Even the sugar of a glass of apple juice affects the oral flora

Sugar consumption changes oral flora and favors tooth decay

The fact that increased sugar consumption can damage one's health and, among other things, lead to tooth decay, is known to most people. But according to researchers, even the sugar from a glass of apple juice can change the oral flora and promote tooth decay.

Health problems due to high sugar consumption

Nutrition and health experts repeatedly warn against increased sugar consumption. When consumed frequently, the sweetener can lead to enormous health problems such as obesity, hypertension or diabetes. In addition, sugar promotes the development of tooth decay (tooth rot). Researchers now point out that even very small amounts of the sweetener can have a negative effect on the oral flora.

A new study has shown that even the sugar of one glass of apple juice a day may possibly be enough for the oral flora to change substantially. (Image: SBH / fotolia.com)

Danger to the teeth

Only recently, a study was published that showed that high sugar consumption in the world leads to billions in dental treatment costs.

But even relatively low sugar consumption can hurt.

As researchers at the University Hospital of Freiburg have now demonstrated for the first time, even the sugar of one glass of apple juice may possibly be enough daily for the oral flora to change substantially.

The study was recently published in the journal "Scienfic Reports".

Caries specific changes in the oral flora

"Changing dietary habits obviously lead to caries-specific changes in the oral flora quite quickly," explained study leader Prof. Dr. med. Elmar Hellwig, Medical Director of the Department of Dentistry and Periodontics of the University Hospital Freiburg, in a statement.

"Especially harmful to the teeth are foods such as sweets or fruit drinks for children, where the sugar stays in the mouth for a long time."

Worldwide, around 2.4 billion people suffer from tooth decay. Holes in the teeth, toothache and inflammation are the result.

The cause is the "extended ecological plaque hypothesis". This states that high consumption of sugars particularly multiply those types of bacteria that produce a great deal of acid as a waste product.

This acid in turn dissolves the calcium from the tooth and causes the holes. Other, protective bacterial species are therefore lost. Whether this hypothesis is correct, but so far could not be clarified under natural conditions.

Every German consumes about 90 grams of sugar every day

The study participants sucked five times two grams of sugar candy a day for three months during the test.

What sounds great at first is only a fraction of the daily sugar dose. Every German consumes about 90 grams of sugar on average during the day. Even a glass of apple juice contains about ten grams.

In the study, the eleven volunteers initially fed five weeks as usual. Then followed the three months with additional sugar candy. During the whole time, the probands brushed their teeth normally.

Towards the end of the control and testing phases, the subjects wore a dental splint containing small pieces of bovine teeth several times for seven days. These are similar in structure to strong human teeth and are therefore often used for testing purposes.

"The subjects were able to remove the splint for eating and brushing teeth. So her own dental health was not endangered. At the same time, a bacterial plaque was formed undisturbed on the dental specimens, "said first author Dr. Annette Carola Anderson, biologist at the Department of Dentistry and Periodontics of the University Hospital of Freiburg.

Together with scientists from the Helmholtz Center Munich, the researchers examined the bacterial plaque, also called biofilm, from a molecular-genetic point of view.

Sugar intake leads to reduced bacterial biodiversity in the mouth

They found that during the consumption of sugar, the number of different types of bacteria decreased significantly. However, individual bacterial species increased more strongly, such as the Streptococcus bacteria involved in caries.

"For the first time, we can confirm the assumption that sugar consumption leads to a reduced abundance of bacteria in the mouth," said co-study director Prof. Dr. med. Ali Al-Ahmad, Laboratory Director and Head of Oral Microbiology at the Department of Dentistry and Periodontics, University Hospital Freiburg.

"Obviously, there is not one species responsible for tooth decay, but many are involved in the genesis."

Under the microscope, the researchers examined whether the demineralization typical for caries was recognizable.

"We found evidence, but no clear evidence. That's why we want to carry out the study with more subjects and a longer duration, "says Prof. Al-Ahmad. (Ad)