Warning about zucchini toxicity and not eating things that taste horribly bitter

From the zucchini wiki

In August 2015, a 79-year-old German man and his wife ate a zucchini grown by a neighbor. The couple noted the unusually bitter taste. Shortly afterwards, they were both admitted to Heidenheim hospital, apparently with symptoms of a gastrointestinal infection. The wife, who had eaten a smaller portion, survived, while the man died. Toxicological analysis of the meal confirmed the presence of cucurbitacin.[23] Investigators warned that gardeners should not save their own seeds, as reversion to forms containing more poisonous cucurbitacin might occur.[22][23]

Thought this was worth noting for permies.
Many of the supermarket cucumber seed I've grown out has exhibited obvious mutant/regressive traits.

Thanks Jondo.  I would think this might be genetic contamination with a wild species, but would love to know more.  Not clear why saving your own seeds would be particularly dangerous other than isolation problems on a case by case basis.  I remember reading about commercially produced delicata squash seeds experiencing a problem with wild genetics sneaking in years ago.

For people wanting to know more, OP is apparently referencing this Wikipedia entry.  From English-language German press at the time, more detail:

Ludwig A. died in hospital two weeks after eating a courgette stew tainted with poison, Bild reported on Wednesday.

The courgettes were home-grown, and had been given to the pensioner and his wife Inge by neighbours at their Heidelberg home.

But neither the couple nor their neighbours were aware of the dangerous toxins hidden within the plants.

"The stew did taste bitter," Inge A. told Bild. "But we're used to bitter. We grow radishes in our garden, which also have this bitter taste."

But shortly after eating the meal, the couple began to feel unwell.

"I had diarrhea, and had to be sick," 80-year-old Inge said.

For her husband, things were even worse. "His face had turned completely yellow," Inge remembered.

The pair were rushed to hospital, where they were diagnosed with severe poisoning.

80-year-old Inge gradually recovered, and was released from hospital after a few days. However, her husband had ingested so much of the poison that he later died.

Naturally occurring killers

The substance was one of a group of chemicals named cucurbitacins.

These naturally occurring toxins are occasionally found in pumpkins and gourds such as courgettes, and are designed to defend the plants from herbivores.

When ingested by humans, they can cause sickness, diarrhea and in some cases, death.

Cucurbitacins can be recognised by their bitter taste. Any courgette that has a strong unpleasant smell or tastes particularly bitter should be avoided.

"Cucurbitacins are toxic at high levels, but they are so bitter that it is almost impossible for anyone to eat sufficient quantities of the toxins to cause significant harm," advises The Food Safety Hazard Guidebook.

For Inge, this held true. Dr Neubert Pfeufer of the accident and emergency department told Bild: "She had eaten much less of the stew, because it tasted so bitter."

However, 79-year-old Ludwig cleared his plate of poisonous courgette stew, meaning medics were unable to save him.

My interpretation: it takes a person as stubborn as only an ancient old German man can be, to clean his plate of "the deadly bitter" and kill himself thereby.  Even his wife (a) ate less of the dish and (b) threw up the partially-eaten meal, thus saving herself.  

This is not a real risk for normal people with normal stubborness levels. You get one mouthful of regressed bitter vegetable, you're going to spit it out and say "What the ever loving fuck?"

P.S.  In my not so humble opinion, there is something DEEPLY wrong with Inge's radishes!

"The stew did taste bitter," Inge A. told Bild. "But we're used to bitter. We grow radishes in our garden, which also have this bitter taste."

This is not a real risk for normal people with normal stubborness levels. You get one mouthful of regressed bitter vegetable, you're going to spit it out and say "What the ever loving fuck?"

Not everyone can taste bitterness to the same degree https://learn.genetics.utah.edu/content/basics/ptc/

I believe the topic starter was in good faith drawing our attention to this anecdote, but in my experience people often draw the wrong conclusion out of this example. They say, "Don't save your own seeds, just buy a package, it doesn't cost much, so why risk your health?" It's probably the right conclusion for people staying on the amateur side of amateur gardening, but as soon as you start to devote a little more attention to it, you'll discover it's not so hard to train yourself in identifying the risks. You'll learn about F1, and which varieties can cross and which not, for one.
As your overall awareness of the food you eat goes up, your health will benefit.

