Some 40 kg of calves' brains has been imported into Japan from the United States this year, with 23 kg having been consumed at five restaurants in Tokyo and other cities, the health ministry said Friday.
The Health, Labor and Welfare Ministry revealed this information in an interim report, following the confirmation of the first U.S. case of made cow disease.
Brains are among the high-risk cattle parts -- along with spinal cords -- that could contain prions, abnormal proteins that are believed to cause bovine spongiform encephalopathy, as the brain-wasting disease is known scientifically.
According to a ministry survey tracing notified U.S.-made beef imports between Jan. 1 and last Tuesday, the brains were imported in three shipments. One of these shipments involved the 23 kg consumed at the restaurants.
Of the 17 kg imported in the two other shipments, 6 kg was found in stock and is now subject to a discard order, the ministry said, adding that it is trying to trace the remaining 11 kg.
Internal organs and bones of cattle were imported from the U.S. in 9,930 shipments during the period in question.