The Ministry of Agriculture, Forestry and Fisheries released a warning in December 2017 not to consume powdered seeds from the rosid group of flowering plants, including loquats, apricots and plums. The Mainichi Shimbun answers common questions readers may have about the warning and why eating the powdered seeds could affect one's health.
Question: Is it true that loquat seeds are bad for your health?
Answer: According to the Food Security Office of the agriculture ministry's Policy Planning Division, the seeds of the loquat and other similar fruits contain toxic cyanide compounds. This can cause headaches, dizziness, vomiting, difficulty breathing and other symptoms of poisoning when a large amount is eaten at once.
Q: But the powdered seeds are sold as a health food, aren't they?
A: Yes, but last summer, a Tokyo Metropolitan Government survey discovered that there was a high concentration of cyanide compounds in the powdered products. A concentration higher than the standard of 10 parts per million is illegal under the Food Sanitation Act, but some merchandise contained as much as 980 parts per million of the cyanide compounds. At that level, even consuming around a teaspoon of the powder would be enough to possibly affect the body. Measures were taken to collect the illegal products.
Q: Do the seeds have health benefits in the first place?
A: For example, the cyanide compound "amygdalin" contained in the seeds is said to be "a type of vitamin" and "effective against cancer," among other claims, and appears to be particularly popular in Europe and North America. However, the vitamin claim has been debunked, and there is not enough evidence of amygdalin's effect on cancer. There have even been cases abroad of cancer patients dying after ingesting the seeds. Just because a fruit is natural does not necessarily mean that it is safe. The same can be said for seeds of apricots and plums, so families that grind up the seeds of those fruits at home for consumption should also stop.
Q: What about the seeds in "umeboshi" (pickled plums) and in the floating fruits in "umeshu" (plum wine)?
A: When the fruits ripen, the amount of cyanide compounds gradually decreases due to the effects of enzyme. When the fruit is still unripe, even the flesh contains trace amounts, but the levels of cyanide compounds in processed umeboshi are low. Eating around one to two of the "jin," or the white part inside the umeboshi seed, is not enough to cause any ill effects. (Answers by Masami Kojima, Lifestyle News Department)