Positive results on tests for steatorrhea in persons consuming olestra potato chips

Olestra is a nonabsorbable fat substitute that consists of fatty acids esterified to a sucrose molecule.

To determine the effect of olestra consumption on measurements of fecal fat excretion.

Controlled cross-over trial.

Clinical research center and outpatient research laboratory.

10 healthy volunteers.

On days 1 to 6 of the study, participants consumed 5 oz of conventional potato chips per day; on days 7 to 12, they consumed 5 oz of potato chips containing 40 g of olestra per day.

Quantitative measurement of fecal fat by the van de Kamer titration, van de Kamer gravimetric, and Jeejeebhoy gravimetric methods and qualitative assessment of fecal fat by Sudan III staining.

Excellent correlation was seen among the three quantitative assays, but the van de Kamer titration method yielded lower measurements than the two gravimetric methods. When participants consumed 40 g of olestra per day, the excretion of fecal fat increased to levels observed in patients with steatorrhea caused by the malabsorption syndrome.

Consumption of olestra can cause false-positive results on tests for steatorrhea and may therefore lead to an erroneous diagnosis of the malabsorption syndrome.