Preservatives in meat linked to dementia

Narelle Towie, science and environment reporter

July 06, 2009 10:16am

PRESERVATIVES added to cured meats, bacon and ground beef have been linked to dementia diseases such as Alzheimer's and Parkinson's.

Scientists say sodium nitrite, which is added to meat and fish to destroy toxins, reacts with proteins in the meat, damaging human DNA cells similar to aging.

US researchers, whose work was edited by the director of the WA Centre of Excellence for Alzheimer's Disease Prof Ralph Martins and published today in the Journal of Alzheimer's Disease, say the problem is compounded by an increase in human exposure to nitrogen-containing fertilisers from soil run-off and water contamination.

More than 20,000 people in WA suffer from dementia - this number increases 10-fold nationally.
Prof Martins says Alzheimer's is reaching epidemic proportions in this country.

"Until this point there has been a lot of focus on defective genes but now it is becoming clear that really represents a small proportion of the total community who are at risk of getting Alzheimer's,'' he said.

"This study is important because it points to the environmental factors that can play a role in Alzheimer's disease,'' he said.

Study author and professor of pathology and lab medicine at Rhode Island Hospital in the US, Suzanne de la Monte, found that a massive rise in fertiliser and processed food sales coincided with an increased prevalence of Alzheimer's, Parkinson's' and type 2 diabetes in the US.

"We have become a 'nitrosamine generation,'' she said.

``The relatively short time interval for such dramatic increases in death rates associated with these diseases (Alzheimer's, Parkinson's and type 2 diabetes) is more consistent with exposure-related causes rather than genetic changes.''

Fertiliser in WA contains nitrogen.

But the Department of Agriculture was unable to provide information on whether consumption has increased here.

WA researchers are studying the link between Alzheimer's disease and type 2 diabetes, Prof Martins said.

Nitrites and nitrates are found in many food products including fried bacon, cured meats, cheese products and beer.

``In essence, we have moved to a diet that is rich in amines and nitrates, which lead to increased nitrosamine production. Nitrites and nitrates belong to a class of chemical compounds that have been found to be harmful to humans and animals,'' Ms De la Monte says.

Prof Martins says this environmental link needs to be studied further in Australia.

At the moment high-fat diet and low-exercise lifestyles are key factors thought to play a role in the onset of dementia, he says.

Heavy metals such as copper and zinc are also being blamed.

"Fish in the diet and omega 3 fatty acids in particular are protective of the brain but in terms of environmental toxins very little work has been done,'' Prof Martins said.