According to the old saying, age is just another number. However, scientists in the U.S. believe that we focus on the wrong number.

These experts claim that instead of measuring the age at which we are in our final years of life, our ability to measure our inflammation age should be used as a way to gauge our state.

The scientists, from Stanford University and the Buck Institute for Research on Aging, have now developed a blood test to measure inflammatory age (or iAge), a measure of chronic inflammation — and say that checking it regularly could provide an early warning of inflammation-related conditions from heart disease to dementia. 

We would have the opportunity to make lifestyle and medication changes that will improve our health.

As Dr Nazish Sayed, an assistant professor of vascular surgery at Stanford, explains: ‘We are all going to age and we are all going to die — the only difference is how well we age,’ he says. 

‘The goal is a healthier old age — to prevent some of the ill health associated with ageing and make ageing more graceful.’

US  scientists have now developed a blood test to measure inflammatory age, or iAge, and say checking it could provide an early warning of inflammation-related conditions (stock image)

US  scientists have now developed a blood test to measure inflammatory age, or iAge, and say checking it could provide an early warning of inflammation-related conditions (stock image)

The research, published in Nature Aging, is based upon the realization that chronic inflammation plays an important role in diseases.

We are all familiar with acute inflammation — the fever, swelling and pain that plays a vital role in the healing of wounds and in fighting off infections, which typically lasts only days.

A chronic, low-level inflammation is, in contrast, something that persists over time and can cause damage to our cells, organs, and may be linked with many diseases like type 2 diabetes, and even cancer.

Levels of inflammation increase as we get older, likely due to ageing cells releasing inflammation-fuelling molecules. Stress, smoking, obesity and pollution can all contribute to inflammation.

The effects of the damage are often gradual enough that it is not obvious for many years. Until we begin to experience symptoms like high blood pressure.

Researchers analysed the blood of more than 1000 people to find out if there were any levels 50 cytokines. These are immune system proteins that can be implicated in inflammation. 

A combination of blood results and information on the health status of participants revealed that there was a cytokine “signature” associated with poor health.

The researchers used this to calculate a person’s iAge — their biological age based on their levels of inflammation.

A 45 year old person with an iAge above 65 would be 20 years younger than they should because of the harmful effects of inflammation. 

Another experiment confirmed the assertion that the inflammatory age of our bodies is a more reliable indicator of our health than our chronological years.

The iAge was calculated using blood samples from 37 Italians.

Half the participants were between 50-60 years of age and were in average health. The other half were in excellent health, having lived 100+ years. 

Levels of inflammation increase as we get older and can also be worsened by factors such as smoking, obesity, pollution and stress (stock image)

The levels of inflammation rise with age and may be increased by stress, smoking and obesity (stock image).

Averagely, the iAge of centenarians was 40 years less than their actual ages. The iAge of most younger people was much higher than their chronological ages.

Some individual results were more impressive.

“We do have an outlier,” says immunologist Dr David Furman. 

Researchers also found that the iAge of a person can be used for predicting who may become frail or needing assistance in daily activities such as washing, dressing and cleaning.

They were also able to identify those who are most likely to suffer from left ventricular hypertrophy, which is a condition that increases the likelihood of developing heart disease. This causes the heart to work harder to pump blood throughout the body.

Good Health spoke to Arne Ashbar, a Professor of Immunology at University College London, and President of the British Society for Immunology. He said that iAge was a sophisticated way of measuring age-related increase in inflammation.

But he says that there are still other ways to determine increased inflammation in the aging process, like measuring C-reactive Protein levels [a compound that is a marker of inflammation and can be measured with a simple blood test]. 

‘This raises the question of how sophisticated the measurement of inflammation should be to predict health — and which is easiest and cheapest.’

While the test may not become widespread for many years, Dr Sayed sees this being performed every year along with regular checks such as cholesterol.

People with high levels of inflammation may try to reduce their iAge. This may be through exercising more or changing their diet — both of which can dampen chronic inflammation. You may also find new iAge lowering drugs.

Researchers found that a cytokine called CXCL9 is strongly connected to iAge. A new drug which lowers it could be beneficial in keeping the body young and healthy.

The biologist, Dr Alan Cohen from Sherbrooke University, Canada warns, however, that drug that treats one component of the immune mechanism could lead to unintended consequences. 

He added: “Ageing can be multidimensional. There isn’t one thing that will tell you exactly what your biological age.”