Go Nuts and Go Extra Virgin Olive Oil!
Mediterranean Diets Reduce Blood Pressure
See related article, pp 69–76
The high population burden of hypertension and elevated blood lipids and glucose, risk factors for cardiovascular disease (CVD), not only emphasize the need for available efficient treatment, but also underscore the need for effective prevention. Above all, effective lifestyle-based prevention is essential because population-wide strategies to shift the entire distribution of risk cannot solely rely on prescription medication. The most reliable form of scientific evidence on effective prevention is produced by randomized, controlled trials because spurious causality and biases are reduced with this type of study design. Thus, results from successful randomized, controlled trials involving dietary interventions are important because these have the greatest potential to influence dietary guidelines as well as healthcare policies and practices with the ultimate aim of maintaining or improving the public health.
Although highly desirable, dietary interventions trials are not without limitations. First, they cannot be tested in a double-blind, placebo-controlled manner. Although proper randomization of treatments minimizes allocation bias, balancing both known and unknown prognostic factors—a potential pitfall of observational studies—dietary interventions suffer from lack of blinding, crossover between studied diets, and nonadherence. Second, if the desired effect of a dietary intervention is meant to be explored independent of a potential weight loss, the different treatment regimens need to be isocaloric and the participants should maintain their body weight, sometimes a task difficult to accomplish. Third, because dietary interventions are both costly and require an extended period to produce results, they often suffer from a too short duration, are performed in high-risk populations, or are restricted to secondary prevention. Additional limitations may concern the fact that a change in consumption of one food often alters the consumption of other foods.
In this issue Hypertension, Doménech et al1 report …