Are Apple Seeds Poisonous? What Is The Safe Limit?
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How Poisonous Are Apple Seeds?
Apple seeds contain amygdalin which, when ingested, releases the toxic chemical, cyanide. But it takes thoroughly chewing at least 165 apple seeds to kill a 50 kg person instantly, but even lower doses can cause symptoms like dizziness, nausea, brain damage, and impotency. There's no risk in swallowing the seeds, and apple seed oil and apple juice, after removing the seeds, are harmless.
Have you been juicing apples, core and all? Or did you swallow apple seeds accidentally while eating an apple? You have probably heard that while apple reduces your risk of a variety of diseases and gives you a healthy lifestyle,1 apple seeds are poisonous. But as you know, the dose makes the poison. And the dose depends on a number of factors like body weight and health status.
So if you’ve accidentally swallowed only a few, don’t worry. Apple seeds have a tough outer cover, which makes them indigestible. You may even pass those undamaged through your stool. Even if you have chewed a few, your body can flush out the toxin. The concern is when you have them in a large number, thoroughly chewed or crushed. Since juicing involves crushing the seeds, it’s slightly risky, but only if you’ve been using a lot of cores.
Apple Seeds Are Poisonous: Amygdalin Releases Cyanide
Apple seeds, as well as peach and apricot seeds, contain a compound called amygdalin, also called laetrile (sometimes, vitamin B17 though it’s not a vitamin),2 which, upon contact with your digestive system, releases the toxic chemical, hydrogen cyanide.3 Depending on the cultivar, apple seeds contain about 1–4 mg amygdalin.4
Amygdalin content in apple cultivars
- Golden Delicious: 3.9 mg/g
- Royal Gala: 3 mg/g
- Red Delicious: 2.8 mg/g
- Russet: 1 mg/g
Now, as you know from history, crime fiction, and spy movies, cyanide is a lethal chemical. And deaths, though not many, have been reported from amygdalin ingestion from chewing pits.5
The more common symptoms of poisoning can vary from weakness to lightheadedness. In cases of severe poisoning, they could include seizures, Parkinsonism, brain damage, impotency, and cardiac failure and sometimes even coma and death.
According to the Centers for Disease Control and Prevention, 1–2 mg/kg is a fatal oral dose of cyanide for 70 kg/154 lbs human.6 But a 1938 study fixes the lowest fatal oral dose at 0.56 mg/kg. So erring on the side of safety, about 39–140 mg cyanide when taken orally is fatal for a 70 kg individual.
But You Need To Eat Over 150 Seeds To Cross The Safe Limit
It doesn’t mean you stop eating apples for fear of accidentally ingesting a few seeds. And it’s highly unlikely that you would chew on apple seeds like they are candies. After all, apple seeds are bitter and inedible. But if you do have a rare penchant for apple seeds, you need to know the safe limit.
Here’s the calculation
- 1 g apple seed contains 1–4 mg amygdalin.
- 1 mg amygdalin can yield 0.06 mg cyanide.7
- 1 g apple seeds can release 0.06 to 0.24 mg cyanide.
- 1 apple seed weighs 0.7 g approximately.
Considering 0.56 mg/kg cyanide as the least possible fatal dose, we have found that it takes thoroughly chewing at least 232 apple seeds to cause lethal poisoning in an adult weighing about 70 kg. If we assume there are roughly 6–8 seeds in an apple, that is eating more than 29–38 apple cores to cause you serious harm!
Here’s a table for how many apple seeds are fatal across age groups. While doses lower than this may not be lethal, they can cause several side effects. Pets and children may be especially vulnerable.
|Weight of person (kg)||Fatal number of seeds||Weight (g)||Cup measure for crushed seeds|
(1 cup = 140 g)
|10||32–132||23–93||1/6th–1/2 cup approx.|
|50||165–665||116–466||4/5th–3 cups approx.|
|70||232–933||163–653||1–5 cups approx.|
Like we’ve mentioned already, swallowing whole apple seeds won’t have any effect on you. But chewing them fine or blending them with juices will. That takes us to the question, how about apple juice, then?
