# Did you know Kidny Beans are poisonous ? **URL:** \ **Category:** Cafe Society\ **Created:** [February 13, 2012, 3:15am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664 "2012-02-13T03:15:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 13, 2012, 3:15am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/1 "2012-02-13T03:15:54Z")
Learned something today. I was reading a mystery and poisoning from Phytohaemagglutinin was part of the plot. I can[t recall ever seeing raw kidney beans at any markets. They’re always in a can. I understand now why. Makes me wonder how primitive people figured out that Kidney beans could be eaten. You’d think after getting sick they’d give up trying long before attempting to cook them. Turns out that poison is in a lot of different beans. > **[Phaseolus vulgaris](https://en.wikipedia.org/wiki/Phaseolus_vulgaris)** > > Phaseolus vulgaris, the common bean, is a herbaceous annual plant grown worldwide for its edible dry seeds or green, unripe pods. Its leaf is also occasionally used as a vegetable and the straw as fodder. Its botanical classification, along with other Phaseolus species, is as a member of the legume family, Fabaceae. Like most members of this family, common beans acquire the nitrogen they require through an association with rhizobia, which are nitrogen-fixing bacteria. > The common bean has a lon... > [@](#): > > The culprit of this intestinal mayhem is the toxin Phytohaemagglutinin (Kidney Bean Lectin) found in quite a few beans, though kidney beans have the highest amount. For example, raw kidney beans contain between 20,000 and 70,000 hau (hemagglutinating units) while white ones contain a third of that and broad beans only contain 5-10% of the figure. The operative word here is ‘raw.’ Once they are cooked properly, they are detoxified. > > Phytohemagglutinin, the sinister chemical that goes along with all the healthy ones that make kidney beans great, makes you very ill, starting with nausea and then onto extreme vomiting and finally ending in waves of diarrhea. You need to ingest a large amount of the compound but the bad news is that _only three beans can be considered a high enough amount!_ [http://www.environmentalgraffiti.com/news-kidney-bean-poisoning](http://www.environmentalgraffiti.com/news-kidney-bean-poisoning) ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [February 13, 2012, 3:19am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/2 "2012-02-13T03:19:51Z")
Per the article, the toxin is present in dried beans, and dried red kidney beans are pretty common. Really, you have to fail to boil them for 10 minutes for this to be a problem; as the article states, you might have that happen if you use a slow cooker where the water doesn’t get to boiling, but you should be fine otherwise. ---
**Author:** ![Zulema](https://avatars.discourse-cdn.com/v4/letter/z/db5fbb/32.png) [@Zulema](https://boards.straightdope.com/u/Zulema)\ **Post date:** [February 13, 2012, 3:22am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/3 "2012-02-13T03:22:45Z")
They sell bags of dried kidney beans at the store and I think they’re dried from raw though I couldn’t definitely find out. The cooking directions do mention that they are toxic if not properly cooked. ---
**Author:** ![Jamicat](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jamicat](https://boards.straightdope.com/u/Jamicat)\ **Post date:** [February 13, 2012, 4:04am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/4 "2012-02-13T04:04:03Z")
How does one eat raw dried kidney beans without cooking the crap outta them? I cooked them for 2 hours alone, drained, and then another 2 hours with the rest of the ingredients for chili…and they were still a little aldante, till’ after a few more reheats over a few days then the chili was at max consistency. :rolleyes: ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [February 13, 2012, 4:10am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/5 "2012-02-13T04:10:10Z")
So [bean flour](http://www.google.com/products/catalog?rlz=1T4GGHP_enUS420US420&q=bean+flour&gs_upl=0l0l1l2142047lllllllllll0&um=1&ie=UTF-8&tbm=shop&cid=4978007773831160588&sa=X&ei=wYw4T4QQo_HSAeaLkbYC&ved=0CEUQ8wIwAQ#) is not directly from ground up dried beans? ---
**Author:** ![Muffin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muffin/32/4341_2.png) [@Muffin](https://boards.straightdope.com/u/Muffin)\ **Post date:** [February 13, 2012, 4:19am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/6 "2012-02-13T04:19:29Z")
[Correctomundo](http://www.google.com/url?sa=t&rct=j&q=%22kidney%20bean%20flour%22&source=web&cd=5&ved=0CEUQFjAE&url=http%3A%2F%2Fwww.wiloludjournal.com%2Fpdf%2Ffodsci%2F2008%2F27-32.pdf&ei=OI44T6a9Darj0QGZkpHaAg&usg=AFQjCNHr4DtuoNSl5oOdfsc-1Z3znfhF7w). They boil the shit out of the kidney beans before drying and milling them. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 13, 2012, 4:55am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/7 "2012-02-13T04:55:51Z")
