Flaxseed causes cyanide in food - what are these food manufacturing companies doing?!

[Jojo&Tutu]

Flaxseed is not recommended for people to eat by the National Food Agency in Sweden. I believe flaxseed oil is also banned in France So why are USA food manufacturers putting it in our cat food. It puts cyanide into the cat food. I sent cans of Lotus Just Juicy Rabbit to a lab who forwarded it to a specialist food testing lab and I consulted Rhian Cope, principle toxicologist for the country of Australia, the toxicologist who wrote the chapter in Merck Veterinary Manual on cyanide poisoning in animals. The cyanide from Flaxseed was found in the cat food to be .3ppm (parts per million) too much for a cat under ten lbs. I wrote Lotus about it but they did nothing. I was told my cat could eat only one can (“tin”) a day but who wants to feed their cat cyanide?! I wrote animal food regulators and they did nothing. If you have flaxseed in your canned cat food have it tested and see how much cyanide is in it. Manufacturers should be testing their product. More of us need to pressure regulators to do their job!!!

 

[Furballsmom]

Thank you for this information.

 

[FeebysOwner]

This information was provided by A Alldara in a separate thread. Just wanted to add it here for any clarity it might give to those who read this thread.

"Heat destroys the enzyme responsible for cyanide production. Most cat foods are cooked at high temperatures.
The issue would be flax in the low temperature cooked foods. "
How Much Ground Flaxseed Can Animals Safely Eat | Nutraceutical Alliance

 

[IndyJones]

There is cyanide in many fruits actualy. It is naturaly occouring and very small in ammount. For example peaches have it in there pits but you would have to eat over 10 peach pits to get near the lethal range.

Simmalarly, apple seeds also have cyanide in them but you would need to eat at least 200 (probably more) to feel any ill effects from them. You would probably puke before then.

My point is cyanide naturaly occours in many perfectly safe -even healthy and good for you- foods. The ammount is so tiny though that it causes no ill effects. Too much anything is bad for you.

 

[5CatDraw]

Thanks Jojo&Tutu for sharing this info and I salute you for the testing you have done, plus the research to learn what an acceptable level of cyanide is for cats, and for letters written.

Flaxseed first came on my radar when looking at the lab reports on cats.com and wondering about the cyanide content for some foods. Then after more research I eventually concluded it is probably due to flaxseed in those foods. You mentioned in a previous thread that tapioca is also a source of cyanide, which I was not aware of. More reading needed . . .

The article posted by FeebysOwner/Alldara is a really good one, and provides some context regarding what levels might lead to problems in animals. Also a good discussion on the destruction by heating issue. My initial conclusion after reading that article was that there is probably low risk for cooked foods. But then after more pondering, I feel that there is just too much uncertainty with this ingredient when it is in commercial foods, because there is no way to know if it is being properly heat treated, or the amount in the food. Your testing of Lotus confirms this fear.

If I am understanding correctly the information you posted, the Lotus you had tested had 0.3 mg/kg of cyanide. Using the acute reference dose for humans of 20 µg cyanide/kg body weight, the Lotus would not be suitable for feeding your cat as the only food. Right? Plus, there is no established acute reference dose for cats. It might be much lower than 20 µg/kg of body weight. Some of the foods tested by cats.com are MUCH higher than 0.3 mg/kg. Instinct Canned Chicken was 0.886 mg/kg. I believe Instinct canned is actually a raw food, so I guess it being so high makes sense.

The above article suggests an approach for establishing an acceptable level of cyanide for dog/cat foods by using the LD50s (lethal dose for 50% of the animals) and limiting consumption to 10x less than that. But I don’t want my cats consuming even 10x less than a lethal dose of cyanide, if it is something they eat every day. So I think a level of consumption of significantly less than 20 µg/kg of body weight is what I would be comfortable with.

I’ve recently been on a mission to get my cats to eat healthier and have been trying to entice them into eating freeze dried raw that contains flaxseed (and probably a lot of it) and they have refused. Maybe they are smarter than I give them credit for.
I’m concerned now about what I’ve been feeding my dogs – several brands of freeze dried raw that all contain flaxseed. But it has become such a popular ingredient in dog and cat food that it will be hard to find replacements.

