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View Full Version : Kidney beans and rhubarb poisonous??



Yenni
07-18-2007, 11:55 AM
This article http://www.livescience.com/health/060704_bad_raw_food.html states that Raw (sprouted) kidney beans and rhubarb are poisonous.


Any truth to this? If so, what else should I look out for?:confused:

DavidZaneMason
07-18-2007, 03:15 PM
Some info:

On Kidney Beans (from Wiki):

Toxicity

Before they are eaten, the raw bean seeds should be boiled for at least ten minutes to degrade a toxic compound - the lectin phytohaemagglutinin - found in the bean which would otherwise cause severe gastric upset. This compound is present in many varieties (and in some other species of bean), but is especially concentrated in red kidney beans. Although in the case of dry beans the ten minutes required to degrade the toxin is much shorter than the hours required to fully cook the beans themselves, outbreaks of poisoning have been associated with the use of slow cookers whose low cooking temperatures may be unable to degrade the toxin. Sprouts of pulses high in haemaglutins should not be eaten. Red kidney beans, especially, should not be sprouted.

On Rhubarb:

Toxic effects

Rhubarb
Rhubarb flower.Rhubarb leaves contain poisonous substances. Rhubarb leaves contain oxalic acid, a corrosive and nephrotoxic acid that is abundantly present in many plants. The LD50 (median lethal dose) for pure oxalic acid is predicted to be about 375 mg/kg body weight,[citation needed] or about 25 g for a 65 kg (~140 lb) human. While the oxalic acid content of rhubarb leaves can vary, it averages about 0.5%,[citation needed] so a rather unlikely five kilograms of the extremely sour leaves would have to be consumed to reach an LD50 dose of oxalic acid. However, the leaves are believed to also contain an additional, unidentified toxin.[4] In the petioles, the amount of oxalic acid is much lower, especially when harvested before mid-June (in the northern hemisphere), but it is still enough to cause slightly rough teeth.[citation needed]

The roots and stems are rich in anthraquinones, such as emodin and rhein. These substances are cathartic and laxative, which explains the sporadic abuse of Rhubarb as a slimming agent. Anthraquinones are yellow or orange and may colour the urine.[citation needed]

-Always keep things in perspective. Out of the many 1000's....perhaps millions of varieties of edible plants....there are only a handful that are toxic. Even the few listed above would have to be consumed in rather large amounts to even cause stomach upset.

-I hope these references are helpful.

-David Z. Mason