Atherosclerosis can develop long before people notice anything is wrong, including in their 20s.
An international study suggests the artery disease is far more common among apparently healthy adults than previously thought.
Researchers studied 16,808 adults in Denmark and Spain, 18 to 70, who had no known atherosclerotic cardiovascular disease.
Imaging found plaque in 57.1% of participants.
The results were published in The New England Journal of Medicine (2026).
The study is the first phase of REACT, an eight-year research project examining silent atherosclerosis throughout adulthood.
Researchers used advanced imaging to look at three major vascular areas.
- Carotid arteries in the neck
- Femoral arteries in the legs
- Coronary arteries supplying the heart
They also collected information about cardiovascular risk factors, blood biomarkers, retinal images and other biological data.
About one in 13 adults 18 to 29 had evidence of atherosclerosis in at least one artery.
By 60 to 70, about nine in 10 participants had detectable atherosclerosis.
Atherosclerosis is the main underlying cause of cardiovascular disease, including heart attacks and strokes.
But having plaque doesn’t automatically mean someone will develop symptoms or suffer a cardiovascular event.
This arterial “sludge” can build up for decades without obvious warning signs.
The researchers found that most people with plaque in their coronary arteries also had plaque in either the carotid or femoral arteries.
Dr. Borja Ibáñez, one of the study leaders, said portable ultrasound, which can look inside carotid and femoral arteries, could potentially become a standard screening tool early in adult life.
Different Patterns in Men and Women
In men, the prevalence started increasing at younger ages.
Their overall pattern appeared about five to 10 years earlier than the pattern observed in women.
Women had their sharpest increase between 40 and 60, a period that broadly coincides with the menopausal transition.
Traditional Risk Scores Can Miss Plaque
Tools such as SCORE2 identified only a small share of participants who already had silent atherosclerosis.
In other words, someone can have a relatively low calculated cardiovascular risk while plaque is already forming inside the arteries.
Atherosclerosis can be detected decades before clinical symptoms appear.
The next question is whether finding silent plaque earlier and treating it sooner can reduce the likelihood of cardiovascular events.
Traditional prevention typically considers measurements such as blood pressure, cholesterol and smoking history.
Imaging via ultrasound can show whether plaque is actually present.
Finding plaque in someone who feels healthy doesn’t necessarily mean immediate treatment is required.
Atherosclerotic plaque varies in amount and characteristics, and the presence of plaque alone does not predict exactly what will happen to an individual.
Still, the high prevalence found in this study suggests that silent atherosclerosis begins much earlier and occurs much more often than many people might expect.
Only a minority of people in the youngest age group showed plaque, but the prevalence increased across adulthood until it was detected in most participants in their 60s.
