The coronavirus outbreak highlights the importance of our immune system; It is this complex network of cells, tissues and organs that is the main weapon that protects our body against diseases and infections, viral and bacterial infections.
Just like any other part of the body, the immune system ages over the years and makes us susceptible to all kinds of diseases.
This is one reason why medical experts believe that people over the age of 65 are more likely to contract the Covid-19 infection and develop a more severe form – in addition to pre-existing medical conditions. disease
However, the aging of our immune system does not coincide with our chronological age.
Shai Shin-Or, an immunologist at the Technion Institute in Israel, told the BBC: “An 80-year-old has the immune system of a 62-year-old, or vice versa.”
The good news is that we can slow down this aging process by following several simple steps. But before reviewing that, let’s remember how our immune system works?
How does the immune system work?
The immune system consists of two branches, each containing a different type of white blood cell that is specifically involved in protecting the body’s organs.
The natural (innate) immune response represents our first line of defense upon detecting the presence of a foreign organism in our body.
This response consists of white blood cells called neutrophils, which primarily attack bacteria, which regulate the immune system and help warn other immune cells, which then work to fight viruses or cancer cells, and these three cells don’t work well with age,” says the University of Birmingham in Britain. Janet Lord, director of the Institute of Inflammation and Aging, explains.
Then comes the role of the adaptive (acquired) response, which consists of T lymphocytes and B cells that fight specific pathogens. It takes days for this response to appear, but once it does, you will remember the pathogen in the future and fight it if it reappears.
He adds: “As you get older, you make fewer new lymphocytes, but you need them to fight a new infection like SARS-CoV-2.”
“Even the things your body made in the past to fight other infections don’t work as you get older.” That is, aging causes a decline in all functions of the immune system.
The natural (innate) response produces a slightly larger number of cells but does not work well, while the adaptive response produces fewer B lymphocytes (produced in the bone marrow and responsible for producing antibodies) and fewer T lymphocytes (produced in the gland). thymus detects and kills pathogens or infected cells).
The reason for the decline in T cells is that “the thymus gland begins to shrink at age 20, becomes smaller and smaller, and by age 65 or 70, only 3 percent of it remains (in the body). , says the Lord.
The loss of cells that store the memory of pathogens not only results in the ability to respond to infections but also the vaccines that prevent them as we age.
In the case of the influenza vaccine, “40 percent of adults age 65 and older do not develop a response to the vaccine,” explains expert Shai Shen-Or.
Another problem is that aging creates more inflammation in the blood and tissues, which scientists refer to as “infiltration.”
Professor Lord explains: “As well as not functioning optimally, immune system cells cause inflammation, which leads to many diseases.”
“All these changes that come with age make it more difficult to recover from an infection or injury, and some of these diseases can become chronic,” University of California researcher Incarnation Montesino told the BBC.
He adds, “Infections that were under control, such as shingles (a viral disease that causes a rash and blisters on a specific part of the body) or tuberculosis, reappear. This increases the chance of infection with new pathogens. The incidence of cancer.”
It’s not always about age
But while we all suffer predictable falls over the years, the rate varies greatly from person to person.
This process is influenced by genetics, but to a large extent by lifestyle. Until recently, our immune age could not be determined.
But Shin-Or and his team, in collaboration with Stanford University in the US, have found a way to get this information that could be critical to the success of the treatment.
“By analyzing the components of 18 types of immune system cells and gene-coding material in a blood sample, we can determine the state of a person’s immune system,” explains Shin-Or.
The difference in the speed of the degeneration process is related to the sex of the person.
“Although both sexes age, by some parameters men and women age at different rates due to specific effects of sex hormones,” says UCLA’s Montesino.
Menopause in women balances the protective effects of estrogen, a hormone that has beneficial effects on women’s immune systems, she says.
Be active
The good news we mentioned at the beginning of this article is that it is possible to slow down the aging process, and the key to this is being physically active.
“Nowadays, sitting for long periods of time is like smoking for the body,” Lord says.
“In studies of people who have been active all their lives into old age—such as those who cycled 100 to 150 kilometers per week until age 80—the results were surprising.”
“They had a lot of T cells and the thymus didn’t shrink,” he adds.
“In another study that tracked the number of steps per day, they found that if you take 10,000 steps per day, your white blood cells (neutrophils) are the same as those of a 20-year-old.”
Lord says, at first, “I thought this number was invented by people to sell pedometers, but when we ran the study, I was completely surprised by the results.”
It all depends on individual fitness levels, but experts say doing simple exercises like standing on your toes, going up and down, climbing stairs and lifting some weights is already a good start.
“Do something,” says the Lord, “anything you do is very good.”
Other factors that may help in this regard include: following a varied diet rich in fiber with fermented foods and little red meat to maintain gut microbiome health (a field of research that is still in its infancy) and optimal sleep. Six and a half or seven hours every night.
Back to dead time
Slowing the rate of aging is one thing, but reversing the process is another. Is the latter possible?
Last year, researchers at the University of California, Los Angeles, published a study in the scientific journal Nature in which they reported that a combination of three common drugs (growth hormone and two diabetes drugs) shaved an average of 2.5 years off biological age. The group consisted of nine volunteers, all of whom were men between the ages of 51 and 65.
The participants’ immune systems also “showed signs of regeneration,” including regenerated thymus tissue in seven of the nine participants, the researchers said.
Shen-Or points out that in a study of a drug that he and his team are working on, the results of his experiment, which have not yet been published, show that it can reverse the course of immune aging (decrease a person’s immune system). Also possible.
“We’ve seen (the immune age) decrease, but we still don’t know if it’s going to be maintained permanently,” he says.
But even reducing the decline can be an important step for our immune system.
