Cholesterol

You’ve heard the term ‘cholesterol’. We have all seen foods and medications advertised on television boasting they will help to reduce your cholesterol levels. But what exactly is cholesterol and why does it need to be low?
 

What is cholesterol?

Most of the cholesterol in our blood is produced by the body itself. It has an essential role in all cell membranes and how every cell in the body functions. However, people with high cholesterol concentrations in their blood have a higher risk of coronary heart disease than people who have lower levels. The risk is particularly high if you have a high concentration of LDL cholesterol and a low level of HDL cholesterol.
 

What are LDL and HDL cholesterol?

LDL (low density lipoprotein) cholesterol and HDL (high density lipoprotein) cholesterol transport fats, including cholesterol, around the body. 
LDL is considered the ‘bad’ carrier as it takes cholesterol from the liver via the arteries (the blood vessels carrying blood away from the heart) to be stored in other parts of the body. If there is too much in our arteries it can accumulate in the blood vessel walls and restrict blood flow and even cause a complete blockage. A blockage in the heart causes a heart attack; in the brain, a stroke. 
HDL is considered the ‘good’ carrier as it carries cholesterol away from the blood to the liver, where the cholesterol is metabolised.
 

How cholesterol levels are measured

Blood cholesterol concentrations can be measured through a simple blood test. It will usually measure total cholesterol, LDL cholesterol and HDL cholesterol, and a ratio of total cholesterol to HDL cholesterol.
 

What causes high cholesterol?

The main factors likely to increase total blood cholesterol levels (in particular LDL) include a family history of high cholesterol levels, eating too many foods high in saturatedfat, being overweight and physically inactive, and high levels of stress.
 

What to do if you have high cholesterol

Unfortunately we can’t change our family history, but we can increase HDL and reduce LDL cholesterol concentrations by being more active, maintaining a healthy weight, eating a healthy diet, reducing stress and not smoking.
 
Making small changes to everyday eating is a good way to lower blood cholesterol levels. Following the tips below will help you minimise foods high in saturated fats, replacing them with polyunsaturated and monounsaturated fats. You should also include foods high in soluble fibre, which may help lower blood cholesterol.  These foods are fruit, vegetables, oats and legumes (baked beans, lentils, red kidney beans, chickpeas).
 
  • Choose low-fat dairy products such as trim (green top) or reduced-fat (light blue top) milk, low or reduced fat cheeses (including edam and cottage cheese) and low fat yoghurts.
  • Choose lean cuts of meat, removing any visible fat from meat and skin from chicken.
  • Reduce fat required for cooking by grilling, baking, stir frying in a non-stick pan or microwaving. 
  • Choose vegetable-based spreads and oils such as olive, canola and sunflower oils.
  • Try a few unsalted nuts (such as almonds or walnuts) as a healthy snack.
  • Try chopped fruit on breakfast cereal, an extra piece of fruit with lunch and some vegetables with your evening meal as easy ways to eat more fruit and veggies. Porridge and baked beans on toast have good amounts of soluble fibre.
  • Some foods are higher in saturated fat than we realise because the fat is hidden in the food. Coconut cream, deep-fried foods, potato chips, cakes, biscuits, pies and pastries are common examples, so it is best to eat these only occasionally.
  • Try margarines containing plant sterols, which prevent the body absorbing cholesterol and hence help to lower blood cholesterol levels. Read the label to find out how much margarine you need to eat each day to get this reducing effect.  
  • Foods rich in soy protein (tofu, soya beans, soy milk) may also contribute to a small cholesterol-lowering effect.
  • Some people may also require medication to help lower their cholesterol levels. Your doctor will advise you on suitable medication if necessary.