Kuhnt Katrin, Wagner Andreas, Kraft Jana, Basu Samar, Jahreis Gerhard
Institute of Nutrition, Friedrich Schiller University, Jena, Germany.
Am J Clin Nutr. 2006 Nov;84(5):981-8. doi: 10.1093/ajcn/84.5.981.
High consumption of trans fat has been associated with high oxidative stress in humans, which could increase the risk of the development or acceleration of several diseases, such as atherosclerosis, cancer, and type 2 diabetes.
Several urinary and blood biomarkers of oxidative stress [8-iso-prostaglandin-F(2alpha) (PGF(2alpha)), 15-keto-dihydro-PGF(2alpha), and 7,8-dihydro-8-oxo-2'-deoxy-guanosine in urine and alpha-,beta-,gamma-,delta-tocopherol, and retinol in plasma] were monitored to evaluate the oxidative stress induced by dietary supplementation of 11trans- and 12trans-18:1 isomers in humans during a 6-wk intervention.
After a 14-d adaptation period free of trans fatty acid supplementation (baseline), the test group (n = 12) received 3.0 g 11trans-18:1/d and 3.0 g 12trans-18:1/d (Sigma 6.0 g/d), and the control group (n = 12) consumed a control oil free of trans fatty acids and conjugated linoleic acids for 6 wk.
The postintervention concentration of urinary 8-iso-PGF(2alpha) (free radical-induced lipid peroxidation) in the test group was significantly higher than baseline and significantly higher than that observed in the control group. The concentrations of 15-keto-dihydro-PGF(2alpha) (cyclooxygenase-mediated inflammatory response indicator) and 7,8-dihydro-8-oxo-2'-deoxy-guanosine (oxidative DNA damage) were not affected by the 11trans- and 12trans-18:1 supplementation.
Although an increase in urinary 8-iso-PGF(2alpha) was observed and the effects of prolonged high (ie, >5.0 g/d) consumption of trans fat could be relevant to the development of disease, the mean intakes of 11trans- and 12trans-18:1 in Europeans are estimated to be significantly below the amounts administered in this study (ie, 6.0 g/d); such low intakes could minimize the possible risk of detrimental effects on human health.
反式脂肪的高摄入量与人类的高氧化应激相关，这可能会增加多种疾病（如动脉粥样硬化、癌症和2型糖尿病）发生或加速发展的风险。
监测几种氧化应激的尿液和血液生物标志物[尿液中的8-异前列腺素-F(2α)（PGF(2α)）、15-酮二氢-PGF(2α)和7,8-二氢-8-氧代-2'-脱氧鸟苷，以及血浆中的α、β、γ、δ-生育酚和视黄醇]，以评估在为期6周的干预期间，饮食补充11反式和12反式-18:1异构体对人体诱导的氧化应激。
在经过14天无反式脂肪酸补充的适应期（基线期）后，试验组（n = 12）每天摄入3.0 g 11反式-18:1和3.0 g 12反式-18:1（Sigma共6.0 g/d），对照组（n = 12）在6周内食用不含反式脂肪酸和共轭亚油酸的对照油。
试验组干预后尿液中8-异-PGF(2α)（自由基诱导的脂质过氧化）的浓度显著高于基线水平，且显著高于对照组。15-酮二氢-PGF(2α)（环氧化酶介导的炎症反应指标）和7,8-二氢-8-氧代-2'-脱氧鸟苷（氧化DNA损伤）的浓度不受11反式和12反式-18:1补充的影响。
虽然观察到尿液中8-异-PGF(2α)有所增加，且长期高摄入量（即>5.0 g/d）的反式脂肪的影响可能与疾病发展相关，但据估计欧洲人11反式和12反式-18:1的平均摄入量显著低于本研究中的给药量（即6.0 g/d）；如此低的摄入量可能会将对人类健康产生有害影响的潜在风险降至最低。
