Western diet seems to be cause of high cholesterol


MEN'S HEALTH MATTERS:Kalahari bushmen, who have the same genetic make-up as us, have much lower cholesterol levels and no coronary disease, writes THOMAS LYNCH.

Q I am 49 years old and had my first check-up with my doctor recently. The only abnormality which he detected was a slightly high cholesterol. What does this mean?

A Cholesterol is a fat, which is a normal part of any diet and normal levels are needed in many animals and in humans. High cholesterol levels, however, have been identified for more than 50 years as likely to lead to a higher risk of heart attack, stroke and peripheral vascular disease (blockages in the legs).

It seems that when high levels of cholesterol have been present for many years, cells stuffed with fat become embedded in arteries in the heart and head. Over time, this deposition of fat will lead to blockages in these arteries, which in turn leads to heart attacks and/or stroke.

This type of build-up is one of the leading killers in the western world. Teenagers in western society start to build up “fatty streaks” in their major blood vessels, which will later lead to real problems.

The real issue is that “normal” cholesterol levels in the western world are, in historical and evolutionary terms, very high.

The Bantu and Kalahari Bushmen (with whom we share the same genetic make-up) have cholesterol levels that are about half of what we would consider to be normal, and they have no coronary disease. It would appear that our western diet has led to very high levels of cholesterol from a very early age.

There is “bad” cholesterol which is called low-density lipoprotein (LDL) as well as good cholesterol: high-density lipoprotein (HDL). It is the balance between the two, which is important.

Cholesterol is one of the real “treatable” factors that help decrease the incidence of coronary disease. Strict diet alone can be very successful in lowering your levels of cholesterol and the key issue is to minimise your intake of animal fats such as butter and to eat moderate amounts of red meat.

Exercise is also very important. In the past 15 years, effective medications have become available which markedly reduce cholesterol. This has in turn been shown to reduce the risk of developing heart attacks and stroke.

Not everyone with high cholesterol is offered these tablets, as the aim is to treat those at highest risk, for example, those with family history, with high blood pressure, smokers and so on).

Q I am 69 and have been having some abdominal discomfort for the past few months. My GP has sent me for a scan as he thinks I may have an abnormal swelling of the main blood vessel in my abdomen. He called it an abdominal aortic aneurysm. Can you tell me what this could be and do I need to worry about it?

A With an abdominal aortic aneurysm, the main artery running through your abdomen (aorta) may be abnormally enlarged. This abnormality is more commonly seen in those over 60. Most people don’t know they have one as they generally do not cause symptoms and they are most commonly detected when you are having investigations for another complaint.

Your GP is absolutely correct to arrange for a scan. This may or may not confirm the presence of an aneurysm and, more importantly, if present will indicate its size. In general, an aneurysm that has grown to a size greater than about 5cm will require treatment.

All surgery is potentially a major undertaking. Conventional surgery to repair an abdominal aortic aneurysm requires a long incision down the centre of your abdomen and the aneurysmal (diseased) part of the aorta is replaced with an artificial tube. This surgery may take up to four hours after which you will return to the intensive care unit.

You may be left on a ventilator (machine to aid your breathing) overnight after which you will then be able to breathe normally. Over the next few days all your drips and tubes are removed and you will slowly be allowed to resume with a normal diet.

Unfortunately complications (heart, lungs, kidneys and bowel) do occur but the team looking after you in hospital will do their best to ensure that you come through with minimal problems.

A new keyhole technique of repairing aneurysms is now available and is carried out in specialist vascular surgical units in Ireland. Two small cuts are made in the groin and a stent graft is passed over a wire and then released to seal the aneurysm. This is an increasingly popular way of treating aneurysms and is rapidly becoming the treatment of choice.

The risk to you is much less with this technique and is in the order of 2 per cent. While the stress to you is much less with this technique, the one drawback is that you will require more regular review following the procedure. There is also a small risk of the aneurysm rupturing – even after a successful repair. In some cases, your surgeon may decide the risk with open surgery is too high and may suggest that nothing is done.

This weekly column is edited by Thomas Lynch, consultant urological surgeon, St James’s Hospital, Dublin, with a contribution from Dr Ross Murphy, consultant cardiologist, and Mr Prakash Madhavan, consultant vascular surgeon, St James’s Hospital, Dublin.

Please send your questions to healthsupplement@irishtimes.com