Naked Science Forum
General Science => Question of the Week => Topic started by: thedoc on 28/09/2010 16:14:00
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My friend told me that I shouldn't eat the core of an apple and that I should throw it away. Is it poisonous?
Asked by Hannah
Find out more on our podcast page (http://www.thenakedscientists.com/HTML/podcasts/show/2010.09.26/)
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We put this question to John Fry, a consultant in food science...
John - Well, it could be but only under rather extreme circumstances. Apple seeds contain a substance called amygdalin that can release cyanide under the right circumstances such as contact with digestive enzymes. The cyanide is linked to sugars in the form of a cyanogenic glycoside and these cyanide-releasing compounds are remarkably common in nature. They occur in more than 2,000 plant species, some of them important foods like cassava. They also crop up in stone fruits like plums, peaches, apricots, and famously, bitter almonds. It’s often said that cyanide smells of bitter almonds, but actually, it’s the other way around; bitter almonds smell of cyanide. You need about 1 milligram of cyanide per kilo of body weight to kill a human being. [img float=right]/forum/copies/RTEmagicC_800px-Klokhuis-001.JPG.jpg[/img] Apple seeds contain about 700 milligrams of cyanide per kilo, so about 100 grams of apple seeds should be enough to dispatch a 70-kg adult human, but that’s an awful lot of apple cores even if you don't eat the rest of the apple first. In addition, the seeds would have to be pretty finely crushed to let the enzymes get to the amygdalin at all. All in all, you're safe eating the occasional apple core. I've done it for years. Just don't try eating a bowl of freshly crushed apple pips.
Diana - If a seed weighs 0.7 grams, then you'd need to munch your way through 143 seeds. Apples can contain anywhere between 2 and 20 pips, but a typical supermarket apple will contain about 8. So you'd have to eat about 18 apple cores in one sitting!
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I think that the apple seeds contain small traces of a cynide compound. Most fruits seeds or pit core has this simularity. This may be a natural protection to preserve the next generation of seedlings?
You would have to eat allot of seeds to have an affect and I am not sure but if the seed is not crushed it may not be digested, just passed.
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Yes apple seeds can provide an disturbing taste experience. I compromise. Eat off the ends which are often tasty and crispy. Just discard the actual core with seeds, or go all the way and discard seeds. Everything else goes down the hatch.
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I think that the apple seeds contain small traces of a cynide compound. Most fruits seeds or pit core has this simularity. This may be a natural protection to preserve the next generation of seedlings?
You would have to eat allot of seeds to have an affect and I am not sure but if the seed is not crushed it may not be digested, just passed.
You are correct, the seeds contain a cyanoglycoside that when eat releases the cyanide. The levels are extremely low but theoretically you could consume enough to kill you.
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I'm sure that I have read of someone who liked apple seeds, collected lots of them, ate them and died. I can't find a reference at the moment. IIRC it took about a cup full.
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Bored chemist,
I wounder how many people enjoy apple seeds.
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Yes, that's true about cyanide, but 10 apple seeds from my apple weights 0.6 grams, I just weight it and eat it.
On the other side there are many claims from doctors of medicine and science that cyanide from apple and apricot seed cures cancer. Thousands of people claims that it saved their lives. You can check it on google or youtube. Maybe it's true and maybe it's not but I don't see a reason for that doctors to lie,risking of loosing licence for something that's practicly free and they don't have a benefits of it.
Apples are healty, and their seeds are not poisonous.
Some people died of drinking too much water, or taking to much vitamins but you can't say it's not healty to drink water. Many people who reed your article will belive you, and it's wrong. You shouldn't write about apple seeds as something leatheal and venomous.
Sorry for bed english but facts are more important than spelling
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So theoretically you could attempt to "dispatch" someone with 143 crushed apple seeds and wind up curing their cancer instead [:o]
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You talked about crushing the seeds. I assume chewing well would be the same.
Many seeds are poorly digested. In fact, that is the plant's goal. Get something to eat their fruit. Digest the seed... then it can come out the other end virtually intact, and still grow. In fact, some plants germinate that way.
I found some notes on Amygdalin, also known as Vitamin B17 (inappropriately labelled as it is NOT a vitamin).
This is a little confusing... but I think related to the "Cancer" notes.
An enzyme found in the small intestine called beta glucosidase catalyzes the release of cyanide from amygdalin. This cyanide molecule is uniquely absorbed and used by the body. Cyanide molecule can only be broken down by an enzyme found in tumor cells, acting as a “cancer smart-bomb”, and neutralized by the body’s other healthy cells. It is this breaking down of cyanide molecule in a tumor cell that makes laetrile a probable cure for cancer.
