Instruct: Classify the given review into positive or negative sentiment.
Query: Warning regarding over dose of flax seed

I was very enthusiastic regarding this book. The recipes were very well done and I did find great relief from menopausal symptoms. However, while traveling I relied on several "portable" flax seed foods for my daily "portions" for estrogen. Shortly thereafter, I was found to have a very irregular heart beat. I have no history of heart problems and, in fact, am an athlete. Research into flax seed showed that more than 2 ounces or 60 grams a day should not be taken internally. It can cause increased respitory rate, gasping, staggering, or convulsions. In early history, it was used as a heart medication - indicating a heart link. There is no warning in the book and in fact, the book encourages higher doses. Please use extreme caution in using these flax seed foods. Use only small amounts per day. There are beneficial amounts (very low doses), but it is toxic in small amounts as well if consumed regularly. There are no warnings on the flax seed bags in stores.