HOME > NEWS&TOPICS > News > Cyanide compounds contained in health tea using loquat seeds - Beware of excessive intake because decomposition thereof in the body may produce hydrocyanic acid

[June 2018]

Cyanide compounds contained in health tea using loquat seeds - Beware of excessive intake because decomposition thereof in the body may produce hydrocyanic acid

Kernels, immature flesh and leaves of apricots, Prunus mume, Prunus salicina, loquats, etc. belonging to the genus Prunus of the rose family contain cyanide compounds such as amygdalin, which may form highly toxic hydrocyanic acid when decomposed in the body. A large intake of cyanide compounds may cause ill effects such as headache and dizziness.1 Usually, cyanide compounds in the above fruits dissipate as the fruits ripen. When the fruits are still unripe, cyanide compounds therein can be reduced by processing appropriately. Among foods that are known to naturally contain cyanide compounds and processed foods thereof, those containing over 10 ppm of cyanide compounds are regulated under the Food Sanitation Act.

In 2017, cyanide compounds were found in high concentration in some powdered loquat seeds products, and these food products were recalled. The Health, Labour and Welfare Ministry urged quarantine stations in Japan to conduct voluntary inspection of imported food products.2 The Ministry of Agriculture, Forestry and Fisheries issued an alert on the intake of powdered loquat seeds and instructed manufacturers of food products made from loquat seeds and other parties concerned to ensure safety of food products they provide.3

Although it is sometimes said that amygdalin is "effective against cancer", safety and effectiveness thereof have been denied by authorities. Moreover, serious health problems due to consumption of supplements containing amygdalin were reported several times overseas.1

Following the guidance by relevant ministries, NCAC randomly chose 10 brands of food products concerned in the market (4 brands of health tea made from loquat seeds or leaves, 4 brands of Prunus mume concentrate, and 2 brands of prune concentrate) and checked if they contain cyanide compounds in high concentration. Here NCAC provides relevant information to consumers based on the findings of the examination.

(The following web pages are written in Japanese)

  1. 1 "Safety and effectiveness of health foods - amygdalin" informed by the National Institutes of Biomedical Innovation, Health and Nutrition
  2. 2 "Handling of foods containing cyanide compounds" informed by the Health, Labour and Welfare Ministry on November 6, 2017
  3. 3 "Don't eat powdered loquat seeds" informed by the Ministry of Agriculture, Forestry and Fisheries

(English page for reference (Ministry of Agriculture, Forestry and Fisheries))

  1. 3Cyanogenic glycosides in loquat seeds

Main test results

Cyanide compound concentration

  • Regarding 3 brands of health tea made from loquat seeds, the cyanide compound concentration of the solution thereof did not exceed 10 ppm. It was considered that consumption of a large amount or highly concentrated solution should be avoided. On the other hand, even if over 10 ppm of cyanide compounds is detected, it may be recognized under the Food Sanitation Act that those consumed in small amounts does not pose a risk of health damage.4
  • Over 10 ppm of cyanide compounds was detected from 3 brands out of 4 brands of Prunus mume concentrate. However, it was considered that the recommended daily intake or less would pose a low risk of ill effects. The cyanide compound concentration of both 2 brands of prune concentrate was less than 10 ppm.
  1. 4 "Handling of flax seeds containing cyanide compounds" informed by the Health, Labour and Welfare Ministry on March 31, 2000

Advertisements and representation

  • Websites run by sellers of the brands, product packages and documents attached to the products did not indicate that the cyanide compound concentration was measured or that the excessive intake should be avoided.

Advice for consumers

  • Before using health tea, etc. made from loquat seeds containing cyanide compounds in high concentration, consider if the product is really necessary for you and get reliable information about safety thereof. When you use it, do not consume in large quantity at one time.

Request to businesses

  • Manufacturers and sellers of health foods, etc. containing over 10 ppm of cyanide compounds, made from loquat seeds or immature flesh of Prunus mume which are known to contain cyanide compounds in high concentration, are urged to consult your local health center right away. Take appropriate measures if necessary.
  • Ensure thorough quality control and take risk reduction measures for health foods, etc. made from ingredients which are known to contain cyanide compounds in high concentration.

Request to the government

  • NCAC requests the government to check health foods, etc. containing over 10 ppm of cyanide compounds, made from loquat seeds or immature flesh of Prunus mume which are known to contain cyanide compounds in high concentration, and to guide the manufacturers and sellers thereof as appropriate.
  • NCAC requests the government to continue thorough guidance for manufacturers and sellers of health foods, etc. made from ingredients which are known to contain cyanide compounds in high concentration.