Lowering your risk

Minimising your risk of having a heart attack (myocardial infarction, MI, coronary) involves looking at your individual heart health and lifestyle factors. Some people may be more at risk (eg, due to a family history of heart disease), but it is still possible to address other risk factors, eg, by being physically active, eating healthily and not smoking.

What is a heart attack?

A heart attack (myocardial infarction, coronary) refers to damage to the heart caused when the blood supply to part of the heart muscle is blocked. A heart attack happens because the blood supply has been cut off by a blockage in a branch of one of the coronary arteries (blood vessels supplying the heart muscle).

Blockage usually results from two processes: the development over many years of fatty build-ups (plaques) in the walls of the arteries and the formation of a clot on a plaque.

What causes the build-up in the arteries?

The process that leads to the narrowing and blockage of the coronary arteries (atherosclerosis) starts as early as adolescence and builds up slowly. No single cause of coronary artery disease has been identified. There are, however, several things known to increase the chances of coronary artery disease and heart attack.

These are called risk factors, and the more risk factors you have, the greater your chance of having a heart attack. Not all the risk factors are known, so some people who do not have the currently recognised risk factors may still have a heart attack. Ask your doctor or nurse about a 'Cardiovascular Risk Assessment'.

Risk factors you can change:

• eating pattern and nutrition 
• being overweight 
• cigarette smoking
• lack of physical activity
• high blood cholesterol 
• high blood pressure (hypertension)
• high blood glucose (sugar) 
• stress (in particular, the way you cope with stress, eg, if by smoking, drinking too much).

Risk factors you cannot change:

• age
• ethnicity 
• gender
• previous history of heart disease
• family history of heart disease.

Keeping blood cholesterol levels low

Lowering the levels of cholesterol in your bloodstream will lower your heart risk. The best things you can do to favourably affect your cholesterol levels are to:

• eat and cook with less fat, especially saturated (animal) fat which is hidden in many snacks and foods
• achieve and maintain a healthy body weight
• be physically active
• stop smoking
• avoid excessive drinking of alcohol.

Blood cholesterol is best measured as part of an overall assessment of your cardiovascular risk. This involves a simple blood test arranged by your doctor. Most people with heart problems should aim for a blood cholesterol level of less than 4 mmol/L (or even lower depending on your medical history and other heart risk factors). You can get more advice from your doctor, practice nurse or dietitian; also see our topic on High blood cholesterol.

How do I maintain a healthy weight?

If you are already overweight, you need to reduce your heart risks by losing weight and trimming your waistline. To do this you need to cut down, slowly and properly, on your food intake (particularly fats) and start to increase the amount of regular physical activity in your life.

Avoid diets that promise rapid weight loss, and do not starve yourself or miss meals. You can ask for more advice from your doctor or a dietitian; also see Healthy weight control.

General rules of healthy eating

• eat more fruit, vegetables, wholegrain breads and cereals
• choose many different foods
• prepare meals with little added fat and salt
• buy foods and snacks low in fat, salt and sugar
• drink plenty of water
• drink a maximum of two or three alcoholic drinks a day and have several alcohol-free days a week.

How does smoking affect my heart?

If you smoke, your chances of a heart attack are two or three times more than for a non-smoker, and you have a higher risk of stroke and many other diseases. Lifetime smokers have a 50% chance of dying from smoking-related diseases, and their lives are shorter by an average of 14 years.

Smoking also affects the health of others around you. If you stop smoking, all the above risks soon become much less – quitting lowers the risk of a heart attack to that of a non-smoker within five years.

Why should I be physically active?

Active people have fewer heart attacks and have a better chance of recovery than inactive people. They also feel good and are less tired, more relaxed and better able to cope with stress. You can do more with less effort, have better heart function and possibly lower blood pressure.

Regular activity helps control weight and lower blood cholesterol levels. Find different activities you enjoy and take opportunities to add physical activity to your day. You need not join a gym – regular brisk walking for half an hour can do the job.

Healthy physical activity should be:

• regular – daily is ideal, three times a week is good, but anything is better than nothing
• brisk – enough to increase your heart and breathing rates, not so hard it is painful or unenjoyable
• sustained – the longer the better, but at least 15 to 30 minutes without stopping is good.

Why is blood pressure important?

High blood pressure can enlarge and weaken the heart. It also damages the blood vessels which, if they become narrow or blocked, may result in a heart attack or stroke. Get your blood pressure checked regularly – and more often if you are older, taking any medication (including the contraceptive pill), overweight, or if you have diabetes or a family history of heart disease.

To keep your blood pressure down you should maintain a healthy diet and body weight, exercise regularly, use less salt and, if you drink alcohol, do so in moderation.

Is controlling diabetes important?

People with diabetes are at greater risk of developing heart disease. Diabetes can affect vessels that supply blood to the heart. Working with your doctor to develop a plan to control your diabetes is the first step in safeguarding your heart. Many of the lifestyle changes suggested for keeping your heart healthy (ie, diet and physical activity) are important in controlling diabetes. Medication may be needed – ask your doctor.

Should we be stressed about stress?

Although it is now clear that factors such as family history and lifestyle are the primary problems, the ways you cope with stress (eg, if by drinking too much, making poor food choices or smoking), can increase your risk of heart disease. It is also advisable for general health and wellbeing to know what stresses us unduly, and to find ways of dealing with stress:

• identify the cause and see if there is a way to change or avoid this situation
• exercise regularly
• relax physically and mentally (relaxation techniques may be helpful) 
• maintain healthy eating habits
• establish regular sleep patterns
• talk to your doctor if you are very anxious or depressed.

Related topics

Also see: Know Your Numbers Heart Age Calculator
Do you need a heart risk assessment?

Original material provided by the Heart Foundation, 2006. Reviewed and edited by everybody, February 2011.