High cholesterol puts us at risk of heart attack and stroke, yet many of us don’t know we have it – or that simple lifestyle changes can make a big difference.
Am I at risk?
You’re more likely to develop high cholesterol if...
your diet’s high in saturated fat
you have a family history of high cholesterol or heart disease
you’re male – although a woman’s risk goes up after menopause
you’re over 40
Do you know your cholesterol level?
If not, you’re far from alone. Many people don’t take the risks of high cholesterol seriously and have never been tested by their GP – yet, according to the Australian Institute of Health and Welfare, 51 per cent of Australian adults have high cholesterol. So could something so common really be a health time bomb?
“Unfortunately, yes,” warns Healthy Food Guide expert Dr Dawn Harper. “The reason doctors worry about cholesterol is because it’s a direct contributor to cardiovascular disease and one of the few early warning alarms for heart disease. In fact, we now know that almost 20% of strokes and over 50% of heart attacks can be linked to high levels of cholesterol. It’s a sign you need to act now to change your lifestyle.”
The problem is that if you have high cholesterol there are no real symptoms – and, unlike obesity, it’s not something that can be diagnosed just by looking at someone. Dr Harper adds that you can be overweight, but have normal cholesterol – or be slender, but have raised levels.
“As a result, few people think to get their cholesterol checked by their GP, leaving them dangerously in the dark”, she says.
Is all cholesterol bad?
Everyone has cholesterol – a waxy substance – circulating in their blood. Some of this comes from the food we eat, but most is made by the liver. And, while it has some vital uses – it’s an essential part of every cell membrane and acts as a building block for some hormones, for example – an excess can spell trouble.
Cholesterol comes in different forms, but doctors focus mainly on two: HDL (high-density lipoprotein) and LDL (low-density lipoprotein). LDL is known as ‘bad’ cholesterol because an excess can build up inside the walls of arteries. This restricts blood flow to the heart and brain and, if pieces break off and form a clot, it can block an artery completely, causing a heart attack or stroke. HDL, or ‘good’ cholesterol, helps to remove bad cholesterol from the blood.
In the past, a cholesterol test revealed the total amount of cholesterol in the blood. But now science has moved on. “Forget total cholesterol – it’s the ratio of HDL to LDL that doctors worry about now,” says Dr Harper, “and the more of the good kind you have, the better.” It’s measured in units called millimoles, per litre of blood (mmol/L).
Ideally, your level of cholesterol should be:
less than 5.5mmol/L in total;
no more than 3mmol/L for bad (LDL) cholesterol;
more than 1mmol/L for good (HDL) cholesterol.
People at high risk of cardiovascular disease should aim for:
less than 4.0mmol/L in total;
less than 2.0mmol/L for bad (LDL) cholesterol.
“The only way to find out your ratio is for your GP to do a blood test,” continues Dr Harper. “It’s something everyone over 40, or with a family history of heart disease, should ask for.”
And if you’re one of the many people who have dodged the test for fear of the results, Dr Harper argues that it’s far better to know, so you can do something about it if you need to before it’s too late.
In the meantime, the important messages are these: get tested and, if you’re diagnosed with high cholesterol, don’t despair. This is one health problem we can all do something about.
Simple ways to lower cholesterol
Adopting the following healthy lifestyle changes has been proven to make a big difference when it comes to preventing and tackling high cholesterol…
1. Overhaul your diet
Changing what you eat can have a big impact on blood cholesterol. Professor David Jenkins from University of Toronto has developed the Portfolio diet, which can reduce cholesterol by 20 per cent – a similar result to using statins (medication commonly used to treat high cholesterol levels, see p36). It’s based on adding the following cholesterol-lowering foods to a healthy diet that’s low in saturated fat:
Eating at least 25g of soy protein daily – in the form of soy beans, milk or tofu – can help reduce blood cholesterol. An example of 25g of soy protein could be 250ml soy milk, 125g tofu and 50g of edamame.
Found in oats, barley, fruits and vegetables, soluble fibre helps reduce cholesterol absorption in the gut when eaten regularly. A study this year by Florida State University found that women who snacked on 75g of soluble fibre-rich dried apple saw their levels of bad cholesterol drop by a quarter. Aim for 2 serves of fruit and 5 serves of vegetables each day and ensure most of your grain serves are wholegrain. A review of studies suggests 3g a day of beta-glucan (found in 60g oats) can reduce cholesterol by 5-10% in people with normal or high cholesterol.
There’s evidence to show products such as milks, cheeses and spreads enriched with plant sterols can lower cholesterol if used daily in the right amounts. To be effective you need 3 servings (2–3g) of plant sterols a day.
Studies have found almonds and walnuts, in particular, can reduce bad cholesterol. Eating nuts regularly can improve blood fats, particularly by lowering LDL (bad) cholesterol. A large analysis combining the results of 25 cholesterol-lowering studies involving nuts found that eating two serves of nuts (67g or around two handfuls) each day lowered total cholesterol by about five per cent and LDL cholesterol by around seven per cent.