I’m really hoping to bring this thread back to life for some more discussion. Thanks again Jojo&Tutu for sharing what I consider to be very valuable information and stirring up my desire to learn more about this topic.

 

[Furballsmom]

Chewy provides an option to select for some Flax-free foods, with one freeze dried dog/cat treat. Unfortunately the list isn't all inclusive but it's a place to start;

https://www.chewy.com/f/flax-free-cat-food_c387_f3v375786

There's also Wysong Archetype, Stella & Chewy's, Primal, Open Farm - who is incredbily transparent and include where every ingredient is sourced, Vital Essentials - states that the product is made in the US, and Purpose Carnivore.

The first two in this list and Open Farm have bone specifically listed in their ingredients, I didn't look to see how much at this point.

 

[5CatDraw]

Chewy provides an option to select for some Flax-free foods, with one freeze dried dog/cat treat. Unfortunately the list isn't all inclusive but it's a place to start;

https://www.chewy.com/f/flax-free-cat-food_c387_f3v375786

There's also Wysong Archetype, Stella & Chewy's, Primal, Open Farm - who is incredbily transparent and include where every ingredient is sourced, Vital Essentials - states that the product is made in the US, and Purpose Carnivore.

The first two in this list and Open Farm have bone specifically listed in their ingredients, I didn't look to see how much at this point.

Thanks for that Chewy tip! Not sure why I didn’t think of that. I’m impressed that Chewy is on top of this issue. I will say though that their filter misses quite a few foods that don’t have flaxseed. They need to update.

And thanks for mentioning a few brands that you know of. I’ve been thinking about some of them anyway, so I’m liking them even more now.
Another Wysong food that doesn’t include flaxseed is Epigen90. I recently bought a bag before flaxseed came on my radar and was relieved to see no flaxseed listed.

 

[Caspers Human]

I looked up the following link from the National Institute of Health: Ion chromatographic determination of cyanide released from flaxseed under autohydrolysis conditions - PubMed

To summarize, scientists mixed ground flaxseed with water then analyzed the result to determine if there was any cyanide in the mixture. They found that there was anywhere from 124 to 196 micrograms of hydrogen cyanide per gram of flaxseed in the samples they tested.

For reference, a lethal dose of cyanide for an average human is in the range of 250 milligrams. That's about the size of one tablet of extra strength aspirin.

124 micrograms is equal to 0.000124 grams. That's 124 millionths of a gram.

250 milligrams is equal to 0.250 grams. That's a quarter of a gram.

124 micrograms is a little less than 0.05 percent (0.000496) of the lethal dose for a human.

If you ate the seeds from one apple and chewed them up before swallowing, you'd likely ingest up to 4 milligrams of cyanide.

The seeds of one apple contains 1.6 percent (0.016) of the lethal dose for a human and approximately 32 percent (0.32) of the amount of cyanide per gram of flaxseed.

In order to get a lethal dose of cyanide from eating apples and chewing the seeds, you'd have to eat somewhere in the neighborhood of 15,000 to 16,000 of them.

In order to get a lethal dose of cyanide from eating flaxseed, you'd have to eat over 2 kilograms or 4.4 pounds.

I don't know about you but I don't think I've eaten 16,000 apples in my entire life and I could never even imagine eating 4 pounds of flaxseed!

Also... Just for clarification... Apple seeds and flaxseed DO NOT actually contain cyanide. They contain cyanogenic compounds that react with water inside the body to produce cyanide. When you eat apples, flaxseed, almonds or other fruits, the cyanogenic compounds in the food TURN INTO cyanide, inside your body. You are NOT actually eating cyanide.

Furthermore, the scientists at the NIH also found that, if they cooked the flaxseed mixtures before testing for cyanide, little to no cyanide was detected.

