Advances in dietary enrichment with n-3 fatty acids.

Evidence for the effectiveness of the enrichment of food products with n-3 fatty acids by inclusion of either plant- or fish-derived materials in the diets of chickens, turkeys, ostriches, cows, pigs, and goats has been reviewed. Both linseed oil/meal and fish products can increase the levels of total n-3 fatty acids in animal products, including milk, eggs, meat, and deli products. The extent of this increase in n-3 fatty acid contents seems to be dependent on the nature of diet supplementation. Encapsulation of linseed oil may result in higher milk cow ALA contents, as compared to unprotected linseed oil. Available literature indicates that the levels of EPA and DHA in food products may be increased more, if the animals' diet was supplemented with fish products rather than linseed products. However, organoleptic properties of food products may be compromised. This pitfall may be reduced by the addition of antioxidants and/or application of micro-encapsulation. Generation of transgenic animals and plants has shown very promising results. Thus far, transgenic pigs and mice have been successfully generated. These animals have a low ratio of n-6:n-3 fatty acids in their tissues and milk. The advantages and disadvantages of the above-mentioned methods have been discussed. The evidence for health-promoting effects of such enriched food products has been included.