Eighteen healthy adult men participated in a six-week controlled consumption study, in which all food or beverage they consumed was provided for them over the course of the study. For the first two weeks, the men were given food with very low amounts of zinc plus a chemical (phytate) that reduces zinc absorption. Then the amount of zinc in their prepared food was increased by over 60%. Measures of zinc status – both functional and static – were taken at the beginning and end of the trial. After the increase in dietary zinc, plasma levels remained the same. However, functional measures of zinc status increased. Specifically, total absorbed zinc as well as serum levels of protective proteins involved in cellular repair increased. Over a thousand proteins were measured, and those that increased in function were proteins that help repair DNA damage and quell inflammation, many of which are zinc-dependent. Although plasma zinc remained the same, functional indicators of zinc status improved after an increase in zinc consumption.
Functional Indicators of Zinc Status Are More Telling Than Plasma Levels
