The Effect of Heat on Marine Fish Oils

Fish oils are highly unsaturated. Consequently, they are very unstable and begin to oxidize immediately upon extraction from the fish. Exposure to heat, metals, oxygen and light increases the oxidation process and can lead to rancidity and serious health complications.

Heat Effects

• Fish oils exposed to heat can pose serious health risks.

  Fish oils should never be heated. Heat increases oxidation, which causes the oils to become rancid in a process that converts the oil to harmful lipid peroxides. Lipid peroxides trigger free radicals that eat up and neutralize the body's stores of vitamin E and other antioxidants. They can also damage fatty cellular membranes, further increasing health dangers.

Health Complications

• Consumption of rancid fish oils has been linked to some degenerative diseases.

  Many people report mild side effects from taking healthy fish oils. These normal symptoms include belching, fishy breath, diarrhea and upset stomach. Blood thinning and bruising are secondary side effects often seen in those who consume a higher than average dosage of fish oils.

  However, consuming oxidized (rancid) fish oils can raise the risk of very serious problems, such as atherosclerosis, blood clots, cancer and other degenerative diseases.

Recommendations

• Purchase fish oils contained in dark brown glass bottles.

  Cold slows oxidation. Refrigerating fish oil capsules is imperative. Fish oil capsules should be stored in dark brown glass in order to reduce exposure to light. Choose fish oil brands that contain vitamin E to prevent oxidation and rancidity. And, finally, never ingest rancid fish oils.