The role of zinc during exercise is not well understood but some zinc-containing enzymes are thought to regulate energy expenditure.
The new trial, although small, suggests that more research should be done on the mineral and its impact on the cardiorespiratory function. It may be an important nutrient for sports nutrition.
A team from the US Department of Agriculture’s Agricultural Research Service tested the effects of low zinc intake on the physical performance of 14 men aged 20 to 31 years old.
They looked in particular at the effects on the carbonic anhydrase enzyme, found in red blood cells and influential on the body's removal of carbon dioxide, and cardiorespiratory function during exercise.
The men were split into two groups and fed either a diet containing only 3.8mg of zinc per day, or a diet supplemented with 18.7 mg of the mineral. They followed the diet for nine weeks, and after a six-week washout period, switched to the alternative diet.
The researchers tested physical performance on two types of exercist tests on a cycle ergometer.
They report in the May issue of the American Journal of Clinical Nutrition (vol 81, No. 5, 1045-1051) that peak oxygen uptake, carbon dioxide output, and respiratory exchange ratio were lower when the men had a restricted zinc intake than during the supplement phase.
Blood tests showed that when the men were on the low-zinc diet, the activity of the carbonic anhydrase enzymes in red blood cells was reduced.
This could explain the poorer muscle strength and increased tiredness seen in previous studies on zinc.
“These findings indicate that low dietary zinc is associated with significant reductions in zinc status, including red blood cell carbonic anhydrase activities, and impaired metabolic responses during exercise,” conclude the authors.
Comment: Zinc is also believed to play an important role in preventing or treating the following conditions:NSI L-Optizinc
Acne
Acrodermatitis enteropathica
Childhood intelligence (for deficiency)
Common cold (using lozenges with 15 to 25 mg of zinc glucanate, glycine or acetate)
Contact dermatitis (using zinc sulfate)
Down’s syndrome
Infertility (male) (for deficiency)
Improve studented growth in children (usually in developing countries)
Night blindness (for deficiency)
Wilson's disease (by interfering with body's ability to use essential mineral copper)
Wound healing (oral and topical)
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Christopher Wiechert's Healthblogger is for educational or informational purposes only, and is not intended to diagnose or provide treatment for any condition. If you have any concerns about your own health, you should always consult with a healthcare professional. To be removed from this e-mail program, reply back and say unsubscribe.
