Archive for Monday, August 23, 2010


Hidden toxins: Beware these summer dangers for children, pets

August 23, 2010


There’s cyanide lurking in your apples.

And those juicy peaches, too.

Your potatoes can be deadly if you’re not careful. Same goes for the leaves on those beautiful, tart rhubarb stalks. And that amaretto flavoring in your morning coffee? It has killer origins.

In fact, several edible plants have poisonous parts or parts that can turn poisonous in the wrong conditions. Here’s a look at a few of the most dangerous of the edibles.

• Rhubarb leaves, kale, spinach and other greens. Yes, dark, leafy greens are fabulous for you — full of vitamins A and C, iron and calcium — but too much of the wrong kind can make you sick.

Those leaves contain a chemical called oxalic acid that, in humans, can cause several undesirable symptoms, including burning of the throat, diarrhea, vomiting, difficulty breathing, convulsions, coma and death.

The leaves of edible rhubarb stalks have the highest concentration of oxalic acid of any of the greens commonly grown in northeast Kansas. But don’t count out the prized spring vegetable on an inedible technicality, says Jennifer Smith, horticulture extension agent for the Douglas County-Kansas State Extension Office, 2110 Harper St.

“Rhubarb leaves are not as poisonous as people think. They will make you sick if you eat a bunch, but it’s like if you eat a bunch of spinach, it’ll make you sick, too,” Smith says. “Rhubarb leaves, and especially the oldest leaves, contain the highest concentration of (oxalic acid).”

According to, it is estimated that it would take 11 pounds of rhubarb leaves to kill a 145-pound person. Those leaves would contain about 24 grams of oxalic acid. Before it would kill you, you’d likely get too ill to finish all 11 pounds of the leaves, though.

That said, too much oxalic acid in one’s everyday diet can create kidney stones and aggravate symptoms of diseases such as gout and rheumatoid arthritis.

• Pits, seeds and almonds. The pits of stone fruits like peaches and apricots, the seeds of apples and certain types of almonds all contain amygdalin, a compound containing sugar and cyanide, a highly toxic substance that robs those who ingest it of their ability to carry oxygen in their blood, thus killing them by asphyxiation.

“I think someone figured out it’s about a cup of apple seeds that could possibly kill an adult,” says Ward Upham, an extension associate at Kansas State Research and Extension in Manhattan. “And so it’s not something you need to be overly concerned with unless you just eat the seeds themselves. If you happen to eat one, it’s not going to cause any problems.”

That is, unless you ingest seeds or pits on purpose, as was the case in the late 20th century, when the cancer drug Laetrile went on the market.

“Laetrile was used to treat cancer probably back in the ’70s, and it was derived from (apricot) pits,” Upham says. “And it wasn’t something that was mainstream — it was one of those, kind of on the side type things, and the active ingredient was cyanide.”

Another direct ingestion example is the Italian amaretto liqueur, which is often made from bitter almonds that would be toxic otherwise. That’s because bitter almonds differ from the common almonds found in a grocery stores. Our everyday almonds are safe thanks to their genetics, Upham says.

“Almonds are a type of peach that has undergone a mutation so that the pits, or the nuts inside those pits, no longer contain cyanide,” he says.

• Potatoes and tomatoes. Though potatoes and tomatoes themselves aren’t toxic (unless you eat green potatoes), their plants are.

“Every once in a while you actually get fruit on potatoes, they’re little small, probably the size of a quarter maybe at most, those are toxic,” Upham says. “And all parts of a tomato except the fruit are toxic.”

Those fruits on the potato plant contain high amounts of the alkaloid solanine, which is also the chemical found in green potatoes. Alkaloids are naturally occurring chemicals and the more famous members of the family include caffeine, nicotine, quinine and morphine.

“I don’t think anyone has ever been killed by it, but it can make you sick,” Upham says.

Similarly, the leaves and stems of the potato’s nightshade cousin, the tomato, contain an alkaloid called tomatine that can do nerve damage and cause severe stomach distress.

• Ornamentals. There are some technically edible plants like certain types of sweet potatoes and plums that Upham says are perfectly plate ready, but can be harmful if they’ve been treated like every other nonedible in a conventional garden.

“Sometimes, I get questions on sweet potatoes — they have ornamental varieties of sweet potatoes — they want to know if those are edible. And they are,” Upham says. “And the same thing holds for purple plum trees. Every once in a while we’ll get fruit on those, and that also is edible, it’s just that they have to be a little bit careful, because if it’s been sprayed as an ornamental, what has been used as a spray may not be something you want to eat the fruit from.”


openyourmind 7 years, 8 months ago

This article is much appreciated. However, it will serve to scare the bejeezues out of people. My mother already called me this morning to tell me to get all this goodness out of my diet. My mother, like many Americans, only sees things at face value and you have sufficiently freaked her out, and dad is beyond happy with the thought that his fruit loops are healthier than my mom's morning potato hash. Can I suggest that you post an article talking about all of the toxins that are in 100 calorie snacks, sugar free jello, and nearly all other products on the shelves of most major grocery stores? Those toxic additives are far more destructive than anything fresh from the soil. As a wise consumer, I enjoyed this article, but if you could have discussed the benefits of all the foods and how they outweigh the risks, it would have been most efficient for those who are now going to put these extremely healthy foods on their don't eat lists.