Apple Juice From The Core Can Be Harmful
A comparative study on the content of amygdalin in apple juice extracted from the core, from the flesh and skin, and from the whole apple found that apple juice from the core contained 75 percent more amygdalin than the juice from the whole apple or apple flesh and skin.8
Drinking about 500 ml apple juice made solely from the core of the Golden Delicious cultivar can be dangerous even for an adult.
Apple juice made from Golden Delicious had the highest amount of amygdalin (0.43 mg/ml), which would yield up to 0.1 mg cyanide. Russet had the lowest (0.13 mg/ml), which would yield a minuscule amount of 0.03 mg/m cyanide. But if you drink more than 500 ml (17 oz), the cyanide could give side effects even to a healthy adult. This quantity would be lethal for a child.
If you have been juicing apple cores, especially for your child, you had better stop. But if you are juicing apple flesh and skin, carry on. Amygdalin content in pure apple juice does not pose any problem to the health.
But Apple Seed Oil Is Good For Health
Naturally, you would wonder if apple seed oil made from apple seeds and known for its many medicinal and cosmetic use is, after all, safe to use? It has a considerably low amount of amygdalin; so, you can stop worrying.
In fact, one study found that apple seed oil is as good as any other edible oil and is a good source of natural antioxidants. It was also found to have anticancer properties.9 Another study found that the oil had a good potential for use in the food industry and pharmacy.10
It’s interesting, however, to note that amygdalin or laetrile was once used for cancer treatment. But it was banned in the US after reports of cyanide poisoning.11
The bottom line is that apple seeds are definitely poisonous but only if you chew them thoroughly and in large numbers. That, however, should not stop you from eating apples.
References [ + ]
|1.||↑||Boyer, Jeanelle, and Rui Hai Liu. “Apple phytochemicals and their health benefits.” Nutrition journal 3, no. 1 (2004): 1.|
|2.||↑||All About Amygdalin, Open Chemistry Database.|
|3.||↑||Holzbecher, Michaela D., Michael A. Moss, and Herman A. Ellenberger. “The cyanide content of laetrile preparations, apricot, peach and apple seeds.” Journal of Toxicology: Clinical Toxicology 22, no. 4 (1984): 341-347.|
|4, 8.||↑||Bolarinwa, Islamiyat F., Caroline Orfila, and Michael RA Morgan. “Determination of amygdalin in apple seeds, fresh apples and processed apple juices.” Food chemistry 170 (2015): 437-442.|
|5.||↑||Amygdalin toxicity in humans. NLM.|
|7.||↑||Alexander, Jan, Lars Barregård, Margherita Bignami, Sandra Ceccatelli, Bruce Cottrill, Lutz Edler, Bettina Grasl-Kraupp et al. “Acute health risks related to the presence of cyanogenic glycosides in raw apricot kernels and products derived from raw apricot kernels.” EFSA Journal (2016).|
|9.||↑||Walia, Mayanka, Kiran Rawat, Shashi Bhushan, Yogendra S. Padwad, and Bikram Singh. “Fatty acid composition, physicochemical properties, antioxidant and cytotoxic activity of apple seed oil obtained from apple pomace.” Journal of the Science of Food and Agriculture 94, no. 5 (2014): 929-934.|
|10.||↑||Tian, Hong-Lei, Ping Zhan, and Kai-Xiong Li. “Analysis of components and study on antioxidant and antimicrobial activities of oil in apple seeds.” International journal of food sciences and nutrition 61, no. 4 (2010): 395-403.|
|11.||↑||Complementary, PDQ Cancer, and Alternative Medicine Editorial Board. “Laetrile/Amygdalin (PDQ®).” (2015).|
Disclaimer: The content is purely informative and educational in nature and should not be construed as medical advice. Please use the content only in consultation with an appropriate certified medical or healthcare professional.