8. Elderberries
The dark purple elderberry has long been used as a natural cold remedy, packed with antioxidants and vitamin C. But cooked or raw, this tiny berry conceals a rather sinister secret. All other parts of the elder plant, including the stem, seeds, leaves, bark, and roots, produce a cyanide-inducing glycoside that is toxic to humans.
Ingesting a sufficient quantity can cause nausea, vomiting, abdominal cramps, and even coma or death in extreme cases.
These berries must be cooked or properly processed to neutralize the toxins. Unfortunately, those seeking a quick cold cure by eating raw elderberries from the shrub have suffered poisoning effects, learning the hard way that moderation and proper preparation is key.