A new study from the University of Bonn suggests that a ketogenic diet may help to prevent asthma attacks. Using a mouse model, the researchers linked a ketogenic diet to a significant reduction of inflammation in the respiratory tract.
Patients who suffer from asthma can experience a severe inflammatory reaction from even low exposure to certain allergens. This inflammation is accompanied by an increase in mucus production, which makes breathing more difficult.
The cells of the innate immune system, called Innate Lymphoid Cells (ILCs), play a central role in asthma flare-ups. ILCs protect the lungs by regenerating damaged mucous membranes. To do this, the cells produce inflammatory messengers that activate the division of mucosal cells and elevate mucus production.
The ILC system helps the body repair damage caused by harmful substances, which are removed from the bronchial tubes through mucus. “With asthma, however, the inflammatory reaction is much stronger and longer than normal,” explained Dr. Christoph Wilhelm.
The current study suggests that if the ILC multiplication process is slowed down, dangerous asthma attacks can be prevented.
“We have investigated which metabolic processes are active in the ILCs when they switch to reproduction mode,” explained Dr. Fotios Karagiannis. “Then we tried to block these metabolic pathways and thereby reduce the speed at which the cells divide.”
Some metabolic pathways are significantly more active in dividing ILCs. For example, extra fatty acids are supplied to help the cells make their membranes. Dr. Karagiannis explained that activated ILCs absorb fatty acids from their environment and store them in their interior for a short time, before using them for energy or building membranes.
The researchers wanted to know what would happen if the cells were forced to use these fatty acids elsewhere. To investigate, they put mice on a ketogenic diet consisting of mainly fats and very few carbohydrates or proteins.
The ketogenic diet is known to change cell metabolism, and cells switch to fat burning for energy. This means that cells will lack the fatty acids that facilitate ILC reproduction.
Among the mice fed a ketogenic diet, the division activity of ILCs was found to be drastically decreased. “Normally, contact with allergens increases the number of ILCs in the bronchi fourfold,” said Dr. Wilhelm. “In our experimental animals, however, it remained almost unchanged. Both mucus production and other asthma symptoms decreased accordingly.”
The ketogenic diet also leads to glucose deficiency, which likely contributed to the weakened ILC activity.
“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,” said Dr. Wilhelm.
Going forward, the experts will focus on patients to investigate whether a ketogenic diet can prevent asthma attacks.”We are trying to determine which components of the dietary change are responsible for the effect,” said Dr. Wilhelm. “Maybe this will open the door to the development of new drugs.”
The study is published in the journal Immunity.