Cholesterol Noadswood Science, 2011

Cholesterol To understand what cholesterol is and how it can have an affect on an individual’s health Friday, August 07, 2015

Exercise & Energy How do you think sleeping / watching television / jogging / swimming compare in terms of the energy the body uses? ActivityKJ/min Sleeping4.5 Watching TV7 Cycling (5mph)21 Jogging (5mph)40 Swimming35 Rowing58 Walking14

Cholesterol Cholesterol (C 27 H 46 O) is a substance found in the blood It is made in the liver and is needed for healthy cell membranes Too much cholesterol in the blood increases the risk of heart disease, and of diseased arteries

Cholesterol Cholesterol is important for a variety of body functions, including: - Cell membranes Hormones Bile acids Insulating nerve fibres

Cholesterol Types The bloodstream transports cholesterol around the body attached to proteins The combination of cholesterol and protein is called lipoprotein, and there are two type: - Low-density lipoproteins (LDLs) - carry cholesterol from the liver to the cells High-density lipoproteins (HDLs) - carry excess cholesterol back to the liver

Cholesterol Types LDLs are often called 'bad' cholesterol because they lead to fat building up on artery walls, which causes heart disease – 70% of cholesterol consisting mostly of fat HDLs are often called ‘good’ cholesterol because they help to stop fat building up in the arteries – 20% of cholesterol consisting mostly of protein

Causes & Prevention CausesPrevention DietBalanced diet Fitness (exercise)Regular exercise AlcoholSensible alcohol intake SmokingNot smoking Family History- Age- Sex-

Food Types A high proportion of HDLs to LDLs is good for a healthy heart Monounsaturated and polyunsaturated oils (found in vegetable oils) help to reduce cholesterol levels in the blood, and also increase the proportion of HDLs compared with LDLs There are also drugs that can improve high blood pressure and high cholesterol levels

Fats Molecules of vegetable oils consist of glycerol and fatty acids Glycerol has 3 carbon atoms and fatty acids have long chains of carbon atoms Glycerol part Fatty acid part

Fatty Acids – Saturated The fatty acids in some vegetable oils are saturated, and only have single bonds between their carbon atoms Saturated oils tend to be solid at room temperature, and are sometimes called vegetable fats instead of oil Lard is an example of a saturated oil

Fatty Acids – Unsaturated The fatty acids in some vegetable oils are unsaturated, and have double bonds between some of their carbon atoms Unsaturated oils tend to be liquid at room temperature, and are useful for frying food They can be divided into two categories: - Monounsaturated fats have one double bond in each fatty acid Polyunsaturated fats have many double bonds

Unsaturated Importance The carbon-carbon double bonds in unsaturated oils can be detected using the elements bromine or iodine These elements react with the double bonds in the oils, and the more double bonds there are, the more bromine or iodine is used up Bromine water is a dilute solution of bromine, which is normally orange-brown in colour – it becomes colourless when shaken with an alkene, or with unsaturated fats (when shaken with alkanes or saturated fats, its colour remains the same)

Unsaturated Importance

Salt Too much salt in the diet can lead to high blood pressure, which in turn leads to an increased risk of heart disease and strokes Salt is found naturally in many kinds of food, but more is added by food manufacturers - and many people add even more when they are eating Processed foods often have a high proportion of salt and fat – salt added to food during processing accounts for about two-thirds of the average salt intake

Salt On average, men in the UK eat about 10g of salt a day and women about 8g a day However, food scientists recommend no more than 6g of salt a day in the die – reducing the amount of salt in the diet will help to reduce the risk of heart disease, and to a greater extent the risk of suffering a stroke

Life Expectancy How has life expectancy changed for men and women in this country over decade? What has driven this change?

Life Expectancy Men’s life expectancy…

Life Expectancy Women’s life expectancy…

Life Expectancy A huge number of changes, ranging from medicines, better food and living standards, to general awareness of life style have helped raised the life expectancy for both men and women in this country over the past decade There are still worrying health trends in the UK, especially due to smoking / unhealthy diets, which are linked to particular areas which generally less well-off