How Aging Affects Your Immune System (and What to Do About It)

Our immune system works throughout life to help protect the body. But just like many other systems in the body, it changes as we get older.

These age-related changes do not mean that immune health is completely outside our control. Nutrition, physical activity, sleep and other everyday habits all contribute to maintaining overall health as we age.

So what happens to the immune system as we get older, and what can we do to support normal immune function? Let’s explore immunosenescence, the nutrients involved in immunity and the lifestyle foundations of healthy ageing.

What Happens to the Immune System as You Age?

The gradual changes that occur in the immune system with age are often referred to as immunosenescence.

Both the innate immune system, our body's first line of defence, and the adaptive immune system, which develops more specific responses to particular threats, can change over time.

These changes are complex and vary considerably between individuals. Genetics, nutrition, physical activity, health conditions and other lifestyle and environmental factors can all play a role.

Why Does Immunity Change With Age?

Ageing affects different components of the immune system rather than simply making the entire system "weaker".

Some of the changes researchers study include alterations in immune cell production and function, changes in inflammatory signalling and differences in adaptive immune responses.

Changes in T Cells

T cells are an important part of the adaptive immune system. They help the body recognise and respond to specific threats.

The thymus, an organ involved in the development of T cells, gradually becomes less active with age. This contributes to changes in the composition and diversity of the body's T-cell population over time.

Changes in Inflammatory Processes

Ageing is also associated with changes in inflammatory signalling.

The term "inflammaging" is used in scientific literature to describe the chronic, low-grade inflammatory state that can accompany ageing.

Research continues to investigate the complex relationship between inflammation, immunity, lifestyle and age-related health.

Changes in Immune Responses

The adaptive immune response can also change with age. This is one reason older adults may respond differently to certain infections and vaccinations compared with younger adults.

However, chronological age is only one part of the picture. Individual health, previous immune exposure and lifestyle factors also influence immune function.

Which Nutrients Support the Immune System?

A varied and balanced diet provides the energy and nutrients the immune system needs to function normally.

Several vitamins and minerals have established roles in normal immune function, including vitamin D, vitamin C, zinc and selenium.

Vitamin D

Vitamin D contributes to the normal function of the immune system.

It also contributes to the maintenance of normal bones and muscle function, making it particularly relevant when considering healthy ageing more broadly.

Vitamin D can be obtained from certain foods, supplements and production in the skin following exposure to sunlight.

Vitamin C

Vitamin C contributes to the normal function of the immune system and to the protection of cells from oxidative stress.

It also contributes to normal collagen formation for the normal function of skin, bones, cartilage and blood vessels.

Good dietary sources include peppers, citrus fruits, berries, kiwi and broccoli.

Zinc

Zinc contributes to the normal function of the immune system and to the protection of cells from oxidative stress.

It also contributes to normal DNA synthesis, normal protein synthesis and the maintenance of normal bones, skin, hair and nails.

Dietary sources include meat, shellfish, dairy products, legumes, nuts and seeds.

Selenium

Selenium contributes to the normal function of the immune system and to the protection of cells from oxidative stress.

Selenium can be found in foods including fish, seafood, eggs, meat, nuts and seeds, although the selenium content of plant foods varies according to the soil in which they are grown.

Why Does Nutrition Matter More as We Age?

Nutritional needs and eating habits can change throughout life.

Factors such as appetite, dietary variety, medication use, changes in digestion and individual health circumstances can influence nutrient intake and nutritional status in older adults.

This makes nutrient-dense foods particularly valuable. Rather than simply focusing on eating more, the goal is to provide the body with a broad range of essential nutrients through a varied diet.

What Foods Support Normal Immune Function?

There is no single food that can "boost" the immune system. Instead, dietary variety helps provide the different nutrients involved in normal immune function.

Useful foods to include regularly can include:

• Colourful vegetables and fruits for vitamin C and other micronutrients
• Nuts and seeds for minerals and healthy fats
• Legumes for protein, fibre and micronutrients
• Whole grains for fibre and B vitamins
• Fish for protein, vitamin D and omega-3 fatty acids
• Eggs and dairy products for protein and various vitamins and minerals
• Fermented foods as part of a varied diet

A colourful and varied plate is a simple way to incorporate a broader range of nutrients into your everyday diet.

What Is the Connection Between Gut Health and Immunity?

The gastrointestinal tract and immune system are closely connected. The gut contains a large community of microorganisms collectively known as the gut microbiome.

