Zinc shown to sharpen teenagers' mental skills

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Zinc shown to sharpen teenagers' mental skills

 

By ANDRÉ PICARD

 

Tuesday, April 5, 2005 Page A17

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PUBLIC HEALTH REPORTER

 

Teenagers who take zinc supplements are more attentive and responsive at

school, according to a new U.S. study. The research, among the first to

look at the impact of the essential micronutrient on adolescents,

suggests that many suffer from zinc deficiency.

 

Studies done on young children have shown zinc is essential for

developing eye-hand co-ordination and reasoning. In adults, it aids in

retaining memory and muscle strength as people age.

 

Dr. James Penland, a research psychologist at the Human Nutrition Center

in Grand Forks, N.D., said that while the new findings are intriguing,

" I wouldn't rush out and start giving my adolescent zinc supplements. "

Rather, he said, the study should lead nutritionists and policy-makers

to rethink how much zinc is required in a healthy diet, and if teens

need supplementation. He said the information could be used to tweak

school lunch menus, and to encourage more detail on food labels.

 

Teens are believed to be at particularly high risk of zinc deficiency

because they are growing quickly and tend to have poor eating habits.

The problem is particularly acute for girls because many adopt

vegetarian diets in adolescence.

 

Zinc is found principally in red meat, fish and whole grains. The

recommended dietary reference intake (known previously as the

recommended daily allowance) for zinc is 10 milligrams daily for

children and 15 mg daily for adults.

 

The new study, which was presented at the scientific conference of the

American Society for Nutritional Sciences in San Diego, involved 209

students in Grade 7 who received a daily fruit juice that contained

either 0, 10 or 20 mg of zinc over a period of 12 weeks.

 

At the beginning and end of the study, the teens underwent a battery of

tests designed to measure mental and motor skills, such as attention,

memory, problem-solving and eye-hand co-ordination. Students, teachers

and parents filled in questionnaires to measure the youths' psychosocial

functioning. Blood samples measured zinc before and after treatment.

 

Dr. Penland and his team found that the students who received the 20 mg

daily supplement of zinc markedly improved scores on all their mental

tests. Those who received either 0 mg or 10 mg of zinc had essentially

the same scores at the start and end -- which suggests the DRI should be

higher, at least for teenagers.

 

Zinc supplementation did not seem to improve motor skills or social

skills, the researchers found.

 

While zinc deficiency is a concern in wealthy countries such as Canada

and the United States, it is a much more severe problem in developing

countries. Chronic zinc deficiency is a leading cause of dwarfism and

stunted growth. Because lack of zinc leaves the immune system weakened,

children with zinc deficiency often suffer from diarrhea and respiratory

illnesses such as pneumonia, both leading killers of children.

 

A report released last year by the Micronutrient Initiative revealed

that as many as two billion people worldwide suffer from vitamin and

mineral deficiencies. This " hidden hunger " -- deficiencies in

micronutrients such as iron, iodine, vitamin A, folic acid and zinc --

causes the deaths of one million children, severe birth defects in

250,000 babies, and mental impairment in another 20 million children

each year.

 

About one in five people worldwide suffer from zinc deficiency.