Symptoms include nausea, diarrhea, vomiting, stomach cramps, burning of the throat, cardiac dysrhythmia, nightmares, headache, dizziness, itching, eczema, thyroid problems, and inflammation and pain in the joints.

In more severe cases, hallucinations, loss of sensation, paralysis, fever, jaundice, dilated pupils, hypothermia, and death have been reported.

[citation needed] Some studies show a correlation between the consumption of potatoes suffering from late blight (which increases solanine and other glycoalkaloid levels) and the incidence of spina bifida in humans.

Solanum glycoalkaloids have been shown to inhibit cholinesterase, disrupt cell membranes, and cause birth defects.

Experiments show that solanine exposure opens the potassium channels of mitochondria, increasing their membrane potential.

[9] Potato, tomato, and eggplant glycoalkaloids like solanine have also been shown to affect active transport of sodium across cell membranes.

[10] This cell membrane disruption is likely the cause of many of the symptoms of solanine toxicity, including burning sensations in the mouth, nausea, vomiting, abdominal cramps, diarrhea, internal hemorrhaging, and stomach lesions.

When the plant's stem, tubers, or leaves are exposed to sunlight, it stimulates the biosynthesis of solanine and other glycoalkaloids as a defense mechanism so it is not eaten.

[citation needed] Though the structures of the intermediates in this biosynthetic pathway are shown, many of the specific enzymes involved in these chemical processes are not known.

However, under stress, such as the presence of a pest or herbivore, they increase the synthesis of compounds like solanine as a natural chemical defense.

[14] This rapid increase in glycoalkaloid concentration gives the potatoes a bitter taste, and stressful stimuli like light also stimulate photosynthesis and the accumulation of chlorophyll.

[16] The largest concentration of solanine in response to stress is on the surface in the peel, making it an even better defense mechanism against pests trying to consume it.

[22] Most home processing methods like boiling, cooking, and frying potatoes have been shown to have minimal effects on solanine levels.

[citation needed] There was a mass solanine poisoning incident in 1979 in the U.K., when 78 adolescent boys at a boarding school exhibited symptoms after eating potatoes that had been stored improperly over the summer.

[31] Potatoes naturally produce solanine and chaconine, a related glycoalkaloid, as a defense mechanism against insects, disease, and herbivores.

[citation needed] When potato tubers are exposed to light, they turn green and increase glycoalkaloid production.

[34] The United States National Institutes of Health's information on solanine strongly advises against eating potatoes that are green below the skin.

Food science writer Harold McGee has found scant evidence for tomato toxicity in the medical and veterinary literature.

[36] Dorothy L. Sayers's short story "The Leopard Lady", in the 1939 collection In the Teeth of the Evidence, features a child poisoned by potato berries injected with solanine to increase their toxicity.