Research from Oregon State University offers new insights into the role that zinc plays in bolstering the immune system — and suggests that our need for the mineral could increase as we age.
“For me, zinc is a nutrient that doesn’t get a lot of press or public attention; it’s kind of an under-the-radar nutrient,” said Emily Ho, an OSU professor and director of the university’s Moore Family Center for Whole Grain Foods, Nutrition and Preventive Health.
Ho is the lead author of a recent study on zinc that was published recently in the journal Molecular Nutrition & Food Research. Co-authors of the study are Carmen P. Wong and Nichole A. Rinaldi of OSU’s College of Public Health and Human Sciences.
Some of us take zinc at the first sign of a cold, and Ho said that the mineral does play a vital role in the immune system.
“One thing I find really interesting about zinc is that, basically if you name a protein in our cells, the majority of them use zinc in some way,” Ho said in an interview last week. “To me, that means if you don’t get enough of it, a lot of different things can go wrong.”
Ho offers an explanation in terms that are, perhaps, not completely scientific: “One of the things that appears to go wrong when you don’t get enough zinc is that your immune system seems to go wonky. It goes wonky in a couple of different ways.”
One way: “The immune system seems to be suppressed, so you’re more susceptible to infections,” he said.
But there’s another way: A zinc deficiency also appears to induce an increase in inflammatory response in cells. That’s potentially a big deal because certain chronic ailments such as cardiovascular disease, cancer and diabetes seem to involve inflammation.
And older people are among the groups most susceptible to zinc deficiencies, Ho said, for a couple of reasons.
First, she said, older people tend to consume less zinc that their younger counterparts, in part because older people tend to eat less of the types of protein-rich foods that are relatively high in zinc.
And there’s another reason: Evidence increasingly suggests that older people don’t absorb zinc as efficiently as do younger people.
“So it’s kind of a double whammy,” Ho said.
To make matters worse, there’s no reliable diagnostic test to determine if someone is suffering from a zinc deficiency. A doctor trying to get even a rough reading on a person’s zinc levels can order a blood test, but Ho said zinc tends to concentrate in the body’s tissues, so those blood levels won’t necessarily reflect actual zinc levels.
Ho said it’s not yet clear why older people tend to absorb zinc less efficiently than younger whippersnappers. More research into that question is required.
But Ho’s work has one strong implication: Currently, the dietary recommendations for zinc (11 milligrams daily for men and 8 milligrams for women) are the same regardless of age. “What I’m trying to do is establish from the research perspective that we need to rethink that,” to build a case that the recommendations need to be higher for people 65 and older.
If that happens, zinc would join a select group of nutrients: Dietary recommendations for vitamin D and calcium are higher for older people, in part because of the role they play in bone health.
It’s all part of Ho’s work to move zinc, that “under-the-radar” nutrient, into the front lines.
“Ultimately,” she said, “my dream would be to be able to establish an age-specific requirement for zinc and to be able to back up all this basic research with a recommendation in terms of older individuals to make sure they get enough zinc.”