A fat chance of bad cholesterol

THE link between high cholesterol levels and increased risk of heart disease and stroke was first established in the mid-1950s.

However, most of us still don’t have a good knowledge of how high cholesterol damages our health, or of what we can do to prevent this.

So, let’s look at how we can tackle this deadly foe.

Cholesterol is a fatty, waxy substance that gets carried around the body in tiny packages.

However, not all of these packages are the same — LDL, or ‘bad’ cholesterol, carries cholesterol out from the liver, where it’s made, and delivers it all over the body, where it’s used as a building block to repair damaged tissue.

HDL, or ‘good’ cholesterol, collects cholesterol from around the body and brings it back to the liver.

As our LDL-cholesterol levels rise, this means we have a greater tendency to deposit cholesterol in the lining of our blood vessels, especially if we smoke or have high blood pressure, two factors which damage the lining of these blood vessels, encouraging the accelerated build-up of cholesterol.

The net effect is a ‘clogging of the pipes’ and the creation of partial blockages, which limit the flow of blood carrying vital oxygen and nutrients to the working tissues downstream.

This is very serious when that working tissue is the heart muscle or brain tissue — in these situations, a heart attack or stroke can arise if the partially clogged vessel becomes fully blocked by a clot.

To add to these woes, cholesterol isn’t alone in blocking our vessels, as there’s a blood fat called triglyceride that causes damage in much the same way.

It’s not all bad news. HDL-cholesterol’s main job is to travel around our circulation, picking up cholesterol before it has a chance to attach to the lining of our blood vessels. Hence, the more of this ‘good’ HDL-cholesterol we have, the less likely we are to get blockages in our blood vessels.

So, how do we get our LDL and triglyceride levels down? And how do we get our HDL levels up? Fortunately, the answers to these questions aren’t complicated.

To reduce LDL levels, we should limit the amount of saturated and trans-fats in our diet. Saturated fats are found in processed red meats (burgers, sausages etc.) and fatty dairy foods, like rich, full-fat cheeses, cream and butter. The trans-fats are found mainly in deep-fried foods, as well as in some processed foods, like pastries, biscuits and sauces. So minimising these foods should see the LDL levels move in the right direction.

But what about triglycerides, the other dangerous type of blood fat?

The main things that elevate triglyceride levels are refined sugars and alcohol. It’s important to minimise our intake of sweet, sugary foods, like cakes, biscuits, sweets, chocolate and, especially, sugar-sweetened fizzy drinks.

Keeping alcohol to a sensible level (no more than a couple of drinks on any occasion, with a few alcohol-free days per week) is also critical.

And to increase HDL? One of the best ways of doing this is to increase our exercise level. There is no need for anything too strenuous, perhaps a half hour walk on five to six days per week. Along with a reduction in sugar intake this should get those HDL levels where they need to be.

If you’re carrying extra pounds, dropping 5-10% of your bodyweight will beneficial all of these parameters, so this is well worth the effort.

Remember, the targets are less than 5.0 for total cholesterol, less than 1.5 for triglycerides, and more than 1.1 for HDL. The closer we get to these the lower our risk will be.

* Dr Daniel McCartney is lecturer in human nutrition and dietetics at DIT