Cadmium may cause cells to age more quickly, study suggests

Human exposure to the metal cadmium can cause much shorter telomeres, according to new research.
Telomeres are protective bits of DNA found on the end of chromosomes. Previous research indicates that the shorter a cell’s telomeres, the shorter its lifespan. Aging cells can cause cardiovascular disease, type 2 diabetes, and other diseases associated with older age.
The study suggests that by causing shorter telomeres cadmium accelerates the aging of cells, thereby increasing the risk of diabetes and other diseases.
The risks associated with cadmium
The World Health Organisation has described environmental exposure to cadmium a “major public health concern.” The metal has been associated with cardiovascular disease, respiratory problems, cancer, and other serious diseases. This study, the largest-ever to examine cadmium exposure and telomeres, suggests that cadmium-caused accelerated cell aging is to blame.
Sources of cadmium
There are a number of everyday sources of cadmium: Tobacco smoke is one source, leading to the World Health Organisation’s call for a ban on smoking in public places. Living near an industrial site is another common source.
The researchers added that the use of fertilizers and sludge on farm fields could also lead to the presence of cadmium in foods such as vegetables and fruit. People should not be put off eating vegetables and fruit, however, as research has consistently shown that a strong intake of fruit and vegetables has strong health benefits.
How the study worked
In the study, researchers examined the blood and urine samples of 6,700 adults. They took purified DNA from blood cells and measured the telomeres using a technique called polymerase chain reaction.
They then measured the levels of cadmium in the blood and urine samples. Based on the concentrations of cadmium in the samples, the study’s participants were divided into four groups. The group with the highest levels of cadmium had telomeres six per cent shorter than the lowest group.
What the findings suggest
Ami Zota, assistant professor of environmental and occupational health at Milken Institute SPH said, “We looked at heavy metal in this study and found a strong association between exposure to low levels of cadmium and telomere shortening.
“Our findings suggest that cadmium exposure can cause premature aging of cells. And they add to other evidence indicating this heavy metal can get into the bloodstream and trigger kidney disease and other health problems.
“People with the highest cadmium exposure had cells that looked an average 11 years older than their chronological age. This study adds to evidence suggesting that no level of exposure to this metal is safe.”
The study was conducted at the George Washington University, and published in the American Journal of Epidemiology.