Wikipedia, however, is a lot more damning, as well as discussing the difference between Amygdalin & Laetrile
http://en.wikipedia.org/wiki/Amygdalin
Several studies in the early 80's have demonstrated that Amygdalin & Laetrile are ineffective in the treatment of Cancer. See the Wikipedia Notes.
It looks like Snopes did a writeup on this.
Apple pips also have a tough protective coating which makes swallowing them even less of a risky proposition; unless the pips are pulverized or masticated, the amygdalin they house remains safely contained within. Apple pips have hard, durable shells that allow them to pass intact through the digestive systems of animals, a quality which helps the apple to reproduce by distributing its seeds to new locations far from the originating trees. Were apple pips susceptible to the eroding effects of digestive juices, apple trees could not reproduce nearly as well as they do — their seeds would not be so widely spread, and a good many of the pips would be destroyed before germinating.
So, that is pretty much what I was thinking. They're ok if you swallow them whole and don't chew them up.
Also, note,
Do not break open and eat Peach and Apricot seeds as one could receive a much higher dosage of Amygdalin. Low does can be metabolised in the body without harm, but high doses can't.
Also note, Cassava, Lima Beans, Flax, and Tapioca contain a related compound, Linamarin (which the first article I linked to didn't mention). Anyway, this is harmful if eaten raw, but rendered inactive by cooking.
http://en.wikipedia.org/wiki/Linamarin
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A good method to off your mate.
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I like the flavor of apple seeds and would chew them thoroughly over the course of eating an apple. I did this literally one apple every day for five years until friends told me not to because they were supposedly poisonous. I agree with the commenter that anything in large quantities will kill you, apparently one apple's worth of seeds every day for years is not enough to kill a 110 lb. healthy woman.
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There is a hard protection around the seeds so most seeds are not digested by mammals who eat the apple so that the seeds be rejected in the animal's (that's you) feces. Many plants use this strategy for reproduction. That means that most if the cyanides will go through you unabsorbed. HOWEVER...
HOWEVER this is not true if you put them in a high-power blender for a smoothie. In powerful blenders such as the Waring Commercial Xtreme, Vitamix or Blendtec the seeds will be opened and crunched. So I suggest that, for smoothies, the seeds be removed.
The same is true for hi-efficiency non-centrifugal juicers (single-auger or twin-gear). Especially twin-gear juicers like the Green Star and the Super-Angel which have stainless steel triturating gears.
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Over the summer I picked large quantities of apples and made many of them into baked goods. As a result I saved large quantities of seeds and deliberately ate several dozen in a single sitting without suffering any adverse effects whatsoever. Furthermore, if you pick wild apples you will periodically find apple coddling moth larvae have burrowed through the flesh of the apple to the core and grow exclusively by feeding off the seeds. Apple seeds do contain cyanide, but they are locked up in the molecules of vitamins, where they can be selectively used or discarded by the body. For example, vitamin B12 (not B17) has one form that contains a cyanide molecule, named cyanocobalamin. Cyanocobalamin can be built in the body using cyanide free radicals. Apple seeds are not toxic, they are a great source of vitamins, fat and protein!
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I had one Apple each day with the seeds, fasten, and after 10 days I had blood in my feces, can be that the cause? Thanks
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what about eating 3 apples cores a day, every day? Is there any cumulative effects (i.e. does the cyanide accumulate in your body over time?
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I shelled and ate Apple pips like sunflower seeds for years, but I never had any ill affects. I would even save 4 or 5 apples worth of pips in a bowl so I could eat them in one sitting. I did this as a child and it carried into my twenties until someone told me I shouldn't and I stopped(for the most part). I wonder if I did any damage.
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c8 seeds per apple X 18 apples = 144 seeds = 100grs
so 1 seed = 0.7g and if 100 gr of seeds can kill a 70 kg adult
1gr of seed = can kill someone of 700 grams,
so now assume new born baby = 3.5 kg or a slight grown baby of 7 kg
5 grs of seed could be good enough to kill a baby i.e equal to 1 or 2 whole apple crushed and fed to a baby, especially with blending foods getting popular now.
Can that really kill !!!!!
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I have been eating apple pips for most of my life. I am 71 now,so what is the problem? Keep on chomping! Maybe an apple tree will grow inside me one day! VolcaniC Ash 3/11/2015
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You need the Thiocyanate (-SCN) the body makes from the amydgalin in the seeds! It keep your White Blood Cells from self-oxidizing themselves... http://www.pnas.org/content/106/48/20515.long
Benzylaldehyde is another by-product of amygdalin. http://www.ncbi.nlm.nih.gov/pubmed/6929727
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I've been eating my apple cores and chewing the seeds for my entire life (and my wife's cores too for over 30 years). I'm in my mid 60s and have never felt this to be a problem. I do eat a lot of apples 2 to 6 a day.
Is this likely to be a problem as I age further?