A relative of mine, still a young man, was diagnosed with cancer a while ago. It didn't look good. He was given the prospect of a long road of chemical treatments, lasting at least year or more. But after only two months into the treatment a scan couldn't reveal any cancer cells anymore. The doctors were amazed, as they never had anyone before where the cancer had disappeared so quickly. They didn't know whether to continue with the chemical treatment or not, and left this decision to the patient. No more treatment was asked for, and the cancer hasn't returned.
This family is very serious about food health, certainly much more serious than I am, but I have no doubt their high awareness of food has helped ward off the cancer. They actually don't grow their own food, but seem to know a lot about the science.

For a healthy body, belonging to a person taking a lot of exercise, it may not make a lot of difference what you eat. You can eat junk and you won't notice. A young man may be able to swallow ten tins of beer and be fine.
But if a body is weak, then it becomes important that you take food with a high nutritional value, to regain strength. If you need to fight off illness, you better eat good food.

My concern with an advice like 'gardeners shouldn't save their own seed' is that we've lost already too much of the link we once had to our own food, and we should restore it. There's a lot to gain by knowing what you eat, and it's easy to see this can save lives.

A quick google search also indicates that as some people age they begin to loose the ability to taste bitter.  At 80 this gentleman may have fit this category.  I've not yet had the experience of tasting cucurbitacins, but from what I've read of them they're in the category of nasty bitter.  I'm planning on doing a little experimental breeding work with a wild cucurbit this summer, so one of the first things I'll do is a tongue dab to make sure I don't have some weird ability to stomach the stuff.  If so that experiment will get nipped in the (taste) bud.

Cucumber beetles are drawn to the bitter taste. The nice mild-tasting ones aren't recognized by them as their natural food. So, it makes sense to grow the nice ones. Avoid the bitterness and avoid bug infestation.

This seems to me to be a very unique case. I wouldn't be surprised if the story gets repeated many times by those wishing to sell commercial seed.

Any story where people die from what they eat, is going to draw attention. About one third of Americans are slowly killing themselves at the dinner table, due to bad food choices and the resultant diabetes and obesity. That's the really big story in food news, but we've all heard it and after a while it becomes white noise.

Investigators warned that gardeners should not save their own seeds, as reversion to forms containing more poisonous cucurbitacin might occur.

Never mind that humans have saved their own seeds for 10,000 years or more!

I have noticed very bitter tasting cucumbers in past gardens.  I've always attributed it to growing conditions and eaten them anyway or even disguised or balanced the bitter in some way and don't remember any intestinal reactions?

Interesting report although it doesn't scare me from saving seeds at all....sort of a silly conclusion if they are saying we should not save any seeds?

I've always thought a small amount of 'bitter' was good for our digestion...a few nibbles before a meal though, not a completely bitter meal.



 

Six years ago i was soo happy that a courgette popped up in my garden. My girlfriend made a soup with it that had the most horrendous taste ever. It was by far the worst taste i ever tasted i washed my tongue for minutes in disgust and could still taste it. After searching the internet we found that if courgettes cross with these courgettes people have for decoration, the next generation go extremely bitter. That’s why these decorative courgettes my neighbour grew had been laying outside last until may. Anything touches it, it’s dead.

Hugo Morvan wrote:Six years ago i was soo happy that a courgette popped up in my garden. My girlfriend made a soup with it that had the most horrendous taste ever. It was by far the worst taste i ever tasted i washed my tongue for minutes in disgust and could still taste it. After searching the internet we found that if courgettes cross with these courgettes people have for decoration, the next generation go extremely bitter. That’s why these decorative courgettes my neighbour grew had been laying outside last until may. Anything touches it, it’s dead.

