Biomedical science is far from being exact and along with medical care suffers from the vastness of the unknown. This can lead to conflicting advice and confusion for patients and the public at large. Although officials at the Centers for Disease Control (CDC) criticize the finding of a European study
that low salt diet increases risk for death from heart attack and stroke and does not prevent high blood pressure, the study does highlight a lack of agreement and controversy regarding the control of salt in the diet. Another example
comes from the Fred Hutchinson Cancer Research Center in Seattle where they found men with the highest blood levels of D.H.A., an omega-3 fatty acid, were 2.5 times more likely to develop high grade, aggressive prostate cancer than those with the lowest blood D.H.A. levels. This is in direct contradiction of the evidence that omega-3 fatty acids help to prevent artery and heart disease. Of course, each of these studies involve groups of people and there are sure to be variations among individuals that might explain these contradictions. And there might be factors in the design and observations of the studies that explain the contradictions. With time more of the unknowns will be identified.