Here is a recap of the stories that appeared last week atScience-Based Medicine, a multi-author skeptical blog that separates the science from the woo in medicine.  

The problem of nonmedical exemptions to school vaccine mandates (David Gorski) There’s overwhelming evidence that the existence of nonmedical (religious and philosophical) vaccine exemptions results in more children remaining unvaccinated, creating a public health risk. The easier it is to get exemptions, the more parents will take them. Arguments from parental rights and religious beliefs complicate the issues; eliminating all nonmedical exemptions is unrealistic in the present political climate, but we can hope to limit exemptions and make them harder to get.  

News flash! Doctors aren’t all compliant pharma drones! (David Gorski) A new study shows that doctors are anything but minions of Big Pharma. They are only half as willing to prescribe new drugs if the research was funded by industry and are twice as willing to trust data from NIH-funded trials. If anything, they may be more skeptical of Big Pharma than necessary.  

The Obesity Paradox (Harriet Hall) Obesity is almost always bad for health, but normal weight patients with diabetes and heart disease are more likely to die than overweight patients. This so-called “paradox” is really just the expression of a complicated situation. Obesity should not be over-simplified or categorically demonized, and we needn’t try to force all patients into the same mold of an ideal BMI range of 20-25.  

XMRV Chronic Fatigue Syndrome Update (Steven Novella) The XMRV virus was reported to cause CFS, but subsequent studies disagreed. Two of the original positive studies were retracted. In a new study, scientists on both sides of the debate collaborated to address all the criticisms of earlier studies and reached a consensus: the XMRV hypothesis is dead and buried.  

Iron supplements for fatigue (Scott Gavura) Pharmacy customers complaining of fatigue often ask for advice about iron supplements; instead, they should be advised to get a medical assessment. Supplementation without a diagnosis can be useless or even dangerous. Iron metabolism and iron supplement products are reviewed.  

Frightening Breast Cancer Patients with Bad Science (James Coyne) A study claims to show that maladaptive coping styles alter circadian rhythms and thereby increase mortality rates in breast cancer patients. The study design is flawed and the article is not transparent enough for independent evaluation of its data. Its conclusion is probably wrong. Believing these claims is potentially harmful: patients who don’t get early psychosocial intervention are made to feel responsible for the progression of their disease.