Ageing is a natural and inevitable biological process, and going through the ageing process can often mean experiencing a myriad of changes to your physical health. In recent decades, the implications of ageing on the immune system have become a popular field of study - this is in part due to an increasing ageing population and their susceptibility to infections and diseases.
In the following article, we’re going to take a look at how ageing impacts the immune system and how small lifestyle changes - from better diet to private medical coverage - can help you maintain optimal immune health as you get older. Let’s take a look!
What is the immune system?
The immune system is a complex network of cells, tissues, and organs working synergistically to protect the body from harmful invaders such as bacteria, viruses, and other pathogens. The primary role of the immune system is to identify foreign substances or 'non-self' entities and eliminate them to maintain the body's integrity and health; in short, protecting you from becoming ill.
This system is divided into two core components: the innate immune system and the adaptive immune system. The innate immune system provides an immediate but non-specific defence against pathogens, and includes physical barriers like skin, chemical barriers such as stomach acid, and immune cells like neutrophils and macrophages that engulf and destroy invaders.
The adaptive immune system - also known as the acquired immune system - provides a specific and long-lasting defence against specific pathogens; it relies on specialised cells, including T cells and B cells, that learn to recognise and remember particular invaders for future attacks.
To highlight a recent example, a study of 12 million people infected with COVID-19 showed that immunological memory for the viral infection was evident within 90% of those infected even after 6-8 months. This could mean that those who get infected with SARS-CoV-19 may benefit from enhanced immunity against the virus for a considerable time - although it’s important to note that COVID-19 can be an unpredictable virus, and not all outcomes are the same.
Why is the immune system important?
So, why is it important to keep the immune system healthy? Serving as the body's primary defence mechanism, the immune system is responsible for a myriad of crucial tasks that safeguard our health and survival:
Protection against infections
Firstly, the immune system helps to identify and neutralise pathogens such as bacteria, viruses, fungi, and parasites that can cause infections. Without a functioning immune system, even the most common microbes could pose a severe threat to our health.
Healing and recovery
Secondly, the immune system plays a critical role in healing and recovery; when an injury occurs, the immune response initiates inflammation to protect the area and promotes healing by clearing debris and facilitating tissue repair.
Fighting off cancer cells
Another important function of the immune system is cancer protection; your immune system is instrumental in detecting and eliminating abnormal cells that may lead to cancer. Through a process known as immune surveillance, the immune system identifies and destroys cells with cancerous or precancerous changes.
Vaccination support
Finally, the immune system is essential for the efficacy of vaccinations. Vaccines work by stimulating the immune system to produce an immune response against specific pathogens, preparing it to fight off future infections effectively. Without a functioning immune system, vaccinations may prove to be less effective.
How ageing impacts the immune system
As we age, our immune system experiences changes known as immunosenescence. This phenomenon encompasses a broad range of alterations in immune function and reactivity, leading to a general decline in the ability of the immune system to respond to infections and diseases:
The innate immune system
The innate immune system experiences changes with ageing, such as diminished physical and chemical barriers and altered function of innate immune cells. The skin becomes thinner and more fragile, increasing susceptibility to infections, while changes in the gut microbiome can affect local and systemic immune responses.
Adaptive immune system
The impact of ageing on the adaptive immune system is even more pronounced: a significant issue is the involution of the thymus, the organ where T cells mature. As we age, the thymus shrinks, leading to a reduction in the production of new T cells, which are essential for fighting off novel infections. Additionally, there's a decrease in B cells' ability to produce high-quality antibodies, leading to less effective responses to vaccination and increased susceptibility to infection.
Increased cancer risk
As our immune system weakens with age, this can impact the body’s ability to fight off abnormal (aka cancerous) cells that develop in the body. This is one of the main reasons that age is the biggest risk factor for cancer, with over 65s in the UK being the most susceptible to developing the disease.
How to keep your immune system strong as you age
Despite the changes that come with ageing, it's important to note that there are several ways to support and enhance your immune health as you age:
Diet and nutrition
Firstly, a balanced and nutritious diet is fundamental to immune health. Vitamins and minerals, such as vitamin C, vitamin D, zinc, and selenium, play crucial roles in maintaining immune function, so ensuring a diet rich in these nutrients - alongside plenty of fruits, vegetables, lean proteins, and whole grains - can support overall immune health.
Private medical cover
If you’re worried about long NHS waiting lists in your area, or you’d simply like to supplement your healthcare needs, health insurance for those over 70 can be a great way to do so. With private medical cover, you can benefit from the highest-quality medical care in the UK, digital GP support, and comprehensive cancer care should you experience a worrying diagnosis. Do note, however, that your level of cover will depend on a number of factors, including your chosen policy and chosen provider. You can take a look at our blog for more information on what you can and can’t get cover for on a private health insurance plan.
Physical activity
Regular physical activity is another vital aspect of maintaining a healthy immune system. Exercise promotes good circulation, allowing immune cells to move through the body more efficiently, enhancing their function.
Sleep and rest
Adequate sleep is equally important, as it's during rest that the body repairs itself, including the immune system; chronic sleep deprivation can affect immune function and increase susceptibility to infections. The general recommendation for adults is between 7 and 9 hours of sleep per night, so try your best to keep within this range for optimal immune function.
Keep on top of your vaccinations
Vaccinations are also crucial, especially in older adults. Vaccines help to 'train' the immune system, increasing its ability to fight off specific infections. Keeping up to date with recommended vaccines can provide a much-needed boost to the immune system.
