Human expectations and the power of the mind may be behind the success of many natural health remedies, according to an Associated Press report on Tuesday about the use and potential risks of alternative medicines.Known as the placebo effect, people sometimes feel better after taking a dummy pill or a faked treatment simply because they expect the treatment will work to improve their condition.  In other words, the brain has the ability to alter physical symptoms, such as pain, anxiety and fatigue.The healing power of the placebo effect was recently demonstrated during tests of a new drug that relieves the symptoms of lupus.