The heart is a complex muscle consisting of four chambers, each separated by valves. The right side of the heart pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the body. About the size of a small fist, this amazing pump sends about four to five litres of blood around the body per minute.
The heart contains veins and arteries including coronary arteries - which supply fresh oxygenated blood to the heart itself.
Like any complex piece of machinery, many things can go wrong with the heart. Coronary Heart Disease (CHD) is the most common, and is the leading cause of death and disability in Australia.1
CHD occurs when fatty deposits or plaques build up inside one or more of the coronary arteries, narrowing or blocking the pathway for oxygen to reach the heart. Untreated, CHD can lead to Angina (pain and tightness in the chest) or a heart attack.
Cholesterol
High blood cholesterol levels are closely linked with heart disease – anything over 5.5 millimoles per litre is a major risk factor.
However there is “good” and “bad” cholesterol. Bad (LDL) Cholesterol is transported to the heart, where it oxidises and clogs the arteries causing heart disease, strokes and high blood pressure. However good (HDL) cholesterol is carried straight to the liver, where it is processed and serves many vital functions in the body including the manufacture of hormones.
HDL cholesterol is thought to actually have a protective effect on the heart, because it scavenges for excess cholesterol in the blood and returns it to the liver to be metabolised.
Research shows that for every 1% drop in the LDL cholesterol level, the risk of a heart attack drops by 2%. Conversely, for every 1% increase in HDL, the risk of a heart attack drops 3-4%.2
Therefore while one cholesterol reading is initially taken, the ratio of HDL/LDL is equally as important and will be examined more closely if cholesterol is high.
Triglyceride Levels
Triglyceride levels refer to the total amount of fat in the blood. Raised triglyceride levels are another risk factor for heart disease as they are closely linked with cholesterol production. Omega-3 fatty acids in fish oil have been shown to lower the levels of triglycerides in the blood by up to 40%.3
High Blood Pressure
If a person has high blood pressure, it increases stress on the whole circulatory system – the heart, arteries and ventricles. Under too much pressure - especially coupled with blocked arteries - the heart may stop (heart attack) or beat irregularly (arrythmia).
Smoking
Cigarette smoke contains chemicals which, along with the carbon monoxide, damage the inner layer of the arteries. This allows cholesterol to enter the artery walls more rapidly and can form blood clots in the arteries which can lead to heart attacks.
Diabetes
Diabetes is another risk factor for heart disease. Many diabetics have a high cholesterol level and may also have raised blood pressure.
If you have a history of heart disease or are over 40 years old, it is wise to visit your doctor for regular blood pressure and cholesterol check and advice on medication. Some doctors may recommend a daily aspirin, which acts as a blood thinner to help prevent the risk of blood clots and blocked arteries. In the meantime however you can greatly reduce the risk of heart disease by leading an active, healthy lifestyle.
Diet can greatly influence the level of healthy cholesterol vs. ‘bad’ cholesterol in the body and assist in the maintenance of general heart health.
LDL (‘bad’) cholesterol levels are raised by the intake of certain saturated fats, while HDL cholesterol is raised by the intake of monounsaturated fats and Omega-3 fatty acids.
Not all saturated fats raise cholesterol. Palmitic acid, which is found in palm oil, cottonseed oil, lard, cocoa butter and beef tallow, is the most powerful at raising LDL cholesterol. These oils are commonly found in fast foods and many packaged commercial products such as biscuits and pastries.
Some dairy products – including cheese – also contain a form of cholesterol-raising saturated fat called Mystiric Acid. Red meat, however, does not appear to raise cholesterol levels. Eggs also contain a ‘safe’ type of cholesterol.
Monounsaturated fats (found in olive oil) and Omega-3 fatty acids (found in fatty fish and fish oil supplements) are the best at lowering ‘bad’ cholesterol and raising “good” cholesterol. The Omega-3 in fish oil helps prevent the oxidisation of bad cholesterol, which reduces deposits in the arteries. It also helps reduce blood platelet “stickiness”, helping prevent blood clots which cause heart attack and stroke. Many studies have shown fish oil to be a protective influence on the heart. One major study suggests daily fish oil supplementation may lower the risk of sudden death by heart attack by up to 45%.4
Exercise is the other part of the equation to living a heart-healthy lifestyle. Obesity and excess weight (particularly around the belly) increase your risk of heart disease. Regular exercise reduces weight, improves circulation and oxygen flow, strengthens the heart and reduces the risk of heart disease by up to 30%.6 Any kind of cardiovascular exercise is good – particularly walking. Aim to build up to 30 minutes each day at a vigorous pace. See your doctor before starting an exercise program.
Available on request.
This material is for information purposes only and is not a substitute for medical diagnosis or treatment. If symptoms persist, please contact your healthcare professional.