Strengthen your immune system? Questions and answers

An optimal immune system can allow us to avoid complications related to certain health problems. It is therefore tempting to want to make it more “efficient”. But is it possible? Experts are speaking out.

Boost your system? One would have wished it were otherwise, but, alas! there is no miracle solution to boost your immune system, according to most scientists. In times of pandemic and public health crisis, many of us would have liked to be told otherwise, wouldn’t we?

It’s not all bad, though. It is possible, by adopting certain lifestyle habits, to ensure that our immune system is functioning at its peak performance.

Can physical activity help strengthen our immunity?
Yes… and no. People who are healthy and have a healthy lifestyle generally deal better with viruses and bacteria. As a result, active people are one step ahead of sedentary people, according to Dr. Ciriaco Piccirillo, Professor in the Department of Microbiology and Immunology at McGill University. Sport stimulates the metabolism, as well as keeping the immune system alert,” he says. However, these benefits diminish when the activity involves a significant stressor, such as in the case of a professional athlete. »

For over 20 years, experts have been searching for the exact mathematical formula to determine how much time we should spend exercising. “The ideal would be to be in motion for a minimum of 120 minutes a week. This includes taking the stairs instead of the elevator, or walking frequently during the workday. In our sedentary lifestyle, every minute counts to improve our health,” adds Dr. Piccirillo.

Can what we put on our plate help?
No particular food is likely to give the immune system a boost. However, we can help it maintain its maximum effectiveness “by reducing our consumption of processed foods and by following the recommendations of Canada’s Food Guide as much as possible,” suggests Martin Guimond, professor and assistant researcher in the Department of Microbiology, Infectiology and Immunology at the Université de Montréal.

The ideal plate? Vegetables and fruits should make up half of it, proteins (tofu, legumes, fish, lean meats…), a quarter, and whole grains (quinoa, brown rice, oats…), the remaining quarter. Such a diet helps to keep obesity and type 2 diabetes at bay, two conditions that make us more vulnerable to infections. “The tissues of overweight people experience more inflammation and are therefore less resistant,” says Jean-Pierre Routy, Clinical Director of the Chronic Viral Diseases Service of the McGill University Health Centre.

To help us, only one method seems to offer promising results so far: intermittent fasting, which requires skipping breakfast every other day, for example. When we fast, the body goes into recovery mode, like hibernating animals,” says Dr. Routy. This allows the body to recycle proteins within cells and reduce inflammation in tissues. Improvements are seen after as little as three weeks. “Intermittent fasting may even reverse a diagnosis of type 2 diabetes, according to several recent studies.

Is smoking as bad for our immune system as they say it is?
Not surprisingly, toxicology studies are not soft on smoking. In addition to being the cause of many cancers, tobacco affects our front-line defenses. It’s a bit like if we let pollution directly into our lungs,” says Martin Guimond. The body is constantly in defense mode against this foreign body, which damages the respiratory walls. »

This continuous response can greatly reduce the effectiveness of the immune system against a virus that is lodged in the respiratory system.

Are the conclusions the same for cannabis use? It’s hard to know at this point, “Too little research has been done so far to support this hypothesis,” says the researcher.

Many people swear by vitamin supplements. Are they wrong?
Both vitamins and minerals contribute to the health of our bodies and organs. In Canada, we are fortunate to enjoy a varied diet, which generally meets all of our nutrient needs. “We can still choose to take vitamins. But there is a good chance that they will be eliminated automatically in the urine,” notes Nathalie Grandvaux, professor in the Department of Biochemistry and Molecular Medicine at the Uni- versité de Montréal.

In fact, in our latitudes, we must be especially concerned about the deficiencies in vita

mine D. The latter can be synthesized by the body following exposure to sunlight, which we sometimes miss during the long winter months. But before rushing to the local pharmacy, it is advisable to consult your doctor. “If you’re really in deficit, and you don’t take the right dose for your needs, the problem won’t be solved,” she adds. Health Canada recommends a dose of 600 IU of vitamin D per day for adults.

In times of stress, are we more vulnerable?
When we find ourselves in a physically, emotionally or psychologically demanding period, it becomes more difficult for the body to maintain its defenses in optimal mode. “When we are anxious or in shock, the body produces hormones called glucocorticoids,” explains Dr. Piccirillo. These hormones have many positive properties when released over a short period of time. They are even used to lower the defenses of patients undergoing a transplant to prevent the body from rejecting the transplant as a foreign element.

But when stress is no longer leaving us, these hormones have a negative effect on the immune system. “This can manifest itself in different ways. For example, some students see cold sores appear on their lips at the end of the session. It’s as if the virus is waiting for the right time to come out of its dormancy,” he says.

And what about insomnia?

People who have trouble sleeping well are more vulnerable to infectious diseases, as several studies have already shown. “Sleep allows all of our body’s functions to regain their balance. It is essential to our health. Complex and reciprocal relationships exist between the immune system and the central nervous system. When one of them is affected, the other feels the effects,” says Nathalie Grandvaux.

Is eating organic food an advantage to better defend against infections?
“It’s certainly not bad, but it’s far from being a guarantee,” says Prof. Jacques Bernier, whose research at the Centre Armand-Frappier focuses on immune system disorders. According to this specialist, you can’t really avoid pesticides…”. They move through the water table. Because farmers cannot control what their neighbors are doing, it is very difficult to reach ground zero. »

But one thing remains: all classes of pesticides would be harmful to the immune system. However, Health Canada considers that those that are found in trace amounts in food are not dangerous for human consumption. “Some pesticides alter the cellular response, while others affect the production of antibodies. An underactive immune system can lead to infections. Conversely, if the immune system is too inactive, it can inhibit normal organ function and worsen the condition of patients, as seen with COVID-19,” he says. The solution? The new habit of washing all your fruits and vegetables well on the way home from the grocery store or market.
What is an effective immune response?

Let’s take COVID-19 as an example. When the virus enters our respiratory system, it immediately encounters a wall of epithelial cells, which protect our body from anything that comes from the outside. This is the innate phase of our immune system, a process that is triggered no matter which virus or bacteria wants to attack us.

As soon as epithelial cells begin to be infected, the body makes specific molecules for the disease that affects us. This reaction is usually memorized by the immune system, which is then protected from future attacks by the virus or bacteria.

However, in the case of COVID-19, the immune system sometimes overreacts. “It’s a bit like using a cannon to kill a fly. It’s a bit like using a cannon to kill a fly,” says Dr. Ciriaco Piccirillo, a professor in the Department of Microbiology and Immunology at McGill University.

When the immune system’s response is too strong, it can lead to significant damage to organs – the lungs in this case – that can no longer function properly.

“A good immune system responds actively and effectively, but not over a long period of time. Aside from medical remedies, there are very few solutions to ensure this balance,” concludes Jean-Pierre Routy, Clinical Director of the Chronic Viral Diseases Service of the McGill University Health Centre.