Group Mean daily saturated fat / g Percentage who exercise regularly / % Cases of CHD per 1000 A 15 65 12 B 32 40 28 C 48 15 55 Coronary heart disease (CHD)...
Question 1 Report
| Group | Mean daily saturated fat / g | Percentage who exercise regularly / % | Cases of CHD per 1000 |
|---|---|---|---|
| A | 15 | 65 | 12 |
| B | 32 | 40 | 28 |
| C | 48 | 15 | 55 |
Coronary heart disease (CHD) is a major cause of death in many countries. Scientists studied three groups of adults with different diets and exercise habits. For each group they recorded the mean daily intake of saturated fat, the percentage who exercised regularly, and the number of new cases of CHD per 1000 people, shown in the table.
(a) Name the blood vessels that supply the heart muscle itself with oxygenated blood. [1]
(b) State the group with the highest number of cases of CHD. [1]
(c) Describe the relationship between saturated fat intake and cases of CHD shown in the table. [2]
(d) Explain how a blockage in one of these blood vessels can lead to the death of heart muscle. [4]
(e) Explain how regular exercise reduces the risk of coronary heart disease. [3]
(f) Suggest two changes, other than exercise, that a person could make to reduce their risk of CHD. [2]
(g) State one factor that increases the risk of CHD but which a person cannot change. [1]
Answer Details
This question uses data on saturated fat, exercise and coronary heart disease (CHD) and tests how CHD develops and how it can be reduced.
(a) The heart muscle is supplied with oxygenated blood by the coronary arteries. [1]
(b) The group with the highest number of CHD cases is group C (55 per 1000). [1]
(c) As saturated fat intake increases, the number of CHD cases increases [1]; this is a positive correlation, supported by the figures, for example 15 g gives 12 cases while 48 g gives 55 cases [1]. [2]
(d) A blockage kills heart muscle through this chain [4]: fatty deposits build up in the wall of a coronary artery [1]; the vessel becomes narrow and a blood clot may form and block it [1]; less blood, and therefore less oxygen and glucose, reaches the heart muscle beyond the blockage [1]; those muscle cells cannot respire (aerobically) and so they die [1]. [4]
(e) Regular exercise strengthens the heart muscle [1]; it helps reduce fatty deposits in the arteries and lowers blood pressure [1]; and it helps a person maintain a healthy body mass [1], all of which lower the risk of CHD. [3]
(f) Any two other changes [2]: eat less saturated fat; reduce salt intake; stop smoking; reduce alcohol; lose weight; reduce stress. (any 2)
(g) One risk factor a person cannot change: age, sex, or genetic (inherited) factors. [1]
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