The Katuk Controversy
It’s important to keep in mind that THE DOSE MAKES THE POISON. Anything we eat too much of can have negative health effect. Excessive consumption of raw katuk for weeks on end may not be good for you. It contains a compound named Papaverine that lowers blood pressure and has a string of other medicinal and pharmacological uses. One group of Taiwanese women trying to lose weight by juicing tons of katuk daily, found out the hard way.
“Green Deane” from Eattheweeds.com did a write up on this “katuk controversy”.
Some vendors in Taiwan convinced people that an extract of raw Katuk was good for weight loss… yep, a fad diet. The vendors sold extract of ground up Katuk leaves mixed with fruit juice. Fifty-four people, 50 females, four males, developed lung problems, most of which went away upon stopping the diet. Four middle-aged women, however, who drank 3.5 to 7 ounces (100g to 200g) a day of the extract for up to two months had to have lung transplants within a year and a half of consuming the extract. This is the human equivalent of over-dosing a lab rat to induce disease. More so, not only did these four take the extract they also ate a lot more raw Katuk while taking the extract. Only mother’s milk wouldn’t hurt you at that rate, and maybe even that would. Despite proven dangerous, this fad diet persisted and 9 cases were found in Japan in 2006 causing one death and one lung transplant.
The poisonings are believed related to papaverine in the plant, which makes blood vessels open up and is not an uncommon treatment for high blood pressure. There is about 580 mg of papaverine per 100g of raw Katuk leaf, or about the same as four prescriptions capsules of papaverine to 3 ounces of raw leaf. The theory is in high doses it permanently damaged the tiny blood vessels in the lung. Researchers have not been able to recreate the symptoms in lab rats which has led some to think the problem might have a genetic component.
A follow-up study of 278 people in Taiwan with non-fatal symptoms found the median consumption of Katuk was 5.3 ounces a day of raw leaf for 20 days. Their consumption was about seven times the average consumption of Katuk by symptom-free Malaysians, which is three to six ounces a week, not a day. It was, it seems, too much of a good thing done wrongly. A 2006 study on rats showed that in a controlled experiment Katuk did help rats lose weight and reduce their triglycerides. Clearly it needs more research. So, what does all this mean, beside don’t eat Katuk if you are taking something to open your blood vessels or lower your blood pressure? Enjoy Katuk as an addition to salads, a lawn-side nibble, and cooked in various dishes like you find in thousands of restaurants. Just don’t consume a half a pound of it a day raw for weeks or months and/or while taking an extract as well. I have been tossing a dozen leaves in my weekly salads for more than five years. I ain’t concerned.
–Green Dean, Eattheweeds.com