The evidence of the connection now receives further support with studies at the Sahlgrenska Academy, where high concentrations of cadmium were detected in atherosclerotic arteries, which have been stored in a biobank.
Atherosclerosis is a contributor to widespread diseases such as heart attack and stroke. What is meant by atherosclerosis is that the artery wall builds up plaque – a local thickening which includes fat and other components. When a plaque becomes inflamed and ruptures, this gives rise to blood clots which in turn can cause serious medical condition, e.g. a heart attack.
Major scientific studies in the USA indicate that cardiovascular diseases are associated with high cadmium levels in blood and urine. Experiments with animals also suggests that cadmium can cause atherosclerosis.
In studies of 4,500 middle-aged men and women, researchers at the University of Gothenburg’s Sahlgrenska Academy have examined in-depth the relationship between atherosclerosis and the body’s cadmium levels. The studies, conducted in joint collaboration with researchers from Malmö University and Lund University, show that increased exposure to cadmium also increases the risk of plaque in the carotid artery. The results persisted even after adjusting for other known risk factors such as smoking, high blood pressure, cholesterol and diabetes.
For many years there has been a biobank at the Sahlgrenska University Hospital, which has collected plaques from the carotid arteries and frozen blood samples from hundreds of patients who were operated because of cerebral symptoms caused by these plaques. Via an analysis of this material, Björn Fagerberg and his research colleagues have shown that the cadmium content in such plaques was 50 times higher than in the blood samples.
“Taken all together, these studies strongly support the hypothesis that cadmium contributes to the onset of cardiovascular disease. The results underline the importance of intensifying efforts to reduce the population’s exposure to cadmium,” observes Björn Fagerberg, a researcher at the Sahlgrenska Academy.
Measures to reduce exposure
Examples of measures to reduce exposure to cadmium include, according to the Gothenburg researchers, the need to improve one’s dietary intake via protecting farmland from cadmium pollution and intensifying efforts against smoking (as exposure to tobacco smoke results in an excessive exposure of cadmium).
Exposure to cadmium via one’s diet occurs primarily via whole meal products, potatoes and root vegetables. According to the Gothenburg researchers, however, in their opinion the health benefits of whole grains outweigh the risk of intake of cadmium.
The article “Is Cadmium Exposure Associated with the Burden, Vulnerability and Rupture of Human Atherosclerotic Plaques?” was published in the journal PLOS One on March 27, 2015.
The article “Cadmium exposure and atherosclerotic carotid plaques – Results from the Malmö diet and Cancer study” was published in the journal Environmental Research, in November 2014.
Cadmium is a toxic, carcinogenic heavy metal that is used in, among other things, plastics, batteries and paint pigments. Cadmium also has been spread via extractive mining operations and industrial processes. A heavy exposure of agricultural land in Sweden occurred in the 1900s via the use of cadmium-containing fertilizers. The cadmium content in arable land varies across the country and is the level is influenced both by the fallout from incineration and various different types of fertilizers.
Cadmium accumulates in the kidneys, liver and other organs, and is excreted very slowly. In Sweden, the overall exposure to cadmium is low compared with the situation in other countries.
Björn Fagerberg, researcher at the Sahlgrenska Academy, University of Gothenburg