seriouscat 7 years, 8 months ago


Just this weekend the LA times had a piece on how pesticides are now being linked to ADHD....only the most die hard denialists didn't suspect that already.

canyon_wren 7 years, 8 months ago

Very good comment, openyourmind! That article was 'way stronger in its warning than necessary and I agree that the processed junk that people eat instead is a lot more harmful.

dontsheep 7 years, 8 months ago

Are you kidding me? Hidden summer toxins? What a misleading title and article. How did you gather this info anyway? A first page google search? There are too many inaccuracies to address in this article than I have time for, so let's just take one.

Apple seeds.

Apple seeds do not contain cyanide. They contain cyanate. When this is bonded with 2 parts of glucose you have a nitriloside. Harmless until they are broken down by the required enzyme which acts like a key. Which cells contain this enzyme? Cancer cells...and only cancer cells. Healthy cells have an added layer of conversion which breaks the nitriloside down further into silicate, which functions like aspirin and provides pain relief.

Apple seeds do contain a poison, but it's a "smart" poison that only targets cancer.

Now go back and research oxalic acid again. I'll give you a has to do with overcooking. Beyond 112F...

gr 7 years, 8 months ago

"Apple seeds do not contain cyanide. "

wiki: - A cyanide is any chemical compound that contains the cyano group

Paul Decelles 7 years, 8 months ago

From the title I was expecting an article about herbicides and other lawn chemicals or perhaps more specific information about plants such as datura or castor oil plant which I suspect are more dangerous than the plants discussed.

beatrice 7 years, 8 months ago

Saliva can cause cancer!

But only if swallowed in small portions over a long period of time. -- George Carlin

thepianoman 7 years, 8 months ago

Do you what's in the air we ingest? The food we consume? The Air in our homes? Did you know bacteria exists on our skin...even the nasty bacteria Mersa....

Did you all know the world is supposed to end in 2012....and there is going to be a massive, devistating earthquake to strike along the New Madrid Fault ( I think this is the fault) the Midwest.....

The moral of all this...You can worry yourself to death over every little thing or just live life to the fullest and use common sense with stuff like this....

mdrndgtl 7 years, 8 months ago

This one time I ate boiled peanuts, I mean a whole lot. I would have liked to have gotten sick.

Ray March 7 years, 8 months ago

don't discourage people from eating fruits and vegetables. when is the last time you ate a cup of just apple seeds or 11 pounds of kale!??!

this is a pointless story!

gr 7 years, 8 months ago

“Laetrile was used to treat cancer probably back in the ’70s, and it was derived from (apricot) pits,” Upham says. “And it wasn’t something that was mainstream — it was one of those, kind of on the side type things, and the active ingredient was cyanide.”

So, did it work?

It's nice the article had things like how many rhubarb leaves it takes to be sickened, but it doesn't tell how many green potatoes one has to eat nor whether Laetrile worked or not. Seems like a bunch of missing information.

Since a couple of sentences were devoted Laetrile, and since the general sense of the article was dispelling myths, it would have been useful to show some numbers such as how many people with cancer took only Laetrile and survived versus how many with cancer took toxic drugs and survived.

Just throwing something out without adequately explaining if it was good or not seems careless to include it if there wasn't space, or otherwise, inadequate reporting.

Maybe the assignment was: You have X amount of words to talk about poisons which aren't harmful contained within common foods. Get it done fast, don't worry about the details.

If so, my apologies to the writer, and thumbs down to the boss.

gr 7 years, 7 months ago

Well, without any more information on this, I find dontsheep gave a mechanism by which it could work. Pywacket only denied it, but did give a site with interesting comments.

Therefore, I would have to conclude, that further investigation would be warranted in understanding the relationships between cyanide and cancer.

But the question to ask is, why do people get cancer? Is it not because of the so called "food" they are ingesting? If some of those were to eat apple seed pits (if one could possibly eat enough of them) and it was killing their cancer, but if they continued eating their refined foods, meat, etc., would they not just get cancer again? And if people are eating healthy, that is fruits, vegetables, seeds and grains, would there be much of a probability of getting cancer in the first place? But then again, if they are eating a variety of natural products, they probably are getting enough cyanide and other compounds which combats the cancer cells which everyone gets all the time.

So in summary, one doesn't need to worry about eating apple seeds or such things. Doesn't sound like a few will hurt you. If you really need them (which would be a lot of them), and popped them in like some sort of magic pill, your lifestyle would be incompatible with the cure anyway. If you don't need them, you are already consuming them and similar compounds in your regular healthy diet. So, don't worry. Either die, or live. Seeking some natural magical cure like the very poisonous chemotherapy won't help. I read chemotherapy only gives you five years.

What about those who haven't been eating right and have cancer? Perhaps eating the cyanide compounds could be beneficial if they are willing to change their diet, too. Those people would need to do further investigation.

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