DALLAS, TEXAS. Olestra is a synthetic fat substitute that resembles fat in texture and taste; it is not absorbed by the body and therefore sharply reduces the number of calories which would normally be absorbed from snack foods like potato chips. The fact that olestra passes through the intestine without being absorbed results in a higher than normal fat content in the stool and this, claims researchers at the Baylor University Medical Center, can cause serious problems when testing patients for suspected steatorrhea (malabsorption of fats).
The researchers performed a controlled cross-over trial involving
10 healthy volunteers. The participants, in addition to their
regular diet, consumed 5 oz of conventional potato chips per day
on days 1 to 6 and 5 oz of chips containing olestra per day on
days 7 to 12. The olestra chips provided 40 grams/day of olestra.
A total of 104 individual stool samples obtained during the
experiment were analyzed for fecal fat using four different
methods. The fat content in the "olestra stools" varied between
14 and 23 grams/day. This compares to a normal upper limit of 7
grams/day. Thus people who have eaten olestra-containing snacks
prior to being tested for malabsorption would be highly likely be
diagnosed as suffering from steatorrhea. This, the researchers
point out, could lead to unnecessary and expensive tests
associated with serious complications. Olestra may remain in the
stool for up to seven days so it is important that physicians
ensure that their patients have not consumed olestra in the week
prior to being tested for steatorrhea.