London, Our kidney function deteriorates with age, even if people do not have any other diseases, say researchers.

Loss of kidney function is something that happens to all humans and is, thus, a way to determine ageing in general.

For the findings, published in the Journal of the American Society of Nephrology (JASN), the research team picked nearly 3,000 people in Norway, Germany and Iceland.

They examined the kidney function of a group of people between the ages of 50 and 70, and two groups of people between the ages of 70 to 95, to discover how the kidney function develops.

"What we see is that what happens in our kidneys when we age is representative of all the other things that happen in our bodies. The kidney function deteriorates, not because we get ill, but as part of ageing," said study author Bjorn Odvar Eriksen from UiT The Arctic University of Norway.

The research team examined many factors that can play a part as to why some of us experience larger loss of kidney function than others.

One of the groups that have participated in the study consists of over 1600 people and stems from The Tromso Study, which is Norway's most comprehensive and best participated population study throughout 40 years.

This group has been through the different examinations three times; between 2007 to 2009, 2013 to 2015, and 2018 to 2020.

The researchers used a precise method of measuring kidney function.

They injected a substance into the blood veins that only separates into the kidneys, and let a few hours pass before they measure how much of the substance remains in the blood.

According to the researchers, this gives a measure of the kidney's ability to remove toxins and waste products.

Eriksen explained that more people may experience loss of kidney function as it becomes more common to survive diseases like cancer and heart and vascular diseases.

"For those who experience loss of kidney function at a high age, this is a considerable burden. That is why this is an area that needs further research to find more answers. We are still looking for the fountain of youth," said Eriksen.