Funny that they don’t explain why they boil the beans at 100 C for 30 minutes. That would kill any toxins but they should have mentioned that. It does sound like bean flour is totally safe. I can’t recall ever using dried Kidney beans. I’ll open a can of kidney beans and put in my pot of chili. Otherwise, I rarely eat them. I prefer dried pinto beans or dried Black-Eyed peas when I fix a big pot with ham hocks. ---
**Author:** ![Eureka](https://avatars.discourse-cdn.com/v4/letter/e/74df32/32.png) [@Eureka](https://boards.straightdope.com/u/Eureka)\ **Post date:** [February 13, 2012, 11:56am UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/8 "2012-02-13T11:56:44Z")
Yes, but I found out because kidney beans were used as a poison in a mystery I was reading, and it boggled my mind, so I Googled it. ---
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [February 13, 2012, 12:02pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/9 "2012-02-13T12:02:19Z")
> [@Eureka](#): > > Yes, but I found out because kidney beans were used as a poison in a mystery I was reading, and it boggled my mind, so I Googled it. According to the references I can find the poisoning consists of a few hours of vomiting and diarrhea, not pleasant for sure but for most not that big a deal. Is that what it was used for in the plot? ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [February 13, 2012, 12:36pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/10 "2012-02-13T12:36:22Z")
I’m amazed at a lot of things that end up as common food. **Bitter Almonds** are poisonous if not treated pro[perly, and I have read that our current almonds are the result of breeding out the poisonous almonds – so that, at first, people were eating a food potentially more dangerous than kidney beams. > **[What are Almonds? (with pictures)](https://www.delightedcooking.com/what-are-almonds.htm)** > > Almonds are the edible seeds of a tree found originally in Asia and North Africa. Contrary to popular belief, almonds are not... **Olives** aren’t poisonous, but they are bitter and sour until pickled. Our ancestors had strong stomachs to be able to stand them in the first place. > **[皇冠428428娱乐娱城-(成都)有限公司](https://www.foodrin.com/home.php)** > > 皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城皇冠428428娱乐娱城 I’m convinced thyat a lot of food choices are the result of making the best of the situation when you’re just above starvation. That explains how _hakarl_ came to be (It may be an ammoniacal in-the-ground-fermented Icelandic shark, buit at least after that treatment it won’t kill you) and _lutefisk_ (fish that tastes of lye isn’t appealing to modern tastes – if you’re not from Minnesota – but it was a way of preserving fish for the lean times) and _Casu Marzu_ (maggotrs got into the cheese and ruined it – but you can still eat it, and them) ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [February 13, 2012, 1:00pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/11 "2012-02-13T13:00:50Z")
I’ve often read that the ancient Greek sect of [Pythagoreans](http://en.wikipedia.org/wiki/Pythagoreans#Vegetarianism) had a taboo against eating beans, but the reasons given have always sounded nutty to me. I’d never thought of it before, but maybe the real reason has something to do with beans’ toxicity? ---
**Author:** ![Muffin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muffin/32/4341_2.png) [@Muffin](https://boards.straightdope.com/u/Muffin)\ **Post date:** [February 13, 2012, 1:48pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/12 "2012-02-13T13:48:28Z")
Legumey. ---
**Author:** ![Malden\_Capell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/malden_capell/32/5274_2.png) [@Malden\_Capell](https://boards.straightdope.com/u/Malden_Capell)\ **Post date:** [February 13, 2012, 1:52pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/13 "2012-02-13T13:52:01Z")
It sounds very plausible to me, **Thudlow Boink** , although I have often wondered why, instead of putting religious taboos on food, they simply didn’t say ‘don’t eat or you’ll feel sick for days/die’… ---
