Incorporation of dairy lipids in the diet increased long-chain omega-3 fatty acids status in post-weaning rats

In human nutrition, optimized the status of n-3 long-chain polyunsaturated fatty acids (LCPUFA) and especially docosahexaenoic acid (DHA) during growth appears to be one of the most important goal We investigated the potential impact of a partial incorporation of dairy lipids (DL) in the diet to increase the n-3 LCPUFA content in tissues, compared to a mixture of vegetable oils Rats were fed with vegetable oil diet or DL diet, supplemented or not supplemented with DHA, from weaning for 6 weeks All diets provided the same quantity of 2.3% of total fatty acids of precursor alpha-linolemc acid LCPUFA levels in brain, retina, liver, heart, red blood cells and epididymal adipose tissue, A-6 desaturase activity and mRNA expression in liver, and plasma cholesterol were measured Rats fed a DL diet increased their DHA content in brain and retina compared with rats fed a vegetable oil diet and reached the same level than rats directly supplemented with DHA The status of n-3 docosapentaenoic acid increased with DL diet in heart, red blood cells and liver The n-3 docosapentaenoic acid specifically discriminated DL diets in the heart DL diet increased alpha-linolemc acid content in liver and epididymal adipose tissue, provided specific fatty acids as short- and medium-chain fatty acids and myristic acid, and increased plasma cholesterol We hypothesized that dairy lipids may increase the n-3 LCPUFA enrichment in tissues by preserving precursor alpha-linolemc acid from beta-mitoehondrial oxidation, associated with the presence of short- and medium-chain fatty acids in DL diets In conclusion, a partial incorporation of dairy lipids in the diet with an adequate u-linolenic acid content improved the n-3 LCPUFA status, especially DHA in brain and retina