Are Green Potatoes Poisonous?

The green itself is not the problem. Purdue University Extension says the green color comes from chlorophyll produced in response to light and that chlorophyll is not toxic, but that light also increases production of a colorless alkaloid called solanine, which rises with the length and intensity of exposure. Iowa State University Extension says potatoes contain two glycoalkaloids, solanine and chaconine, found throughout the tuber but most concentrated in the leaves, flowers, sprouts, green skin and the area around the eyes.

Oregon State University Extension says low levels of glycoalkaloids can cause abdominal pain, diarrhea, sweating, bronchospasm and vomiting, and that higher doses cause acute intoxication with severe symptoms including neurological disorders, rapid pulse, low blood pressure, coma or death. North Dakota State University Extension says solanine tastes bitter and can cause vomiting and diarrhea if you eat enough, and illness or even death in extreme cases, but that because of the bitter taste most people do not eat enough to get sick.

Cut it away or throw it out. Iowa State University Extension says peeling and cutting out green portions removes most of the toxin, but a potato with more extensive greening into the tuber should be thrown away, and tubers that are green beneath the skin should never be eaten. It says cooking does not destroy glycoalkaloids, so sprouted and shriveled potatoes or those with deep green parts should not be used, while firm potatoes with only small sprouts or skin-deep greening can be eaten if the whole sprout and any green-tinged parts are cut away. A 2020 European Food Safety Authority assessment found that for adults, exposure indicates a health concern only in the surveys with the highest intakes.