fibres-alimentaires

The link between poor diet quality and the risk of developing type 2 diabetes has been established by many scientific investigations. Some of these studies have suggested that people with a high dietary intake of fibres could have lower odds of developing type 2 diabetes. However, most of these studies have been performed in the United States and few large studies on this topic have been conducted in European countries. Additionally, the relationship between dietary fibres sources and the risk of developing type 2 diabetes is not clearly established, especially in European populations.

In the latest issue of Diabetologia (http://www.diabetologia-journal.org/files/InterActConsortium.pdf), investigators of the EPIC-InterAct Study have sought to establish the association between dietary fibres intake and the risk of developing type 2 diabetes in a subcohort that included study participants from eight European countries: Denmark, France, Germany, Italy, the Netherlands, Spain, Sweden and the United Kingdom. The study included 12,403 study participants who developed type 2 diabetes during the course of the 11 years of study follow-up who were compared to 16,835 participants from the same study who did not develop type 2 diabetes during the study follow-up. Dietary intake over the previous 12 months before recruitment was assessed using food frequency questionnaires and the amount of dietary fibre intake from cereals, fruits and vegetables was also obtained. The authors found that compared to the individuals of the bottom quartile of dietary fibre intake (<18,9 g/day), those in the top quartile (>26,4 g/day) had an 18% reduced risk of developing type 2 diabetes, even after taking into account other lifestyle and dietary factors that may correlate with dietary fibre intake. After adjusting for body mass index, the association between dietary fibre and type 2 diabetes risk was no longer observed, which suggests that people of who eat more fibre could be at reduced risk of diabetes because they are usually characterized by a lower body weight, and more specifically lower levels of abdominal adiposity.  Interestingly, when the investigators studies fibres sources, they found that fibres derived from cereal and vegetables, but not fruits were most strongly associated with type 2 diabetes risk reduction.

Speculating on the mechanisms that could link fibre intake to type 2 diabetes risk, the investigators suggested that other beneficial micronutrients which are frequently consumed along with fibre-rich foods such as magnesium and vitamin B1, C and E. They also suggested that the low glycaemic index of diets rich in total or cereal fibre could favourably impact blood sugar levels and the longer-term risk of type 2 diabetes. The beneficial impact of fibres on the gut microflora diversity and on the production of appetite-regulating peptides has also been suggested to potentially explain these associations.

This study is one of the largest studies thus far to have investigated the relationship between total and food-specific fibre intake and the risk of type 2 diabetes. This study has some limitations. For instance, the data on fibre intake was self-reported. Additionally, the observational study design cannot enable the authors to conclude that fibres are directly implicated in the pathophysiology of type 2 diabetes. However, based on the results of the EPIC-InterAct investigators and many previous intervention studies, it is reasonable to conclude that dietary fibres, especially those found in vegetables and cereal are part of a healthy dietary pattern that is associated with a reduced risk of developing type 2 diabetes in the longer term.