By Karen Angelo
There’s a lot that scientists know about the benefits of zinc. The essential nutrient boosts the immune system, heals wounds and supports brain development in children. We even need zinc to smell and taste. Dive a little deeper, however, and the real mysteries of zinc emerge.
One of them – how zinc is distributed to tissues and cells – is the root of Prof. Shannon Kelleher’s research, which aims to reveal the role that zinc plays in the development of inflammatory bowel disease and food allergies.
“Zinc is critical for intestinal health, but we have little information on what it actually does in the intestine,” says Kelleher, who is based in UMass Lowell’s Biomedical and Nutritional Sciences Department in the Zuckerberg College of Health Sciences. “Our goal is to understand how zinc affects intestinal function, the gut microbiome and the risk for intestinal disease.”
We asked her to explain.
Q. What do we know about zinc and its effect on intestinal health?
A. We know that the right amount of zinc is critical to intestinal health. If we consume too much or too little zinc, the intestinal barrier falls apart. An over- or underabundance of zinc can cause shifts in the gut microbiome, and cause diarrhea and inflammation.
The only way that people can consume too much zinc is through supplements. If you get zinc only through foods in your diet, then you really can’t consume toxic amounts. However, if you only rely on your diet, then you may not be consuming enough. So finding the right balance is important.
Q. Is zinc deficiency a big problem?
A. One study from the National Institutes of Health shows that 35 to 45 percent of adults over 60 years old had lower-than-average zinc intakes. Scientists believe that about 7 to 10 percent of the U.S. population is severely lacking in the nutrient. Women of reproductive age are most likely moderately zinc-deficient due to menstruation and not eating the right foods. Symptoms of too little zinc include dry and itchy skin, loss of hair, reduced ability to taste food and a compromised immune system that leads to more colds.
Q. How much zinc should we be consuming?
A. The recommended daily allowances for zinc are 11 mg for men and 9 mg for women. Foods high in zinc include red meat, oysters, poultry, fish and some fortified breakfast cereals. But since excess zinc is also not healthy, don’t overdo it with supplements.
Q. Why is it important to find out how zinc travels through our bodies and cells?
A. If we knew how zinc gets into our cells, where it goes in our cells and what it does, then we could use this information to develop new therapies to fight a variety of diseases. These could include new drugs, delivery systems or personalized dietary recommendations.
Q. What else could your research results be used for?
A. Our research could also inform personalized nutrition. I teach an undergraduate course about an emerging field called nutrigenetics. We are now able to sequence your DNA and, based on your genetic blueprint, assess your risk for nutritional disorders and develop personalized diets that match your genetics. It helps to understand why individuals who eat similar diets can have different health outcomes. Your genetics play a crucial role in how you respond to what you eat.
Q. How does your work differ from nutritional science?
A. Nutritional science is often thought of as studies that look at how diet and foods affect human health and the risk for disease. The type of research we do is referred to as molecular nutrition. My research dives a little deeper to understand how specific nutrients – in this case, zinc – affect cellular and molecular processes that then cause the positive or negative effects we see in the body.