| Identification of disease risk and healthy lifestyle choices are the strategies promoted to reduce the increasing demand of chronic diseases on health, as well as fiscal resources. Among the preventative lifestyle choices, a plant-based diet is highly regarded. Dietary lignan and isoflavone and other plant derived substances have been studied for their multiple health benefits. Regarding cancer and CVD, these benefits include lowering oxidative stress in the body via antioxidants. Collectively, endogenous and exogenous antioxidants are viewed as significant in mitigating the effects of oxidative stress related to the development of chronic diseases. The objective of this study was to quantify two biomarkers of oxidative stress, 8-epi-PGF 2alpha isoprostane and 8-hydroxydeoxyguanosine (8-OHdG) following supplementation with the rich sources of lignan and isoflavone, flaxseed and soy respectively. There is considerable interest in these biomarkers for use to identify populations at increased risk for CVD and cancer. Urine samples were obtained during two separate randomized crossover trials that administered flaxseed or soy treatment. The flaxseed study included 31 postmenopausal nuns between 52 to 82 years who consumed their habitual diet in addition to a 0g, 5g or 10g supplement of ground flaxseed for 7 weeks. The soybean study included 19 adult men (n=10) and women (n=9) between 18-35 years, who also maintained their regular diet in addition to a 0g or 29g soy supplement. Results from both the flaxseed and soy studies showed no change in urinary excretion of 8-epi-PGF2alpha and 8-OHdG. We also measured the mammalian lignan, enterolactone produced following consumption of 0g, 5g, and 10g flaxseed and found a dose-dependent increase in serum enterolactone. |
