(Press-News.org) Researchers have highlighted the serious health risks associated with the diets of indigenous people by linking the accumulation of mercury in their primary food source to a decrease in the power of antioxidants.
Published today, 21 November, in IOP Publishing's journal Environmental Research Letters, the study used Alaskan huskies to demonstrate the risk posed by contaminants, such as mercury, in the subsistence diets that both indigenous people and huskies live on.
Huskies are an ideal model for humans as they are exposed to the same environmental hazards and have already been proven as an effective indicator of human ageing, immune function, toxicology and cognitive disorders.
Data taken from the huskies maintained on a diet of black bear, moose, pike and salmon showed an inverse correlation between mercury exposure and antioxidant status: as the mercury exposure increased, the antioxidant status of the huskies decreased.
Antioxidants – substances that play a critical role in protecting cells – stop electrons being ripped from other molecules. If antioxidants are not functioning properly, electron removal, also known as oxidation, can trigger chain reactions leading to cell damage and eventually cell death.
This damage, also known as oxidative stress, is thought to contribute to the development of a wide range of diseases including Alzheimer's, Parkinson's, diabetes and motor neuron disease. As such, antioxidants are widely used ingredients in a large number of dietary supplements, and have been investigated in the prevention of cancer and cardiovascular disease.
People in rural Alaskan communities live a subsistence lifestyle firstly to survive, and also to uphold traditional, cultural and spiritual values; however, they are becoming increasingly concerned with the health implications from foods such as pike and other fish due to the vast array of pollutants, such as mercury, making their way into the ecosystem. The main sources of mercury injection into the ecosystem are coal-generated power plants.
The researchers, from the University of Alaska Fairbanks, analysed groups of 12 huskies in four villages along the Yukon River and in a reference kennel. The huskies were typical racing dogs with similar lineage, sex and age and in their peak racing years. The huskies kept in the reference kennel were fed on a balanced, commercial diet.
After two months of feeding the huskies on the subsistence diets, blood samples were taken to determine their antioxidant power whilst hair samples were taken to determine total mercury concentrations in their body.
The lead author of the study, Professor Kriya Dunlap, said: "The amounts of mercury in the salmon are well below Environmental Protection Agency limits and the health benefits compared to processed food are still quite significant; however, the fact that health indices may be impaired by mercury levels indicates that monitoring should continue and that mercury generation should be monitored."
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Notes to Editors
Contact
1. For further information, a full draft of the journal paper or contact with one of the researchers, contact IOP Press Officer, Michael Bishop:
Tel: 0117 930 1032
E-mail: Michael.bishop@iop.org
Mercury interferes with endogenous antioxidant levels in Yukon River subsistence-fed sled dogs
2. The published version of the paper "Mercury interferes with endogenous antioxidant levels in Yukon River subsistence-fed sled dogs" (Kriya L Dunlap, Arleigh J Reynolds, S Craig Gerlach and Lawrence K Duffy 2011 Environ. Res. Lett. 6 044015) will be freely available online from Monday 21 November.
Environmental Research Letters
3. Environmental Research Letters is an open access journal that covers all of environmental science, providing a coherent and integrated approach including research articles, perspectives and editorials.
IOP Publishing
4. IOP Publishing provides publications through which leading-edge scientific research is distributed worldwide. IOP Publishing is central to the Institute of Physics (IOP), a not-for-profit society. Any financial surplus earned by IOP Publishing goes to support science through the activities of IOP.Beyond our traditional journals programme, we make high-value scientific information easily accessible through an ever-evolving portfolio of community websites, magazines, conference proceedings and a multitude of electronic services. Focused on making the most of new technologies, we're continually improving our electronic interfaces to make it easier for researchers to find exactly what they need, when they need it, in the format that suits them best. Go to http://ioppublishing.org/.
The Institute of Physics
5. The Institute of Physics is a leading scientific society promoting physics and bringing physicists together for the benefit of all.
It has a worldwide membership of around 40 000, comprising physicists from all sectors, as well as those with an interest in physics. It works to advance physics research, application and education; and engages with policymakers and the public to develop awareness and understanding of physics. Its publishing company, IOP Publishing, is a world leader in professional scientific communications. Go to http://www.iop.org
Huskies lend insight into mercury risk
2011-11-21
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