Mild intermittent fasting can have a surprisingly negative effect on immunity: skipping breakfast led to a 90% drop in white blood cell count.
Skipping breakfast may impair immune function.
Skipping breakfast adversely affects immune health, a new study in mice shows. Mice that skipped breakfast experienced a 90 percent drop in white blood cell numbers and demonstrated impaired immune function.
Researchers investigated the effects of fasting on immune health in two groups of mice. One group of mice ate breakfast upon waking, while the other group fasted, skipping breakfast. The researchers measured white blood cell numbers immediately after both groups of mice woke up and at four and eight hours after waking. Then they infected the mice with a type of bacteria that commonly causes pneumonia to see how their immune systems responded.
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They found that after just four hours, the white blood cell numbers in the blood of fasting mice decreased by 90 percent, having accumulated in the bone marrow. Upon refeeding, the number of white blood cells in circulation increased markedly, and most of these cells were older and exhibited pro-inflammatory characteristics. After exposure to the pneumonia-causing bacteria, the mice that fasted were more likely to die (and died sooner) than the mice that didn’t fast.
These findings suggest that skipping breakfast during fasting impairs immunity. They also align with evidence that an earlier eating window when practicing time-restricted eating (which involves a long overnight fast) is more beneficial](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8634676/) than a later one. Learn more about time-restricted eating in this episode featuring Dr. Satchin Panda.](https://www.foundmyfitness.com/episodes/satchin-panda-3)