The company says it has tested 3g of glycine on a group of men with sleep problems. Taking the supplement within an hour before going to bed, the researchers said the subjects showed brainwave patterns associated with non-REM sleep sooner and slept longer than those who did not take the amino acid.
A study of the brains of rats revealed that glycine accumulates in the pineal gland, a part of the brain associated with the rhythms of waking and sleeping.
The market for natural sleep aids could be significant. Over 12 million sleeping pill prescriptions are issued each year in the UK alone, according to the Sleep Council, but conventional sleep aids have unwanted side effects such as drowsiness during the daytime.
Natural products already promoted as a sleep aid include milks with high levels of the hormone melatonin available in the UK and Finland. Research on green tea has found that the plant could also lull the brain into a deep sleep.
Ajinomoto, which has recently reorganised its European ingredients operations to improve operational efficiency and accelerate growth, is seeing growing sales of amino acids. In the year to 31 March 2004, its amino acid division posted a 14 per cent increase in sales to Y154.9 billion, while operating profits from the unit rose by 9.7 per cent to Y26.6 billion.
Most of the improvement came from a sharp rise in sale of feed-use amino acids such as lysine, threonine, and tryptophan, but food-use amino acids also performed well, in particular in Japan where there was strong demand for infusion applications and sales to beverage manufacturers.