Runner beans raw ; warning!
Sat, 14/03/2009 - 11:42 — renetsil
HI everyone , I have recently found out that there is a toxin in raw runner beans . Apparently it is common practice to eat a few out in the garden as a snack but large amounts are a bad idea , especially for children.
Does anyone else have any information on this?
Thanks
legumes
Almost all legumes (peas, beans, etc) contain toxins in their raw form that are broken down by heat. Not to mention all legumes contain indigestible protiens which are present in higher levels in the raw product. This is what can contribute to the 'gas' caused by eating lots of beans etc. So technically even legumes that are often sold / consumed raw (for instance snow peas) should not be eaten raw if you do not want to consume low levels of toxins. Obviously it's unlikely that you'd die from these toxins, but they can have effects on other bodily functions such as nutrient absorbtion etc.
The toxins do not require that much cooking to be broken down, however some of the proteins do take a long cooking time to break down, hence why some kinds of beans need to be cooked for hours.
Adding a strip of 'kombu' (a kind of kelp) to a pot of boiling legumes can assist in the breakdown of indigestible proteins and toxins. Apparently even the bull kelp commonly found along our shore lines contains the required enzymes to facilitate in this process.
Vegetable eating guide
Now that we're on this topic, here is a short excerpt from the book 'Natural Health, Natural Medicine' by Andrew Weil M.D. (a widely recognised expert on integrating Eastern medicine and naturopathy with the western medical system and culture) on the topic of which vegetables are best eaten raw or cooked, etc. It points out to us that the commonly held assumption that 'raw foods are the best for you' is not always true.
"Many vegetables contain natural toxins. The sprouts and green skins of potatoes are poisonous and should always be removed before cooking. Celery, especially when affected by a very common fungus disease called pink rot, contains natural toxins that sensitize us to sunlight and may damage our immune systems. Pink rot is responsible for the brownish patches that discolour many celery plants. Avoid these.
Most of the natural toxins in vegetables are heat-labile; that is, they are easily destroyed by the heat of cooking. All cruciferous vegetables (the cabbage / brassica family), for example, contain such toxins. Small amounts of raw cabbage or cauliflower will not hurt you, but they (and Brussels sprouts, kale, collards, mustard greens and broccoli) are better for you when lightly cooked. They may then offer some protection against colon cancer by affecting the chemical environment of the colon in a favourable way.
Raw spinach, silverbeet, and beet greens contain oxalic acid, which removes calcium and iron from the body and may have other harmful effects; light cooking breaks down this compound. Raw cultivated white button / portobello mushrooms contain three natural carcinogens. Two of them are destroyed by heat, but the third (agaritine) is not and is enough of a worry that I urge you to be cautious about including these mushrooms in your diet at all (although agaritine is not present in Oyster, Shiitake, and other non-agaricus mushrooms). In addition to the natural toxins in vegetables is the problem of residues of pesticides and fungicides used on commercial produce."
Here are some guidelines about how to eat vegetables:
NEVER EAT RAW: Peas, beans, alfalfa sprouts, lentil sprouts, mung bean sprouts, mushrooms, peanuts
BEST WHEN COOKED A LONG TIME: Beans, lentils, chicpeas, eggplant
BETTER COOKED THAN RAW: Beets and beet greens, silverbeet, spinach, cabbage, broccoli, cauliflower, kale, Brussels sprouts, collards, mustard greens, winter squash, green beanss. Do not over-cook green vegetables.
GOOD BOTH RAW AND COOKED: Carrots, celery, onions, garlic, chives, scallions, summer squash, trunips, endive, asparagus, sunflower sprouts, tomatoes, peppers.
BETTER RAW: Lettuce, other salad greens (but not brassica tribe e.g. kale, mustard), cucumbers, radishes, buckwheat sprouts.
PS I have moved this topic to the 'eating what you grow' forum as it is probably more relevant there.
Peas are no risk Beans a low risk
The varieties of pea which have toxins are not those which we eat, There are many many other species which are toxic but you'll never encounter them on your plate, raw or mushy!
I've eaten hundreds of runner beans raw this season my symptoms thus far are that I have a curious crunching feeling whenever move my jaw up and down followed by gushing of sweet fluid all through my mouth. It happens sometimes ten times a day, I think i need to go on a detox diet!
Last summer however I did experience intoxication from 'broad' beans resulting in very long mannic dreamfilled nights and headaches. Not fun.
Don't eat raw broad beans in huge quantities.
hi daikon
I would agree that it is possible, as in many cases in science, that these toxins were picked up in the test tube but they may be of little pracital risk to a human. But it is also faulty logic to dismiss this based on you having no short-term symptoms. A smoker can go 30 years or more before developing cancer; same goes for expoure to many other carcinogens and other environmental toxins. While something may not poison you acutely and dramatically, that doesn't mean that it doesn't have harmful effects. Effects could be subtle and delayed, such as toxins which block the bodys absorbtion on specific vitamins or minerals.
Having said that I would agree that a lot of other things will probably kill you sooner than munching down on a few raw runner beans (and I still do this myself if I'm hungry in the garden). However looking at it from a historical perspective, I can't think of any traditional cultural dishes / anthropolical examples that I've heard of where raw legumes were consumed. Across all the continents any given legume containing dish that I can think of off the top of my head, is cooked. From lentil dahl to chilli beans to stir fries etc. I'd be interested to see an example of raw legumes being eaten by groups prior to the 1800's or so...(which is when extensive global trade introduced many cultures to foods which they were unfamiliar with, lending them to the increased chances of using those foods in untested ways)
rapid onset food poisoning
Good point. however, from what i've read indications are that the reaction to the toxin is reasonably quick, like a couple of hours. I think it's not bioaccumulative but just acts like extreme food poisoning. i.e profuse vomiting and violent diarrhoea! (R18 kind of stuff)
so at least we could conclude
so at least we could conclude that it's probably not advisable to run large quantities of raw legumes through your juicer then!
'Warning over lupin
'Warning over lupin beans'
http://www.stuff.co.nz/life-
03/08/2009
A bean that is finding popularity because of its low GI properties can be deadly if not prepared in the correct way, authorities have warned.
Lupins, which come in bitter and sweet varieties, are being added to products like bread to lower its rating on the glycemic index and in sausages to reduce fat.
They can also be eaten raw as a snack, but doctors say they must be treated first to remove dangerous levels of a toxic alkaloid.
The warning comes after two women were taken to an Australian hospital after being inadvertently poisoned by the beans.
They suffered blurred vision, light-headedness, lethargy and had difficultly walking.
"Fortunately, neither of the two women who presented to hospital became seriously ill," says Nevada Pingault, an epidemiologist at WA Health's Communicable Disease Control Directorate.
"But lupin poisoning can be fatal."
An investigation revealed a quantity of bitter lupins had been milled into flour to meet a local shortage in supply.
It was onsold to stores, but it contained 1,000 times the alkaloid level permitted for flour.
Ms Pingault said there was an "increasing consumption of lupin products" across the community, but consumers and food makers may not be aware of the risks.
"We recommend that information be provided ... about the dangers of selling and eating products containing bitter lupins that have not been appropriately treated to remove toxic alkaloids," she says.
The warning is published in the Medical Journal of Australia.
Phytates
Toxins aside (and yes they do exist)
Most leguminous or grain foods have phytates which effectively bind the essential nutrients making them hard to digest, this diminishes their benefits and can give us wind.
Cooking is the best way to remove this - for a suitable amount of time. You should also lightly acidulate your soaking water with a touch of vinegar or lemon.
Soy beans are especially bad and should really only be eaten after fermentation.