Oyster

Oyster

The word oyster is used as a common name for a number of distinct groups of bivalve molluscs that live in marine or brackish habitats. The valves are highly calcified.

Some kinds of oysters are commonly consumed, cooked or raw, by humans as a delicacy. Other kinds, such as pearl oysters, generally not eaten by humans, are harvested for the pearl produced within the mantle.

As food:

Oysters in the early 19th century were widely consumed by mostly working class individuals. As their demand grew, oyster beds began to dry up, and the prices for these bivalves continued to rise. Today, oysters are considered a high-end food. Most varieties of oysters can be consumed, and many types can be eaten raw or "on the half-shell." In general, smaller oysters are best served raw, while larger varieties, such as the Pacific oyster, are used in cooked recipes. Oysters can be steamed, roasted or grilled,stew, and they are commonly fried, particularly in southern sections of the United States.

In the Philippines, a local oyster species called Tikod Amo, is a favorite seafood source in Southern part of the country. Because of its taste, it commands good prices in the market.

Nutrition:

Oysters are an excellent source of zinc, iron, calcium, and selenium, as well as vitamin A and vitamin B12. Oysters are low in food energy; one dozen raw oysters contains 110 kilocalories. Oysters are considered most nutritious when eaten raw.

Dietary supplements may contain calcium carbonate from oyster shells, though no evidence shows this offers any benefits beyond what calcium may offer.

Benefits and Caution:

Oyster is boiled, steamed, fried, or enjoyed on the half shell. Some people avoid eating oysters because of their high cholesterol content.

They're high in protein:
Oysters are a decent source of low fat protein with six medium oysters containing about six grams of protein. The protein found in oysters is high in quality and is usually easier to digest than land based forms of protein such as chicken and beef.

They may really be an aphrodisiac:
A study presented to the American Chemical Society revealed that oysters contain two amino acids that raise levels of the sex hormones testosterone and estrogen. Higher levels of testosterone generally have a positive effect on sexual response, although it's less clear-cut whether higher estrogen levels are important for libido. Nevertheless, there may now be some scientific basis for calling oysters aphrodisiacs.

They're high in zinc:
Oysters are the richest source of zinc of any food around. Zinc plays an important role in wound healing and in maintaining a healthy immune system. It also may help to prevent night blindness. Zinc deficiencies are common in alcoholics and people with kidney disease. They're also a good source of other minerals including calcium, magnesium, and iron.

A good source of vitamins:
Oysters are a good source of vitamins including vitamins A, B, C, and D. Seafood is one of the few natural dietary sources of vitamin D, a vitamin that's showing new promise for disease prevention.

Not So Good about Oysters:
Oysters are relatively high in sodium making them a poor choice for people with heart disease or hypertension. They also may contain a bacteria called Vibrio that can cause illness when oysters are eaten raw, particularly in those with a weakened immune system. The best way to reduce this risk is to broil or grill them until well done. They're also not a good source of omega-3's as are some forms of seafood.

Read More at Wikipedia
Recipe for Oyster  Link1     Link 2