That probably explains what happened Hugo.  I don't think I've ever seen decorative courgettes here in the US.  Now I'm curious!  How close was your neighbor's garden to yours?

Decorative squash is very common here and yes it tastes foul, (we are next door to Germany :)) No one with normal working taste and smell would ever not notice eating one. I got caught out the first time because some of the decorative squash they grow here looks very similar to small squashes grown in the UK, but I had never come across a decoration only one in the UK! I sell vegetables here and last year I grew Little dumpling winter squash, small single portion green/yellow striped with cream. taste lovely but people didn't want to eat them because they look pretty so they must be poisonous.

http://www.clever-storage.com/food-storage/issues-of-home-economics/beware-of-poisonous-surprises-in-your-garden.html#.XNlweXdFymQ

"the responsible gene has been switched off, it is still there and can be reactivated either by spontaneous mutation or cross-pollination with wild or ornamental species"

I take this as a case of a suggestion being made by authorities to cover themselves. An army marches at the pace of its slowest, and governments must legislate to protect those least able to do so themselves.

It's the pasteurisation argument all over again. If you pasteurise a product and seal it up, nice and tight, against further bacterial colonisation, it can't possibly contain any pathogens. It also can't possibly contain any good microbiota, and it might be transformed into a form less-digestible, but I guess that's where this simile falls apart.

Honestly, this kind of thinking could be remediated by people learning a bit more, as opposed to relying on being told what they need to know by either government or whoever is taking their money. This is vegetal husbandry, and doing it wrong can have consequences. Some of them can be serendipitously delicious, and others obviously lethal.

Education, not legislation, I say.

-CK

Lethal only to someone with an unusual genetic inability to discern unpleasant bitterness levels or wild levels of stoic stubbornness...

I find the story one of those "1 in a billion" type situations, but I also deem it pertinent to know of the possible dangers of not following the body's warnings too.
Most people will spit out anything that taste bitter enough, thus they are heeding the warning sign, many plants use poisons to protect their fruits from being eaten by the wrong animals.

As far as the seed saving issue, I do believe that was a ploy by marketers for the purpose of selling more seeds.
Saving your own seeds is just a small business instead of the huge business the seed companies use.
The methods are the same for both the seed saving gardener and the seed selling company, it is only a matter of scale of the operation that is different.
There may be one important difference though, that of how much knowledge there is involved in the creating of the seeds and how much testing is done of the plants from those seeds.
Hybridization can be very lax or it can be very controlled, most seed companies do things within the confines of strict control while the gardener might not.
Problems can arise at either end of the spectrum, but the problems will be caught by the large seed company before the home gardener might catch them because once the seed company grows the seed, they then grow the plants from those seeds for testing lots of things.

As long as you are aware such problems could arise, there is no reason to not grow your own seeds for the next seasons growing.

Redhawk

One of the joys of tasting every fruit before saving seeds from it, is that over the years I end up selecting for great taste. I love the poisons in squash, beans, cucumbers, lettuce, and potatoes, because they are well behaved. They tell me right up front that they are poisonous.

One season, I threw away the entire production of cantaloupe seed, because I inadvertently planted a poisonous "pocket melon" into the patch. Ooops.

The huge seed companies cannot taste every squash before saving seeds from it. Some years ago, the company that was providing Delicata seed to the world let their crop cross with a poisonous wild relative. Then they put the contaminated Delicata seed into the seed distribution network. It was years before that mess got cleaned up, and Delicata still hasn't recovered it's former reputation for quality.

Greg i don’t recall the details of where my neighbour grew her decorative plant that crossed with mine, but it wasn’t far. Maybe 10 meters, 30 feet.

Thanks Hugo.  I'm planning on crossing zucchini back to a bitter wild ancestor this year and will be doing it in a different forest opening than the one with the garden I may save normal seed in.  I suspect I should be good, and will do taste controls anyway moving forward, just would prefer not to loose everything in that other garden.  My two garden clearings are several hundred feed apart.  

