Just like the gadgets we use every day are designed with a limited lifespan in mind, the immune system also experiences a type of “planned obsolescence” as we age.
The immune system runs best for a certain period, but eventually shows signs of wear and tear — it’s harder to recover from a strenuous activity, you seem to catch whatever bug is going around, or it takes longer to bounce back when you do get sick. Your immune system still works, just not as well as it once did, like a smartphone that still functions but can’t hold a charge as long.
“As people get older, decreased immune function places them both at higher risk for initial infection and at higher risk for severe disease if they are infected,” says Brian Labus, an assistant professor in the department of epidemiology and biostatistics at the University of Nevada, Las Vegas. In fact, “it would be strange to work with an infectious disease where age-related immune changes don’t play a major role.”
Read on to learn more about how the immune system changes with age, infections to watch out for and what to do to stay healthy.
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A Healthy Immune System
To understand how aging affects your immunity, it’s important to know how the immune system should work in healthy individuals.
The immune system is made up of two systems: innate immunity and adaptive immunity.
The innate immune system is the body’s quicker, more general response to pathogens. It includes:
— Physical barriers, such as the skin or mucous membranes
— Special cells that digest germs or destroy infected cells
— Immune cells that trigger inflammation and activate the adaptive immune system
The adaptive immune system is the body’s slower, more precise defense against pathogens. It targets specific pathogens by identifying its unique traits:
— B cells produce antibodies, which tag the pathogen for destruction.
— T cells coordinate an immune attack or directly kill the infected cells.
These immune responses can’t run indefinitely, however. Over time, due to a combination of genetic, lifestyle and environmental factors, the effectiveness of the immune system diminishes.
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What Is Immunosenescence?
Many changes can occur as the immune system ages, says Dr. Austin Perlmutter, a Seattle-based board-certified internal medicine physician. “But the most prominent of them is the development of what is called ‘immunosenescence,’ a progressive state of worsening of the overall immune system function.”
Some of the hallmarks of immunosenescence include:
— Fewer immune cells. During aging, an organ called the thymus shrinks. The thymus is responsible for immune cell production, and as it shrinks, it produces less T cells. Perlmutter says there are alterations to the ratio of immune cells, creating more memory cells and less fresh cells.
— Worn out immune cells. The immune system is full of older immune cells, which are less effective at fighting infections.
— Chronic inflammation. This is also known as “inflammaging,” where the immune system stays activated even without a threat present.
— Weaker immune response to infections and vaccines. This is often caused by inflammaging.
Perlmutter shares that the impact of immunosenescence is far-reaching, including:
— Worsening of overall immune system function
— Increased susceptibility to infections
— Worse response to vaccinations
— Increased risk for autoimmune conditions
— Greater risk for a variety of conditions, such as cardiovascular disease, cancer, metabolic disease or brain dysfunction
Together, the symptoms of immunosenescence create a less resilient immune system, making it harder to recover from illness and stay healthy.
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High-Risk Infections for Older Adults
As the immune system weakens, it’s important to be aware of specific conditions that can pose a greater risk to older adults.
Opportunistic infections take advantage of an older, weakened immune system, which include:
— Shingles, which is caused by varicella-zoster virus, the same virus that causes chickenpox. The two-shot shingles vaccine series is recommended for everyone at age 50.
— Urinary tract infections, especially UTIs that are multi-drug-resistant infections
— RSV, or respiratory syncytial virus, which is a virus that causes respiratory tract infections. It’s also common in babies. Labus shares that the most common diseases he sees in older adults tend to be respiratory disease.
— COVID-19. “People 75 and older are nine times more likely to die from COVID than younger adults,” Labus says.
— Pneumonia. About 1 million adults are hospitalized from pneumonia every year, and about 50,000 people die from it, according to the American Thoracic Society.
— Influenza. “Every year, the vast majority of influenza hospitalizations and deaths occur in people 65 and older,” Labus says. “Because of age-related immune decline, our vaccines are also not as effective in older adults. This is why we have a high-dose influenza vaccine for people 65 and older.”
Staying informed about high-risk infections can help you stay on top of the recommended vaccine schedules, make travel plans carefully or isolate from other vulnerable individuals when needed.
Ways to Stay Healthy
Although the immune system changes with age, there are some proactive steps you can take to protect it throughout your life.
You can support your immune system through:
— Regular exercise. A 2021 review in Frontiers in Immunology found that regular exercise might help counter immunosenescence.
— Sleep. “Getting good sleep is widely known to support overall health across the lifespan, but may especially protect healthy immunity in the short run and in the long run,” Perlmutter says. Those short-term and long-term effects include decreasing our chances of getting a cold or protecting against immunosenescence, respectively.
— Stress management. “Stress management and social connectivity appear to have protective effects on immune wellness,” Perlmutter says.
— A healthy diet. “Research supports the role of a minimally processed diet similar to a Mediterranean-pattern diet in enhancing immune health,” Perlmutter says. He adds that key nutrients include omega-3 fatty acids, lactobacillus and polyphenols. A diet rich in probiotics, plant-based foods, healthy fats and herbs and spices can support these nutrients. “For those eating a more conventional diet, replacing sugary or highly processed foods with less processed alternatives is a great start,” he says.
— Treating comorbid conditions. “We see an increased prevalence of chronic diseases, like diabetes, and increased use of medications that can suppress the immune system,” Labus says.
The Bottom Line
While aging inevitably changes the immune system, there are ways to support and strengthen your immune system throughout your life. Staying up to date on vaccinations, implementing healthy lifestyle habits and managing chronic conditions can help reduce the risk of severe infections and allow you to recover more easily. By taking proactive steps, you can protect your immune system and yourself as you age.
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How Aging Affects Your Immunity originally appeared on usnews.com
Update 02/27/25: This story was previously published at an earlier date and has been updated with new information.
