Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Avoid anything with Stephen Barrett's name

If you hope to read accurate, objective and well researched information about anything having to do with vitamins, nutrition, or alternative medicine, AVOID any book with Stephen Barrett's name on it. He is so biased that it makes you squirm, he has no credentials in the field, and his information is extremely poorly researched and inaccurate.