My parents were Italian immigrants. Even though they became fully American in all aspects of their lifestyle, my father built a fixture in the fireplace and all winter long, he would build fires and cook a pot beans in it, because that’s what his parents did “in the old country”.
I'm one of those people who cooks dried chickpeas in her slow cooker, and thus I'm interested in the lectin "controversy." As far as I can tell, it's only kidney beans that should never be cooked this way. I do see many sites misquoting Dr Greger of Nutrition Facts regarding cooking beans in a slow cooker -- he was talking specifically about kidney beans ONLY. Do you have other info to contradict this?
Hi Bette. I’m relying on scientific papers, as hopefully they provide the most reliable information.
The problem is, there’s no comprehensive set of information that I can find. Kidney beans are the notable example of beans that are toxic when raw and need to be boiled before eating. However, other beans have as high or higher levels of lectins.
My best source measured the lectin levels of a wide range of different beans and other vegetables. Kidney beans has 13,200 units, but Lima beans had 26,500 and black beans had 26,400. Other beans with high levels were pinto beans (13,600), white beans, rashti beans and borlotti (13,300).
There are different types of lectins, and some may be more toxic than others, but I think it’s safe to assume that all of these should be boiled before going into the slow cooker.
Hi Miriam. I can’t claim to being an expert on this topic. My go to resource is a research paper where they measured the lectin levels of a wide variety of different beans.
In that, sugar snap beans have a low level, around that of tomatoes (~250 units). Green beans have much higher lectin levels at 6650 units. For context, kidney and lima beans, which are considered highly toxic when uncooked, have levels of 13,200 and 26,500 respectively.
My understanding is that different plants have different lectins, and they don’t have the same effects on us, and some people might be more sensitive than others.
So, you’re fine eating sugar snap peas. As for the green beans, they don’t seem to be doing you any noticeable harm, but I wouldn’t feel comfortable saying they were harmless when eaten raw.
Here in Thailand eating raw beans is normal, but the bean si consumed is othe so called Chinese long bean. The raw flavor is pretty much that of a typical green bean, quite grassy, but the bean is normally uncooked when mixed into a dish, and sections cut about 3” long are very typical served with other raw veggies like raw cabbage, cucumber, lettuce leaf, and loads of fresh herbs as a table condiment.
That’s interesting. Someone asked a similar question about raw green beans. My resource for this is a paper in which they measured the lectin content of a wide variety of beans: https://www.mdpi.com/2304-8158/10/11/2796
Chinese long beans aren’t on there. One would assume that where eating certain beans raw is a routine part of the diet, generations of humans have weeded out the ones that can cause harm. There’s not a great deal on the topic in the medical literature.
In addition to the small measured life span improvement, I believe there is an improvement in quality of life, which admittedly is harder to measure, with addition of beans and lentils. I suspect the change in microbiome accompanying regular beans and lentils might contribute to quiet improvements behind the scenes in things such as mitochondrial function and neurochemistry. As we see better research in effects of gut microbiome, perhaps we will see such items quantified.
I hadn’t thought about it that way, but I think you’re right. I certainly feel much better after eating a meal where the protein came from legumes vs one with lots of meat. I’m not sure how much is physiological and how much is the psychology of being glad you ate something ‘healthy’.
There’s plenty of evidence that a plant heavy diet is linked with a microbiome profile that’s linked to better health. Like you, I think that’s an exciting field that we’ve so far just scratched the surface of.
I really love this, "(If any New Zealand readers can explain why you eat so many more beans and lentils than your Australian neighbours, I’d genuinely love to know.)"
My parents were Italian immigrants. Even though they became fully American in all aspects of their lifestyle, my father built a fixture in the fireplace and all winter long, he would build fires and cook a pot beans in it, because that’s what his parents did “in the old country”.
That’s fantastic! It was clearly so important to him. Do you also have happy memories of those beans? Do you get nostalgic for them?
Do I ever! I eat beans every day! Many such memories: polenta, figs, etc.
