Age-Proof Your Immunity: The Science of Staying Healthy in Mid Life
This time of year can be hard for many of us in mid life due to the sheer number of viruses going around offices, transport systems and pretty much any social gathering. Why am I constantly picking up heavy colds and the like seems to be a constant refrain in the office. It doesn’t help that as we age our immune system tends to decline in efficacy increasing the risk of infections, reducing vaccine effectiveness, and contributing to the pathogenesis of age-related diseases.
How does ageing affect the immune system?
Ageing affects the immune system in several significant ways, leading to a phenomenon known as immunosenescence. Key aspects of how ageing impacts the immune system include:
Decreased Production of Naive T Cells: The thymus, where T cells mature, involutes with age, leading to a reduced output of naive T cells. This decrease limits the immune system's ability to respond to new pathogens, resulting in an increased susceptibility to infections.
Accumulation of Memory T Cells: As individuals age, there is an accumulation of memory T cells. While these cells are important for responding to previously encountered pathogens, their reduced diversity and functionality can hinder effective immune responses to new infections or vaccinations.
Impaired B Cell Function: Ageing leads to decreased B cell proliferation and antibody production. This impairment results in lower levels of antibodies being produced in response to vaccinations or infections, reducing the overall effectiveness of the immune response.
Altered Innate Immune Responses: The innate immune cells, such as neutrophils and natural killer (NK) cells, exhibit reduced functionality with age. This includes diminished chemotaxis, phagocytosis, and the ability to kill infected or cancerous cells, which can lead to increased vulnerability to infections and cancer.
Chronic Inflammation: Ageing is often associated with chronic low-grade inflammation, also known as "inflammaging," characterised by elevated levels of pro-inflammatory cytokines. This chronic inflammatory state contributes to tissue damage, functional decline, and an increased risk of various age-related diseases.
Telomere Shortening: With each cell division, telomeres—the protective caps on the ends of chromosomes—shorten. In immune cells, particularly T lymphocytes, this shortening leads to replicative senescence, resulting in a reduced pool of functional immune cells capable of responding to new antigens.
The cumulative effects of the above factors contribute to greater vulnerability to infections, weakened responses to vaccines, and higher incidence of autoimmune diseases and cancers.
The good news is that we can all do something about this. It’s not something that we just have to accept. Some recent research finds that how we live our lives has a big impact on our ageing immune systems.
The research was conducted by two institutions:
Institute for Biomedical Aging Research, Faculty of Biology, University of Innsbruck, Austria.
Department of Pediatrics, Medical University of Innsbruck, Austria.
The research explored the complex biological mechanisms behind immunosenescence and how various lifestyle and intervention strategies may influence these processes. The teams hypothesis was that factors such as diet, exercise, stress management, and sleep can modulate the rate and extent of immunosenescence at both cellular and molecular levels, potentially leading to better health outcomes for older populations.
Findings:
The research found that chronic low-grade inflammation, often referred to as "inflammaging," is closely tied to the ageing process and the onset of various age-related diseases. Key points from the findings include:
Elevated Inflammatory Markers: Inflammaging is characterised by increased levels of inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in older adults. These markers are associated with a pro-inflammatory state that can lead to tissue damage and functional decline .
Impact on Immune Function: Chronic inflammation contributes to immunosenescence. This decline affects both innate and adaptive immune responses, resulting in increased susceptibility to infections, reduced vaccine efficacy, and a higher incidence of autoimmune diseases and cancer .
Connection to Age-related Diseases: The interplay between chronic inflammation and immunosenescence significantly contributes to the development and progression of various age-related diseases, including cardiovascular diseases, type 2 diabetes, Alzheimer’s disease, and certain cancers. Inflammaging creates a vicious cycle that not only exacerbates immune decline but also accelerates the ageing process itself.
Senescent Cells and the SASP: Senescent cells accumulate with age and express a senescence-associated secretory phenotype (SASP), producing pro-inflammatory cytokines that foster a chronic inflammatory environment. This is a critical factor in the inflammaging process.
The research teams found that by changing to more healthy lifestyles, reduces the chronic inflammation which in turn slows down ageing of the immune system.
What specific lifestyle changes help reduce immunosenescence?
The research highlights several specific lifestyle changes that can help combat immunosenescence:
Regular Physical Activity: Engaging in moderate-intensity exercise consistently can enhance various aspects of immune function and reduce chronic low-grade inflammation associated with ageing. Physically active older adults show improved immune responses compared to sedentary individuals.
Stress Management: Chronic stress accelerates the ageing of the immune system. Interventions such as meditation, yoga, and deep breathing exercises can reduce stress and support immune function. Mindfulness practices have been shown to decrease pro-inflammatory gene expression in older adults.
Adequate Sleep: Aiming for 7–9 hours of quality sleep per night is crucial, as inadequate sleep can impair immune function. Poor sleep quality is linked to increased susceptibility to infections and reduced vaccine efficacy.
Nutrition: A balanced diet, particularly a Mediterranean-style diet, is beneficial. This dietary pattern can help reduce inflammation and support immune health as one ages.
Weight Management: Maintaining a healthy body weight through diet and exercise is essential, as obesity is associated with chronic inflammation, which can accelerate immunosenescence.
Social Connections: Building and maintaining strong social ties can positively impact immune function. Social isolation has been correlated with adverse immune health outcomes.
Smoking Cessation and Moderation of Alcohol Consumption: Avoiding smoking and moderating alcohol intake are vital for maintaining immune health.
As mid life athletes, staying active and maintaining a healthy lifestyle are not just about peak performance or aesthetic goals; they are crucial defences against the effects of ageing on our immune system. By embracing regular exercise, nutrition, stress management, and quality sleep, we can counteract the challenges of immunosenescence and bolster our immune health. Remember, every stride, every healthy meal, and every moment of rest contributes to a stronger, more resilient you.