Tuesday, July 07, 2009

Nitrates May Be Environmental Trigger For Alzheimer’s, Diabetes And Parkinson's Disease

Researchers have found a substantial link between increased levels of nitrates in our environment and food with increased deaths from diseases, including Alzheimer's, diabetes mellitus and Parkinson's. The study was published in the Journal of Alzheimer's Disease.

Researchers studied the trends in mortality rates due to diseases that are associated with aging, such as diabetes, Alzheimer's, Parkinson's, diabetes and cerebrovascular disease, as well as HIV. They found strong parallels between age adjusted increases in death rate from Alzheimer's, Parkinson's, and diabetes and the progressive increases in human exposure to nitrates, nitrites and nitrosamines through processed and preserved foods as well as fertilizers. Other diseases including HIV-AIDS, cerebrovascular disease, and leukemia did not exhibit those trends.

Susan De la Monte, a professor of pathology and lab medicine at The Warren Alpert Medical School of Brown University, says, "We have become a 'nitrosamine generation.' In essence, we have moved to a diet that is rich in amines and nitrates, which lead to increased nitrosamine production. We receive increased exposure through the abundant use of nitrate-containing fertilizers for agriculture." She continues, "Not only do we consume them in processed foods, but they get into our food supply by leeching from the soil and contaminating water supplies used for crop irrigation, food processing and drinking."

Nitrites and nitrates belong to a class of chemical compounds that have been found to be harmful to humans and animals. More than 90 percent of these compounds that have been tested have been determined to be carcinogenic in various organs. They are found in many food products, including fried bacon, cured meats and cheese products as well as beer and water. Exposure also occurs through manufacturing and processing of rubber and latex products, as well as fertilizers, pesticides and cosmetics.

Nitrosamines are formed by a chemical reaction between nitrites or other proteins. Sodium nitrite is deliberately added to meat and fish to prevent toxin production; it is also used to preserve, color and flavor meats. Ground beef, cured meats and bacon in particular contain abundant amounts of amines due to their high protein content. Because of the significant levels of added nitrates and nitrites, nitrosamines are nearly always detectable in these foods. Nitrosamines are also easily generated under strong acid conditions, such as in the stomach, or at high temperatures associated with frying or flame broiling. Reducing sodium nitrite content reduces nitrosamine formation in foods.

Nitrosamines basically become highly reactive at the cellular level, which then alters gene expression and causes DNA damage. The researchers note that the role of nitrosamines has been well-studied, and their role as a carcinogen has been fully documented. The investigators propose that the cellular alterations that occur as a result of nitrosamine exposure are fundamentally similar to those that occur with aging, as well as Alzheimer's, Parkinson's and Type 2 diabetes mellitus.

The study was funded through grants from the National Institutes of Health. Two subsequent papers have been accepted for publication in the near future that demonstrate experimentally that low levels of nitrosamine exposure cause neurodegeneration, NASH and diabetes.

Steve - this is a timely study because there needs to be a distinction between nitrates/nitrites from processed meat and naturally-occurring forms in fruits and vegetables. A recent study appeared in the July issue of American Journal of Clinical Nutrition (see July 1 in our blog) exhibiting for the first time the benefits of nitrates/nitrites that occur naturally in fruits and vegetables. But those researchers were quick to point out there should be a major distinction between these and the chemical form that comes from processed foods. Meat products with added nitrates/nitrites for processing, preserving, and curing only apply; not steak, pork tenderloin, or ground beef for example.

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