Eating a healthy diet can go a long way in helping you lose weight and prevent disease. But on some days we always want to treat ourselves to something special. However, such so-called “cheat days” can significantly impair our immune system.
Researchers at the University Medical Center Hamburg-Eppendorf (UKE) have discovered that repeated short-term deviations from a regular and balanced diet in favor of high-fat food with little fiber can have significant consequences for the human immune system. Their research results were published in the journal “Nature Immunology”.
Reduction of microbial metabolites
According to a statement, the international research team led by Prof. Dr. Nicola Gagliani, research group leader in the clinic and polyclinic for general, visceral and thoracic surgery of the UKE, carried out various laboratory experiments for the study and then a study with test persons.
The participants received a high-fiber diet for five days; they then ate a high-fat, low-fiber diet for another five days.
The scientists were able to determine that the lower fiber content in a diet high in fat and energy leads to a reduction in microbial metabolic products, so-called short-chain fatty acids.
According to the information, this reduces the function of CD4+ T cells, an important cell type of the adaptive immune system.
Effects only temporary
While these effects are only temporary, because resuming a balanced diet with enough fiber restores the body’s immunity. At the same time, the researchers were able to show that switching to a diet high in fat and low in fiber is associated with a higher susceptibility to infections.
“The window of immunodeficiency opens for a period of time. In our study, we were able to show how synchronized our eating habits and our immune responses are, and how even a short-term switch to gluttony leads to a rapid impairment of the immune system,” explains Prof. Gagliani.
“Our data shows how quickly and profoundly our everyday food choices can affect our health. Put positively, this means that the effectiveness of vaccines and immunotherapies could be maximized with the help of a regular, balanced diet,” adds first author Dr. Francesco Siracusa, UKE Clinic and Polyclinic for General, Visceral and Thoracic Surgery. (ad)