The exact role of different types of dietary fat and the best approach to prevention in cardiovascular disease has been somewhat controversial. However, the level of controversy among experts is much less than that being generated in the public by outliers and contrarians. Since cardiovascular disease remains a major source of morbidity and mortality, it’s important for the public to be kept up to date as the science progresses. We now have decades of research that have explored many of the nuances in this area and can make some solid recommendations.
A recent review helps clarify where we are in terms of treating cholesterol for the primary (before an event has occurred) and secondary (after an event has occurred) prevention of vascular disease, including heart attacks and strokes.
One of the issues that may have previously been controversial is the role of LDL (low density lipoprotein – the “bad” cholesterol) in vascular disease. But we now have enough evidence to confidently say that LDL does lead to increased clogging of the arteries which contributes to the risk of heart attacks and strokes. Further, lowering LDL is effective in reducing vascular risk. And further still, medications, such as statin drugs, that lower LDL are both statistically and clinically effective in reducing vascular events and prolonging survival.
They point to the published evidence which shows that statin drugs are more effective than any other current intervention at lowering LDL, and therefore should be considered first line therapy. As always, this should be combined with lifestyle changes, which are independently effective. However, it’s often difficult to get patients to comply with lifestyle change, and they can take a long time to take effect, and so immediate use of statins should be done in the meantime.
They point out that 40% of the American public have so-called metabolic syndrome (a combination of obesity, hypertension, and insulin resistance) and only 21% get sufficient exercise every day. Also, lifestyle changes are effective even in people who are already on statins.
They further recommend that statins should be started at high dose. Often we start medications at the low end of the dose range in order to assess for tolerance and effectiveness and then titrate up the dose as needed and as tolerated. This is a good generic approach. However, they point out that the evidence clearly shows that statins, such as rosuvastatin and atorvastatin, are more effective at the higher dose, and people tend to stay at the dose they are initially prescribed. Therefore, at a population level, prescribing high doses initially may be more effective.
Given the evidence, other interventions should be considered adjunctive or secondary. There is good evidence for aspirin in secondary prevention, for example, but for primary prevention the evidence is less clear and individual decisions need to be made.
The authors are less enthusiastic about newer drugs, such as ezetimibe and evolocumab. The evidence for their efficacy is not as strong and the overall benefit may be less than statins. They worry that these newer drugs are being overused, perhaps because of their novelty, when the older statins are supported by more robust evidence.
What about HDL – omega 3 fatty acids or good cholesterol? Evidence for the efficacy of omega 3 remains fairly weak, which the authors suspect is because of the widespread use of statins obscuring any benefit. There is possibly one exception – the REDUCE-IT trial showed that icosapent ethyl reduced major cardiac events by 25%.
As always, the purpose of this article is not to make personal medical recommendations, but rather to educate the public about the state of the science. Consult your physician for individual recommendations. There is a lot of misinformation on social media and in the public about dietary fat and cholesterol-lowering medications. It’s good to know that the science has continued to chug along, and an increasingly clear picture has emerged. LDL is a risk factor for vascular disease. The evidence supports a heart-healthy diet, regular exercise, control of blood pressure, avoiding smoking and limiting alcohol. Further, drugs that lower LDL are clearly effective. The benefits of supplementing HDL are less clear.
Like all medications, statin drugs may have side effects, but not necessarily. Don’t be scared off of trying them if it is clinically appropriate to do so. If you have not discussed managing your vascular risk factors with your doctor, now is a good time to do so.
