Key findings:
In postmenopausal women, the bioavailability of fatty acids and lignans and the antioxidant and lipid-lowering effect s of bars containing 25g of whole unground flaxseed and sesame seed or their combination were assessed. Fatty acids and lignans were absorbed and metabolized. There were no changes in blood lipids or biomarkers of oxidative stress. Serum ALA and EPA increased after a combination of sesame seed with flaxseed but not following flaxseed alone. The bars showed antioxidant capacity in vitro as measured by TEAC but this did not translate into decreased oxidative stress, as assessed by the FRAP assay, A dose of 25g may not have been sufficient in a whole unground seed form to affect blood lipids over a 4wk period.
ABSTRACT:
Fatty acids and lignans in ground flaxseed and sesame seed are absorbed, metabolized, and exert some health benefits in vivo. However, it is unclear if they are absorbed, metabolized, and exert health benefits when consumed as unground whole seed; therefore, it was investigated in this study. In a randomized crossover study, 16 postmenopausal women supplemented their diets with food bars containing either 25 g unground flaxseed, sesame seed, or their combination (12.5 g each) (flaxseed + sesame seed bar, FSB) for 4wk each, separated by 4wk washout periods. Total serum n-3 fatty acids increased with flaxseed (p<0.05) and FSB (p>0.064) while serum n-6 fatty acids increased with sesame seed (p<0.05). Urinary lignans increased similarly with all treatments (p<0.05). Plasma lipids and several antioxidant markers were unaffected by all treatments, except serum gamma-tocopherol (GT), which increased with both sesame seed (p<0.0001) and FSB (p<0.01). In conclusion, fatty acids and lignans from unground seed in food bars are absorbed and metabolized; however, except for serum GT, the 25 g unground seed is inadequate to induce changes in plasma lipids and several biomarkers of oxidative stress. (Author’s abstract)
Link to Full Text