From chapter 4.3 of the book: Live Young 4 – Don’t Be a Slave to Your Genetics

Throughout our lives, the immune system constantly changes. Since it has to defend us against infections from the outside world, it spends part of our early childhood distinguishing between “self” and “non-self”. It must differentiate between what is part of our body and what is not, so as not to react against our own organs and our own tissues. Unfortunately, this system can go out of order and attack parts of our body such as muscles (myopathy), organs (Lupus), peripheral nerves (peripheral neuropathy), the lining of the nerves (multiple sclerosis), joints (rheumatoid arthritis) or cells of the pancreas (type 1 diabetes). These are called autoimmune diseases.

In this first article, we will try to explain to you how the immune system works, but also some realities concerning our lifestyles that can harm or help with its proper functioning. There is a lot of belief about the use of lemon and some old wives’ tales. For example, lemon in your tea is good for taste, but it will not make a good remedy for the flu. There is, however, no downside in doing so if you are comfortable with it, or if it has become a tradition.

The innate or acquired immune system

We often hear that it is necessary to be in contact with germs in order to develop our immune system. Why exactly? Is it true ? Do you think we live in a too sanitized world?

The immune system has two main lines of defense: innate defenses and acquired defenses.

Innate defenses respond quickly to all types of invaders, causing inflammation and are nonspecific. They will respond in much the same way to different types of infections. The cells of the innate immune system are called natural killer cells (NKs), granulocytes (different types) and phagocytes (including macrophages).

Acquired defenses are based on the recognition of an antigen. The immune system recognizes certain molecules and associates it with bacteria or viruses. It is as if, during an infection, the acquired immune system takes note so that it can respond more effectively the next time of occurrence. It is these “notes” that are transferred via vaccines, so that the system responds effectively to serious illnesses, even if it has never been in contact before. The idea is simple: many of the serious diseases we vaccinate for can kill or leave people disabled upon the initial infection. Vaccines thus provide the “notes” or “defense manual” necessary to respond, as if one had already been infected with the disease and survived. This response is slower than the innate response, but more efficient. These are cells called lymphocytes that produce antibodies (B lymphocytes) and recognize antigens in order to coordinate the attack (T lymphocytes).

Unfortunately, the system is not perfect and sometimes interprets so-called “allergenic” proteins, recognized by the “notes” of the acquired system, as dangerous intruders. It then causes a sometimes-disproportionate response that can be dangerous like peanut allergies.

Antibodies are molecules that specifically recognize bacterial proteins or viruses (the “non-self” = proteins or molecules called antigens) that allow these intruders to be identified with labels (antibodies), so that they are recognized as intruders and are quickly destroyed by the warriors of the immune system.

It is therefore partly true that contact with our environment helps develop the immune system. The good bacteria in our gut are an interesting example and they are necessary for the balanced functioning of the immune system. The immune system is constantly in balance, ready to defend us or produce inflammation.

You should know that mild systemic inflammation, inflammation throughout the body, increases with age, and is linked to an increased risk or increased rate of development of many diseases.

A recent study has even shown that a poor diet reprograms certain immune responses. The innate immune system reacts quickly to a diet high in fat and sugar. It would thus cause systemic inflammation similar to that of a bacterial infection.

These are results obtained from mice, but what is most interesting, is that these mice retained the memory of this diet which facilitates inflammation. It is a process of epigenetic programming from the use of certain genes.

This memory, which is coined as “training the innate immune system,” is linked to certain markers that were later identified in the blood cells of 120 people. Some of these people had strong markers of the immune system, linked to the consumption of junk food. Thus, this memory identified in animals would also be present in humans. The training of the innate immune system would make the inflammatory processes more aggressive. People who eat fast foods are more likely to have inflammation problems and/or too high systemic inflammation. This increases the risk of cardiovascular disease, nerve degeneration, joint problems, pain, allergies, weight gain, and many other health problems associated with aging.

In getting older

As we age, the incidence of some diseases increases because the immune system has a tendency to malfunction. This is very characteristic of aging. It is the constant increase in mild systemic inflammation that we call “inflammaging” for “inflammation-aging”. This is the production of molecules that stimulate inflammation (pro-inflammatory molecules) through aging cells. This process is present, at more or less important levels, for all aging people. It interferes with the proper functioning of the human body and facilitates the development of a large number of diseases. Good news: the effectiveness of the immune system, as well as the level of systemic inflammation, are directly related to our lifestyles. As mentioned above, fast foods that are high in fat and sugar, should be avoided.

For the positive facets, in order to maintain a good immune system, it is important to:

Regarding diet, it is possible to reduce the consumption of so-called “pro-inflammatory” foods (red meat, dairy products and refined sugars) and increase the consumption of so-called “anti-inflammatory” foods (fatty fish, olive oil, whole grains, vegetables, nuts, seafood and probiotics). These so-called “anti-inflammatory” foods are also rich in zinc and magnesium, two minerals essential for the proper functioning of the immune system as we age.

To make sure you don’t miss any of the recommendations that can help maintain a healthy immune system, stay tuned for our next article on this topic!


Other suggested items:




  • Christ et al, 2017. Western Diet Triggers NLRP3-DependentInnate Immune Reprogramming. Cell172, 162–175, January 11, 2018
  • Goldberg et Dixit, 2015. Drivers of age-related inflammation and strategies for healthspan extension. Immunol Rev. 2015
  • Mejías-Peña et al, 2017. Impact of resistance training on the autophagy-inflammation-apoptosis crosstalk in elderly subjects. Aging (Albany NY). 2017
  • Olivieri F et al. 2018. Cellular Senescence and Inflammaging in Age-Related Diseases. Mediators Inflamm. (2018)
  • Rea IM et al. 2018. Age and Age-Related Diseases: Role of Inflammation Triggers and Cytokines. Front Immunol. (2018).