Researchers continue to investigate how changes in the microbiome throughout life interact with immune function and healthy ageing.

A varied diet containing fibre-rich plant foods can help support the gut microbiome.

Foods such as vegetables, fruits, legumes and whole grains provide different types of dietary fibre, while fermented foods can also form part of a varied diet.

Can Exercise Support Healthy Ageing?

Regular physical activity is an important part of maintaining health throughout life.

Rather than focusing on one specific type of exercise, a balanced routine can include aerobic activity, resistance training, mobility and everyday movement.

Walking, swimming, cycling, strength training and yoga are all examples of activities that can be adapted to individual ability and preferences.

Maintaining muscle mass and physical function also becomes increasingly important with age, making regular movement and adequate nutrition valuable parts of a healthy ageing routine.

Why Is Sleep Important for the Immune System?

Sleep is an important part of recovery and normal physiological function.

Sleep patterns can change with age, but maintaining a consistent routine can still support overall wellbeing.

Useful habits can include maintaining regular sleep and wake times, creating a calm evening routine, limiting late caffeine intake and keeping the bedroom comfortable and dark.

Persistent changes in sleep or ongoing sleep difficulties should be discussed with an appropriate healthcare professional.

What About Stress and Immune Health?

The body's stress response and immune system interact through multiple biological pathways.

Occasional stress is a normal part of life. However, creating regular opportunities for recovery can be valuable for overall wellbeing.

Simple habits such as walking outdoors, spending time with others, reading, breathing exercises or taking genuine breaks can all become part of a balanced daily routine.

Do You Need Supplements for Immune Health as You Age?

Not everyone needs the same supplements simply because they are getting older.

Supplementation can be useful when it helps meet a specific nutritional requirement or when adequate intake is difficult to achieve through diet alone.

Individual needs depend on factors such as diet, lifestyle, nutritional status, medication use and health circumstances.

Food supplements should complement rather than replace a varied and balanced diet and healthy lifestyle.

Frequently Asked Questions About Ageing and Immunity

Does the immune system get weaker with age?

The immune system changes as we age, a process often referred to as immunosenescence. Rather than simply becoming "weaker", different components of the immune response change in complex ways over time.

What is immunosenescence?

Immunosenescence is the term used to describe age-related changes in the immune system, including changes affecting immune cells and adaptive immune responses.

What is inflammaging?

Inflammaging describes the chronic, low-grade inflammatory state associated with ageing. Researchers are investigating how it relates to immune function and different aspects of age-related health.

Which vitamins support the immune system?

Several vitamins contribute to normal immune system function, including vitamins A, B6, B9, B12, C and D.

Which minerals support immunity?

Zinc, selenium, iron and copper contribute to the normal function of the immune system.

Is vitamin D important as you get older?

Vitamin D contributes to normal immune system function and the maintenance of normal bones and muscle function. Individual vitamin D requirements and status can vary, so supplementation should be considered according to personal circumstances.

Can you boost your immune system?

The immune system is complex, and describing foods or supplements as simply "boosting" immunity can be misleading. A more useful approach is to support normal immune function through adequate nutrition, physical activity, sleep and other healthy lifestyle habits.

Key Takeaways

• The immune system naturally changes throughout the ageing process.
• These changes are commonly described as immunosenescence.
• Inflammaging describes chronic low-grade inflammatory changes associated with ageing.
• Vitamin D, vitamin C, zinc and selenium contribute to normal immune system function.
• A varied, nutrient-dense diet helps provide the nutrients the immune system needs.
• Gut health, physical activity, sleep and recovery are all part of the bigger healthy ageing picture.
• Supplement needs vary between individuals and should complement a balanced diet rather than replace it.

Supporting Your Immune System Through Healthy Ageing

Ageing is a natural part of life, and so are changes within the immune system. But healthy ageing is about much more than trying to prevent those changes.

Good nutrition, regular movement, adequate sleep, social connection and time for recovery can all form part of a lifestyle that supports your body throughout every stage of life.

Rather than looking for one ingredient that promises to "boost" immunity, focus on the everyday foundations that help provide your body with the nutrients and support it needs.

This article is for informational purposes only and is not intended to diagnose, treat, cure or prevent any disease. Individual nutritional and health needs can change with age. If you have concerns about your immune health, nutritional status, medication or supplementation, consult an appropriate healthcare professional.