USE OF MANUFACTURED FOODS ENRICHED WITH FISH OILS AS A MEANS OF INCREASING LONG-CHAIN N-3 POLYUNSATURATED FATTY-ACID INTAKE

The objectives of the present study were to determine the feasibility of using manufactured foods, enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as a means of increasing the intake of these n-3 polyunsaturated fatty acids (PUFA), and to determine the ef fect of the consumption of these foods on postprandial lipaemia and ot her metabolic responses to a high-fat mixed test meal. Nine healthy, n ormotriacylglycerolaemic, free-living male volunteers (aged 35-60 year s) completed the randomized, controlled, single-blind, crossover study . The study consisted of two periods (each of 22 d) of dietary interve ntion, separated by a 5-month washout period. During these two periods the subjects were provided with the manufactured foods enriched with EPA and DHA (n-3 enriched) or identical but unenriched foods (control) . A mixed test meal containing 82 g fat was given to the fasted subjec ts on day 22 of each dietary intervention period. Two fasting,and ther eafter hourly, blood samples were collected from the subjects for an 8 h period postprandially. Plasma triacylglycerol, total and HDL-choles terol, non-esterified fatty acids (NEFA), glucose and immunoreactive i nsulin levels, post-heparin lipoprotein lipase (EC 3.1.1.34) activity and the plasma free fatty acid and phospholipid fatty acid composition s were measured. A mean daily intake of 1.4 g EPA + DHA (0.9 g EPA, 0. 5 g DHA) was ingested during the n-3-enriched dietary period, which wa s significantly higher than the intake during the habitual and control periods (P < 0.001) assessed by a 3 d weighed food intake. A signific antly higher level of EPA + DHA enrichment of the plasma fatty acids a nd phospholipids (P < 0.001) after the n-3-enriched compared with the control intervention periods was also found. The energy intake on both of the dietary intervention periods was found to be significantly hig her than on the habitual diet (P < 0.001), with an increase in body we ight of the subjects, which reached significance during the n-3 PUFA-e nriched dietary intervention period (P < 0.04). The palatability of th e enriched foods was not significantly different from that of the cont rol foods. Significantly higher fasting plasma HDL cholesterol and glu cose concentrations were found after the n-3 PUFA-enriched compared wi th the control intervention period (P < 0.02 and P < 0.05 respectively ). No significant differences were found for the postprandial lipid an d hormone measurements, except for significantly lower levels of NEFA at 60 min after the n-3-enriched intervention period (P < 0.04). Enric hed manufactured foods were a feasible vehicle for increasing n-3 PUFA intake. However the nature of the foods provided as the n-3 vehicle m ay have contributed to the increased body weight and higher energy int akes which were adverse consequences of the intervention. These factor s, together with the short duration of the study may have been reponsi ble for the failure to observe significant plasma triacylglycerol redu ctions in response to daily intakes of 1.4 g EPA + DHA.