Do You Know Nutrition: Oysters contain a raft of vitamins and minerals
Nov. 29, 2011 at 5:29 a.m.
By Phylis Canion
I love oysters, but do not recall reading an article about them in your column. I recently opened a shell and found a tiny crab. Is that unusual? Is it true that there are certain months to eat oysters? Does the sex of an oyster make a difference? Why do some oysters have a pearl? Guess you can see where I am headed with my questions, so anything you can share would be most appreciated.
Thank you for being such a diligent reader, and you are correct - I have not had an article about oysters. Hope this answers some of your questions.
Oysters are mollusks that breathe much like fish, using both gills and a mantle, which extract oxygen from the water and expel carbon dioxide.
Tiny crabs have evolved to live harmoniously inside the oyster's shell and are sought after by gourmands around the world although the co-habitating crabs are not abundant.
Many years ago, people were advised not to eat oysters in months that did not contain the letter "r." The reason was because these months, May through August, are warm-weather months, and adequate refrigeration methods were an issue. Because keeping oysters chilled is not a problem now as it was in the past, you can eat oysters throughout the year.
The meat of the oyster does become thicker when water temperature cools down. There is no way to identify the sex of an oyster by examining the shell, although they do have separate sexes. An interesting note is that an oyster may change its sex one or more times during its life span because they have gonads that generate eggs, as well as sperm.
Only one in 10,000 oysters will produce a pearl in the wild. A pearl develops when foreign matter becomes trapped inside the shell. The oyster responds to the irritation by producing nacre, which is a combination of calcium and protein. The nacre coats the foreign material and over time produces a pearl. Most pearls produced now are because of human intervention.
And now you are wondering how healthy oysters are for you. Oysters contain a raft of vitamins including C, D, B1, B2, B3, and minerals including calcium, copper, iron, iodine, magnesium, manganese, phosphorous and zinc.
Although I do not recommend fried foods, frying oysters in coconut oil might be a safer option, since raw oysters may carry bacteria, and raw is not recommended for those individuals who suffer from liver disease, immune system disorders or cancer.
In case you are wondering how to tell if an oyster is alive, whether you dig it up or purchase them at a local market - if the shell is open, tap on it with your fingers, and if it snaps shut, it is alive.
Phylis B. Canion is a doctor of naturopathic medicine and is a certified nutritional consultant, email her at firstname.lastname@example.org. This column is for nutritional information only and is not intended to treat, diagnose or cure.