They say it is possible to use the readings to calculate the lifetime risk of heart disease and stroke.
The study, in The Lancet, is the most comprehensive yet to look at the long-term health risks of having too much "bad" cholesterol for decades.
The researchers say, however, the study suggests that earlier intervention can lower younger people's risk for heart disease.
The observational and modelling study used data from 398,846 people. It confirms that high blood levels of "bad" (or non-HDL) cholesterol are associated with a greater risk of developing cardiovascular issues including stroke and heart disease.
To learn just how much, the researchers analyzed individual-level data from almost 400,000 participants in 38 studies from 19 countries in Europe, Australia and North America. Study participants had no cardiovascular disease at the start of the analysis and were monitored for up to 43.5 years for the occurrence of a fatal or non-fatal coronary heart disease event or ischemic stroke. Here are five foods that can raise your bad cholesterol levels and you must avoid them if you have high cholesterol.
Looking at data for all age groups and both sexes, the authors found that the risk for a cardiovascular event decreased continuously with decreasing non-HDL levels.
Two U.S. heart experts unconnected to the study agreed that high levels of non-HDL cholesterol are problematic at any age.
The researchers collected data from 38 studies conducted in North America, Europe and Australia, comprising about 400,000 people without cardiovascular disease, a third of whom were younger than 45. Meanwhile, a man older than 60 with exactly the same characteristics has a 21% probability of having a heart problem by age 75.
Among women younger than 45, those percentages were 6% and 24%, respectively.
A slim, fit man of 34, he found he had a surprisingly high "bad" level of 4.0 mmol/L, which would give him a 19 percent chance of suffering a heart attack or stroke by the age of 75. In general, individual risk depends on cholesterol level and the presence of other cardiovascular risk factors, the authors emphasized. "Whether you get there with lifestyle or medication, it is imperative to substantially reduce lipid levels to reduce risk".
Their findings suggest that lowering cholesterol at an early age can significantly cut heart risk in later life.
"The second message is that you need to show these young people their potential risk". For women, the risk level was 16 per cent.
Rising levels of cholesterol among young adults is strongly tied to long-term odds for the number one killer, heart disease, a new study finds.
Researchers said that even those who were young and lived a healthy lifestyle could benefit from their hypothesis if they had a genetic risk.