Smoking

The good news is that the benefit to your heart starts as soon as you stop smoking. The bad news is that people who smoke have twice the risk of a heart attack of those who do not.

The carbon monoxide smokers take in reduces the ability of the blood to carry oxygen to the heart and all other parts of the body. Nicotine stimulates the body to produce adrenaline, which makes the heart beat faster and raises the blood pressure, causing the heart to work harder.

Smoking also increases the clumping of blood platelets that makes blockages in the arteries (atherosclerosis) more likely as well as increasing the chances of blood clots. All in all, you are making life very difficult for your heart if you smoke.

If you stop smoking, it will be the best single thing you can do to help your heart – not to mention your lungs and many other functions. For help, visit the Give Up Smoking website or call the NHS Smoking Helpline free on 0800 169 0 169.

Cholesterol levels

Cholesterol is one of the body's fats. We need it to build cells, make hormones and produce energy. But when there is too much in your blood, it contributes to the hardening and narrowing of the arteries (atherosclerosis), which is one of the main causes of coronary heart disease.

What most people don't realise is that very little cholesterol comes from food, what's important is the amount of saturated fat that you eat, because your body then turns this into cholesterol.

There are two sorts of cholesterol: a 'bad' sort called low-density lipoprotein (LDL) and a 'good' sort called high-density lipoprotein (HDL) which actually protects against atherosclerosis. It is the proportion of bad cholesterol to good cholesterol that is important for keeping your heart healthy.

The level of 'bad' cholesterol can be lowered by eating a low fat diet and, if necessary taking medication. Exercising can raise 'good' cholesterol.

People with normal levels of cholesterol, suffering from either heart disease or stroke, may be given cholesterol lowering drugs as part of their treatment.

A note on diet and cholesterol

To keep your heart healthy it is crucial to eat the right fats and to lower the intake of all fats. Monosaturated fats can help lower the 'bad' LDL levels and do not lower 'good' cholesterol (HDL). Olive oil, walnut oil, sunflower and rapeseed oils are monosaturated fats. Other fats known as omega-3 can help to prevent blood clotting. They're found in fish oil and oily fish such as pilchards, sardines, salmon, mackerel and trout. If you don't eat fish, consider taking a fish oil supplement.

Cholesterol is only present in foods that come from animals – eggs, offal and shellfish have high levels. However, when you have a lot of saturated fat in your diet, your liver responds by making more cholesterol, so it makes sense to avoid saturated fat when possible. As a rule, more saturated fat is found in animal than vegetable foods.

Fruit and vegetables are your best bet because they contain substances called antioxidants, which are very important for keeping your heart working well. Green leafy veg contain folates that help control homocysteine. See our Healthy Eating info on fruit and veg.

One in 500 people have high cholesterol because of an inherited problem called 'familial hypercholesterolaemia', which makes the risk of early coronary heart disease higher. It is important to know if you have this condition, so that you can take preventative action and receive treatment. There is another inherited condition called 'familial combined hyperlipidaemia' that leads to high cholesterol levels and also high levels of another fat called triglyceride. Again, knowing you have the condition is important.

High cholesterol is also linked to problems with metabolism, kidney disease, diabetes and alcohol abuse. Whatever your state of health it is helpful to know what your cholesterol level is and to take action to lower or maintain it.

How am I doing?

You cannot tell if you have a high cholesterol level, but it can be measured from a blood sample. The following is only a rough guide, as it doesn't take the ratio of 'good' to 'bad' cholesterol into account. Also, remember that the benefit of low cholesterol can be cancelled out by other risk factors such as being a smoker or having diabetes. People who know that they have heart disease should aim to keep their total cholesterol level below 5mmol/l and their LDL below 3mmol/l.

Cholesterol levels in the blood

Ideal level	less than 5mmol/l
Mildly high	between 5 and 6.4mmol/l
Moderately high	between 6.5 and 7.8mmol/l
Very high	above 7.8mmol/l

The guide that most doctors follow is to treat someone whose total cholesterol level is above 6.5 mmol/l (that's one in four men and one in three women). The ratio of 'good' to 'bad' cholesterol will be important, as well as whether someone has other risk factors for heart disease.

Cholesterol levels increase as we get older. In the UK, the average total cholesterol level is 5.7mmol/l - which is above the healthy threshold of 5mmol/l. Cholesterol levels in northern European countries are higher than in southern Europe.

High blood pressure

To get round the body, blood has to be under considerable pressure. If the pressure of blood in the arteries is too high there is a greater risk of hardened and blocked arteries (atherosclerosis) and a greater chance of stroke, kidney disease and general heart problems.

