Cruciferous vegetables such as broccoli and cabbage contain a molecule shown to create a ‘barrier’ in the lungs. Scientists say this can then give the body a boost in fighting off the flu or other respiratory infections.
Immunologist Dr. Andreas Wack, of the Francis Crick Institute, said: ‘People may be less likely to maintain a good diet when they’re ill, so aren’t taking in the molecules from vegetables which make this system work.
‘It’s a good idea to eat lots of cruciferous vegetables anyway.’ But this shows it’s even more important to continue eating them when you’re ill.’
Researchers at the Crick examined a protein called the aryl hydrocarbon receptor (AHR).
Natural molecules found in cruciferous vegetables, like kale and cauliflower, can activate it, kickstarting an internal chain reaction.
The effect AHR has on immune cells is well understood but the new study, published in the journal Nature, have found that it also plays a role in endothelial cells lining blood vessels in the lung.
The lung has a barrier made up of two layers — one of endothelial cells and one of epithelial cells, which allow oxygen to enter. But the barrier has to be kept strong to ward off pollution, viruses and bacteria.
Researchers conducted a series of experiments on mice which found that AHR plays an important role in helping maintain a strong barrier.
Mice with flu were found to have blood in air spaces between their lungs because it had leaked across a damaged barrier.
But AHR appeared to stop it leaking as much. When AHR was ‘overactivated’, less blood was seen.
Mice with enhanced AHR activity, obtained through diet, did not lose as much weight when infected with flu, results showed.
Rodents were also better able to fight off a bacterial infection given to them at the same time as the original virus. When AHR was prevented from being expressed in lung endothelial cells of mice, there was greater damage to the barrier.
Dr Wack added: ‘Until recently, we’ve mainly looked at barrier protection through the lens of immune cells.
‘Now we’ve shown that AHR is important for maintaining a strong barrier in the lungs through the endothelial cell layer, which is disrupted during infection.’
Dr. Claire Brourke, an expert in infection and immunology at Queen Mary University of London, who was not involved, welcomed the research. She said: ‘The exciting part about this study is that it identifies a previously unknown way in which cells lining blood vessels in the lung can contribute to defence against lung damage by flu. -Daily Mail.uk