Effects of dietary sesame seeds on plasma tocopherol levels

The tocopherols, the major vitamers of vitamin E, are believed to play a role in the prevention of human aging-related diseases such as cancer and heart disease, yet little is known concerning determinants of their plasma concentrations. Evidence from animal studies suggests that the dietary source of gamma-tocopherol can significantly affect plasma levels of this tocopherol as well as its functional vitamin E activity. To determine whether plasma levels of tocopherols in humans are similarly altered, a study was undertaken in which subjects (n = 9) were fed muffins containing equivalent amounts of gamma-tocopherol from sesame seeds, walnuts, or soy oil. We observed that consumption of as little as 5 mg of gamma-tocopherol per day over a three-day period from sesame seeds, but not from walnuts or soy oil, significantly elevated serum gamma-tocopherol levels (19.1% increase, p = 0.03) and depressed plasma beta-tocopherol (34% decrease, p = 0.01). No significant changes in baseline or postintervention plasma levels of cholesterol, triglycerides, or carotenoids were seen for any of the intervention groups. All subjects consuming sesame seed-containing muffins had detectable levels of the sesame lignan sesamolin in their plasma. Consumption of moderate amounts of sesame seeds appears to significantly increase plasma gamma-tocopherol and alter plasma tocopherol ratios in humans and is consistent with the effects of dietary sesame seeds observed in rats leading to elevated plasma gamma-tocopherol and enhanced vitamin E bioactivity.