The immune system relies heavily on several different systems and processes within the body to function as it should. As the body ages from birth to adulthood, those systems and processes evolve and change, and with this can come a change in the immune system.

The way the immune function responds to outside pathogens won’t be the same when you’re three as it is when you’re 30. Unfortunately, the state of the immune response is on a steady decline as the years go by, and that means the older you get it, the harder it can be to fight off infection and disease.

How does the immune system change with age?

When foreign substances, also referred to as pathogens or antigens, enter the body, the immune system is the first to recognize them. The innate immune system identifies every foreign substance, while the acquired immune response works to create specific fighter cells depending on the type of pathogen.

These specific cells that are created by B cells are called antibodies. They do their job by locking onto specific antigens to help remove them from the body. Although the mechanics of the immune response tend to stay the same throughout your life, the way it responds and how well it works varies with age.

Birth to adolescence

Children and adolescents are new to the world, which means that they haven’t encountered the same amount of germs or pathogens needed to build up the acquired immune response. The innate immune system is the main driver of immunity during the earliest years of life, because there are little to no available antibodies to fight off specific infections.

The cells in the innate immune system response include neutrophils, monocytes, macrophages, and dendritic cells. The response in newborns is weak, as each of these cells will develop and mature at different times during fetal growth. The cells in newborns have reduced efficacy against pathogens, and thus infants are more susceptible to disease and infection.  

Image by Mi Pham on Unsplash: How does the immune system change with age?

Soon after birth, the acquired immune response begins its development. T-cells, which play a vital role in acquired immunity, develop in the thymus. The thymus is largest during the first year of a person’s life, and thus T-cells are created in abundance at this time. Infants can also receive antibodies from their mother that can help them build up their immune system as they age.

In young children, both the innate and acquired immune systems begin to mature. At this time, they continue to be susceptible to infection, but are more likely to recover from any pathogen or illness if proper medical care is sought and the immune system is maturing as it should. Children often receive vaccinations early so their immune systems can begin to develop protective responses. The immune system is fully developed by the time a child reaches eight years old.

Adulthood

During adulthood, a healthy and functioning immune system is running at its best. This is because it has had years to continuously fight off pathogens, creating a strong and resilient acquired immune response. During adulthood, some may see a decline in their immune system while others do not. The immune system does not hit a certain age where it begins declining; the timeline for immune decline is different for everyone.

Old age

As a person grows older, their immune system declines and remodels itself. This leads to a higher risk of viral and bacterial infections in older adults. It can also lead to a higher rate of grave complications should an infection occur. The immune system struggles because it can’t fight off infection as it once could and because it has a more difficult time tolerating self-antigens, or cells that pose no threat to the body. This can trigger an immune response when none was needed, leading to autoimmune dysfunction in older adults.

Does the immune system decrease with age?

The immune system inevitably begins to decline with age, but all people are different in this regard. It’s not fully understood why the immune response becomes weaker over time, but there is some research that suggests why this is the case. For instance, the thymus plays a big role in the maturation of T-cells, and it begins to shrink by the time a person is a young adult; this could lead to less functional T-cells to ward off infection. Age can also affect how macrophages (the white blood cells that ingest antigens) slow down and become less effective against disease.

There is also a decline in white blood cell count as a person ages, leading to a lessened response against antigens. Antibody production can also decrease in response to any given antigen.

What age group has the best immune system?

The health of the immune system depends on a number of different factors, so it can be hard to pin down exactly what age group has the best immune system. For many, immune health is determined by lifestyle; a healthy 40-year-old will likely have a healthier immune system than an unhealthy 20-year-old. When considering a completely healthy group of individuals, however, it is likely that people in their 20s will have a better immune response than older adults.

Research has also found that sex may also play a role in the overall health of the immune function, in the sense that women are more likely to experience a stronger immune response than men. Studies have found that this could be due to the fact that women store more inflammatory substances in their mast cells, which leads to a more aggressive immune response during times of illness. Unfortunately, this can also lead to women suffering from the adverse effects of an overactive immune response, such as autoimmune disorders.

Image by Matthew Bennett on Unsplash: Does the immune system decrease with age? 

Adopting a new lifestyle to deal with how immunity changes as we age

People of all ages should be living healthy lifestyles to maintain their overall health and the function of their immune system. This means eating a varied diet full of the vitamins and minerals the body needs to function at its best, getting enough exercise and sleep, and mitigating stress levels wherever possible. Supplementation such as GenBoost’s Immune Range is also a good idea if the diet isn’t up to par; it can help feed the immune system the nutrients it needs to stay on top of its game.

As mentioned, it’s hard to determine a specific age that one must start to pay closer attention to their immune health, as everyone ages differently. However, a good rule of thumb is to simply pay attention to the body. If you find yourself getting sick more often or having illnesses last longer, it may be time to make a few lifestyle changes to help boost your immune function.

Featured image by Ray S on Unsplash