杏吧原创

AN INDEPENDENT statistician has dealt a fresh blow to the credibility of
experiments that questioned the safety of genetically modified food.

Graham Horgan of Biomathematics and Statistics Scotland (BioSS) took another
look at data compiled by Arpad Pusztai, a biochemist who used to work at the
Rowett Research Institute in Aberdeen. Pusztai claimed that potatoes engineered
to produce a lectin, a type of protein, caused abnormal development of internal
organs and immune suppression in rats
(This Week, 20 February, p 4).

Lynne Jones, Labour MP for Birmingham, Selly Oak, revealed Horgan鈥檚
conclusions at a hearing of the House of Commons Science and Technology
Committee on 8 March. 鈥淣o consistent pattern of changes in organ weights was
discernible,鈥� Jones told the committee.

Horgan鈥檚 reanalysis was commissioned by Pusztai himself, who also gave
evidence at this week鈥檚 hearings. But he seems to have drawn a different
conclusion from Horgan鈥檚 work. The studies 鈥渉ave now been fully verified by
independent statistical analysis鈥�, says his written evidence to the
committee.

Ron Kempton, director of BioSS, supports the conclusions described by Jones.
鈥淭here鈥檚 too much fog and background variation to pull out any systematic
effects,鈥� he says.

Data still to come may help to resolve the controversy. Stanley Ewen of the
University of Aberdeen, who examined the guts of Pustzai鈥檚 rats, has submitted
his work for publication in a peer-reviewed journal.