Their study published in the journal BioMed Central found that benfotiamine -- a synthetic derivative of the vitamin B1 -- does not actually dissolve and penetrate cell membranes as well as the researchers say is often claimed.
The findings highlight the problem of many widely available non-prescription medicines and supplements that are not regulated or vetted by scientific bodies.
"We studied the compound and found its properties were not as advertised," said Lucien Bettendorff, a biochemist at the University of Liege in Belgium, who led the study.
"It is said it is good for the brain but this is not the case, according to our study."
Vitamin B1, or thiamine, plays a key role in keeping cells healthy, and previous research has shown that diabetics have less of it in their blood.
Studies in mice have also suggested the synthetic compound could prevent blood vessel damage in diabetics. Bettendorff said his findings did not contradict these claims but noted such trials used very high doses of benfotiamine.
Instead, simple lab tests showed that benfotiamine as sold to consumers was not lipid-soluble -- which means it did not dissolve in organic solvents and oils to boost health by working quickly, he added.
The findings mean people who buy the supplement may be basing their decision on incorrect information because many manufacturers advertise benfotiamine as lipid-soluble, he added.
"It did not dissolve so it can't work its way through the membranes," Bettendorff said in a telephone interview. "This is clearly an error from a chemical point of view."
Güncelleme Tarihi: 12 Haziran 2008, 15:59