I'm hoping in about 3 or so years to capture all the traits I want and expel all the ones I don't.  We'll see...good fun either way.  

The majority of plans are not edible or palatable to humans. Luckily, most of the ones that are really bad for us, give us a strong signal with bad taste or smell. I think it's highly unlikely that this would happen to a squirrel or a monkey. They would smell it and if that seemed alright, they would taste it. And if it was horribly bitter, that would be the end of it. They might even teach their offspring to avoid it. And they don't grow poisonous plants that look just like the ones they eat.

Nature gives us lots of good clues. I know not to ever touch a brightly colored frog or any other creature that doesn't naturally flee from people. And if I see something that looks really tasty but it's not touched by the deer or birds, that's an indication that maybe nobody can eat this. But just because a bird can eat it, doesn't mean I can. They can deal with a lot more cyanide. There are insects that can live on things that are really harmful to humans, so not much of an indication at all.


I've always found it strange that people will put in an ornamental with a nice tasty looking berry that is poisonous, when they have small children. There are thousands of choices that would be good for the kids. But instead they warn them to never eat anything that grows out in the yard.

Greg Martin wrote:Thanks Hugo.  I'm planning on crossing zucchini back to a bitter wild ancestor this year and will be doing it in a different forest opening than the one with the garden I may save normal seed in.  I suspect I should be good, and will do taste controls anyway moving forward, just would prefer not to loose everything in that other garden.  My two garden clearings are several hundred feed apart.  

I'm hoping in about 3 or so years to capture all the traits I want and expel all the ones I don't.  We'll see...good fun either way.  

The University of Arkansas test fields are separated by a minimum of 1320 feet (1/4 mile) to prevent cross pollination (so the agri professor told me).
I have no idea if that is necessary, perhaps Kola lofthouse will chime in, he is far more experienced in pollination than I am.

Redhawk

Thank you Redhawk.  Definitely further away than I can manage unless I open up another hole in the forest at the far corner of my land.  

I am channeling my inner Joseph right now and guessing that is only needed if one must be 99.9+% free of crosses and that for the rest of us we can keep them apart as far as possible (I'm assuming more than 100' would be needed) and just rogue out the small percentage of undesired crosses by tasting them.  My follow up guess is "it depends".  

Joseph, was I remotely close?

I am guessing, by the way, that 1/4 mile of open pasture or cropland isn't the same thing at all as 1/4 mile of forest between two garden or field plots; I am guessing that the forested space would be a much greater barrier to cross-pollination, so you could probably get away with less.

But I, too, would like to hear more from kola Lofthouse.

-CK

I've seen stories like this a few times.  Sensationalized warnings of growing our own food.

But then I looked and a lot of these stories are of the same handful of individuals, just told differently to look like new examples.

I've stopped paying attention to these stories.  I am more likely to get sick and dead from mishandled fresh veg from the supermarket than from something I grow in my garden.  

r ranson wrote:I've seen stories like this a few times.  Sensationalized warnings of growing our own food.

The reason this one got under my skin is that it is super sensationalized.  It is common for cucerbit vegetables to develop a bit of these bitter compounds, especially in the skins or in the ends.  As others in the thread have pointed out, the amount can go up if the plant is under drought or insect stress, too.  It's very common with cucumbers that you need to peel them, or chop off the ends, to avoid that hint of bitterness, if you don't like it.  The thing is, that little bit of bitterness is perfectly harmless.  This is very much a "dose makes the poison" situation and it's a matter of orders of magnitude, not just ratcheting it up a few percent. People with normal taste receptors will be retching and gagging and spitting long before they get a dose sufficient to make them sick.  

The rational public health warning is "Don't eat things that taste bad."  Advice in the "to be safe, buy commercial seed only" category is from the school of public health that assumes everybody is an idiot and nobody can be trusted to exercise even the simplest discretion.  Obviously that's not the kind of world that we are trying to build here at Permies.com.  

