Flaxseed increased alpha-linolenic and eicosapentaenoic acid and decreased arachidonic acid in serum and tissues of rat dams and offspring.

The effects of dietary flaxseed (FS), and defatted flaxseed meal (FLM) on serum and tissue fatty acid profiles were investigated. Pregnant Sprague-Dawley rats were fed AIN-93 based diets balanced in calories, fat, nitrogen, and fiber. Diets contained 0, 20%, 40% FS or 13% or 26% FLM by weight. The control, FS and FLM diets differed in linoleic acid to alpha-linolenic acid (ALA) fatty acid ratio. These diets were fed continuously during gestation, suckling period and 8 weeks post-weaning (F(1)). FS fatty acids were bioavailable and metabolized by pregnant and F(1) rats. ALA and eicosapentaenoic acid increased; linoleic and arachidonic acid decreased; and docosahexaeonic acid was unchanged in serum, 'gastric milk' and liver of FS and FLM-fed pregnant and F(1) rats. FS more than FLM, changed fatty acids profiles, but FLM and 40% FS significantly reduced serum cholesterol. Dietary 40% FS may have increased oxidative stress as evidenced by a reduction in liver vitamin E.