The cardiovascular system is made up of the heart and our blood vessels, therefore cardiovascular diseases are diseases of the heart such as stroke, heart attack and angina. In order to look after the health of our heart it is extremely important that we maintain/reduce our cholesterol levels to that which is considered healthy which we will talk about later.

Cholesterol is a waxy fat-like substance which is found in the blood. Our livers produce approximately 1-2 grams of cholesterol every day. This production decreases when we eat cholesterol rich foods and increases when we are lacking cholesterol in the diet. The reason we produce a certain amount of it ourselves is because it’s not all bad – a certain amount of it is needed by the body to produce steroid hormones, vitamin D, and produce bile which helps digest fat. However, too much of it can be detrimental to our health. Cholesterol is something that should not be overlooked and should be monitored regularly.

If too much cholesterol is present, it causes plague to form against artery walls. Once this plague builds up it may block the artery and restrict or completely cut off blood flow to the heart causing heart problems or death.

If you would like to be aware of your cholesterol levels it’s simply a matter of arranging to have a blood test done with your GP.


Low density lipoproteins (LDL) – Bad cholesterol that may cause plague build up. The more presence of LDL cholesterol the higher the risk of heart disease.
High density lipoprotein (HDL) – Good cholesterol that helps decrease bad cholesterol in the blood. The higher the better. If HDL cholesterol is too low, risk of heart disease increases.

– Cholesterol is measured in units known as millimoles per litre of blood. You will see this as

– In Ireland cholesterol levels are recommended to be less than 5mmol/L.
– Half of Irish adults have a cholesterol of 5mmol/L or more.


Diet – A diet rich in saturated fats will increase cholesterol levels
Exercise – 30 mins exercise a day can reduce bad cholesterol (LDL) while increasing good cholesterol (HDL)
Weight – Overweight and obesity is a major risk factor for heart disease. Reducing weight can reduce bad cholesterol (LDL) while increasing good cholesterol (HDL)
Age – Cholesterol increases as we get older and LDL cholesterol tend to increase in women after the menopause.
Diabetes – Cholesterol levels increase when diabetes is poorly controlled
Heredity – Your DNA determines how much cholesterol your body makes.


Too much bad cholesterol (LDL) and not enough good cholesterol can lead to heart problems so it’s important to maintain the right cholesterol ratio. This ratio is determined by the good cholesterol (HDL) and the total cholesterol. This ratio varies from person to person to it’s important to speak with your GP to find out what your ideal ratio is.
An optimal level of LDL cholesterol is less than 3.37 millimoles per liter (mmol/L). Higher numbers mean a higher risk of heart disease. To calculate your cholesterol ratio, divide your total cholesterol number by your HDL cholesterol number. So if your total cholesterol is 5.2 mmol/L and your HDL is 1.3 mmol/L, your ratio would be 4-to-1. Ranges higher than this mean higher risk of heart disease.

These ratios have been proven to be one of the best indicators for cardiovascular disease. Millan, 2009)

A popular study used to highlight the risk factors associated with heart disease is The Framingham Study (1948). Today this study remains one of the greatest cardiovascular researches to date and remains core to the knowledge of heart disease that is common to us today.

if you’re interested in this study follow this link:

Important points to take from this study:
For men:
–  A cholesterol ratio of 5 indicates average risk of heart disease.
– If a mans ratio reaches 9.6 he doubles his risk of heart disease.
– Men cut their average risk of heart disease in half when having a cholesterol ratio of 3.4.

For women:
– A cholesterol ratio of 4.4 indicates average risk for heart disease
– If a womans ratio reaches 7 she doubles her risk of heart disease.
– Women cut their average risk of heart disease in half while having a cholesterol ratio of 3.3


“Heart disease is almost non-existent in places where blood cholesterol is very low. If your cholesterol is around 4.1mmol/L or less, your risk of heart disease is virtually zero.”

–Dr. Terry Shintani


Ireland’s Health Service. (n.d.). Introduction – Ireland’s Health Service. [online] Available at:,-high/ [Accessed 22 Feb. 2018].
J Millan. (2009). Lipoprotein ratios: Physiological significance and clinical usefulness in cardiovascular prevention. [online] PubMed Central (PMC). Available at: [Accessed 23 Feb. 2018].

Mahmood, S., Levy, D., Vasan, R. and Wang, T. (2014). The Framingham Heart Study and the epidemiology of cardiovascular disease: a historical perspective.

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