Experts develop new method to quantify the physiological status of zinc

The deficiency of Zinc is prevalent worldwide. The shortfall of this mineral in children leads to embryonic malformations, stunting, and neurobehavioral abnormalities. Science has advanced the knowledge on zinc metabolism over the past decades, however, a precise, comprehensive assessment tool for its physiological status in the human body has stayed evasive to date.

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Cornell food scientists recently created a novel evaluation method to precisely evaluate from biomarkers the physiological status of a subject—the Zinc Status Index.

Zinc is required by the human body needs zinc to increase immunity, control metabolism, and aid heal wounds. However, over 1 billion people—around 17% of the world population—experience dietary zinc deficiency. The World Health Organization requested the scientists of the world to develop a strong test to precisely identify if an individual is zinc deficient.

With global food insecurity and increasing domestic obesity rates, malnutrition is hitting vulnerable and low-income populations. These issues are a major concern, as they can lead to dietary zinc deficiency. Because of the complexity and sophistication of zinc metabolism, it is very difficult to accurately measure zinc status.”

Elad Tako, Associate Professor, Food Science, College of Agriculture and Life Sciences, Cornell University

Elad Tako created the index along with first author Jacquelyn Cheng ‘15, a doctoral student in food science, and Haim Bar M. S. ’10, PhD ’12, associate professor, University of Connecticut.

The study was published on September 27^th, 2021 in the Nutrients journal.

This research presents a significant advancement in the field of zinc nutrition and the associated physiological status. Using the Zinc Status Index will provide a better understanding of the challenges that are linked to poor zinc nutrition, and improve the ability to quantify the impact of dietary interventions aimed at alleviating zinc deficiency.”

Jacquelyn Cheng, Study First Author and Doctoral Student, Food Science, Cornell University

The Zinc Status Index includes a statistical model and pivots on three pillars:

• The ratio of linolenic acid (a fatty acid) to dihomo-gamma-linolenic acid ratio (another fatty acid)—called the LA: DGLA ratio. This was a Cornell-developed biomarker announced in 2014 by the Tako laboratory group (Spenser Reed ’14, first author)—which shows the subject’s physiological status
• Gene expression of zinc-dependent proteins impacted by zinc status
• The gut microbiome as a further tool to contemplate zinc physiological status

Moreover, Tako’s team demonstrated that mild zinc deficiency can alter gene expression in the body and that the microbial environment of the intestine is important for zinc metabolism. Zinc deficiency negatively impacts the composition of microbial populations in the intestine.

Tako states that it is possible to find out severe zinc deficiency.

However, it is difficult to differentiate between mild and moderate cases of zinc deficiency. Therefore, relying on only one biomarker may sometimes be an issue, which has led us to think how we could develop an accurate zinc status index, based on a panel of predictive biomarkers.”

Elad Tako, Associate Professor, Food Science, College of Agriculture and Life Sciences, Cornell University

Tako is worried about the undernourishment worldwide and the over nourishment in the United States. Undernourishment can result in zinc deficiency globally, specifically among vulnerable populations—including children.

Tako concludes, “Malnutrition is something that is becoming more of an issue in the US, particularly the double burden of malnutrition that basically connects obesity and mineral deficiencies, which means zinc and iron.”