A study has suggested that the amount of fat on people's tongues is linked to sleep apnea, a disorder that can leave people gasping for breath at night.
The study, published in the American Journal of Respiratory and Critical Care Medicine, found that when sleep apnea patients lose weight, the reduction in the amount of fat on their tongues causes the resulting improvements.
Obese patients more commonly have larger and fattier tongues but the researchers said that other people with fatty tongues may also be at risk of developing the sleep disorder. They say that they are now planning to determine which low-fat diets are particularly good at slimming down the tongue.
Study author Dr. Richard Schwab of Perelman School of Medicine in Philadelphia said: "You talk, eat and breathe with your tongue - so why is fat deposited there? It's not clear why - it could be genetic or environmental - but the less fat there is, the less likely the tongue is to collapse during sleep."
People with sleep apnea are prone to loud snoring, noisy breathing and jerky movements when asleep. It can also cause sleepiness during the day, which can affect quality of life.
Obstructive sleep apnea is the most common type of this disorder, in which the upper airway gets partly or completely blocked during sleep. The condition can more likely be found in people who are overweight or who have a large neck or tonsils.
The researchers examined 67 people with obstructive sleep apnea who were obese and had lost 10% of their body weight, causing their symptoms to improve by 30%. They found that the patients' weight loss also led to a reduction in the size of a jaw muscle that controls chewing and muscles on either side of the airway.
Dr. Schwab said: "Now that we know tongue fat is a risk factor and that sleep apnea improves when tongue fat is reduced, we have established a unique therapeutic target that we've never had before."
