Most people know that having high cholesterol can have a negative impact on heart health. While it is commonly associated with poor arterial blood flow, cholesterol may be a term many are familiar with, but not necessarily fully understand. National Cholesterol Month aims to address this issue, and raise awareness of high cholesterol and its potential effects.
To find out more about high cholesterol, this week we got in touch with Barbara Dinsdale, Lifestyle Manager at Heart Research UK. She gave us her expert insight into the different types of cholesterol, how they work in the body, and how these might impact upon heart health.
What is Cholesterol?
The overriding misconception when it comes to cholesterol is that it is a ‘bad’ substance, but this isn’t true. In fact, as Barbara explains, the body needs cholesterol in order to properly function:
‘Cholesterol is an essential building block for cell walls and is involved in the production of vitamin D, bile acids and some hormones such as testosterone and oestrogen. Your liver makes most of the cholesterol your body needs and, although some foodstuffs contain some cholesterol, it is the type of fat you eat and your lifestyle that influences both the amount and type of cholesterol your body produces.’
‘Good’ and ‘Bad’ Cholesterol
Barbara goes on to explain that there are two main varieties of cholesterol, and it is when these are significantly out of balance that health issues begin to manifest:
‘Cholesterol travels around in the bloodstream encased by proteins in particles called lipoproteins. The two main types of lipoproteins that play a part in the furring up of arteries (atherosclerosis) and heart disease are:
- Low Density Lipoproteins (LDL), often referred to as ‘bad cholesterol’ carry cholesterol to where it is needed
- and High Density Lipoproteins (HDL) often referred to as ‘good cholesterol’ returns the cholesterol not needed by the body back to the liver
‘Problems occur when LDL cholesterol levels are high and HDL cholesterol levels are low because excess LDL cholesterol is likely to be deposited on the artery walls, the process known as atherosclerosis.’ Barbara tells us.
‘HDL, on the other hand, is returned to the liver, away from the artery walls. Excess LDL and low HDL, especially if other risk factors are present, can exacerbate atherosclerosis, whereby the arteries harden and narrow due to plaque buildup. This is a primary cause of heart disease. In fact, nearly half of all deaths from CHD in the UK are thought to be caused by raised cholesterol.’
So while it isn’t strictly completely accurate to refer to HDL and LDL as ‘good’ and ‘bad’ cholesterol respectively, an imbalance can lead to a ‘bad’ or unhealthy situation.
As is the case with most conditions, there are a number of factors that can increase an individual’s chances of developing high cholesterol. Unfortunately, some of these may be out of our control:
‘Cholesterol levels tend to rise as we get older and, in women, after the menopause. Occasionally raised cholesterol levels can be caused by an inherited condition called Familial Hyperlipidaemia. So it goes without saying that the people most at risk of high cholesterol levels are those aged over 40 and people with Familial Hyperlipidaemia, as well as diabetics, people who are overweight or obese, or people of South Asian origin.’
Having a family history of stroke or heart disease may also put someone at increased risk. But, as Barbara goes on to say, lifestyle is also a major contributor:
‘In most cases, high cholesterol is a direct result of our diet, in particular the amount of saturated fat we eat.’
Smoking too can be an exacerbating influence on high cholesterol, as chemicals found in cigarettes can affect the function of HDL, and cause the arteries to become clogged.
Signs and Symptoms
Most illnesses provide warning signs in the form of symptoms when they establish a presence in the body, however high cholesterol does not. In fact, the first indicator someone may get of having the condition may be when they encounter heart or circulation problems.
‘There are no obvious symptoms of raised cholesterol levels though some may be present in those with Familial Hyperlipidaemia.’ explains Barbara.
These may include raised bumps, which are small cholesterol deposits, appearing on or around the knuckles or the achilles, or a yellow build of deposits around the eye.
However, for most, getting tested is the only way of being certain, and this is done through a blood sample; usually taken through a finger-prick test.
‘A cholesterol test should be done every five years after the age of 40,’ says Barbara, ‘but it’s useful for all adults to be tested at least once before then or whenever possible if the opportunity arises.’
Prevention and Treatment
So what can someone do to limit their risk of developing high cholesterol? Having a healthy diet, Barbara tells us, is key:
‘This should include plenty of fibre, so fruit, vegetables, cereals, beans and pulses as well as soluble fibre (beta glucan) found in oats, monounsaturated fats from foods such as olive and rapeseed oil, nuts, seeds and avocadoes and soya based products.’
In addition, those who lead a mostly sedentary lifestyle can lower cholesterol through physical activity (the NHS website provides an excellent set of guidelines on how much exercise you should be doing each week), and those who smoke can limit their risk by quitting.
You can find out more about the work Heart Research UK are doing and make a donation by visiting their website.