On May 4, 2011, a team of European researchers published the results of a study measuring the effects of amounts of sodium excreted in the urine with incidences of increased blood pressure and cardiovascular disease. The final conclusion reached from their study data indicated that lower sodium levels in the urine were associated with increased incidence of death from cardiovascular disease.
Attention from the media was immediate; this study's conclusion seemed to fly in the face of traditional medical wisdom that a low sodium diet promoted better control of blood pressure and decreased risk of cardiovascular disease. And the media is correct in making this information available to the public.
The public--you and me--need to make use of our critical thinking skills when considering research studies and their conclusions. Not all studies are equal--some have few participants, others have many participants but are not representative of the general population. Some studies take place over short periods of time. And it's always good to keep in mind that the yardstick of scientific research is that the results must be replicable by at least one other study.
Some of the problems associated with the European study include only measuring sodium output in the urine, not sodium intake in the diet, a small group of study participants for this type of research, average age of participants was 40 at the beginning of the study, and only white Europeans were study participants. Other variables not measured during the research include weight, physical activity levels and diet.
As consumers of information, we should view single studies such as this one with interest, but not consider the conclusions reached to be set in scientific stone.