Potato

Scientific Name(S): Solanum tuberosum L

Common Name(S): Potato, white potato

Botany: The potato is a weedy plant recognized for its tuberous growth and valued as a commercial foodstuff. Potatoes are propagated vegetatively from the underground runners of the plant from the "eyes" of the potato.

History: Potatoes have been cultivated since 500 BC; the Central and South American Indians were probably among the first to select hardy cultivators of the potato as a food staple. Despite the Spaniard introduction of the plant into Europe in the late 1500s, the tubers did not become a popular food source until the 17th century because of church and mythological concerns about the toxicity of the plant. Once accepted, potatoes were widely disseminated to Germany, other parts of Europe and Russia.

By the 17th and 18th centuries, potatoes formed such a significant part of the Irish diet that intake for adults exceeded 8 Ibs/day. However, the potato blight destroyed more than 80% of the crop, resulting in the starvation of more than 3 million Irish.

Traditional uses of the potato include: Using raw potato poultices for arthritis, infections, boils, burns and sore eyes; brewing potato peel tea to soothe edema or bodily swelling; and drinking raw potato juice to soothe gastritis or stomach disorders. (No clinical data exist to support these uses.)

Uses of Potato:

Potatoes are rich in starch and may affect glycemic control and insulin levels of diabetic persons.

Side Effects of Potato:

Ingestion of damaged or green potatoes can result in GI and neurological disturbances. Exposure to potato dust has demonstrated a high incidence of work-related respiratory and general symptoms.

Toxicology: The toxicity is related to the presence of the steroidal solanum alkaloids. The solanum glycosides, such as solanine, produce gastrointestinal disturbances including nausea, vomiting, diarrhea and hemolytic and hemorrhagic damage to the gastrointestinal tract. Solanine may also cause an exanthemous syndrome which, together with gastrointestinal and neurological symptoms, may be severe enough to be fatal. Solanine is not destroyed in the cooking process. Ingested solanine is relatively less toxic than that administered parenterally. The biological half-life of solanine is 11 hours.

Even though human fatalities due to the consumption of green potatoes have been reported periodically, proof that solanine was the causal agent has not been firmly established. Concentrations of 38 to 45 mg/100 g solanine have been found in potatoes implicated in human fatalities, compared to 3 to 66 mg/100 g in fresh, healthy potatoes. A level of 20 mg/100 g is generally considered the upper limit of safety.

Solanine has been specifically implicated in the development of fetal malformation in livestock. Solasodine is teratogenic in hamsters when given orally; in some experiments in which pregnant hamsters were fed potato extracts, more than one-quarter of the pups exhibited malformations. Other studies have found that neural tube defects in hamsters may be caused by the solanidine triglycosides, alpha-chaconine and high-dose solanine.

The association between the ingestion of blighted potatoes by pregnant women and subsequent fetal deformities in offspring has not been well established, but remains a growing concern. Anencephaly may have been associated with the ingestion of potatoes infected with Phytophora infestans in women in the Congo.

Potatoes also contain contain a variety of compounds that may potentially interfere with biological systems. These include cholinesterase inhibitors, invertase inhibitors and protease inhibitors; all may have evolved as part of a defense mechanism toward invading microbes.

Because potatoes may be high in bacteria and fungi counts, persons exposed to potato dust have demonstrated a high incidence of work-related respiratory and general symptoms; in one survey, 46% of those assessed had respiratory symptoms secondary to exposure to potato dust.

Potatoes may affect glycemic control and insulin levels; therefore, diabetic persons may eat the vegetables as appropriate starch equivalents.

Summary: The potato remains an economically and socially important food product. While its ingestion is safe, persons should refrain from eating damaged or green potatoes which may have elevated levels of solanum alkaloids that have been associated with a variety of types of toxicity.