Explain how a diet high in saturated fat can lead to cardiovascular disease.

Edexcel GCSE Biology (1BI0) — 5.3 Non-communicable diseases · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Cardiovascular disease is one of the leading causes of death in the United Kingdom. Research has shown a strong correlation between diets high in saturated fat and the development of cardiovascular disease.

Model answer (4 marks)

A diet high in saturated fat raises the level of low‑density lipoprotein (LDL) cholesterol in the blood.
LDL cholesterol carries fatty acids to tissues, but excess LDL deposits cholesterol in the intima of arteries.
These deposits form atheromas (plaques) which grow and narrow the arterial lumen.
The narrowed lumen reduces blood flow to the heart muscle, increasing the risk of a heart attack, and can also favour clot formation, leading to stroke.

Examiner tips

Show the chain from saturated fat → ↑LDL → plaque formation → narrowed lumen → reduced blood flow and heart attack/stroke
Use the exact terms: LDL, atheroma, lumen, heart attack, stroke

Common mistakes

Confusing HDL with LDL as the harmful cholesterol
Failing to mention that plaques narrow the lumen
Not linking reduced blood flow to heart attack or stroke

Mark scheme (4 marks)

A diet high in saturated fat leads to raised blood cholesterol levels / increased lipid levels in the blood
Cholesterol / fatty deposits build up in artery walls to form atheromas (plaques)
Atheromas narrow the lumen of arteries, restricting / reducing blood flow
Reduced blood flow to heart muscle causes a heart attack / increases risk of a blood clot forming / stroke

Key terms in this question

cardiovascular disease