 

[5CatDraw]

I looked up the following link from the National Institute of Health: Ion chromatographic determination of cyanide released from flaxseed under autohydrolysis conditions - PubMed

To summarize, scientists mixed ground flaxseed with water then analyzed the result to determine if there was any cyanide in the mixture. They found that there was anywhere from 124 to 196 micrograms of hydrogen cyanide per gram of flaxseed in the samples they tested.

For reference, a lethal dose of cyanide for an average human is in the range of 250 milligrams. That's about the size of one tablet of extra strength aspirin.

124 micrograms is equal to 0.000124 grams. That's 124 millionths of a gram.

250 milligrams is equal to 0.250 grams. That's a quarter of a gram.

124 micrograms is a little less than 0.05 percent (0.000496) of the lethal dose for a human.

If you ate the seeds from one apple and chewed them up before swallowing, you'd likely ingest up to 4 milligrams of cyanide.

The seeds of one apple contains 1.6 percent (0.016) of the lethal dose for a human and approximately 32 percent (0.32) of the amount of cyanide per gram of flaxseed.

In order to get a lethal dose of cyanide from eating apples and chewing the seeds, you'd have to eat somewhere in the neighborhood of 15,000 to 16,000 of them.

In order to get a lethal dose of cyanide from eating flaxseed, you'd have to eat over 2 kilograms or 4.4 pounds.

I don't know about you but I don't think I've eaten 16,000 apples in my entire life and I could never even imagine eating 4 pounds of flaxseed!

Also... Just for clarification... Apple seeds and flaxseed DO NOT actually contain cyanide. They contain cyanogenic compounds that react with water inside the body to produce cyanide. When you eat apples, flaxseed, almonds or other fruits, the cyanogenic compounds in the food TURN INTO cyanide, inside your body. You are NOT actually eating cyanide.

Furthermore, the scientists at the NIH also found that, if they cooked the flaxseed mixtures before testing for cyanide, little to no cyanide was detected.

Thanks for sharing your thoughts. I’m a numbers person, so I do like to see numbers. But I’m afraid my concerns are not alleviated by what you presented.

I prefer to look at it from the perspective of the acute reference dose for humans (for chronic consumption), which is 20 µg cyanide/kg body weight per day. And as I mentioned before, I’m not even sure that I’m comfortable with that level for cats since there have been no studies on safe levels for cats (that I’m aware of).

Using this figure as a guideline, and the actual cyanide levels in cat foods tested, from the source I mentioned earlier, I find the level of cyanide detected in some of the foods to be enough to be concerned about.

Here is an example of one that I had done the math on because I used to feed it. I won’t mention the name, but it is a dry food, so it makes it simpler to not have to correct the computations for moisture.
The food contained 0.591 mg/kg of cyanide
Caloric value of the food is 3,953 kcal/kg A 10 lb cat (neutered adult) consumes approx 305 kcal/day, so if they ate nothing but this food they would consume 0.05 mg cyanide per day. Using 20 µg cyanide/kg body weight, the “probably safe” level for the cat would be 0.09 mg cyanide per day. So this food would be safe, if one has confidence that the acute reference dose for cats is the same as for humans. But it’s not safe by a HUGE margin, as the figures you presented would suggest. Also, this is a dry food, so evidently the heat for production of this food did not destroy all of the cyanogenic compounds.
The Lotus food that Jojo&Tutu had tested had a cyanide level of 0.3 mg/kg. That too is a cooked food.

So in my mind there is still enough uncertainty that I’m concerned about flaxseed in cat food. Especially for a cat with health issues.

 

[Caspers Human]

Something isn't right about those figures. 591 mg is twice the average lethal dose for a human!

Somewhere, somehow, there must be a mistake in calculation or an error in the number of decimal places because those figures don't stand up to scrutiny with me.

 

[5CatDraw]

Something isn't right about those figures. 591 mg is twice the average lethal dose for a human!

Somewhere, somehow, there must be a mistake in calculation or an error in the number of decimal places because those figures don't stand up to scrutiny with me.

The cyanide content of the food was 0.591 mg/kg. I’m confident the units are right.
The sample that Jojo&Tutu had tested had a level of 0.3 mg/kg. You can look at that lab report above.

