New method paves way for better dietary zinc test

April 10, 2014 by Krishna Ramanujan
New method paves way for better dietary zinc test
Elad Tako, left, and Spenser Reed ’14 collaborate in the lab.

(Medical Xpress)—Unlocking ways to monitor a key nutrient, Cornell research unveils a new method to test for zinc deficiency, a vital measurement that has posed problems for doctors and scientists.

After iron, is the most abundant trace mineral in human cells, playing a role in immunity, protein synthesis and wound healing. Dietary zinc deficiency affects one-quarter of the world's population, so accurate and sensitive measurements are needed. Measuring the micronutrient is complex because cells efficiently export zinc, which can be toxic.

The study, published March 20 in the journal Nutrients and led by first author Spenser Reed '14, uses ratios between two red blood cell fatty acids. One of those fatty acids, linoleic acid, requires a zinc-dependent enzyme to produce the second fatty acid, dihomo-gamma-linolenic acid (DGLA). In other words, without zinc, DGLA doesn't get made.

By measuring the abundance of linoleic acid relative to DGLA, and vice versa – the ratio of linoleic acid to DGLA becomes higher as zinc deficiency increases – the researchers have identified a potentially sensitive biomarker for testing the body's zinc status.

"One of the major challenges is to find a parameter that can detect differences between mild zinc deficiency and severe zinc deficiency, according to [standards set by the] the World Health Organization," said Elad Tako, the paper's senior author, a physiologist at the U.S. Department of Agriculture's Robert W. Holley Center for Agriculture and Health and a courtesy food science professor at Cornell. While more study is needed, the method holds promise as a nuanced biomarker, Tako added.

The researchers used broiler chickens in the study, partly due to their omnivorous appetites – which allowed the researchers to feed them purified diets – and because of their red blood cells, fatty acids and genetic similarities to humans.

In the study, one set of chickens was fed a controlled, purified diet with adequate zinc, while another set was fed a zinc-deficient but otherwise identical diet.

"We had to make sure that … the only difference was the dietary zinc and nothing else," said Reed, who works in Tako's lab. The researchers examined weekly blood samples, isolated the and extracted to determine the ratios of linoleic acid to DGLA.

Corroborating their findings, the researchers also examined zinc levels in feather and nail samples and measured the expression of 16 intestinal and liver genes related to zinc metabolism.

To measure a subject's zinc status, a wide variety of biomarkers are necessary, Reed said. The researchers hope to "add to the compendium of different markers that could be sensitive to ," said Reed, who plans to complete ongoing experiments in Tako's lab after graduating, with an eye toward medical school later. The researchers also plan to study the use of the ratio for testing zinc levels under natural diets.

Explore further: Potential diagnostic marker for zinc status offers insights into the effects of zinc deficiency

Related Stories

Potential diagnostic marker for zinc status offers insights into the effects of zinc deficiency

August 29, 2013
According to new research published in The FASEB Journal, a drop in blood zinc levels does not directly harm the blood vessel cells. Rather, zinc regulates the production of a small molecular compound, which then circulates ...

A link between zinc transport and diabetes

September 24, 2013
Individuals with a mutation in the gene encoding a zinc transporter, SLC30A8 have an elevated risk of developing type 2 diabetes. Insulin granules that are released from pancreatic β cells contain high levels of zinc; however, ...

Zinc deficiency mechanism linked to aging, multiple diseases

October 1, 2012
(Medical Xpress)—A new study has outlined for the first time a biological mechanism by which zinc deficiency can develop with age, leading to a decline of the immune system and increased inflammation associated with many ...

Zinc supplementation does not protect young African children against malaria

November 22, 2011
A study led by Hans Verhoef, a researcher at Wageningen University, the Netherlands, and the London School of Hygiene and Tropical Medicine, UK, and published in this week's PLoS Medicine shows that supplementing young Tanzanian ...

Recommended for you

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

A sodium surprise: Engineers find unexpected result during cardiac research

July 20, 2017
Irregular heartbeat—or arrhythmia—can have sudden and often fatal consequences. A biomedical engineering team at Washington University in St. Louis examining molecular behavior in cardiac tissue recently made a surprising ...

Engineered liver tissue expands after transplant

July 19, 2017
Many diseases, including cirrhosis and hepatitis, can lead to liver failure. More than 17,000 Americans suffering from these diseases are now waiting for liver transplants, but significantly fewer livers are available.

Lunatic Fringe gene plays key role in the renewable brain

July 19, 2017
The discovery that the brain can generate new cells - about 700 new neurons each day - has triggered investigations to uncover how this process is regulated. Researchers at Baylor College of Medicine and Jan and Dan Duncan ...

'Smart' robot technology could give stroke rehab a boost

July 19, 2017
Scientists say they have developed a "smart" robotic harness that might make it easier for people to learn to walk again after a stroke or spinal cord injury.

New animal models for hepatitis C could pave the way for a vaccine

July 19, 2017
They say that an ounce of prevention is worth a pound of cure. In the case of hepatitis C—a disease that affects nearly 71 million people worldwide, causing cirrhosis and liver cancer if left untreated—it might be worth ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.