Fish Oil Vs. Omega-3

Omega-3 fatty acids are beneficial to the body in many ways. Although there are several fatty acids within the omega-3 classification, there are three main types of omega-3 fatty acids related to nutrition: alpha linolenic acid (LNA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Each of these fatty acids has its own specific benefits, however, DHA and EPA also are the two major components of fish oil. An understanding of each of the omega-3 fatty acids, as well as their differences and similarities, may better define their roles within the body.

Alpha-linolenic Acid (LNA)

Alpha-linolenic acid, or LNA, is derived from plants. It is contained in certain vegetable oils, including canola and soybean oils. LNA is also found in flaxseeds, English walnuts and linseed (or flaxseed) oil.
Although LNA is not a component of fish oil, research has demonstrated similarities between LNA and fish oil regarding cardiovascular health. In a meta-analysis (or summary of studies) performed by Brouwer and colleagues in 2004, a distinct correlation between LNA and lowered risk for cardiovascular disease was illustrated.
One of the greatest differences between LNA and the other fatty acids is the fact that it is derived from plants. EPA and DHA, on the other hand, are derived from the fatty tissue of fish.

Docosahexaenoic Acid (DHA)

Docosahexaenoic acid, or DHA, is one of the two main components of fish oil. The primary source of DHA intake is in the ingestion of fatty fish or by supplementation with fish oil capsules.
In particular, DHA is believed to play a key role in the normal function of the adult brain. According to a study published by Horrocks and Yeo in 1999, DHA can improve the ability to learn, whereas a deficiency of DHA is strongly correlated to learning disabilities. Additionally, DHA reduces triglycerides, lowers the risk of blood clots and decreases the chance of cardiac arrhythmias. The consensus of most research indicates that DHA is the most active component of fish oil.

Eicosapentaenoic Acid (EPA)

Eicosapentaenoic acid, or EPA, is the other major component of fish oil. According to the University of Maryland Medical Center, EPA is usually found in cold water fish, such as salmon or tuna, or in fish oil supplements.
Extensive research has been performed on the role of EPA within the body. A study published by Barberger-Gateau and colleagues in 2008 demonstrated a significant decrease in depression in elderly people taking EPA. Moreover, in tandem with DHA, EPA can also lower blood pressure and cholesterol (particularly triglycerides), as well as decrease the risk for cardiovascular disease.

American Heart Association Recommendations for Omega-3 Fatty Acids

Within the recommendations put forth by the American Heart Association in 2002, there are specific suggestions for dietary intake. It is important to note that the AHA's recommendations are largely based on the ingestion of fish oil, as LNA is easily obtained through the use of vegetable oil in the diet. Moreover, the AHA has divided the general population into the categories of those without cardiovascular disease, those with documented cardiovascular disease, and those with elevated triglycerides.
For people with no evidence of cardiovascular disease, the American Heart Association recommends eating fish at least two times per week. Oily fish are preferred, as they contain more of the beneficial oils. The AHA also suggests eating foods containing alpha-linolenic acid, such as flaxseed and walnuts.
Those in whom cardiovascular disease has already been diagnosed should take in approximately 1 g of DHA and EPA each day. The preferred method of intake is by way of ingesting fish with higher proportions of oils, though supplementation with fish oil capsules may be considered pending physician approval.
If a person has been diagnosed with elevated triglycerides, the AHA recommends supplementing with 2 to 4 g of DHA and EPA each day. This amount of fish oil is commonly provided via capsules under a physician's supervision.

Conclusions

There are three main omega-3 fatty acids important to human nutrition: LNA, DHA and EPA. While LNA is derived from plants, the oils from fish tissue are the best dietary sources of both DHA and EPA. Each of the omega-3 fatty acids have been shown to reduce the risk of cardiovascular disease. In addition, the components of fish oil can improve adult brain function, reduce triglycerides and decrease depression. Although they have both similar and separate roles within the body, the omega-3 fatty acids have all been proved to be beneficial to health.