 

[cejhome]

I feed our Buddy Lotus Just Juicy Venison and Pork (as well as other non-Lotus canned foods in rotation). There is no flax seed listed in the ingredients on the cans or on their website at least for these two varieties. They may have used flax seed at some point in the past, but there isn't any in it now.

 

[5CatDraw]

I feed our Buddy Lotus Just Juicy Venison and Pork (as well as other non-Lotus canned foods in rotation). There is no flax seed listed in the ingredients on the cans or on their website at least for these two varieties. They may have used flax seed at some point in the past, but there isn't any in it now.

That’s interesting. It looks like all of the Lotus pates contain Ground Whole Flaxseed Meal, but their Just Juicy recipes do not. I like companies who provide full nutrient info online, and Lotus does. I may give them a try. Their dog foods too. No rabbit recipes for either though.
Thanks for calling my attention to this.

 

[Alldara]

That’s interesting. It looks like all of the Lotus pates contain Ground Whole Flaxseed Meal, but their Just Juicy recipes do not. I like companies who provide full nutrient info online, and Lotus does. I may give them a try. Their dog foods too. No rabbit recipes for either though.
Thanks for calling my attention to this.

If the cat food is cooked at high temperatures, it kills the cyanide in the seeds as per the link I posted.
It's an issue if you're feeding freeze dried or raw

 

[Catlady528]

Hmmm, I eat a smattering of whole flaxseed daily in my yogurt. I'm not necessarily chewing them all up, but I do chew since I also add Grape Nuts to it. The flaxseed seems to keep me regular.

 

[Alldara]

Hmmm, I eat a smattering of whole flaxseed daily in my yogurt. I'm not necessarily chewing them all up, but I do chew since I also add Grape Nuts to it. The flaxseed seems to keep me regular.

Flax seeds for human consumption are already heat treated to destroy the cyanide.
Most seeds have some level of cyanide in them, even apple seeds!

 

[Catlady528]

Flax seeds for human consumption are already heat treated to destroy the cyanide.
Most seeds have some level of cyanide in them, even apple seeds!

Good to know about the heat treatment. I never ate the seeds in apples. Well, a few when I was a kid, but I never do on purpose. I always remove them. I rarely eat raw apples anyways. I've known for years about cyanide in apple seeds and peach pits, but who eats peach pits?

 

[5CatDraw]

Hmmm, I eat a smattering of whole flaxseed daily in my yogurt. I'm not necessarily chewing them all up, but I do chew since I also add Grape Nuts to it. The flaxseed seems to keep me regular.

Yeah, at one point I was consuming a lot of flaxseed too because of the health benefits – mostly on cereal. I still eat Flackers crackers pretty frequently. I’ve continued doing a lot of research on the subject and there are many articles that suggest flaxseed can be problematic (or at least undesirable effects) even in moderately high quantities. And of course one can find articles saying it takes consumption of huge amounts to be a problem.

Honestly, I’m not terribly worried about myself, and probably won’t give up my Flackers completely, but I am going to stop feeding my dogs and cats commercial raw foods that contain it, plus minimize the canned foods that contain it. In my mind, there is just no way to know how much flaxseed those foods contain and even for cooked foods, whether the flaxseed was heat treated in a way to destroy the cyanogenic glycosides.

Another thing I learned from my research is that cyanide in food converts to thiocyanate which can cause iodine deficiency and lead to thyroid disease. Both of my dogs have recently developed hypothyroidism and I made a change in their diet about 18 months ago – feeding mostly freeze dried raw foods containing flaxseed. Maybe a coincidence, maybe not . . .

Here is a study that looked at the cyanide content of smoothies with flaxseed. They found it didn’t take a lot of flaxseed added to a smoothie to produce a cyanide content of potential concern.
“The highest TCN (cyanide) was detected in drinks containing raw flax seed followed by unpasteurized raw almond milk, then fresh whole apple juice.”
Cyanide Toxicity of Freshly Prepared Smoothies and Juices Frequently Consumed