Omega 3 fish oil essential fatty acids derived from seafood and cardiovascular diseases.

Omega 3 fish oil essential fatty acids

The Scientific Committee of the American Heart Association published a scientific statement on omega-3 fatty acids from seafood, including sea fish, freshwater fish and shellfish, as well as nutritional supplements In the context of cardiovascular disease.

The omega-3 fatty acid content in seafood is not uniform. The highest content of omega-3 fatty acids is found in fatty fish derived from cold water, such as salmon, anchovies, herring, mackerel, tuna, and sardines. On the other hand, lower content is found in shrimps, lobster, scallops, tilapia, and cod.

Content of Omega-3 fatty acids in selected fish.

Common fish species	DHA + EPA, mg / 4oz. (~ 113g) i
Salmon, Atlantic	2,400-1,200
Anchovies, marinated	2,400-2,300
Mackerel from the Atlantic Ocean and the Pacific	2,100-1350
Tuna albacore	1,700
Sardines from the Atlantic Ocean and the Pacific	1,600-1,100
Oysters, the Atlantic Ocean	1,550
Trout, fresh water	1,100-1,000
Tuna: white (albacore), canned	1,000
Clamery, squid	750
Pollock from the Atlantic	600
Crab	550-200
Fish, freshly frozen	350
White Clams	300-200
Light tuna, canning	300-150
Catfish	250-100
Code from the Atlantic and Pacific	200
Seaweed and hake	200
Lobster	200
Crayfish	200
tilapia, fresh water	150
Shrimps	100
Shark	1,250
Swordfish	1,000
King Mackerel of the Atlantic Ocean	450

Research has been conducted on the health benefits and risks of seafood consumption and dietary supplements

An online publication in circulation summerized the available research evidence for omega-3 fatty acid effects from seafood origin on cardiovascular health. 

Omega-3 fatty acids are integrated into cell membranes and have a wide range of proven physiological effects. The available research evidence for their effects from a seafood source is more limited than that in supplemental effects.

Among the effects are: beneficial changes in the function of ion channels in the heart, positive effects on beta- 1 adrenergic receptors and other receptors, effects on intracellular signaling pathways, intracellular communication, as well as increased membrane leaks. 

Higher intake of seafood was also associated with other parameters, including lower heart rate, slower atrioventricular transmission, lower likelihood of abnormal resapitalization and optimal heart rate variability. 

These effects are associated with a lower risk of ventricular arrhythmia and sudden cardiac death. Compared to non-consumption or low intake of fish, consumption of 1 to 2 servings of fish per week was associated with a lower risk of sudden cardiac death. Higher consumption does not contribute to a further reduction in risk.

• Higher seafood consumption was associated more strongly with a lower risk of fatal coronary heart disease than non-fatal events.

• Fish oil supplements, a source of omega-3 fatty acids, have been found to significantly improve endothelial function and increase arterial elasticity. The effectiveness of seafood omega-3 fatty acids in their effect on endothelial function and arterial elasticity is less clear and further studies are needed.

• Seafood has been reported to have a protective effect on the heart by preventing platelets, which cause thrombosis.

• Omega-3 fatty acids have been reported to lower triglycerides (fats) in the blood.

• Consumption of fatty fish has been reported to increase the HDL- 6 particles in patients with coronary heart disease. Similar findings were found for dietary supplements.

• There was an inverse association between seafood intake and omega-3 fatty acids and the incidence of new cases of coronary heart disease in a healthy population. The effect is greater when seafood consumption replaces unhealthy foods.

• Evidence from studies supports a regular combination of seafood diets to reduce the risk of  stroke.

Concerns about the presence of mercury in seafood

Experts explain that higher concentrations of mercury are found in large prey fish, such as sharks and swordfish. Mercury has neurotoxic effects on all mental processes in fetuses and children. 

However, the study evidence suggests that the benefits of consuming 1 to 2 servings of fish per week by adults outweigh the risks, especially when consuming a variety of seafood.

It is important to note that the American Heart Association recommended consuming omega-3 fatty acids at an average of 250 milligrams per day. It is sustainable and can be obtained by consuming fish, including fish grown in ponds, 2-1 times a week instead of other sources of animal protein. 

Increased seafood consumption can be achieved by a wide choice of seafood, including fatty fish from different geographical regions.

Conclusions of the Advisory Committee of the American Heart Association

Some evidence supports the recommendation to consume 1-2 times a week non-fried seafood, especially fish with higher omega-3 fatty acids, because of their benefits of reducing the risk of cardiovascular disease, including lower risk of coronary heart disease, and stroke.

The dietary guidelines for Americans recommend consuming 8 ounces of seafood (about 226 grams) or 2 servings per week, which are sustainable. Seafood is recommended as a good source of protein, vitamin D, vitamin B12, and omega-3 fatty acids.

The dietary guidelines for Americans include seafood as a component of a healthy diet, and as a component of  a dietary approaches to stop hypertension and as a component of the Mediterranean diet. All recommendations are consistently associated with a lower risk of coronary heart disease.

In conclusion

The current research evidence strongly supports the recommendation that seafood should  be an integral component of a heart-healthy diet pattern.