Increased intakes of zinc may decrease the risk of type-2 diabetes by 28 per cent, according to a new study from Harvard.
Before any firm conclusions can be drawn, however, the researchers, led by Qi Sun, caution that more studies are needed to confirm these finding, as well as to elucidate potential mechanisms.The results are published online ahead of print in the journal Diabetes Care.
Zinc, one of the most plentiful trace elements in the body, second only to iron, mediates many physiological functions.
It is believed to be essential for maintaining a healthy immune system; recent science suggests the mineral could also influence memory, muscle strength and endurance in adults. Zinc nutrition in very young children has been related to motor, cognitive and psychosocial function.
The Harvard study involved 82,297 women aged between 33 and 60 taking part in the Nurses' Health Study. Over the course of 24 years, 6,030 cases of type-2 diabetes were documented.
After relating the incidence of the disease with data obtained from a validated food frequency questionnaire, the researchers note that women with the highest average dietary intakes of the mineral were 10 per cent less likely to develop diabetes, while women with the highest average total intakes had their risk reduced by 8 per cent.
Further number crunching by the researchers took into account other potentially confounding factors, and showed that increasing intakes of the mineral were associated with a reduction up to 28 per cent.
The mechanism behind the effects is not known, and needs further study. Also, the research does not prove causality.
An estimated 19 million people are affected by diabetes in the EU 25, equal to four per cent of the total population. This figure is projected to increase to 26 million by 2030.
In the US, there are over 20 million people with diabetes, equal to seven per cent of the population. The total costs are thought to be as much as $132 billion, with $92 billion being direct costs from medication, according to American Diabetes Association figures (2002).
Source: Diabetes Care
Publish online ahead of print 26 January 2009, doi: 10.2337/dc08-1913
“A Prospective Study of Zinc Intake and Risk of Type 2 Diabetes in Women”
Authors: Q. Sun, R.M. van Dam, W.C. Willett, F.B. Hu