Healthy Eating & Physical Activity for:

a healthy immune system

This fact sheet aims to identify the main age-related changes and conditions affecting the the immune system; it will also outline healthy eating and physical activity that may help prevent, or delay, onset of these changes/conditions.

Age-related changes and conditions

As we age, there is a natural decline in body composition, including the immune system. The immune systembecomes progressively overactive but less efficient. Our immune system mass declines (thymus, bone marrow), which means we are at a higher risk of bacterial or viral infections; we also develop chronic low-grade inflammation, which contributes to the development of diseases, such as arthritis, but also type 2 diabetes, cardiovascular diseases, Alzheimer’s and Parkinson’s disease.


Arthritis is characterised by the inflammation of joints. It comprises of osteoarthritis (associated with obesity, affecting weight bearing joints), rheumatoid arthritis (affecting multiple joints) and gout (uric crystals accumulate in the joints).

Alzheimer’s and Parkinson’s

Alzheimer’s disease is characterised by cognitive decline: a gradual loss of memory, reasoning, ability to communicate, and physical capability. Parkinson’s disease is characterised by motor decline: tremors, slowed movements, rigid muscles, impaired posture and balance, loss of automatic movement, speech and writing changes. Oxidative stress and inflammation are implicated in both conditions, and individuals with high bloodpressure, diabetes, or obesity are at higher risk of developing these conditions.

Cardiovascular diseases

Hypertension is characterised by a blood pressure above 140/90 mmHg. People with hypertension are at higher risk of developing cardiovascular diseases e.g. coronary heart diseases and stroke.Coronary heart disease and stroke are caused by the blockage of the vessels supplying the heart and brain, respectively. They are often linked to the build-up of fats in these vessels; people with higher cholesterol levels or high blood pressure are more at risk.

Type 2 diabetes

Type 2 diabetes is characterised by hyperglycaemia (an excess of glucose in the blood), due to an inability of the body to respond to insulin (insulin resistance). It is associated with obesity, and people with type 2 diabetes are at higher risk of developing cardiovascular diseases.

Key nutrients

Key nutrients to maintain a healthy immune system include:

  • Protein
  • Omega-3 PUFAs
  • Vitamins A, B6, Folate, B12, C, D, E
  • Calcium
  • Magnesium
  • Iron
  • Zinc
  • Copper
  • Iodine
  • Selenium

Immune system cells and antibodies need protein to function properly. Some proteins containing purines (mainly animal proteins) which exacerbate gout, so should be restricted in sufferers of gout. Vitamins A, C, D, E, folate and all mentioned minerals contribute to immune system function while Omega-3 PUFAs, vitamins A, B6, folate, B12 and zinc contribute to reducing chronic low grade inflammation.

Main factors increasing risk of immune system related conditions

  • Smoking and excess alcohol
  • Family history
  • Gender/hormones– females are at higher risk of inflammatory and autoimmune diseases than males.
  • Age
  • Physical inactivity
  • Psychological issues and stress
  • Lack of sleep
  • Medications – some medications may adversely
    affect the immune system – ask your GP.
  • Uncontrolled diabetes
  • Poor diet
  • Too much salt
  • Obesity
  • High blood pressure

Did you know?

80% of our immune system activity occurs in the intestines.

Foods to eat

The immune system is complex with many nutrients contributing to its function. Maintaining a healthy weight and eating a balanced diet, based on the “Eatwell Guide”, will reduce risks of age-related immune system conditions.

  • Fruit and vegetables
  • Wholegrains
  • Oily fish
  • Eggs
  • Dairy products
  • Nuts and seeds
  • Lean red meat and poultry

Physical Activity

There are two types of physical activity: strength/resistance and cardiovascular. Both strength and cardiovascular exercise are essential to maintaining a healthy immune system.


  • Over 50? Medical condition? – consult a GP before starting an exercise programme.
  • Engage a personal trainer; optimise YOUR needs, and YOUR health.
  • Warm up before exercise and cool down after.
  • Do exercises correctly to reduce risk of injury.

This table provides a rough guide to foods containing key micronutrients with the approximate % of daily requirement (%DR); this is not a comprehensive list.