Measuring Zinc, a Trace Element with a Large Impact

The trace mineral zinc has long been established as important in many organs of the body, from the pancreas, the central nervous system and even in the health of the retina.  Zinc reacts with over 300 enzymes in the body and is essential for processing carbohydrates, proteins lipids and other micronutrients.  Zinc is involved in maintaining immune function for fighting infections; it helps in healing wounds and is also important for the senses of smell and taste. A diet with adequate amounts of oats, wheat, eggs, meat and nuts usually provides all the zinc necessary. But as people age, their ability to absorb zinc from their food diminishes, and zinc deficiency can develop.
 Signs of zinc deficiency are often taken as simply the diseases of aging.  Frequent infections, memory problems, skin lesions and sleep disturbances are some of the signs but lack of zinc also plays a role in macular degeneration.  According to the original Age Related Eye Disease Study (AREDS) study subjects who took antioxidant supplements that included zinc had a 25% reduction in disease progression of macular degeneration.  The formula developed by this research study is frequently prescribed to help people who are in the early stages of macular degeneration to prevent or at least delay the onset of advanced macular degeneration and the loss of vision that accompanies it.
 But too much of a good thing can also be toxic.  Excess amounts of zinc can accumulate slowly over time or happen quickly if an abnormally high dose is taken.  Zinc can also be accumulated from exposure to paint or pesticides or even from inhaling fumes from welding or other manufacturing processes.  Zinc can accumulate in the kidneys and cause injury.  Cardiac and pancreas functions can also be impaired from excess of zinc. Too much zinc can present as nausea, irritability, headaches, lethargy or simply a bad taste in the mouth. Ultimately, too much zinc could even be fatal..  Using zinc supplements to ward off the diseases of aging, such as arthritis and macular degeneration should always be taken under the direct supervision of a physician to ascertain the correct dose for each individual patient.
 Zinc is mostly stored inside of cells and the amounts found circulating in blood are not adequate indicators of overall zinc .Laboratory analysis of blood is not always an accurate way to measure zinc levels in the body. Because it is a trace mineral that does its work inside many different types of cells, measuring the amounts of zinc in a body presents many challenges.  Now a group of researchers at Queen Mary University in London have discovered a technique to measure zinc content inside cells.  They created a range of small molecular probes with a selective sensitivity to bind with zinc on the surface of the cell that will indicate how much zinc is inside of the cells.  Different probes respond to specific tissue types.  Using one of the newly developed probes, they were able to observe in vitro the release of insulin from living islet cells in the pancreas. 
 The researchers believe that their newly developed technique will soon allow the creation of probes unique to different tissue samples and diseases with which to study zinc and zinc processes
Age-Related Eye Disease Study Research Group. A randomized, placebo-controlled clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS Report No. 8. Arch Ophthalmol. 2001;119:1417–1436. [PMC free article] [PubMed]
 Biologically targeted probes for Zn2+: a diversity oriented modular “click-SNAr-click” appro
J. Pancholi, D. J. Hodson, K. Jobe, G. A. Rutter, S. M. Goldup and M. Watkinson  
Chem. Sci., 2014, Advance Article DOI: 10.1039/C4SC01249F, Edge Article 
“Please before adding this or any other mineral or vitamin check with your medical doctor and eye care professional”

Review by Marcia McCall