August 16, 2023 – Vegetables like broccoli and kale should not only dietary heroes due to their fiber content – they could have a hidden power that helps us fight lung infections, based on a study published today within the magazine Nature.
Scientists on the Francis Crick Institute in London have deciphered how certain compounds in these green plants, which belong to the cruciferous family, act as secret signals for a protein that protects essential defense points of the body akin to the intestines and lungs.
When we eat these leafy greens, cabbage, cauliflower and other cruciferous vegetables, they send instructions to a protein called aryl hydrocarbon receptor (AHR) positioned within the blood vessels of our lungs. This ensures a healthy environment in our lung area, which serves as a very important barrier between our internal systems and the skin world.
“When you talk about the immune system, you are talking about barriers that mark the boundary between the inside of areas like the gut and lungs and the outside world,” said Andreas Wack, PhD, principal group leader on the Francis Crick Laboratory for Immunoregulation“The lungs are a place that needs to be protected, but also needs to be very permeable to certain things. In a way, it's a balancing act.”
The effect of the AHR protein on immune cells is well-known, but this study reveals a brand new facet: its influence on the cells that form one in all the 2 layers of the lung barrier.
The researchers tested this by infecting mice with the flu virus and located that the mice that consumed a food regimen wealthy in cruciferous compounds suffered less lung damage.
AHR helped prevent leaks within the lung barrier that resulted in less blood within the lung spaces. Mice with increased AHR activity also resisted weight reduction and were higher capable of fight off each viral and bacterial infections.
“This study is important because it shows how the cells that line the lungs protect against damage after a viral infection and that protection against infectious disease is not the sole job of the immune system,” said Dr. John Tregoning, an infectious disease specialist at Imperial College London. The study shows, he said, that a compound derived from broccoli (and other cruciferous vegetables) could help protect the lungs from viral damage.
The study's findings have “exciting potential for many of us in the pulmonary and intensive care units,” said Dr. Joseph Khabbaza, an intensive care and pulmonary specialist on the Cleveland Clinic.
When lung barriers are destroyed as a consequence of injury or inflammation, fluid entering the airways may cause patients to change into depending on ventilators, he said.
“People who eat poorly and are in poor health have a harder time developing inflammatory diseases, as we have seen with COVID,” Khabbaza said. “Studies like this suggest that it is important to stay healthy before you get sick and to practice healthy behaviors when you are sick.”