When your doctor gets you to reduce your cholesterol level it’s usually because you’re at increased risk of a heart attack or stroke over the next five or ten years. And that depends on more than your cholesterol levels: things like your age, your blood pressure and whether you smoke. Age though, is the big factor in your risk of heart disease so it tends to swamp cholesterol in the mathematical equations used by doctors and doesn’t take into account people who may have had higher than normal levels since their 30s or 40s. These people may be exposed to slow and steady damage to their arteries, which could be slowed or prevented by more attention to their blood fat (cholesterol) levels.
A US study has looked at the effects of long-term, prolonged exposure to high cholesterol early in life on future risk of heart disease.
They took adults at the age of 55 and looked back 20 years to see how many years of raised cholesterol that they had – defined as an LDL of about 3.4 millimoles per litre. To put it in context, about one in three Americans will have an LDL above that cut-off. Adjusted for the fact that people with high cholesterol for a long period of time had other risk factors, they found that every 10 years that somebody had elevated cholesterol before the age of 55, their risk of heart disease increased by 40%. That was cumulative, so after 20 years it was 80%.
That doesn’t mean that someone with a high LDL who’s aged 30 or 40 should be on a cholesterol-lowering drug. But it does mean they should fix up their diet and lifestyle to get things under control now. Talk to your doctor about it.