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A clinical-culinary study to investigate bad breath

I'd like some gyros with tzatziki, please!

Bad breath, or halitosis, can have a variety of causes. Often bacterial activity is cited, based on inadequate dental hygiene. Sometimes the odor comes from gingivitis or other infections in the oral cavity. In addition, the consumption and food habits may play a role. For example, the intake of tobacco, alcohol, garlic and onions support the occurrence of bad breath.

When we were asked to investigate the ability of a toothpaste to reduce consumption-related bad breath, our project team had to answer the question of how the bad breath was to be produced in the participating 60 subjects. In this case, tobacco and alcohol were ruled out as possible mouth odor triggers, with discussion of an alcohol halitosis study alone adding to the general amusement.

Relatively quickly, the intake of 'garlic and onions' was favored as a possible bad breath trigger, but the question of form remained: Can we expect subjects to eat raw garlic cloves and onions? No. What if we serve pickled garlic and onions? No. Maybe serve a garlic and onion smoothie? Absolutely not!

In the end, everyone on the team agreed that the Greek classic 'gyros with tzatziki' would be a not only reasonable, but quite attractive option. In the interest of maximum standardization, the study protocol called for the intake of 200 grams of gyros, with a defined amount of onion rings and tzatziki, with a defined tzatziki recipe consisting of natural yogurt, peeled and finely grated cucumber, pressed garlic and salt and pepper.

On the day of the trial, the food was served by our study technician, Kerstin Janssen, who had to be specially provided with a health certificate for handling food. With a well-filled stomach, the next step was for the test subjects to undergo a baseline examination and then to use the test product, i.e. to brush their teeth. Subsequently, several organoleptic examinations of the breath were carried out up to 4 hours after the meal and the odor intensity was documented on a 5-point scale. In addition, the subjects were asked about their subjective perception.

This project excellently demonstrates that standard solutions are only sufficient in the case of standard studies. A conventional study of oral odor would have been inappropriate here. It is precisely this agility that distinguishes us and that our team enjoys. The particularly nice thing about this project: the team was happy about the challenge, the sponsor about the results and the volunteers about the food.

The study tzatziki recipe:

  • 500 g natural yogurt
  • 1/2 cucumber
  • 3 garlic cloves
  • Salt and pepper

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