Unit 1 GCSE Biology - Cholesterol & Fats

Cholesterol is affected by both diet and genes. It is made in the liver and is used for:

• Making cell membranes
• Making hormones
• Insulating nerve fibre

Cholesterol on its own is insoluble and has to be combined with protien to be transported in the blood. The molecules used to transport it are called Lipoprotiens. There are two types of lipoprotiens;

High Density Lippoprotiens (HDL's) -

Often known as the "good cholesterol". HDL's transport cholesterol to the liver.

Low Density Lipoproteins (LDL's) -

The "bad cholesterol", which transports cholesterol from the liver to the cells. An excess amount of LDL's can cause a build up of fat in the arteries.

Cholesterol is found in fats - however, our diet and the type of cholesterol we consume affects our health as well as our genes, so not all fats are bad for us. You should always have a higher porportion of HDL's to LDL's in the body. 

There are 3 main fats:  

Saturated Fat - "Bad fat"!

Saturated fat is sourced from animal products and increases the number of LDL's in our body.

Mono-unsaturated

and

Poly-unsaturated fat:

Found in plant products. These fats increase the body's count of HDL's.

Statins come in the form of pills and are prescribed by doctors to lower LDL's produced by the liver. Due to the benifits provided by a lower amount of LDL's in the body, statins are currently in higher demand to be available over the counter. There are a number of advantages and disadvantages to statins: 

Advantages:

• Lowers LDL count
• Reduces the risk of heart disease
• Can increase HDL production by up to 10%
• Reduces the ammount of fats in the blood
• Less chance of heart attacks   

Disadvantages:

• Liver damage, which may leave to not enough HDL's being produced
• Joint pains
• Diarrhoea
• Flatulence
• Fatigue
• Headaches