Chronological age is an unreliable guide to our future health prospects. Some people are robust in their nineties; others are chronically sick decades earlier.
So, top scientists have come up with a better gauge of health – the level of inflammation within the immune system.
Researchers say that this inflammatory aging clock, or iAge, predicts how soon we’ll become frail, and whether we’re likely to suffer a whole host of age-related diseases.
Low grade, chronic, body-wide inflammation starts to develop as we get older. It damages organs and tissues, and increases the risk of cancer, cardiovascular disease, neurodegenerative disorders, and other illnesses.
Moreover, because many hallmarks of aging are linked to sustained systemic inflammation, it could play a critical role in regulating the aging process. Scientists at Stanford University and the Buck Institute for Research on Aging measured inflammatory markers as they relate to aging, and their findings were very interesting.
Better Predictor of Frailty
They began their research by drawing blood from 1,001 healthy participants aged eight to 96. The researchers tested the blood samples and then employed artificial intelligence to boil down the data to a set of inflammatory predictors that they called an inflammatory clock, or iAge.
The team identified a set of fifty immune-signaling proteins (cytokines) as the strongest predictors of aging. These generated an inflammatory score that was successful in tracking each participant’s immune response and their likelihood of incurring any one of the diseases of aging.
The next phase of the study involved 30 adults, aged 65 or older, whose blood was drawn in 2010 and who also undertook a battery of physical tests. In addition, these participants completed a questionnaire about their ability to live independently.
Seven years later, the researchers found that using the participants’ iAge was superior to using their chronological age to predict frailty.
But the researchers didn’t stop there. For the next test they turned to Italy and some of the oldest people in the world.
Centenarians Have Young Immune Systems
The scientists obtained blood samples from 28 Italians aged 100 or older living in the city of Bologna. The team believed that their inflammatory ages, which on average were 40 years younger than their calendar age, was the reason for their long lives. For example, one remarkable individual had an inflammatory age 80 years younger than the 105 candles on his birthday cake.
Next the research team turned to the long running Framingham study, which has been tracking the health of participants and their children since 1948. Although data on the blood proteins the scientists needed was lacking, they were able to use genetic information as a proxy, since the genes that dictate the production of inflammatory cytokines are well known.
The researchers found iAge gene signatures of the participants were significantly associated with all-cause mortality.
CXCL9 – a Key Indicator of Heart Health
In their studies of the 50 gene components, one called CXCL9 stood out.
CXCL9 is a cytokine secreted by types of immune cells and by endothelial cells that line the blood vessels. Levels of CXCL9 rise quickly after the age of 60 and have been implicated in cardiovascular disease.
To test the importance of this marker they selected almost a hundred people aged 25 to 90 who appeared to be in excellent health. Then they monitored for impairments to this marker and whether or not these impairments could lead to strokes, heart attacks and kidney failure in the future.
They found that high iAge scores and CXCL9 levels were linked to these hidden cardiovascular risk factors. The research also revealed that with advanced age CXCL9 levels rise rapidly in the endothelium of blood vessels, diminishing its ability to function normally.
The scientists’ final tests were conducted on mice and human cells. These tests showed that by reducing CXCL9, the researchers restored youthful endothelial cell function.
Study leader Nazish Sayed explained the importance of the research, saying, “Eventually, iAge could be a powerful diagnostic marker…to identify healthy older adults who risk developing early cardiovascular aging as well as younger people at risk for life-threatening diseases.
“In the end, all we hope is that iAge becomes part of a person’s annual check-up, another indicator that contributes to making aging healthy.”
As far as I can tell, the iAge test is not yet available to consumers. If you’d like to learn more about the test, visit the company website at https://edificehealth.com/iage/