London - Young people should have a cholesterol check at 25 to save them from heart attacks and strokes later, say scientists.
And those who find they have a high level should consider taking statins from 30 onwards.
Experts who tracked 400 000 people over four decades have now developed a new way of calculating heart risk over longer periods.
Their findings suggest that lowering cholesterol at an early age can significantly cut heart risk in later life.
A team from Queens University Belfast and the German Centre for Cardiovascular Research worked out that if someone with high cholesterol took statins from 30 they would cut their risk of suffering a heart attack or stroke by the age of 75 by 10 percent.
For every four otherwise healthy men, one heart attack or stroke would be avoided, along with one for every eight women who took the pills.
Professor Stefan Blankenberg of the University Heart Centre in Hamburg said less than a third of Britons know their level of high non-HDL.
"You should determine your cholesterol at the very young age," he added. Researcher Fabian Brunner, also from Hamburg, used the findings to calculate his own risk.
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.
But if he cut his cholesterol by half, his risk would fall by nearly a quarter to 12.7 percent.
Brunner said: "First of all, I will follow up whether or not I can lower my non-HDL due to lifestyle modifications.
"If not, I will definitely think about statin intake to prevent future cardiovascular events.
"However, I’m aware that evidence about the long-term intake of statins – for me it would be 40-50 years – and potential side-effects are sparse."
Non-HDL cholesterol is known to contribute to the stiffening and narrowing of arteries and experts say the increased risk for younger people with high levels could be due to much longer exposure.
Statins work by slowing down cholesterol production by the liver and they are taken by about eight million patients in the UK. But many say that they provoke muscle pain – and some patients give up on the drugs.
Study co-author Professor Frank Kee of Queens University Belfast said statins are not the right approach for everyone, and diet, exercise and weight loss should also be attempted.
Professor Sir Nilesh Samani, medical director at the British Heart Foundation, added: "This large study again emphasises the importance of cholesterol as a major risk factor for heart attacks and stroke.
"It also shows that for some people, taking measures at a much earlier stage to lower cholesterol, for example by taking statins, may have a substantial benefit in reducing their lifelong risk from these diseases."