**Author:** ![Terraplane](https://avatars.discourse-cdn.com/v4/letter/t/74df32/32.png) [@Terraplane](https://boards.straightdope.com/u/Terraplane)\ **Post date:** [February 13, 2012, 3:09pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/14 "2012-02-13T15:09:39Z")
> [@Thudlow\_Boink](#): > > I’ve often read that the ancient Greek sect of [Pythagoreans](http://en.wikipedia.org/wiki/Pythagoreans#Vegetarianism) had a taboo against eating beans, but the reasons given have always sounded nutty to me. I’d never thought of it before, but maybe the real reason has something to do with beans’ toxicity? I don’t think so, kidney beans are a New World crop. I’m not sure if any of the edible Old World beans have the same issue. ---
**Author:** ![Cat\_Whisperer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cat_whisperer/32/4839_2.png) [@Cat\_Whisperer](https://boards.straightdope.com/u/Cat_Whisperer)\ **Post date:** [February 13, 2012, 3:37pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/15 "2012-02-13T15:37:34Z")
[Castor beans can kill an adult human if you eat just a few beans.](http://www.usatoday.com/tech/columnist/aprilholladay/2006-03-20-poison-fish_x.htm) You know, FYI. 🙂 ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 13, 2012, 4:26pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/16 "2012-02-13T16:26:34Z")
The book I read was by Dick Francis and at least 50 people at a dinner party got sick for a day or two. It nearly ruined the reputation of the main character who was a chef. If someone was in bad health already then I could see dehydration as potentially life threatening. But, generally the effects would just make you ill for a couple days. > [@grude](#): > > According to the references I can find the poisoning consists of a few hours of vomiting and diarrhea, not pleasant for sure but for most not that big a deal. > > Is that what it was used for in the plot? ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [February 13, 2012, 4:46pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/17 "2012-02-13T16:46:52Z")
> [@Jamicat](#): > > How does one eat raw dried kidney beans without cooking the crap outta them? > > I cooked them for 2 hours alone, drained, and then another 2 hours with the rest of the ingredients for chili…and they were still a little aldante, till’ after a few more reheats over a few days then the chili was at max consistency. :rolleyes: The description I’d read was that you’d get someone who’d throw the beans in a crockpot with water, turn it on low, and let it cook all day or so. The water never got to boiling but the beans were cooked. I do tend to use my crockpot for cooking dried beans but I turn it on high and there is boiling going on. I have read - and seen for myself - that acids like tomatoes slow the cooking rate of dried beans, so I’d probably pre-cook kidney beans until done or nearly so before adding them to chili. (Example: About 2.5 hours to cook dried chickpeas in a crockpot on high. Dried chickpeas in a recipe for kabuli chana, containing tomatoes, mango powder, and pomegranate powder? 14 hours on high. Not kidding.) ---
**Author:** ![Archergal](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Archergal](https://boards.straightdope.com/u/Archergal)\ **Post date:** [February 13, 2012, 5:11pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/18 "2012-02-13T17:11:55Z")
Aren’t there really a lot of foods that are widely eaten that have to be treated/cooked to be safe to eat? Like [taro](http://en.wikipedia.org/wiki/Taro). I’m pretty sure the humble potato [can’t really be digested in raw form](http://www.livestrong.com/article/523041-the-risks-of-eating-raw-potatoes/). It makes you wonder how people ever figured this stuff out to begin with. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [February 13, 2012, 5:35pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/19 "2012-02-13T17:35:49Z")
> [@Archergal](#): > > Aren’t there really a lot of foods that are widely eaten that have to be treated/cooked to be safe to eat? > > Like [taro](http://en.wikipedia.org/wiki/Taro). > > I’m pretty sure the humble potato [can’t really be digested in raw form](http://www.livestrong.com/article/523041-the-risks-of-eating-raw-potatoes/). > > It makes you wonder how people ever figured this stuff out to begin with. It literally is a case of “What does not kill me makes me stronger”, because, y’know, back when they were figuring this stuff out, you were likely to die of starvation if you didn’t find another food source. ---
**Author:** ![Archergal](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Archergal](https://boards.straightdope.com/u/Archergal)\ **Post date:** [February 13, 2012, 5:38pm UTC](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664/20 "2012-02-13T17:38:20Z")
Good point. [Next page](https://boards.straightdope.com/t/did-you-know-kidny-beans-are-poisonous/612664.md?page=2)