Jannina Viljakainen-Diop Defends Her Dissertation - Folkhälsan

26 October 2020

Jannina Viljakainen-Diop Defends Her Dissertation

Jannina Viljakainen-Diop, Master of Health Sciences, started working as a field worker in the Fin-HIT study in 2014. In recent years, she has been writing her doctoral dissertation. Now she receives the reward for her efforts as her dissertation day approaches.

Jannina, what is the subject of your doctoral dissertation?

I have investigated eating habits and their relation to obesity, overweight and underweight, as well as to saliva microbiota in preadolescents. I wrote my master's thesis on iron deficiency anemia in pregnant and breastfeeding women. Therefore, it felt interesting and meaningful to build on with new knowledge about children and preadolescents’ eating habits.

Why is it important to explore this particular topic?

Eating habits are strongly associated with health and weight, and as we know, obesity is a major health problem among children and adolescents. Adolescence is a critical developmental period, and habits formed during childhood and adolescence usually persist into adulthood. Therefore, it is important to understand what is happening at this stage of life. In Finland, the eating habits of adults and young children have been studied extensively, but there is less knowledge about preadolescents from large cohort surveys. The associations between saliva microbiota and eating habits are even less known.

What are the key findings of your research?

In my doctoral dissertation, it emerged that preadolescents have a lot to improve regarding the current use of vegetables, fruits and berries. Many also skip meals. Those who did not eat breakfast were at greater risk of overweight and obesity. In addition, the saliva microbiota was more diverse in those who ate breakfast and dinner regularly compared to those who skipped these meals. An interesting finding was that Prevotella bacteria was more abundant in those who skipped meals and ate vegetables less often. Prevotella in the mouth has previously been linked to periodontitis (gum disease), but on the other hand, it has been found to be more abundant in the intestinal microbiota of vegetarians compared to omnivores. This shows that this topic needs to be explored further. Abundant consumption of vegetables, fruits and berries as well as a regular meal rhythm supports health, and therefore it is important to encourage children and adolescents to do so.

Jannina Viljakainen-Diop's dissertation will take place on Wednesday, October 28, 2020 at 9 at the University of Helsinki. It is possible to follow the event remotely via this link (live stream password 959595). The title of the doctoral dissertation is “Eating habits, body mass and saliva microbiota in Finnish adolescents” (Dietary habits, weight and the bacterial flora of saliva in young Finns). The opponent is Professor Lauren Lissner from the University of Gothenburg and the Custos Professor Anna-Elina Lehesjoki. You can read the dissertation (in English) and its summary (in Finnish and English) here.