OCR GCSE Biology A: Non-communicable disease, cardiovascular treatment, lifestyle and cancer (J247)

This guide covers statements B6.3r to B6.3u of module B6.3 (Monitoring and maintaining health) in OCR GCSE (9-1) Gateway Science Biology A (J247), specification Version 4.0 (August 2026), for first assessment in 2018. None of these four statements is shown in bold in the specification, so the content is tested in both Foundation and Higher Tier papers. Other statements of B6.3 (communicable disease, defence against infection, medicines, stem cells and genomics) are taught on separate pages. Course pages: OCR GCSE Biology hub | printable checklist | revision notes | practice questions | free 10-minute diagnostics.

What this unit covers

Statement	What you must be able to do
B6.3r	Recall that many non-communicable diseases are caused by an interaction of a number of factors. Examples: cardiovascular diseases, many forms of cancer, some lung diseases (bronchitis), some liver diseases (cirrhosis) and diseases influenced by nutrition, including type 2 diabetes
B6.3s	Evaluate different treatments for cardiovascular disease: lifestyle, medical and surgical
B6.3t	Analyse the effect of lifestyle factors (exercise, diet, alcohol, smoking) on the incidence of non-communicable diseases at local, national and global levels
B6.3u	Describe cancer as the result of changes in cells that lead to uncontrolled growth and division

The mathematical outcomes for this module that apply here are: translate between graphs and numbers, construct and interpret frequency tables, bar charts and histograms, understand sampling, and use a scatter diagram to identify a correlation.

B6.3r: non-communicable diseases and multiple causes

A non-communicable disease cannot be passed from one person to another. No pathogen is involved. Most are long-lasting.

Most are also multifactorial: they develop because several factors interact, not because of one cause. The factors fall into three groups.

Group	Examples
Inherited	Gene variants that raise the risk of a disease
Lifestyle	Smoking, alcohol, diet, lack of exercise
Environment	Exposure to radiation or to chemicals in the air or workplace

The specification names these examples.

• Cardiovascular diseases affect the heart and blood vessels. Coronary heart disease is the one to know in detail.
• Cancers (many forms).
• Bronchitis, a lung disease in which the airways are inflamed and produce extra mucus.
• Cirrhosis, a liver disease in which healthy liver tissue is replaced by scar tissue.
• Type 2 diabetes, a disease influenced by nutrition. Body cells respond poorly to insulin, so blood glucose stays high. Being overweight raises the risk.

“Interaction” matters. A person can carry a risk-raising gene variant and never become ill. Another person with the same variant who smokes and eats a poor diet has a much higher risk. One factor may make another more harmful.

A common misconception is that cancer is a genetic disease you inherit. Most cancers start with changes in body cells during a lifetime and are not passed to children. Inherited variants can raise the risk, but they are only one factor.

B6.3s: treating cardiovascular disease

In coronary heart disease fatty material builds up inside the coronary arteries and narrows them. The heart muscle gets less oxygenated blood. Narrowing can cause chest pain on exertion. If a coronary artery becomes blocked, part of the heart muscle is starved of oxygen and a heart attack follows. Look back at the coronary arteries in the circulatory system guide if you need to.

There are three types of treatment to evaluate.

Lifestyle changes

Stop smoking, eat less saturated fat and salt, keep to a healthy body mass, take regular exercise and drink less alcohol.

• Benefits: cheap, no operation, and they lower the risk of several other diseases.
• Drawbacks: they need sustained effort, results come slowly, and they cannot remove a blockage that already exists.

Medical treatment (drugs)

Drug type	Purpose	Points to weigh up
Statins	Lower blood cholesterol, which slows the build-up of fatty deposits	Taken for years; can cause side effects such as muscle pain; acts on a risk factor (cholesterol) and does not clear existing deposits
Drugs that lower blood pressure	Reduce the strain on the heart and artery walls	Long-term use; effects must be monitored
Anticoagulants or anti-clotting drugs	Make clots in arteries less likely	Increased risk of bleeding

Drugs avoid surgery and suit many patients. They have to be taken regularly, and benefits depend on the patient following the course.

Surgical treatment

Operation	What it does	Points to weigh up
Stent	A wire mesh tube is expanded inside a narrowed coronary artery and holds it open	Quick recovery, but a blood clot can form on the stent and the artery can narrow again
Coronary bypass	A length of blood vessel (often taken from the leg) is joined around the blocked section	Major open surgery, longer recovery, but can treat several blockages
Heart valve replacement	A damaged valve is replaced by a mechanical or biological valve	Mechanical valves can need long-term anti-clotting drugs
Heart transplant	A damaged heart is replaced by a donor heart	Donors are scarce; the immune system can reject the organ, so drugs that suppress it are needed

How to evaluate

Evaluate means weigh the advantages against the disadvantages and reach a judgement. Use a pattern: benefit, then drawback, then a conclusion that depends on the patient. For example, lifestyle change is the first choice for everyone, drugs suit a patient with high cholesterol, and surgery is for a patient whose artery is already seriously blocked.

Worked example 1: evaluating a statin trial

In a trial, 1000 people took a statin and 1000 took a placebo for five years. The statin group had mean blood LDL cholesterol of 3.1 mmol/dm³ at the end, compared with 4.6 mmol/dm³ at the start. In the placebo group 71 people had a heart attack. In the statin group 48 did.

