A new study in the US finds that intakes of copper and zinc, two minerals found in many common foods, may be less than optimal in older adults.

A new study in the US finds that intakes of copper and zinc, two minerals found in many common foods, may be less than optimal in older adults.

Introduction

Copper and zinc may seem more like metals that belong in a hardware store than on a dinner plate. While you may find them in the plumbing supply aisle, the fact is that both are nutrients that everyone needs in order to maintain good health. They are essential components of enzymes that keep the body running, including one that helps remove potentially damaging "free radical" oxygen particles from cells. Even though the body uses only very small amounts of copper and zinc, health experts worry that the diets of some older adults may be short on these essential minerals. To evaluate this issue, scientists examined data from a large-scale, US food intake survey. Their results were published in a recent Journal of Nutrition.

Older adults may not be getting enough

Almost 3000 men and women over age 60, recorded everything they ate for 2 days as part the 1994-96 Continuing Survey of Food Intakes by Individuals (CSFII) in the US. Researchers analyzed their diets and compared their intakes of zinc and copper to the levels recommended by nutrition experts. Their results show that 75% of the volunteers did not consume the recommended amount of zinc and none met the intake guideline for copper. Men were more likely than women to meet nutrient recommendations for these minerals. This is often the case simply because men typically eat more food than women.

These finding are not surprising; other studies show that seniors consume sub-optimal amounts of a number of nutrients, including zinc and copper. Current recommendations do not differentiate by age for adults, largely because we are still collecting the data on which to set such recommendations. This is a concern because some research suggests that individuals may have even higher requirements as they get older, possibly because they absorb and utilize these nutrients less efficiently than do younger adults.

What is interesting about zinc is that, while there is no specific "zinc deficiency disease," too little can lead to weight loss, poor wound healing, taste changes, decreased appetite, and mental sluggishness. Any or all of these can occur as one grows older. Does that mean the so-called "inevitable" effects of aging are actually a zinc deficiency? That is quite unlikely. But marginal nutrient intake can effect general health and well-being.

Copper and zinc: food not pills

Researchers advise against using zinc or copper supplements. High doses are dangerous and can interfere with the absorption of other essential nutrients. So, these minerals should come from food. Oysters provide whopping amounts of both, but they are not routinely on most people's menus. The best way to ensure adequacy not only of these minerals, but of other essential nutrients as well, is to eat three meals plus a snack or two each day. A diet that includes whole grains, lean meats, legumes, and potatoes is particularly likely to deliver adequate amounts of zinc and copper.

Source

• Zinc and copper intakes and their major food sources for older adults in the 1994-96 Continuing survey of Food Intakes by Individuals (CSFII). J. Ma, NM. Betts, Journal of Nutrition, 2000, vol. 130, pp. 2838--2843

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