Oil-based products enriched with plant stanol esters can lower low-density lipoprotein (LDL) cholesterol concentrations by 10 - 14%. Effectiveness of low-fat products, however, has never been evaluated, although such products fit into a healthy diet. We therefore examined the effects of plant stanol esters emulsified into low-fat yoghurt (0.7% fat) on fasting concentrations of plasma lipids and lipid-soluble antioxidants, which may also change by plant stanol consumption. Sixty non-hypercholesterolemic subjects first consumed daily three cups (3 x 150 ml) of placebo yoghurt for 3 weeks. For the next 4 weeks, 30 subjects continued with the placebo yoghurt. while the other 30 subjects received three cups of experimental Yoghurt. Each cup provided 1 g of plant stanols (0.71 g sitostanol plus 0.29 g campestanol) as its fatty acid ester. LDL cholesterol (mean +/- S.D.) increased by 0.06 +/- 0.21 mmol/l in the placebo group, but decreased by -0.34 +/- 0.30 mmol/l in the experimental group. The difference in changes between the two groups of 0.40 mmol or 13.7% was highly significant (P < 0.001: 95% confidence interval for the difference, - 0.26 - -0.53 mmol/l). Effects were already maximal after 1 week. HDL cholesterol and triacylgiyeerol concentrations did not change. Total tocopherol levels increased by 1.43 mumol/mmol LDL cholesterol (14.0%, P = 0.015). beta-carotene levels, however, decreased by -0.02 mumol/mmol LDL cholesterol (-14.4%, P = 0.038). Decreases in absolute beta-carotene concentrations were found in all apoB-containing lipoproteins. LDL-cholesterol standardised phytofluene levels decreased by 21.4 +/- 25.7% (P < 0.001), while other plasma carotenoid (lutein/zeaxanthin, beta-cryptoxanthin, lycopene and alpha-carotene) levels did not change significantly. We conclude that low-fat yoghurt enriched with plant stanol esters lowers within 1 week LDL cholesterol to the same extent as oil-based products. LDL-cholesterot standardised concentrations of tocopherol increased. The observed decrease in beta-carotene levels, as found in many other studies, appears not to be limited to the LDL fraction. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.