“One example of the Prevention Paradox occurs in the first weeks when people with high LDL or “bad” cholesterol start taking fish oil supplements. Researchers found that using fish oil (which is high in omega-3 fatty acids from mackerel, herring, tuna, halibut, salmon, cod liver, and even whale blubber) is associated with a wide range of changes in LDL levels across the population, from down by 50 percent to up by a whopping increase of 87 percent.6 Researchers have dug deeper to demonstrate that people who supplemented their diets with the so-called healthy fats found in fish oil actually had a greater negative change in their cholesterol levels if they were carriers of a gene variant called APOE4. Meaning that supplementing with fish oil may be good for some and very bad for other people’s cholesterol levels depending on which genes they’ve inherited.”