It is not recommended to force ourselves to eat in the morning if we are not hungry. Do not eat breakfast is like practicing intermittent fasting. Numerous studies have already shown that fasting can have a positive impact on health by speeding up the metabolism and detoxifying the body. digestive system.
A news study calls, however, for prudence for people who fast in the morning. Giving up breakfast could be detrimental to infection control and could lead to an increased risk of heart disease. This is the finding of a new study from the Icahn School of Medicine at Mount Sinai published on February 23, 2023 in the journal Immunity.
“There is an awareness about benefits of fasting and there is indeed plenty of evidence of its benefits. Our study warns, as it suggests that it may also involve a health risk, says the study’s lead author, Filip Swirski, Ph.D., director of the Institute for Cardiovascular Research at Icahn Mount Sinai. The study shows that there is a conversation between the nervous and immune systems.”
Fasting in the morning can affect white blood cells
Researchers sought to better understand how fasting affects the immune system. They analyzed two groups of mice. A group that had breakfast just after awakening (breakfast is their biggest meal of the day), and the other group didn’t have breakfast. The researchers took blood samples from both groups when the mice woke up, then four hours later and eight hours later.
The scientists noticed a clear difference in the fasting group. Specifically, they found a difference in the number of monocyteswhich are white blood cells made in the bone marrow and released throughout the body. These white blood cells play many essential rolesranging from fighting infection to heart disease to cancer.
Initially, all mice had the same amount of monocytes. But after four hours, the monocytes of the mice in the fasting group were significantly affected. The researchers found that 90% of these cells had gone of the bloodstream and that their numbers had further decreased after eight hours. During this time, the monocytes of the breakfast group did not move.
Fasting in the morning can make the body less efficient in fighting infections
In fasted mice, the researchers found that monocytes returned to the bone marrow to hibernate. At the same time, the production of new cells in the bone marrow has been reduced. Bone marrow monocytes, which generally have a short lifespan, have changed dramatically. They survived longer due to their stay in the bone marrow and aged differently than monocytes that remained in the blood.
The researchers continued to fast mice for up to 24 hours, then reintroduces food. Cells hidden in the bone marrow returned to the bloodstream within hours. This push led to a increased level of inflammation. Instead of protecting against infection, these altered monocytes were more inflammatory, making the body less resistant to fighting infection. Clearly, it is when you eat again after fasting that you can generate inflammation, which can be harmful to immunity.
Fasting causes a stress reaction in the brain
This study is among the first to link immune cells and fasting. The researchers found that specific regions of the brain controlled the monocyte response during the fast. They demonstrated that fasting causes a stress response in the brain – it’s what makes people “hungry” and it instantly triggers a large-scale migration of these white blood cells from the blood to the bone marrowand then back into the bloodstream shortly after food is reintroduced.
“The study shows that, on the one hand, fasting reduces the number of circulating monocytes, which one would think is a good thing, because these cells are important components of inflammation. However, the reintroduction of food creates a surge of monocytes, a return in the blood which can be problematic” explains Dr. Swirski, one of the authors of the study.
“Because these cells are important against heart disease or cancer, it is essential to understand how their function is controlled.”