Mental "Exercise" Linked to Faster Dementia Progression Reuters While staying mentally active in old age has been linked to a delayed onset of dementia, seniors who engage in such brain "exercise" may actually have a faster rate of decline once Alzheimer's is diagnosed, researchers reported Wednesday. Americans Blind to the Obesity Epidemic HealthDay A Harris Interactive/HealthDay poll finds 30 percent of those overweight think they're normal size. Differences Found in Individuals' Immune Systems CNN Humans’ immune systems are not as different from person to person as previously thought, according to scientists at the Fred Hutchison Cancer Research Center reported Wednesday. Abbott's Diet Drug Study Renews Calls for U.S. Ban Reuters A study funded by Abbott Laboratories offered more detailed evidence that its weight-loss drug Meridia increases heart risks, prompting renewed calls by consumer advocates and others to pull the drug from the market. Direct-to-Consumer Genetic Testing: Road Map or Tarot Cards? Science-Based Medicine (blog) Over the past several years, diagnostic tests have emerged that appear to be science-based and offer gene-level insights into your health. Just a swab of saliva and a credit card get you reams of information on your genetics, traits, and risks of dozens of diseases. How could this information be anything but helpful? Doctors: Michael Douglas' Cancer Therapy Is Grueling USA Today (feature) Actor Michael Douglas says he is upbeat in spite of a diagnosis of advanced throat cancer, which he discussed Tuesday on The Late Show With David Letterman. 5 Big Health Issues on Campus NPR (blog) With students streaming back to campuses, we wondered what health concerns are topping the agenda now.