Zinc is an often overlooked mineral that is essential for health and immunity. Peta Bee explains why you should get enough
Certain vitamins and minerals are always top of an athlete’s agenda thanks to their purported immune-boosting, injury-defying properties, yet many of us never think about zinc. It’s to our cost because this mineral, found in plentiful amounts in meat, milk, eggs, fish, nuts and pulses and wholegrain cereals, is essential for performance and health.
Zinc helps to keep the immune system primed for attack from illness and viruses and is needed for cell division and wound healing. With too little in your diet, the chances of you bouncing back from injury or a bout of the sniffles will be compromised.
Why it’s crucial for athletes
There are other reasons to ensure you get enough. “Zinc is needed for growth, cell reproduction and testosterone production,” says the sports nutritionist Anita Bean, author of Sports Supplements: which nutritional supplements really work (Bloomsbury, £12.99).
“In theory, a deficiency may reduce the body’s anabolic hormone levels and adversely affect muscle mass and strength.”
Studies have shown that a lack of zinc can impair performance.
How it can cut a cold short
Last year, a meta-analysis of studies involving over 200 people and published in the journal Open Forum Infectious Diseases concluded that zinc lozenges can triple the speed of recovery from a cold – heartening news for those of you whose training is frequently stalled by the virus.
However, your zinc attack needs careful planning. According to the team of Finnish researchers who conducted the trial, doses need to be much higher than those commonly recommended by nutritionists to have the desired effect.
Indeed, daily doses of zinc ranged from 80 to 92mg a day—significantly higher than the recommended daily amount (RDA) in the UK, which is 5.5-6.5mg a day for men and 4.0-7.0mg for women.
Other studies have produced similarly promising results. And while it’s not certain how the mineral helps to aid cold recovery, it seems to have antiviral properties that prevent the cold virus from replicating or attaching to nasal membranes.
Where do you find it?
Good dietary sources include meat, milk, eggs, fish, chickpeas, baked beans, pumpkin seeds and muesli. Peanut butter, dried figs and Brazil nuts are reasonable sources, too.
In health food shops, zinc is widely sold either in its own right as lozenges or as a ZMA (Zinc, Magnesium Aspartate) supplement.
“It’s claimed that ZMA combination can boost testosterone production, increase strength and improve muscle mass as well as promote recovery after exercise,” Bean says.
“One study in 2000 found that ZMA increased testosterone and strength in a group of football players, but the study was small and with a high dropout rate.”
Not all zinc is equal
Zinc supplements and lozenges vary substantially and not all seem to offer the same benefits. In the Finnish trial, participants took zinc acetate lozenges or a placebo with the zinc tabs coming up trumps. The researchers pointed out that only properly formulated zinc acetate lozenges increase the rate of recovery from the common cold and that many other zinc products on the market appear to have either too low doses of the mineral or contain substances that bind zinc ions, such as citric acid.
Dr Harri Hemilä, one of the scientists behind the cold trial, suggests that “given the strong evidence of efficacy and the low risk of adverse effects, common cold patients may already be encouraged to try zinc acetate lozenges not exceeding 100mg of elemental zinc per day for treating their colds.”
Can you get too much?
“Very high intakes of zinc – more than 50mg a day – can interfere with the absorption of iron and other minerals, leading to a possible iron deficiency,” Bean says.