembling the so-called Mediterranean diet, in which fish is eaten daily or several times a week and green vegetables, beans, nuts, grains, and fruit are used extensively, sometimes along with small portions of cheese and other dairy products.
That dietary regime is low in saturated fats and high in antioxidants. The scientifically supported health benefits of pescatarianism are generally similar to those of vegetarianism, since the consumption of large amounts of red meat is associated with heart disease, colorectal cancers, and other lifestyle-related illnesses. Broader claims include less-supported arguments that eating land-based animals is linked to obesity, type 2 diabetes, dementia, and depression.
A common claim for the benefits of a fish-based diet is the presence of omega-3 fatty acids in fish, particularly “oily” fish such as salmon, tuna, and cod. The protein content of these and other recommended fishes, such as haddock and freshwater trout, is high and of excellent quality. Fish of all kinds contain useful minerals such as iron, zinc, and choline and vitamins B12 and D.
The U.S. Food and Drug Administration (FDA) strongly recommends that women eat two or three servings of fish weekly during pregnancy to enhance the cognitive development of the child. Because of environmental pollution that can introduce mercury and other toxins into the food chain, the FDA adds that certain kinds of fish should be avoided, among them shark and swordfish.
Pescatarianism remains an ethical as well as a dietary choice. At a practical level, for those who adapt a pescatarian diet, environmentalists and nutritionists recommend eating fish procured locally (or as locally as possible) as well as from sustainable populations as monitored by the Monterey Bay Aquarium’s Seafood Watch program.