It is a perennial problem for lovers of garlic – while the pungent ingredient adds a piquant kick to many otherwise bland dishes, it is also known to cause bad breath.
But now, scientists have discovered that the best way to get rid of the lingering odour is to eat yogurt.
The protein in whole-milk plain yogurt acts to neutralise the garlic smell and counteract the sulphur-based compounds that cause it.
The scientists behind the study, published in the scientific journal Molecules, found that yogurt was most effective in clearing “garlic breath” if it was eaten soon after a meal containing garlic.
Dr Sheryl Barringer, a senior author of the study and professor of food science and technology at Ohio State University in the United States, has previously investigated other foods to explore whether they can lead to fresher breath.
Lettuce, apples, milk and mint have all been shown to combat garlic breath.
Dr Barringer and Manpreet Kaur, a first author of the study and a PhD student in Dr Barringer’s laboratory, placed equal amounts of raw garlic in glass bottles – ensuring the cluster of offending sulphur-based volatiles were released in concentrations that would be detected by the human nose.
They used the analytical tool of mass spectrometry to measure the levels of the volatile molecules in gaseous form which were present both before and after each treatment.
The researchers found that yogurt alone reduced nearly all (99 per cent) of the major, odour-producing raw garlic volatiles.
Fat, water and protein components of yogurt were tested separately and also had a deodorising effect on the raw garlic, with fat and protein performing better than water. A higher butter fat was found to be more effective in cleansing the odour.
The proteins studied included forms of whey, casein and milk proteins that were all effective at deodorising garlic.
But a casein micelle-whey protein complex was found to perform the best.
“High protein is a very hot thing right now,” Dr Barringer explained. “Generally, people want to eat more protein.
“An unintended side benefit may be a high-protein formulation that could be advertised as a breath deodoriser in addition to its nutritional claims.
“I was more excited about the protein’s effectiveness because consumer advice to eat a high-fat food is not going to go over well.
“We know proteins bind flavour – a lot of times that’s considered a negative, especially if a food with high protein has less flavour.
“In this case, it could be a positive.”
Greek yogurt most effective
The researchers additionally tested yogurt’s deodorising effects on fried garlic, but, in the process, discovered that frying the garlic significantly reduces most of its odour-causing volatile compounds anyway.
Dr Barringer said that the study set a good basis to explore how different proteins could be used to create a product to eradicate garlic breath but that in the meantime Greek yogurt, with its higher protein value than whole milk plain yogurt, could be the most effective food to use to freshen breath.
She added that it is important to consume yogurts immediately after eating garlic and that even flavoured yogurts could work.
“With apples, we have always said to eat them immediately,” said Dr Barringer.
“The same with yogurt is presumed to be the case: have your garlic and eat the yogurt right away.”