Research suggests that ditching carbohydrates and eating lots of fat may give some protection against flu.
Feeding mice the so-called keto diet seems to boost certain immune cells, which may be responsible for the effect.
The keto diet forces the body to burn fat for energy, which can help with weight loss, and individuals may get flu-like symptoms known as the “keto flu” as they adapt to eating fewer carbs. Embracing a keto diet involves cutting on carbs and getting calories more from fat and protein-rich food sources.
Akiko Iwasaki and colleagues (Goldberg et al., 2019), at Yale School of Medicine, previously found that the keto diet reduced inflammation in mice with gout.
Because inflammation is common to both gout and flu, they thought the diet may also help with flu-related inflammation, which can severely damage the lungs.
To test this, the team fed mice infected with influenza A – the most serious type of flu – either a keto or standard diet for a week before infection.
After four days, all seven mice fed a standard diet succumbed to the flu, compared with only five out of the 10 mice on the keto diet.
The keto diet mice also did not lose as much weight, which is usually a clear sign of flu infection in animals.
These mice had more of a type of T cell found in the lungs that is key to an immune response.
Goldberg, E.L., Molony, R.D., Kudo, E., Sidorov, S., Kong, Y., Dixit, V.D. & Iwasaki, A. (2019) Ketogenic Diet Activates Protective γδ T Cell Responses against Influenza Virus Infection. Science Immunology. 4(41), eaav2026. DOI: 10.1126/sciimmunol.aav2026.
Li, G. (2019) High-Fat, Low-Carb Regime Helps Mice Avoid the Flu. New Scientist. 23 November 2019, pp.19.