Fish oil supplements that are not linked to increases in bad cholesterol


The Fatty Acid Research Institute (FARI), in collaboration with the Cooper Institute, has published a new research paper on the omega-3 fatty acids EPA and DHA in fish oil and low-density lipoprotein cholesterol (LDL-C).

Omega-3 fatty acids have a long history of being “heart healthy” and are known to lower blood triglycerides (but usually not cholesterol). Recently, however, questions have been raised about one of the two “fish oil” omega-3 fatty acids – DHA (docosahexaenoic acid) – and the possibility that it could actually raise levels of LDL-C, the “bad” cholesterol.

There is good evidence that people with very high serum triglyceride levels (> 500 mg / dL) who are treated with high doses of omega-3, i.e. 4 g / day EPA (eicosapentaenoic acid) and DHA, often have increases in LDL. See -C whether this occurs in the “real world” in generally healthy people who take fish oil supplements for cardioprotection is not clear.

A recent study by the Cooper Center Longitudinal Study (CCLS) and FARI sheds new light on this question.

Investigators used data from 9253 healthy men and women who had at least two checkups at Cooper Clinic in Dallas over a 10-year period. These tests routinely included both blood cholesterol tests and measurements of the Omega-3 Index (i.e., EPA + DHA red blood cell (RBC) levels from OmegaQuant Analytics). Questions about the current use of fish oil supplements were also collected.

With this information, the researchers then asked 2 questions: 1) Did people who started taking fish oil supplements experience increases in LDL-C levels between visits, and 2) did LDL-C levels increase in people whose RBC- Did DHA levels rise between visits? ?

The answer to these two questions turned out to be “no”. Indeed, a 1 unit increase in RBC-DHA levels was associated with a small (1-2 mg / dL) but statistically significant decrease in LDL-C. And this analysis took into account concurrent changes in background use of cholesterol-lowering drugs such as statins. This small decrease in LDL-C is not clinically relevant, but this study shows that the use of fish oil supplements in the general population does not affect LDL-C.

Dr. William Harris, President of FARI and co-inventor of the Omega-3 Index, was the lead author of this study. In his view, “these new results from the CCLS clearly show that people who take fish oil supplements don’t need to worry that they will negatively affect their cholesterol levels, as some have suggested.”

He also found that these results also go well with the conclusions of a recent American Heart Association recommendation on the use of omega-3 fatty acids in the treatment of high triglyceride levels. This comprehensive review found that “there is no strong evidence that DHA-containing prescription omega-3 fatty acid actives, used alone or in combination with statins, increase LDL-C in patients with high triglyceride levels.1”

This large Cooper Clinic study shows that RBC-DHA levels are not linked to higher (actually lower) LDL cholesterol levels, and the addition of omega-3 supplements was also not linked to increases in LDL-C.

Dr. Carl Lavie, cardiologist and medical director, Cardiac Rehabilitation and Prevention Program, John Ochsner Heart and Vascular Institute, New Orleans, LA

Dr. Lavie and colleagues recently published data from 40 studies involving over 135,000 participants in the Mayo Clinic Proceedings, suggesting that the combined dose of EPA and DHA predicted a reduction in key cardiovascular outcomes2. “These new data from the Cooper Institute compliment the cumulative evidence of the safety and effectiveness of omega-3s from food sources and supplements, including the combination of EPA and DHA,” he said.


Fatty Acid Research Institute (FARI)

Journal reference:

Harris, WS, et al. (2020) Elevations in Red Cell DHA Are Not Associated with Elevations in LDL Cholesterol: Longitudinal Study by the Cooper Center. Journal of Clinical Lipidology.


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