The green color that sometimes appears on potatoes is caused by chlorophyll, the same natural pigment that gives leaves their green appearance. Chlorophyll itself is harmless. However, when potatoes are exposed to light, they may also produce higher amounts of naturally occurring compounds called glycoalkaloids, particularly solanine and chaconine. These substances help protect the potato plant against pests, but consuming excessive amounts can be harmful to humans.

Eating potatoes containing elevated levels of these compounds may cause nausea, vomiting, abdominal discomfort, and diarrhea. In more serious cases, people may experience headaches, dizziness, confusion, or other neurological symptoms. Fortunately, severe poisoning is uncommon, especially when potatoes are stored and prepared correctly. Nevertheless, the possibility of illness is why food safety experts recommend paying attention to green discoloration, extensive sprouting, and unusual bitterness.

So, can removing the green sections make a potato safe? If the discoloration is limited to a very small area, generously cutting away the affected portion and peeling the potato can reduce exposure. However, this doesn’t guarantee safety because harmful compounds may also be present beneath the surface. Potatoes that are extensively green, heavily sprouted, damaged, or bitter should be discarded. Cooking methods such as boiling, baking, and frying cannot be relied upon to eliminate these compounds completely.

Preventing the problem is relatively simple. Store potatoes in a cool, dry, dark, well-ventilated place, away from direct sunlight. Avoid leaving them on bright kitchen countertops for extended periods, and check them regularly for sprouts, damage, or discoloration. Buying only the amount you expect to use within a reasonable period can also help reduce waste. If someone develops significant symptoms after eating suspect potatoes, they should seek medical advice or contact a poison center.

The important lesson is that green potatoes aren’t automatically poisonous, but their appearance can signal increased levels of potentially harmful substances. When a potato has extensive green discoloration or an unusual bitter taste, throwing it away is the safest choice. A small precaution in the kitchen can help prevent an unnecessary health problem.