Q: I have a family history of cardiovascular disease and at one time had high blood pressure and high cholesterol. I have been controlling my blood pressure and cholesterol with exercise and diet. I was able to reduce my total cholesterol to 170. Since adding 3 grams of EPA/DHA fish oil, my LDL has increased to 230. I was also diagnosed with a low thyroid and have started taking thyroid medication. My doctor said that the fish oil could be increasing my LDL. My TG/HDL ratio is 1.2, and my CRP is normal. I did read on the Internet that fish oil can elevate LDL. Taking the fish oil has helped me in many ways -- better mood, better insulin areas, improved energy levels, better appetite, etc. Have you seen elevated LDLs from taking fish oil and should I continue to take the fish oil? My doctor suggested I stop taking the fish oil.
Q: Fish oils can elevate LDL levels because there is a competition between the reduction of LDL receptors on smooth muscle cells (which would increase serum LDL levels) and a reduction of cholesterol synthesis in the liver (which would decrease LDL levels). Depending on which of these two events occurs first can give a transient increase in LDL levels. However, the fish oil also reduces the serum TG levels, thus making the LDL particles far less atherogenic since they become larger as the TG levels drop. I would consider reducing your fish oil dose to about 1.5 grams of EPA and DHA per day while your new thyroid medication is stabilizing (this will take about three months). Then take you cholesterol test again, and I believe your LDL will be much improved. Then consider going back to the 3 grams of EPA and DHA per day.