Ditch saturated fat
The cholesterol found in foods such as eggs and prawns doesn’t affect the level of cholesterol in your blood. It’s saturated fat that you should be avoiding. Limit it by choosing lean meat, skinless chicken and low-fat dairy products, and cook with small amounts of heart-healthy fats, such as canola or olive oils. Cut right down on processed foods such as biscuits, cakes, chocolate and fast food.
Eat oil-rich fish
Fish rich in omega-3 fats, such as salmon and mackerel, helps boost levels of HDL cholesterol, maintain a regular heartbeat and reduce the chance of blood clots. Taking fish oil supplements may be useful if you don’t eat much fish – talk to your doctor about the right dose for you. Turn to page 83 for more heart-friendly foods, or visit the Heart Foundation of Australia’s website: www.heartfoundation.org.au.
2. Lose weight
“If you’re overweight, losing just 10 per cent of your body weight can slash bad cholesterol by 10 per cent,” says Dr Harper. The good news is that if you are making heart-healthy changes to your diet and exercise routine, you will most likely see weight loss too.
3. Stop smoking
When you stop smoking, your good cholesterol is likely to improve by as much as 10 per cent. Talk to your doctor for advice on giving up, call Quitline on 131 848 or visit www.quitnow.gov.au.
4. Get moving
“We’re all too sedentary these days,” says Dr Harper, “but regular exercise can lower bad cholesterol and increase good cholesterol levels by as much as five per cent.” Choose a cardio activity that boosts your heart rate, such as running, swimming or walking briskly, and aim for at least 30 minutes (or up to 60 minutes if you are also trying to lose weight) on most days of the week.
Other ways to bring down your cholesterol level
Lifestyle changes have long been the first line of treatment for high cholesterol, and there’s an increasing amount of research to show just how effective they can be.
However, says Dr Harper: “If your level of bad cholesterol is very high, lifestyle measures may not be enough.”
This is where statins come in. These drugs have revolutionised the treatment of high cholesterol, and are now the most heavily prescribed drugs in Australia’s Pharmaceutical Benefits Scheme, costing $1.25 billion per year and rising.
Statins work by blocking the production of cholesterol in the liver and are very effective in correcting LDL to HDL ratios. Despite some controversy, they’re seen as a safe treatment. “The main side effect, which a few people experience, is muscle pain,” says Dr Harper, “but this can usually be avoided by starting with a lower dose and working up slowly.”
While most doctors agree that statins are vital when it comes to preventing a second heart attack in people who have had one, there are hugely differing views on whether otherwise healthy people with borderline high cholesterol should be given these drugs routinely.
It is best to discuss the use of statins with your GP as they will have your full medical history and be able to make the best recommendation for you.
Who should take statins?
There are clear guidelines about who should be prescribed statins. GPs work out your level of risk according to your age, sex, ethnicity and how many risk factors you have: these include smoking, high cholesterol, high blood pressure or diabetes, or being overweight.
A recent review of current studies by the respected medical database Cochrane Library took a different line. It suggested that if you haven’t had a heart attack or a stroke, taking cholesterol-lowering drugs might be a waste. Dietitian and author of Eat to Beat Cholesterol, Nicole Senior, says an increasing number of people are saying they prefer a natural solution rather than taking a drug for the rest of their lives. “We know diet and lifestyle changes are effective in improving cholesterol levels as well as other risk factors, yet this is not well known, understood or promoted and drugs are seen as an easy fix. Even if statins are prescribed for high-risk individuals, a heart-friendly, cholesterol-lowering diet is essential.”
Diet and exercise also address blood pressure, body weight, blood sugar levels and reduce inflammation (just to name a few) which all protect the heart – and with no side effects. A healthy diet is also good for the whole family, including the increasing number of children with high cholesterol. A recent study of 283 children (average age 9½) by the Westmead Millennium Institute in Sydney found 60 per cent of the overweight children had high cholesterol. In the obese group of children, the figure was 70 per cent. The researchers were surprised so many children had high cholesterol and put this alarming result down to poor diet and not enough exercise, as well as excess weight.
Inherited high cholesterol
Although high cholesterol is often due to poor lifestyle choices, people with the condition familial hypercholesterolaemia (FH) have a genetic predisposition to raised levels – regardless of how healthy their diet is. “People with this little known but potentially lethal disorder can’t clear cholesterol from their blood,” explains Dr Harper. The Cardiac Society of Australia and New Zealand estimates between one in 200 and one in 500 people are affected by FH, with many being unaware of their condition. “If a family member has had a heart attack at a young age, you should tell your GP so they can check your cholesterol straight away,” says Dr Harper. People with FH often have a cholesterol level of above 7.5mmol/L – much higher than average levels – and will require statins to bring it down.
Did you know? Recent studies have suggested that high cholesterol could increase your risk of developing Alzheimer’s disease.
Remember: High cholesterol is the one health problem we can all do something about, so it’s important to get tested.