We've known for decades that fatty deposits in the blood vessels lead to heart attacks, but the precise mechanism has not yet been completely described.
High blood cholesterol however is a well recognised risk-factor for heart attacks, so lowering your cholesterol will help reduce your risks.
One third of us will die of heart disease, no matter what we do. That is a statistical fact, and remains true even after 20 years of active treatments for high cholesterol.
However the reality is that with effective life-style changes and newer medical treatments, we can live much longer with the diseases we do get, and that includes heart problems.
Another third of us will get cancer, and that figure also remains constant. The last third (roughly) will die of respiratory problems (bronchitis and pneumonia), much of which is cigarette related.
Yes, we are living longer, but the actual causes of death have not changed much in a generation.
So what has changed? Well, we know from studies that lowering cholesterol reduces stroke and heart attack, at every age. We also know that lowering cholesterol for diabetics prolongs life, regardless of the actual level of cholesterol.
So there is much good news out there for those with increased risks, because 20 years ago we had no effective treatments for high cholesterol.
In the 1970s we used drugs like Fibrates, but these were poorly tolerated, had significant side-effects, and didn't really seem to make much difference to the final outcome.
Since the late 1980s we have had a new class of drugs called statins. These lower cholesterol production in the liver, which is the source of 80% of the body's cholesterol. Diet alone only accounts for up to 20%, so if you do develop high cholesterol despite a healthy diet, it is usually down to your genes.
Statins have been shown in studies to reduce the risk of stroke and heart attacks at all ages, so it can be okay for a person of 80 to go on them. Having said that, it is still important for all of us to limit our fat intake. It can make a difference. High circulating cholesterol can trigger a heart attack, and lowering this will reduce risk.
In more recent years there has been much public discussion about "good" cholesterol and "bad". Trying to distinguish these can be difficult, even for a doctor, so I'm not sure it's a helpful discussion.
Suffice it to say that a blood test can distinguish the levels on a particular day, but the next day might give a different balance of results.
In general it is better to check cholesterol and other fats after fasting overnight. This can give a better breakdown, and gives a more valid picture of the total cholesterol story.
Figures for cholesterol can be misleading but mostly we want to see it below 6.5 at all ages. If there is another recognised risk factor (e.g. high blood pressure, obesity, smoking, diabetes or significant family history) then we want a much lower figure.
The American Diabetic Association last year pushed the figure down to 4.5, and that means that those with a higher risk need active treatment with statins.
Statins include Lipostat, Lipitor, Zocor, Lescol and Inegy. They must be taken daily. Some must be taken at night (Zocor, Lipostat and Inegy), while Lipitor can be taken anytime, and is probably best taken in the morning with food, as this is the time that most people remember. Failure to take the medication regularly is the commonest reason for apparent drug failure.
In fairness these medications are quite safe and effective. Liver problems and muscle pains can occur occasionally, so it is important that liver-function blood tests are done at regular intervals (at least annually).
Keeping the cholesterol down can be the biggest challenge. Diet and exercise are vital. You won't burn off the fat if you don't exercise. Taking medication alone is not the total answer. Exercise is also a key ingredient.
Experts suggest that the right amount of exercise to promote good heart-health is simply walking 40 minutes, four days a week. It's not much, is it? Yet those few minutes can make the difference in living another ten healthy years. It's a good deal, if you buy in.
Everyone over 30 should have an annual cholesterol check. There are no symptoms to high cholesterol, so you must check it. In general our cholesterol rises a little every year, so a figure of 3.4 at age 38 can be 6.7 by 45. Without checking, you simply won't know.
Women too should be checked. High cholesterol is not a male thing. In fact women after the menopause have a higher risk of heart problems than men of a similar age. Indeed heart specialists call female heart disease that occurs after the menopause the silent epidemic. It's that common.
So that's the cholesterol story. It's a significant problem, but lowering cholesterol helps at every age. Exercise and a sensible low-fat diet are important, and drug treatment is usually only offered when diet has failed to lower the cholesterol sufficiently.
Don't be afraid of treatment. It can help, and most people have no problem whatsoever with their statins.
In fact checking your cholesterol annually is a vital part of minding yourself as you get older.
Sadly most of us look after our cars better than we do ourselves. That needs to change. The evidence, after 30 years of studies is clear. Treatment can save your life.