Raised LDL cholesterol is the “major cause” of heart disease, one of the leading causes of death in Ireland.

Every adult should know their own cholesterol level and be aware of the difference between HDL or ‘good’ cholesterol and LDL or ‘bad’ cholesterol, a leading cardiologist has advised.

Giving a public health talk on cholesterol at Tallaght University Hospital this week, Professor Vincent Maher, Consultant Cardiologist and Lipidologist at the hospital, advised that raised LDL cholesterol was the “major cause” of heart disease, one of the leading causes of death in Ireland.

Cholesterol is a type of fat found in your blood. You need a certain amount of cholesterol for all your body cells and to produce important hormones. However, if there is too much cholesterol in your blood, it sticks to your artery walls to form atheroma or plaque.

There are two main types of cholesterol – HDL cholesterol (high density lipoprotein) and LDL cholesterol (low density lipoprotein). HDL cholesterol is called good cholesterol, because it mops up cholesterol left behind in your arteries and carries it to your liver where it is broken down and passed out of your body. Regular physical activity can help increase your HDL level. High levels of HDL cholesterol can protect you against having a heart attack or a stroke.

LDL cholesterol travels from your liver through your arteries to other parts of your body. LDL is called bad cholesterol because it sticks to the walls in your arteries – making them narrow. This reduces the blood supply to your heart or brain. Eating too many foods high in saturated fat can raise your LDL cholesterol. High levels of LDL cholesterol increase your risk of heart disease and stroke.

According to Prof Maher, while smoking, diabetes and high blood pressure also increased the risk of heart disease, the main risk factor was raised LDL cholesterol.

“The key point is that even though you may be very slim and eating a very healthy diet, you still can end up with quite damaging cholesterol levels because of your genes,” Prof Maher said.

He explained that 80 per cent of cholesterol levels were genetically determined and 20 per cent were modified by diet and exercise. Therefore, if somebody who was very overweight and ate fatty foods every day totally transformed themselves through diet and exercise, the most they could hope to reduce their cholesterol by would be 20 per cent. However, Prof Maher said that for the average person it would be between 10 t0 15 per cent.

“One of the key things is, that if you have proven abnormal cholesterol levels and proven vascular disease, you need to get treatment. Diet and exercise are very important, they are the backbone of the treatment, but without medications you cannot achieve safer cholesterol levels.

“The main way to counteract genes is with medication, a really heathy diet and exercise are very beneficial and the longer you can afford good diet and exercise the better for your health, but sometimes you have to fight a gene and when you are fighting a gene you need medicines to help you with that,” Prof Maher added.

If you are born with a cholesterol raising gene, your cholesterol levels as a child are higher than the child beside you and it is just around a different trajectory, he explained.

Prof Maher, a former Medical Director of the Irish Heart Foundation, said that according to current guidelines, if you have proven vascular disease you need your LDL cholesterol below 1.8mmol/L

However, he added that recent trials have achieved a reversal of artery disease by driving LDL down to 0.8 mmol/L, therefore he said he believed that future guidelines would be driving LDL much lower for people with proven vascular disease.

“I think every adult should know their cholesterol level and they should know how to differentiate the good from the bad and to realise that while diet and lifestyle are excellent that sometimes there are genes there that are dictating a different path for them and not to be afraid to take their medicines either,” Prof Maher stated.

Prof Maher was speaking as part of the Tallaght University Hospital Public Health Talks – a series of public information meetings on a range of different health conditions such as stroke, dementia, women’s health and arthritis which take place over the coming months.