It has been hypothesized that phytochemicals found in fruits and vegetables are responsible for the inverse association observed between diets high in fruits and vegetables and risk of certain chronic diseases and cancer. This paper assesses the potential for olestra to affect the absorption of dietary phytochemicals and estimates the effect of olestra on the availability of carotenoids when olestra-containing snacks and foods containing carotenoids are eaten in free-living diets. Experimental data compiled on the effects of olestra on the availability of 29 compounds, mainly nutrients and oral medications, showed that olestra affects the availability of only molecules having octanol-water partition coefficients greater than approximately 7.5. Partition coefficients compiled for 382 dietary phytochemicals showed that only two classes of phytochemicals, phytosterols and carotenoids, contain molecules with octanol-water partition coefficients in the range in which olestra could potentially affect bioavailability. The potential effect on the bioavailability of phytosterols would be <10% and would not be expected to be of concern inasmuch as the hypothesized benefit of consuming pharmacological amounts of phytosterols is to reduce cholesterol availability, a function also of olestra. A 5.9% reduction in the average effective beta-carotene intake was calculated for individuals eating olestra-containing snack foods in free-living diets. The calculation was made by assuming that carotenoid bioavailability would be reduced to the extent measured in human clinical studies each time olestra-containing snacks and carotenoid-containing foods are eaten together and that all snacks eaten are made with olestra. Among individuals with low carotenoid intakes (the lowest 10%) the calculated reduction was 6.0%; for heavy snack eaters (the top 10%) it was 9.5%. These effects on carotenoid bioavailability are similar to those that can occur with other dietary factors.

Caprenin is a triglyceride that contains primarily caprylic (C8:0), capric (C10:0), and behenic (C22:0) acids and modest amounts of arachidic (C20:0) and lignoceric (C24:0) acids. Using the fat-balance technique, the absorption of C20:0, C22:0, and C24:0 was measured in 20 healthy adult men and women aged 20–60 years consuming a chocolate-flavored caprenin confection. The absorption values for these very long-chain fatty acids (VLCFAs) were determined based on measurements of their dietary intake and fecal excretion during a 5-day treatment period and a 7-day posttreatment washout period after correcting for baseline excretion of VLCFAs. Each subject consumed 4.7 g C20:0, 52.8 g C22:0, and 0.84 g C24:0 from the test confection during the treatment. Absorption averaged 41.6% ± 3.6% (SEM) for C20:0, 28.8% ± 4.4% for C22:0, and 14.8% ± 3.9% for C24:0. Using a modification of the Atwater method, the physiological fuel value (caloric value) of caprenin was then calculated. This modified method takes into account the partial absorption of VLCFAs and the heat loss due to the metabolism of the medium-chain fatty acids C8:0 and C10:0. The results of this study demonstrate that the caloric value of caprenin is 5 kcal/g compared to the value of 9 kcal/g for other dietary triglycerides.

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Caprenin (CAP) is a triglyceride that primarily contains caprylic (C8:0), capric (C10:0), and behenic (C22:0) acids. This study was undertaken to determine whether or not CAP is qualitatively digested, absorbed, and rearranged like other dietary fats and oils that contain these medium-chain and very long-chain fatty acids. In vitro results showed that neat CAP, coconut oil (CO) and peanut oil (PO) were hydrolyzed by porcine pancreatic lipase. All of the neat triglycerides also were digested in vivo by both male and female rats. This was shown by the recovery of significantly more extractable lymphatic fat than with fat-free control animals and by the recovery of orally administered triglyceride-derived fatty acids in lymph triglycerides. However, substantially more PO (74%) and CO (51%) were recovered in lymph relative to CAP (10%). These quantitative differences are consistent with the fatty acid composition of each triglyceride and primary routes of fatty acid uptake. The 24-h lymphatic recovery of CAP-derived C8:0, C10:0, and C22:0 averaged 3.9%, 17.8%, and 11.2%, respectively, for male and female rats. The C8:0 and C10:0 results approximated those obtained with CO (2.0% and 16.3%, respectively). In contrast, the 24-h absorbability of C22:0 in CAP was significantly less than that seen in PO (55.4%). Finally, there was no evidence of significant rearrangement of the positions of fatty acids on glycerol during digestion and absorption. Those fatty acids recovered in lymphatic fat tended to occupy the same glyceride positions that they did in the neat administered oils. However, the lymph fats recovered from all animals dosed with fat emulsions were enriched with endogenous lymph fatty acids. It is concluded that CAP is qualitatively digested, absorbed, and processed like any dietary fat or oil that contains medium-chain and very long-chain fatty acids.