1. Change in cholesterol = 3.1 − 4.6 = −1.5 mmol/dm³.
2. Percentage change = (−1.5 ÷ 4.6) × 100 = −32.6% (a fall of 32.6%).
3. Fewer heart attacks = 71 − 48 = 23 per 1000 people.
4. As a percentage of the placebo figure, 23 ÷ 71 × 100 = 32.4% fewer heart attacks.

Conclusion: the statin lowered cholesterol and was linked to fewer heart attacks. A good answer also notes the limits: five years only, and the figures do not show side effects.

B6.3t: lifestyle factors and the incidence of disease

Incidence counts the people who newly develop a disease during one stated period. To compare places of different sizes, convert to a rate, for example cases per 100 000 people.

Lifestyle factor	Diseases it is linked with
Smoking	Lung cancer, bronchitis, coronary heart disease
Alcohol	Cirrhosis; excess also raises the risk of some cancers
Diet	Obesity, type 2 diabetes, coronary heart disease
Exercise	Regular exercise lowers the risk of coronary heart disease and type 2 diabetes

Smoking gives an example of cause. Tar in cigarette smoke contains chemicals that damage the DNA of lung cells and can lead to cancer. Smoking also damages the lining of the airways, which leads to bronchitis, and damages artery walls, which helps fatty deposits form.

Local, national and global

• Local: a town or region. Incidence can differ between neighbouring areas because of differences in smoking rates, diet, income and age.
• National: a whole country. Governments collect data and run health campaigns.
• Global: comparing countries. Type 2 diabetes and cardiovascular disease are becoming more common in places where diets and activity levels have changed.

Worked example 2: comparing incidence

Town A had 36 new cases of a lung disease in one year and a population of 48 000. Town B had 52 new cases and a population of 91 000.

• Town A: 36 ÷ 48 000 × 100 000 = 75.0 per 100 000.
• Town B: 52 ÷ 91 000 × 100 000 = 57.1 per 100 000.

Town B has more cases but the lower rate. Comparing raw numbers would mislead.

Interpreting data

Frequency tables and histograms. The ages at which 200 people were first diagnosed with coronary heart disease:

Age (years)	40 to 49	50 to 59	60 to 69	70 to 79	80 to 89
Frequency	12	34	71	58	25

The total is 12 + 34 + 71 + 58 + 25 = 200. The modal class is 60 to 69, which holds 71 ÷ 200 × 100 = 35.5% of cases. Because the classes are equal in width, the bars of a histogram are the same width and touch. Their heights show frequency.

Scatter diagrams and correlation. Six regions had mean weekly alcohol intake per adult (units): 4, 6, 9, 11, 14, 17. Their new cirrhosis cases per 100 000 were 6, 8, 13, 14, 21, 24. Plot intake on the x-axis and cases on the y-axis. The points rise from left to right, so there is a positive correlation. A line of best fit could be drawn through them.

Correlation is not proof of cause. To argue that alcohol causes cirrhosis, you need more: a biological mechanism (alcohol is broken down in the liver, and heavy drinking damages liver cells), and consistent results from different studies. Other factors, such as diet or income, may differ between regions.

Sampling. A study cannot test everyone. A sample should be large enough and chosen at random so that it represents the population. A small, self-selected sample can give a biased result. Diseases also take years to develop, so a long study is needed.

B6.3u: cancer

Cancer is the result of changes in cells that lead to uncontrolled growth and division. Normally the cell cycle is controlled and cells divide only when the body needs new cells. In a cancer cell a change (a mutation) in the genes that control division makes the cell divide again and again by mitosis. See the mitosis and stem cells guide and the mutations guide.

A mass of abnormal cells is called a tumour.

	Benign tumour	Malignant tumour
Growth	Grows in one place	Invades neighbouring tissue
Spread	Does not spread	Cells break off, travel in the blood and form secondary tumours elsewhere
Description	Not cancer	Cancer

Known risk factors (things that raise the chance of a mutation) include tobacco smoke, ultraviolet radiation, ionising radiation and some inherited variants. The disease is multifactorial, which links back to B6.3r.

Worked example 3: why uncontrolled division becomes serious

One cancer cell divides every 24 hours, and each division doubles the number of cells.

• After 10 divisions: 2¹⁰ = 1024 cells.
• After 20 divisions: 2²⁰ = 1 048 576 cells.
• After 30 divisions: 2³⁰ = 1 073 741 824 cells, after 30 days.

The cell number grows exponentially. Real tumours grow more slowly because some cells die and some cannot get enough oxygen, but the pattern explains why early growth goes unnoticed and later growth is fast.

Common errors

• Writing that cancer is “caused by a virus” or “catching it”. Cancer is not communicable.
• Saying a factor “causes” a disease on the strength of a correlation alone.
• Comparing the number of cases instead of a rate per 100 000.
• Listing the treatments for cardiovascular disease without a drawback for each, in an “evaluate” answer.
• Saying a stent “removes” fatty material. It holds the artery open.
• Calling every tumour cancer. A benign tumour does not spread.

Test yourself next with the practice questions.

Official syllabus

OCR GCSE (9-1) Gateway Science Biology A (J247), specification Version 4.0 (August 2026), for first assessment in 2018, published by OCR.