Many fish contain specific oil, Omega 3 fatty acid, which is proving to have impressive health benefits.  Research proves that Omega 3 fatty acids reduce the risk of heart attack and breast cancer which are two compelling reasons for women to pay attention.

The easiest way to characterize the essence of recent scientific studies is to think of Omega 3 fatty acid as the "good oil" and Omega 6 fatty acid as the "bad oil." Omega 3 is plentiful in cold-water fish (salmon, tuna, trout, mackerel, sardines, herring, and yellow tail) and flax seed oil.  Lesser amounts are present in soy and canola oils and in wheat germ.

Omega 6 is the predominant fatty acid in polyunsaturated vegetable oils such as corn and safflower oil. To advance down the road to better health, imprint these lists in your memory, eat fish twice a week and reduce your intake of bad oils. These relatively minor lifestyle changes appear to be reasonably reliable life extenders.

In a study involving patients with breast cancer at the UCLA School of Medicine (reported in the August, 2004, Journal of the National Cancer Institute), corn and safflower oils were found to favor the growth of mammary tumors, while Omega 3 fish oils inhibited mammary tumor growth.
In recent studies on the heart, researchers at the University of Washington in Seattle found that individuals who ate the equivalent of four 3 ounce servings of salmon per month were 50 percent less likely to experience primary cardiac arrest.  Findings indicate the Omega 3 fatty acids found in cold water fish increases the levels of fatty acids in blood cell membranes.  This reduces the clumping of blood platelets and coronary spasm.  Even small increases in the percentage of Omega 3 total fatty acids can substantially lower the risk of heart attack (and as the percentage of Omega 3 increases, the risk decreases accordingly).

If you are vegetarian or do not savor fish then try taking about a tablespoon of flax seed oil daily. It is okay to use flax seed oil in salad dressings, however do not cook with it as heat destroys some of its nutritional properties. 
Omega 3 fatty acids also inhibit adult-onset diabetes, some skin diseases, and rheumatoid arthritis. If you decide to take an Omega 3 nutritional supplement, be sure to choose a reputable manufacturer and a good quality (high purity grade) of supplement.

A COMPARATIVE VIEW OF OMEGA 3 FATTY ACIDS IN FISH

(more than 1.0 grams)
Salmon, Anchovy, Herring, mackerel, sardines, Atlantic bluefish, Most shellfish, Pacific oysters and Squid.

(0.5 to 0.9 grams)
Rainbow trout, Striped bass, Shark, Sea bass, Snapper, Clams, Lobster, Scallops, Crab, Mussels, Shrimp

(less than 0.5 grams)
Carp, Cod, Grouper, Pacific halibut, Ocean perch, Mahi mahi, Orange roughy.