With squash, I get less than 5% cross pollination when small patches are separated by 100 feet in the same field, where there is intense bee activity. That wouldn't be good enough if I were growing poisonous squash in the same field as edible squash. It's perfectly fine with me if I get a little bit of crossing between edible squash. A forest between fields would lower the cross pollination rate even more.

The approximate  mathematics of pollination, is that it's quadratic in nature. If I double the distance between two flowers, I reduce the chances of cross pollination to 1/4th what it would have been at the original spacing. If I ten times the distance between flowers, the chances of crossing are reduced to 1/100th of what they would have otherwise been. Isolation distances in miles are excessive for small scale growers. When mega-seed companies are growing seed for an entire world, it's worth while for them to take extravagant precautions against cross pollination. If they don't, they could recreate the Delicata fiasco. The farm hands are not tasting seeds from every fruit. A human might not even touch the fruits or look at them.

If I were crossing poisonous squash and edible squash, I would intend in the F2 generation, to go into the field and smell/taste fruits from every plant very early in the season. And cull any plants with bad tasting fruits, or that haven't produced fruits yet. Then remove every fruit in the patch, and grow a crop of squash that is pollinated only by pollen from plants that had non-poisonous tasting fruits.

Thank you Joseph...makes great sense to me.  Would you select for only that one trait in the F2 or just start with getting rid of that one first as it's damn nasty and then steer from there in future gens?

I would make getting rid of the poison the highest priority selection criteria.

It might also be possible to do the selection by tasting the cotyledons. I keep telling myself that one of these years I want to do cotyledon tasting/selection on my cucumbers.

This is pretty low on my list of things to freak out about.

However, this does remind me of Fukuoka and (iirc what he says in his book) his practice of tossing vegetable seeds out and seeing what manages to pop up, which he says are often reversions to wilder vegetable ancestors—more bitter and tougher than overbred modern veg. Some folks I know who do this see the bitterness of their survivor veg as a sort of badge of honor. Don’t need no tasty sissy veg around here! So, good to know that this is maybe not the best idea.

 Bitterness is a desired taste among some cultures,  here in the states,   not so much.
I grew up eating regular  cucumbers with the skin on,  my wife peels cumbers,  unless they are "English" cucumbers.
I've never tasted bitterness in a zucchini, actuality bitterness is hard to find in most food in the US.
Even the citrus is usually  only eaten for the sour/sweet.
Citrus rind might be bitter,  grapefruit pith is the only really bitter thing I can think of as mainstream foodstuffs in the states,and most people avoid that part.
Collards, cabbage, turnip, mustard,  kale,  are things people call bitter,  but I just don't sense it that way.
Probably a subculture thing,  Southern,  black or Appalachian, we all eat greens of some sort.
When potentially deadly pokeweed is on the menu, a little bitterness may not even register.
Is Coffee bitter?
Maybe,  but good coffee,  no and bad coffee tastes  sour to me.
Strait coco powder?  
I'll have to try that again, it's been a while since I last tasted it.
The most bitter thing I've ever tasted was unblanched chicory leaf,strait from my front  garden.
The first taste was so bitter it gave me an immediate and persistent headache.
My bunnies eat it like candy, go figure.
Taste isnt a reliable indicator of edibility, but we should question anything that seems off to our taste buds.
Or,  you can do what my baby daughter did.
Before she would let me feed her anything, she shoved it into my mouth with her dimples little fist,  and watched my face intently.
If I seemed OK after a few mouthfuls, she might indulge, but only then.

I had bitter gourd for dinner last night. Yum!

They are a somewhat popular vegetable in India and the rest of the subcontinent, and I understand also in China and Chinese communities around the world. Pretty much everyone hates them at first, but many people suddenly switch to loving them after several tries.

I think more than half of the meals I had in the Philippines during a two month stay, contained some bitter gourd. It is common to mix it with scrambled eggs to chunk up pieces of it that go into pancakes. So you get the sweetness of whatever is being put on the pancake and the bitterness of the gourd. I was not fond of it at first, but when eggs were served up plain, I wondered where the bitter gourd was.

