Source:-newscientist.com
Ditching carbohydrates and eating lots of fat may give some protection against the 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 people may get flu-like symptoms known as the “keto flu” as their body adapts to so little carbohydrate. The keto diet has also been linked to improved heart health and control of blood sugar in diabetes, but much of the evidence is conflicting.
Akiko Iwasaki at Yale School of Medicine and colleagues previously found that the keto diet reduced inflammation in mice with gout. Because inflammation is common to both gout and flu, the team thought the keto diet could similarly deal with flu-related inflammation, which can severely damage the lungs.
To put this theory to the test, the team fed mice infected with influenza A – the most serious type of the virus – either a keto or standard diet for a week before infection. After four days, all seven of the mice fed a standard diet succumbed to the infection, compared to only five out of the 10 mice on the keto diet. These keto diet mice also didn’t lose as much weight, which is usually a clear sign of flu infection in animals.
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The team found that the keto diet amped up the numbers of a specific type of T cell – key players in the body’s immune response – found in the lungs. Boosting these T cells dampened the sensitivity of cells lining the lungs to infection and increased mucus production.
It seems that this extra mucus is important for protecting the mice, says Iwasaki, because it traps the flu virus to stop it spreading. It still isn’t clear what these T cells do outside of this study though, she says.
Although mouse and human metabolisms differ, the finding could mean that people get a similar protection from influenza when on the keto diet.
“We already knew of a link between diet and immunity,” says John Tregoning at Imperial College London, who wasn’t involved in the work. Eating foods rich in vitamin C, for example, is known to strengthen our immune system. Switching to a keto diet may help boost the immune system so that it is better programmed to fight off the infection, says Tregoning.