PLASMA-LIPOPROTEIN PROFILE AND LIPOLYTIC-ACTIVITIES IN RESPONSE TO THE SUBSTITUTION OF LEAN WHITE FISH FOR OTHER ANIMAL PROTEIN-SOURCES IN PREMENOPAUSAL WOMEN

A crossover study was conducted to examine the effects on plasma lipop rotein concentrations of substituting lean white fish (LWF) for beef, pork, veal, eggs, and milli products (BPVEM) within prudent isoenerget ic diets. Fourteen premenopausal women received 8784 kJ-20% as protein , 50% as carbohydrates, and 30% as lipids [ratio of polyunsaturated to monounsaturated to saturated fatty acids (P:M:S) of 1:1:1 compared wi th 0.4:1:1 in preexperimental diet]-and 260 mg cholesterol/d. After 4 wk, the BPVEM diet significantly reduced concentrations of plasma chol esterol, low-density-lipoprotein (LDL) cholesterol, high-density-lipop rotein (HDL) cholesterol, apolipoprotein B, HDL-apolipoprotein A-I, an d LDL-apolipoprotein B (P < 0.05) as well as plasma postheparin hepati c triacylglycerol lipase activity compared with the preexperimental di et. These effects are probably attributable to elevation of the P:M:S. These responses were not observed with the LWF diet, suggesting that fish protein in LWF maintains unchanged plasma cholesterol concentrati ons despite a high P:M:S. The LWF diet, compared with the preexperimen tal diet, reduced very-low-density-lipoprotein triacylglycerol (P < 0. 05) and also the ratio of LDL cholesterol to apolipoprotein B (P < 0.0 5), revealing the presence of denser LDL particles. Compared with the BPVEM diet, the LWF diet induced lower concentrations of very-low-dens ity-lipoprotein triacylglycerols (P < 0.05) and higher concentrations of LDL triacylglycerol and LDL apolipoprotein B (P < 0.05), which were not associated with any increase in lipoprotein lipase activity. Thes e results suggest that LWF as a substitute for BPVEM in isoenergetic d iets with an elevated P:S produces minimal improvement in the lipoprot ein profile in premenopausal women.