I'm one of those people who cooks dried chickpeas in her slow cooker, and thus I'm interested in the lectin "controversy." As far as I can tell, it's only kidney beans that should never be cooked this way. I do see many sites misquoting Dr Greger of Nutrition Facts regarding cooking beans in a slow cooker -- he was talking specifically about kidney beans ONLY. Do you have other info to contradict this?
Hi Bette. I’m relying on scientific papers, as hopefully they provide the most reliable information.
The problem is, there’s no comprehensive set of information that I can find. Kidney beans are the notable example of beans that are toxic when raw and need to be boiled before eating. However, other beans have as high or higher levels of lectins.
My best source measured the lectin levels of a wide range of different beans and other vegetables. Kidney beans has 13,200 units, but Lima beans had 26,500 and black beans had 26,400. Other beans with high levels were pinto beans (13,600), white beans, rashti beans and borlotti (13,300).
There are different types of lectins, and some may be more toxic than others, but I think it’s safe to assume that all of these should be boiled before going into the slow cooker.
You can have at the look at the list for yourself at: https://www.mdpi.com/2304-8158/10/11/2796- Table 3
I prefer most vegetables raw and this includes sugar snap peas and green beans. Are you saying these should not be eaten raw?
Hi Miriam. I can’t claim to being an expert on this topic. My go to resource is a research paper where they measured the lectin levels of a wide variety of different beans.
In that, sugar snap beans have a low level, around that of tomatoes (~250 units). Green beans have much higher lectin levels at 6650 units. For context, kidney and lima beans, which are considered highly toxic when uncooked, have levels of 13,200 and 26,500 respectively.
My understanding is that different plants have different lectins, and they don’t have the same effects on us, and some people might be more sensitive than others.
So, you’re fine eating sugar snap peas. As for the green beans, they don’t seem to be doing you any noticeable harm, but I wouldn’t feel comfortable saying they were harmless when eaten raw.
If you wanted to check that list, you’ll find it at: https://www.mdpi.com/2304-8158/10/11/2796
Thanks so snap peas raw and green beans cooked. Got it. And thanks.
Here in Thailand eating raw beans is normal, but the bean si consumed is othe so called Chinese long bean. The raw flavor is pretty much that of a typical green bean, quite grassy, but the bean is normally uncooked when mixed into a dish, and sections cut about 3” long are very typical served with other raw veggies like raw cabbage, cucumber, lettuce leaf, and loads of fresh herbs as a table condiment.
That’s interesting. Someone asked a similar question about raw green beans. My resource for this is a paper in which they measured the lectin content of a wide variety of beans: https://www.mdpi.com/2304-8158/10/11/2796
Chinese long beans aren’t on there. One would assume that where eating certain beans raw is a routine part of the diet, generations of humans have weeded out the ones that can cause harm. There’s not a great deal on the topic in the medical literature.
In addition to the small measured life span improvement, I believe there is an improvement in quality of life, which admittedly is harder to measure, with addition of beans and lentils. I suspect the change in microbiome accompanying regular beans and lentils might contribute to quiet improvements behind the scenes in things such as mitochondrial function and neurochemistry. As we see better research in effects of gut microbiome, perhaps we will see such items quantified.
I hadn’t thought about it that way, but I think you’re right. I certainly feel much better after eating a meal where the protein came from legumes vs one with lots of meat. I’m not sure how much is physiological and how much is the psychology of being glad you ate something ‘healthy’.
There’s plenty of evidence that a plant heavy diet is linked with a microbiome profile that’s linked to better health. Like you, I think that’s an exciting field that we’ve so far just scratched the surface of.
I really love this, "(If any New Zealand readers can explain why you eat so many more beans and lentils than your Australian neighbours, I’d genuinely love to know.)"
Beans worked well into a Mediterranean and related style diet. Though many call for white beans and will do. https://www.themediterraneandish.com/?s=beans
With meat prices these days, this can be an economic alternative.
Good work!
Another great article, Ben.
I've given it a prominent link in an update to my post about beans:
https://drmick.substack.com/p/about-beans