Zinc Helps Children Think

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Zinc Helps Children Think

04-11-2005 Eleven-year-olds that took zinc supplements for five days each week

had better mental performance after three months than their classmates, said

researchers yesterday.

The children taking an extra 20mg of zinc responded more quickly and accurately

on

memory tasks and with more sustained attention than classmates who did not take

the mineral.

Beneficial effects were seen regardless of the youngsters' previous zinc status,

said

the researchers led by Dr Penland from the US Agricultural Research

Service's Grand Forks Human Nutrition Research Center in North Dakota.

The findings, presented at the Experimental Biology meeting this week, suggest

that

there could be new demand for fortified foods and supplements for this age

group.

Although zinc nutrition has been related to motor, cognitive and psychosocial

function in very young children and adults, this is the first study of its

effect in

adolescents.

Zinc deficiency is not uncommon, even in nations such as the United States, and

the risk is particularly high in adolescents, said Dr Penland, because they are

undergoing rapid growth and often have poor eating habits. They may not consume

enough zinc-rich foods like red meat, fish and grains.

In the study, 111 girls and 98 boys consumed four ounces of fruit juice

containing

either 0, 10 or 20 mg of zinc gluconate each school day for 10 to 12 weeks.

Students, their parents and teachers did not know who was receiving which, if

any,

zinc supplementation.

At the beginning and end of the study, students performed a battery of tasks

designed to measure mental and motor skills, like attention, memory, problem-

solving and hand-eye coordination.

Students, their parents, and teachers filled out questionnaires about the

students'

mental, physical and social abilities and skills, school performance, and

problems in

any of these areas to provide a measure of psychosocial function.

Blood samples measured zinc status before and after the treatment.

Compared to the students who received no additional zinc, students who consumed

an additional 20 mg zinc each day decreased reaction time on a visual memory

task

by 12 per cent versus 6 per cent; increased correct answers on a word

recognition

task by 9 per cent versus 3 per cent; and increased scores on a task requiring

sustained attention and vigilance by 6 per cent versus 1 per cent.

Those who received only 10 mg a day, the US Recommended Dietary Allowances

(RDA) for this age group, did not significantly improve performance, however.

Supplementation at either the 10 mg or 20 mg did not appear to improve motor and

social skills, although girls receiving the placebo experienced a 10 per cent

increase

in conduct problems during the study while the behaviour of girls receiving any

level

of zinc supplementation remained unchanged, reported the researchers.

Previous studies have shown that zinc is needed for growth and immune function

and may be important for eye-hand coordination and reasoning in very young

children. It also appears to influence memory, muscle strength and endurance in

adults.