n − 3 PUFAs in cardiovascular disease

Many large, randomised clinical trials and some meta-analyses have shown that treatment with n − 3 polyunsaturated fatty acids (n − 3 PUFAs) is associated with consistent benefits on cardiovascular (CV) events, primarily due to a reduction of coronary and CV deaths in patients with coronary heart disease. At variance with such evidence, some clinical trials and meta-analyses showing a neutral effect of n − 3 PUFAs have been recently published, raising concern about the consistency of the evidence on the CV benefits of n − 3 PUFAs. Several methodological and clinical aspects of these recent trials deserve to be considered. Indeed, the low rate of events or the overoptimistic expectations of the benefit of n − 3 PUFAs used for sample size calculation led to an inadequate statistical power of several studies. The improvement of background medical therapy, serum baseline levels of n − 3 PUFAs, and different doses and/or treatment duration might have downplayed the benefit of n − 3 PUFAs. Similarly to old drugs shown to be effective some years ago, it is possible that the benefits of treatment with n − 3 PUFAs are not as great in a modern CV prevention strategy so rich in many effective drugs compared with past trials testing CV drugs when less effective therapies were available.