High blood pressure is also known as hypertension. If you have a blood pressure measurement that is consistently more than 140/90mmHg then you have high blood pressure.

However most of us could do with lowering our blood pressure. This can be done through having a healthier diet, more exercise, less salt and drinking sensibly. For more information see our section on healthy ageing.

The Blood Pressure Association website has more information.

Diabetes

Having diabetes makes developing coronary heart disease more likely although it is not yet exactly clear why. It seems likely that raised glucose levels contribute to the narrowing and hardening of arteries and the development of atherosclerosis. See our section on diabetes.

Inactivity

Exercise is the key to a healthy cardiovascular system. Aerobic exercise (the kind that makes you warm, increases your breathing rate and makes your heart beat faster) helps to improve the 'electrical stability' of the heart, making heart attacks less likely. It strengthens the heart muscle and keeps the arteries elastic, both of which enable more oxygen to reach the brain, muscle and other tissues. Exercise lowers blood pressure and increases 'good' cholesterol and reduces 'bad' cholesterol.

If you haven't exercised for a while remember to start slow and go easy. If you are at risk of a heart problem, talk to your GP about 'exercise on prescription'. Find out more in our section on exercise.

Family history of heart disease

If you have close male relatives who had coronary heart disease before they were 55 or female relatives who had it before 65, you may be at increased risk of developing it – for several reasons.

As mentioned above, one in 500 who people have high cholesterol because of an inherited problem, called familial hypercholesterolaemia, which means they have a high risk of early coronary heart disease. If you have a parent with familial hypercholesterolaemia you have a 50/50 chance of getting it yourself.

There is another inherited condition called familial combined hyperlipidaemia that leads to high cholesterol levels and also high levels of another fat called triglyceride. Other factors that influence how healthy your heart is can be inherited. Researchers are working hard to pin down the genes that make heart disease run in families. At the moment we know that people who have at least one close family member with early coronary heart disease are four times more likely to develop similar problems themselves.

Visible genetic traits

You may have heard about a link between a specific form of earlobe crease on both ears and an increased likelihood of coronary heart disease. This is an example of an inherited genetic trait being outwardly visible. Similar links with coronary heart disease have been found with other physical characteristics such as short rather than tall people, or women with 'apple' shaped physiques. But these are only links, not everyone with these characteristics is likely to have heart disease – there are lots of other factors at play. However, if you have any concerns go and talk to your doctor, have your cholesterol checked and find out how your heart is doing.

Alcohol

The saying that alcohol can be a good friend but a bad enemy really holds true when it comes to heart health. Moderate drinking has been shown to help protect the heart against heart disease, but heavier drinking can contribute to heart disorders, including high blood pressure and stroke.

Moderate really does mean moderate – research shows that alcohol only helps to protect the health of your heart when you drink between one and two units of alcohol a day. The protective effect only works for men aged over 40 and for women who have gone through the menopause. One unit of alcohol equals half a pint of ordinary beer or a small glass of wine or a pub measure of spirits.

In 1995, the Government changed its sensible drinking advice from weekly to daily guidelines. The advice is that men drinking between three and four units of alcohol a day will not be causing any significant risks to their health. Regularly drinking over that amount means there is an increasing risk to your health. Women drinking between two and three units of alcohol a day will not be causing any significant risks to their health. Regularly drinking over that amount means there is an increasing risk to your health.

The government guidelines also recommend that you have one alcohol free day every week.

People from south Asian or Afro-Caribbean backgrounds

People who originate from the south Asian population - from India, Bangladesh, Pakistan and to a lesser degree Sri Lanka - have some of the highest rates of death from coronary heart disease compared to any other population in the world. A genetic predisposition is to blame for this high rate of heart problems.

Afro-Carribean people are more likely to have diabetes and high blood pressure leading to further health conditions such as stroke and heart problems, than people from a European background. It is not exactly clear why this is; it may be a combination of social and biological factors.

Although ethnic origin is fixed, don't think that you can't do anything about this risk factor. If you are from a south Asian or Afro-Caribbean background it makes sense to reduce your chance of developing heart disease by reducing your other risk factors.

Is it different for girls?

Until the menopause women have less risk of heart disease than men, but the hormonal changes that happen at that time take away the natural protection leaving women vulnerable to the affects of athersclerosis and other causes of heart problems.

Research shows that women underestimate the likelihood of developing heart disease and so may ignore advice about how to prevent it. A British Heart Foundation survey found that most women thought that breast cancer was a bigger threat to their health. But statistics show that women are four times more likely to die from heart disease than breast cancer.

Visit the British Heart Foundation's microsite for women for more information.