I read a government report that was produced in Manila, saying that the best thing they had found to naturally control diabetes, was a mixture of bitter gourd, turmeric and a curry powder containing many spices. I'm not sure how much of this has to do with the bitter gourd and how much of it has to do with the idea that things containing it, seldom contain sugar, which is otherwise used to excess in many of their foods. Our landlady had diabetes and she eats it with every meal.

In a salad that contained vegetables and little pieces of fruit, the fruit seem to pop more, when mixed with the slightly bitter taste. The gourd was chopped up quite small when used in this way.

Dale Hodgins wrote:In a salad that contained vegetables and little pieces of fruit, the fruit seem to pop more, when mixed with the slightly bitter taste. The gourd was chopped up quite small when used in this way.

Wow, that sounds delicious! Is it a common salad in the Philippines? I've gotta try that!

I'm growing cucumbers for the first time this year and they are near my courgettes and squashes which I usually can't resist saving seed from.  Is there a risk the cucumbers will cross with the squashes and create this bitterness problem?

Hester Winterbourne wrote:I'm growing cucumbers for the first time this year and they are near my courgettes and squashes which I usually can't resist saving seed from.  Is there a risk the cucumbers will cross with the squashes and create this bitterness problem?

I don't believe cucumbers and squash will no.

I've had some bitter cucumbers very randomly as other cucumbers from the same plant at the same time were fine, and I can say they were NOTHING like the bitter squash I have tasted, not even close. I made the squash into a lasagna (before tasting them obviously) so they were perhaps less than 10% of the ingredients and the entire thing was totally inedible.

I didn't suggest we should avoid seed-saving cucurbits.
Just something to be mindful of.
Not everyone is equally sensitive to bitter tastes.
I've known many organic gardeners who truly believe that 'Bitterness = Healthiness' without exception.

Always nice to see science and journalism misrepresented as a conspiracy though.

Rebecca Norman wrote:

Dale Hodgins wrote:In a salad that contained vegetables and little pieces of fruit, the fruit seem to pop more, when mixed with the slightly bitter taste. The gourd was chopped up quite small when used in this way.

Wow, that sounds delicious! Is it a common salad in the Philippines? I've gotta try that!

I'll be there in 3 weeks. This time for 3 months, unless my fiance gets a Visa sooner. I will send pictures and a description of how it's done.

I have hated almost every salad I've ever had in my life. I don't like things that are the consistency of snot, so not a big dressing fan. Nova also dislikes stuff like that. She mixes things so perfectly, that all of the tastes balance out and you don't need any sort of slime smeared on it.

My mom used to hate it when I would describe her food to people. :-)

 Zucchini or Gourgette are in the genus Cucurbita and species pepo. They are insect pollinated as are all plants in the Cucurbitaceae family. Generally these plants will cross only with others in the same species. The species C. pepo includes, besides zucchini: some pumpkins, acorn, crookneck, scallop, spaghetti, and the small striped and warted gourds (the decorative gourds found in stores around Thanksgiving here in the U.S.) I'll bet the zuchinni in the story had genes from this type of "gourd", or similar, which is not edible, although I have not heard of it being poisonous.
Susan Ashworth in her book "Seed to Seed" recommends that any Cucurbits grown for seed should be 1/2 mile from any other in the same species. I have saved seeds from"Bennings Green Tint" Paddy Pans (my favorite) for many years now. Also saved one of each of the moschata and maxima species, each year different ones, but all Winter squash. Fortunately no one within 1/2 mile grew any other squash or pumpkins.
 A guy I know grew what he hoped would be a giant pumpkin from home grown seed someone had given him, in a mound of composted horse manure. It was a giant all right, but not a prize winner, as it was green and elongated, probably a cross with a Hubbard, which is also C.pepo.  C. pepo squash are one of the most difficult for saving seeds, because there are so many extreme differences among them.
 BTW; Cucumbers are Cucumis sativus, not even in the same genus as squash, and will not cross with them.
 I highly recommend Susan Ashworth's book, if you are interested in saving seeds.