It’s a bitter truth: What tastes good is not always healthy. Nature had planned it differently, not expecting that there could be an abundance of food. The idea of evolution: Sweet provides a lot of energy, which humans need for life and growth, while bitter should be avoided, often even indicating toxic substances, so that humans and animals will avoid ingesting it. Plants use this to drive away their predators, and thus ensure their survival. Alkaloids such as nicotine, the atropine from the deadly nightshade, and even strychnine, which occurs naturally in the nux vomica, are harmful or even deadly to humans. Additionally, solanine, which occurs in green potatoes, can cause nausea and vomiting.