Overview
About Yam bean
The yam bean is neither a yam nor a bean you eat, and both halves of that name mislead in ways that matter.
It is Pachyrhizus erosus, a vine in the pea family whose swollen root is the only food part: crisp, wet, faintly sweet, eaten raw in Mexico and across Southeast Asia. The pods and mature seeds that give it the bean half of its name contain rotenone and are genuinely toxic, historically used as a fish poison and a garden insecticide. The root itself is clean on the sensitivity chemistry, grading A for galacto-oligosaccharides, lactose, gluten, dairy protein, caffeine, sulfites and nitrites, with histamine, salicylate, oxalate, tyramine and nickel all mild at B. The one real gut caveat is fructans, which grade D here, alongside a D for total FODMAPs, so the trigger to watch is fructan load rather than anything chemical.
Sensitivities
How Yam bean scores
Watch for
What trips people up
- Fructans grade D and total FODMAPs grade D, so the storage sugars in the root are the thing to log. Galacto-oligosaccharides, polyols and excess fructose are all clean, which is unusual for something in the pea family
- Only the root is food. The pods, the mature seeds and the vine carry rotenone, and eating the seeds is a real poisoning risk rather than a folk warning. If you buy it whole or grow it, discard everything except the tuber
- It travels under a confusing pile of names: yam bean, Mexican turnip, sengkuang, bengkoang, sa kot, jicama. Log it under one name consistently or your own history will not add up
- Nothing else scores high. Histamine, salicylate, oxalate, tyramine, nickel and free glutamate all sit at B, so if you react hard and fast to this root, suspect what it was dressed with, typically chilli, lime and salt
Diet fit
Where it fits
Swap ideas
More alternatives
FAQ
Common questions about Yam bean
Is a yam bean the same as a yam?
No, and they are not even distant relatives. True yams are Dioscorea, a monocot family of starchy tropical tubers that must be cooked. The yam bean is Pachyrhizus erosus, a legume vine whose root is mostly water, crunchy raw and barely starchy by comparison. The name comes from the tuber shape and the bean-family flowers, not from any relationship to yams.
Are yam bean seeds poisonous?
Yes. The mature seeds and the pods contain rotenone and related compounds, which is why the plant has been used to poison fish and as a botanical insecticide. Only the swollen root is edible. This is one of the few foods where the toxic part is the one the common name points at, so treat any pods that come attached as garden waste, not as a vegetable.
Is yam bean low FODMAP?
Not at this grade. The root grades D for fructans and D for total FODMAPs, which is a real fermentable load. What it does not have is the legume signature: galacto-oligosaccharides grade A, and polyols and excess fructose are clean too, so the discomfort pattern looks like a fructan food such as onion or wheat rather than like a bean. Portion size drives it, since raw batons are easy to eat in quantity.
Is yam bean the same thing as jicama?
They are the same plant, Pachyrhizus erosus. Jicama is the Mexican Spanish name, yam bean is the older English and colonial-trade name, and sengkuang and bengkoang are the Malay and Indonesian names. Triggerbites carries both entries because shoppers genuinely meet the root under both labels, and the fermentable-sugar figures reported for it vary with how the root is sold, how mature it is and how large a portion is measured. Pick whichever name is on your receipt, use it consistently and let your own log settle the question.
References
Read the background
Ratings reflect the Triggerbites ingredient database and may vary with portion size and preparation.