The research, published in Nutrition, analysed data from more than 1200 Chinese people, finding that those who had the highest intakes of MSG had a higher probability of sleep-disordered breathing (SDB) – a range of breathing abnormalities that occur during sleep, including obstructive sleep apnea (OSA), central sleep apnea, and periodic breathing.
Led by Zumin Shi from the Jiangsu Provincial Center for Disease Control and Prevention, China, the research team analysed data from 1227 Chinese subjects who participated in the Jiangsu Nutrition Study, finding that those with high intakes of MSG were also at higher risk from SDB.
“We found a positive association between the intake of MSG at baseline and snoring and SDB at follow-up in Chinese adults with a normal body weight,” said the researchers, who added that there was “a significant additive interaction between overweight and MSG intake in relation to snoring and SDB.”
Shi and colleagues compared the ‘extreme quartiles’ of MSG intake in subjects with a body mass index lower than 23, finding that those with the highest intake had higher incidence of snoring – odds ratio of 2.02 (95% confidence interval 1.02–4.00) – and SDB – odds ratio of 3.11 (95% confidence interval 1.10–8.84).
However, the research team noted that the findings are limited because the study used self-reported sleep data instead of the more valid polysomnographic method to confirm the diagnosis of SDB.
“Another limitation is the measurement of MSG consumption, which was determined by the total amount of MSG consumed in the household divided by the number of individuals per household and then adjusted for the proportion of the household energy intake,” said Shi and colleagues.
“This method may under or overestimate MSG intake, although in a large epidemiologic study, this would be the most practical way of measuring MSG consumption.”
Published online ahead of print, doi: 10.1016/j.nut.2012.08.011
“Association between monosodium glutamate intake and sleep-disordered breathing among Chinese adults with normal body weight”
Authors: Zumin Shi, Gary A. Wittert, Baojun Yuan, Yue Dai, Tiffany K. Gill, et al