AQA GCSE Lifestyle and Non communicable disease (Biology)

 Lifestyle and Non communicable disease

Non-communicable diseases include things like cancer, diabetes, heart disease and obesity — illnesses that cannot be spread from person to person.

Cost of Non Communicable disease

1.To an individual:

Pain, disability, reduced quality of life, emotional stress, loss of income, cost of treatment.

2.To a local community:

Pressure on local hospitals, people missing work, less productivity, families needing support.

3.To the country:

NHS costs, fewer people able to work, government having to spend money on healthcare instead of other services.

4.Globally:

Huge burden on health systems, reduced economic development in poorer countries, global health inequality.

Explain how lifestyle affects disease rates

You should be able to talk about how lifestyle choices affect the chances of getting non-communicable diseases:

Lifestyle factorEffect
DietPoor diet can lead to obesity, type 2 diabetes, heart disease.
SmokingIncreases risk of lung cancer, heart disease, respiratory diseases.
AlcoholCan cause liver disease, brain damage, addiction, some cancers.

And you must explain this at different scales:

1.Local level: e.g., higher smoking rates in a town = more lung disease locally

2.National level: e.g., obesity rates rising in the UK

3.Global level: e.g., worldwide increase in type 2 diabetes because of unhealthy diets

Risk Factors

Risk factors are linked to an increased rate of a disease.

This means that if a person has a risk factor, then they are more likely to suffer from a particular disease.

Risk factors could be:

1. Aspects of a person’s lifestyle

2.Substances in the person’s body or environment.

Aspects of a Person’s Lifestyle

Aspects of a person’s lifestylePossible non communicable disease
SmokingLung cancer, heart disease
Poor dietObesity, diabetes, heart disease
Lack of exerciseHeart disease
Too much sunSkin cancer

Substances in the person’s body or environment.

Substances in the body or environmentPossible non communicable disease
Asbestos (environment)Lung disease/cancer
Air pollution (environment)Asthma, lung disease
High cholesterol (in body)Heart disease
Chemicals in tobacco smoke (body)Cancer

Causal mechanism

A causal mechanism has been proven for some risk factors, but not in others.

Causal mechanism proven means scientists have found the biological reason why a risk factor leads to a disease.

No proven mechanism yet this means scientists know there is a link, but they do not fully understand how it causes the disease.

Risk FactorCausal mechanism proven or unproven?Mechanism
High-fat diet (cardiovascular disease)Provenhigh cholesterol → plaque in arteries → heart attacks
Smoking (cardiovascular disease)ProvenChemicals damage arteries → plaque formation
Lack of exercise (cardiovascular disease)ProvenObesity → strain on heart
Obesity (Type 2 diabetes)ProvenExcess fat causes insulin resistance → blood glucose cannot be controlled → Type 2 diabetes develops
Alcohol (Liver and brain function)ProvenLiver: Alcohol metabolised → toxic byproducts damage liver cells → cirrhosis

Brain: Alcohol affects neurotransmitters → impaired brain function, memory, coordination
Smoking (Lung disease and lung cancer)ProvenChemicals in smoke damage lung tissue → chronic bronchitis / emphysema

Mutagens in smoke → DNA mutations → lung cancer
Smoking and alcohol (effect on unborn babies)Partially provenSmoking: Carbon monoxide reduces oxygen → low birth weight

Alcohol: Interferes with fetal development → Fetal Alcohol Syndrome

Some exact mechanisms in development are still being studied
Carcinogens (e.g., ionising radiation) (cancer)ProvenRadiation damages DNA → mutations accumulate → uncontrolled cell division → cancer

Some risk factors (like smoking and cancer, obesity and diabetes) have clear causal mechanisms. Others (like stress and heart disease) are linked but the exact biological process is not fully understood.

Multiple factors

Many diseases are caused by multiple factors.

Example: Cardiovascular disease can be influenced by diet, smoking, exercise, genetics, and stress

Causal mechanisms may interact, making some effects harder to prove individually

Practice Questions

1.Describe what is meant by a non communicable disease

2. State 3 life style factors that can affect our health

3. Explain what is mean by the term proven causal mechanism.