Red meat and cholesterol
Last updated: October 2015
Raised blood cholesterol levels is one of the risk factors for coronary heart disease. Cholesterol is a fatty substance that is found in the bloodstream and in all cells. It has an important role as part of the walls of each cell. It is also a key component in the manufacture of hormones (chemical messengers in the body) and bile acids (that promote the absorption of fat from the diet).
There are two main types of blood cholesterol, which are often referred to as ‘good’ and ‘bad’ cholesterol. Low-density lipoprotein (LDL) is the main cholesterol carrier in the blood. If too much LDL cholesterol circulates in the blood, it can build up in the lining of arteries and form fatty deposits (atheromas) causing the arteries to narrow in a process called atherosclerosis. A raised level of LDL-cholesterol is associated with increased risk of heart disease, and is therefore referred to as ‘bad’ cholesterol.
High-density lipoprotein (HDL) is called ‘good’ cholesterol as it carries cholesterol away from the arteries and back to the liver. High levels of HDL-cholesterol help protect against the development of atheromas in the arteries, while a low level of HDL cholesterol may increase risk of atherosclerosis. A low LDL/HDL ratio is desirable as it reduces the risk of atherosclerosis.
Only a small proportion of cholesterol in the body comes from the cholesterol in food. It is made mostly in the liver and this process is stimulated by saturated fats. Therefore consuming high amounts of saturated fatty acids can raise blood LDL cholesterol levels. Lack of physical activity, family history, being overweight, drinking alcohol excessively and smoking can also adversely affect blood cholesterol level.
Contrary to popular belief, lean red meat does not contain high levels of fat or saturated fat. The total fat content of red meat has been considerably reduced over the last few decades and the amount of fat in red meat is actually much lower than most people think. Lean red meat also happens to be low in dietary cholesterol.
Typically the total fat content of lean red meat is between 4g - 10g per 100g. In addition, about half of the fat found in red meat is of the healthier polyunsaturated or monounsaturated types. Choosing lean cuts of meat and trimming off any visible fat helps to reduce the fat and saturated fat content further.
What do we know?
For some years we have known that saturated fats raise total and LDL (bad) cholesterol and that consuming a low fat diet can lower blood levels of total and LDL cholesterol. Furthermore it would seem that substituting polyunsaturated fats for saturated fats is also beneficial for lowering total and LDL cholesterol. However, substituting refined carbohydrates (such as those found in sugar, white bread and pasta) for saturated fats decreases the good (HDL) cholesterol and therefore is not recommended.
As a result of this observation some researchers are now suggesting that this ‘fat theory’ may be too simplistic. Not all saturated fatty acids have the same cholesterol raising effects. For example stearic acid, found in red meat, has no impact on blood cholesterol levels. In addition, other components in the diet such as wholegrains, fruit and vegetables, are now also thought to have a role to play in maintaining healthy blood cholesterol levels.
This has once again turned attention to considering the overall balance of the diet as a whole. Low fat diets that are high in complex carbohydrate, (such as those found in wholegrain cereals) with plenty of fruit and vegetables are now recommended. These are usually lower in energy (calories) and in combination with physical activity can also help reduce body weight and improve blood cholesterol levels.
Although cholesterol is important in the body high levels of the ‘bad’ LDL cholesterol in the blood can damage arteries and is linked to heart disease. A high intake of saturated fat and/or refined carbohydrate can have a negative impact by raising the bad cholesterol or reducing the ‘good’ HDL cholesterol. Lean red meat is not high in saturated fat and consumed as part of healthy balanced diet containing wholegrains fruit and vegetables does not adversely effect total cholesterol or LDL cholesterol levels in the blood.
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