It was the love of microwave buttered popcorn that caused a relatively healthy 53-year-old American to develop severe breathing problems. The cause of his illness was tracked down to the microwave popcorn he loved so much that he would inhale steam from the bag as it came out of the oven. The link between the man's illness and popcorn was established by Dr Cecil Rose, who had been dealing with popcorn workers' lung for years as a consultant to the food industry. "I said to him this is a very weird question but bear with me, are you around a lot of popcorn? His jaw dropped,' she told The New York Times, 'How could you possibly know that about me? I am Mr Popcorn. I love popcorn'," the patient replied. He had eaten buttery microwave popcorn at least twice a day for the past 10 years. When he broke open the bags, after the steam came out, he would often inhale the fragrance because he liked it so much," Dr Rose said. Dr Rose found levels of diacetyl in the man's home after he made the snack were similar to those in microwave popcorn plants. She put him on a microwave popcorn-free diet. Six months after his diagnosis, the man has lost 50lb and his lung function has improved.
The popped kernels are not the problem; the cause of the condition is a chemical called diacetyl which is used as the butter flavouring. In high levels it is known to cause Popcorn workers lung (because of its prevalence among workers in the food industry) or more, properly, Bronchiolitis obliterans. The condition causes inflammation then destruction of the bronchioles. This results in severe shortness of breath and dry cough. Lung capacity is reduced by about 75%.