Immune system changes in older people

Immune system response in older people

Have you ever wondered why elderly and older people get more sick? Why many older people cannot survive with Covid-19 infections? What makes their system so fragile?

As we age our immune system slows down resulting in weakening immune system. The immune system is essential for body’s defense against foreign invaders such as microorganisms like Covid-19 viruses, cancer cells, parasites such as worms and to transplanted organs and tissues. The same defense system that protects our body for longtime changes as we age.

While defending the body, immune system distinguishes self from non-self. It eliminates harmful molecules and foreign invaders from the body. Any molecule that Immune system recognizes are called antigens.

Our skin, cornea and mucosa are body’s first line of defense and these three physical barriers also have active immune function. In case, any molecules breach these systems then our body further triggers two types of immune response called: Innate and acquired.

Innate immune system does not require prior exposure to an antigen to be effective and responds immediately for a foreign invader. Innate immunity recognizes antigens that are broadly distributed in our system. 

Whereas, acquired immunity requires prior exposure to an antigen and takes time to develop after the initial encounter with a new molecular. It remembers past exposure and its response is antigen specific. It contains two components called T and B cells.

In newborns, immune system will not be fully developed. Those antibodies present in newborns are transported from mothers through placenta and through breast milk. The function of the antibodies is to help newborn from infections until the immune system fully develops.

Why elders are more susceptible for infections and diseases?

Low-grade chronic inflammation is linked to many conditions in older age including, diabetes, heart conditions, dementia and cancer. Chronic inflammation plays a major role in certain autoimmune conditions that adults experience as they age. With age, immune system also adapts and changes in different ways that leads to sickness.

  • Immune system will not be able to clearly distinguish between self and foreign antigens. As a result, in elderly people infections and autoimmune disorders becomes common.
  • There are specialized cells that play a role in immune system called macrophages function of which is to ingest microorganisms, cancer cells and foreign antigens. Macrophage activity slows down with age.
  • There will be fewer WBC production and these WBC cannot respond to antigens and defending becomes difficult.
  • Less number of lymphocytes to fight new antigens.
  • T Cells of acquired immune system responds slowly to antigens. The function of T Cells is to encounter and respond to antigens by remembering them.
  • There will be lesser production of antibodies. This results in infections such as pneumonia, flu, tetanus and other serious infections. Sometimes there will be recurrence of herpes or shingles like conditions. These infections could be fatal to older people.
  • Vaccines becomes less effective due to less antibody production capacity.
  • Elderly people with preexisting conditions such as diabetes, heart issues, kidney and liver problem etc. will already have a weakened immune system. This makes it nearly impossible for them to fight deadly infections and diseases.

How to strengthen immune system?

Studies from Harvard University suggests that practicing yoga and meditation and, good diet helps to fight diseases like Covid-19. By following good diet and practicing exercise practice one can protect immune system.

  1. Consume yogurt to maintain healthy gut
  2. Consume enough water
  3. Include citrus fruits to get Vitamin C that helps to prevent developing cold and infections
  4. Include good green vegetables in daily diet like broccoli, spinach, khale, Brussels sprouts, cabbage.
  5. Consume required amount of fiber that your body needs for your age.
  6. To prevent development of infections include barley and oats. Beta glucan in these foods helps to fight flu type of infections.
  7. Almonds and dry fruits that supply proteins and vitamin E and fresh fruits with manganese, zinc and potassium helps to maintain the vital essentials of the body.
  8. Get regular vaccines as suggested by your doctor.
  9. Limit intake of alcohol and do not smoke.
  10. Daily exercise must be part of your life. Practice meditation and yoga, Pilates for peaceful mind and body helps to maintain strong immune system.


Image curtesy: Image by Josep Monter Martinez from Pixabay (Free for commercial use)

Author: Sumana Rao | Posted on: October 6, 2020

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