Researchers at the University of Bonn found that mice that switched to a so-called ketogenic diet showed significantly reduced inflammation of the respiratory tract.
According to the study, the low-carb, high-fat diet lowers the inflammation of the respiratory tract, which may then help reduce the prevalence of the respiratory condition.
The researchers explained that asthma attacks occur because of severe inflammation of the bronchi and increased mucus production. Their study showed that increased consumption of fats on keto diet could help prevent these changes.
The keto diet helps reduce inflammation by improving the functions of Innate Lymphoid Cells (ILC) in the immune system, they said. These cells play an important role in protecting the lungs by repairing damaged mucous membranes. ILC works with cytokines that stimulate division of the mucosal cells and promote mucus production. The two cells help the body speed up the process to fix damage caused by pathogens or harmful substances.
However, ILC and cytokines can also contribute to the occurrence of asthma. In people with the lung condition, the inflammatory reaction caused by the cells is "much stronger and longer than normal", according to Christoph Wilhelm, a professor at Bonn’s Institute for Clinical Chemistry and Clinical Pharmacology.
ILC rapidly multiplies and releases large amounts of cytokines that could lead to higher inflammation and problems with breathing. Researchers said reducing or slowing down the division of the cells may help prevent asthma.
"The prevalence of asthma has increased dramatically over the last few decades. Perhaps this is also related to an increasingly common high-sugar and high-fat diet," added Wilhelm.
Keto and coronavirus
Does this study suggest the keto diet can help with the coronavirus (individuals with chronic respiratory conditions are at a greater risk of serious illness from COVID-19)?
“Not really,” according to the author of the study. There is no evidence following the keto diet will not protect you against coronavirus despite claims, yet a surge of posts on social media claimed this diet could potentially ward off COVID-19.
Many advocates of the keto diet are using the crisis as an excuse to hammer home their message that there is clear evidence to suggest that low-carb and ketogenic diets can be effective tools for treating and reversing metabolic conditions such as type 2 diabetes which put individuals at a higher risk of complications from Covid-19.
“While we can’t prove that low-carb nutrition boosts immune function per se, it makes sense to limit the conditions (e.g. high blood pressure or high blood sugar) that might make things worse,” wrote Dr Bret Scher in a blog post. The post flagged one recent study which showed that a keto diet reduces the risk for mice infected with influenza.
“That’s a far cry from saying a keto diet will do the same for influenza in humans or for COVID-19,” added Scher. “But one question we should ask is, if we follow a diet that is proven to help with weight loss and metabolic health and may also beneficially affect immune function, what do we have to lose?”
'Lipid-droplet formation drives pathogenic group 2 innate lymphoid cells in airway inflammation'
Authors: Fotios Karagiannis, Schekufe Kharabi Masouleh, Klaus Wunderling, Jayagopi Surendar, Vanessa Schmitt, Alexander Kazakov, Marcel Michla, Michael Hölzel, Christoph Thiele & Christoph Wilhelm