Writing in Clinical Nutrition, the team behind the work note that while legumes such as lentils, chickpeas, beans and peas, have long been though to offer protection against type 2 diabetes, to date there has been little research to confirm this association.
The study analysed data from more than 3,000 people at high risk of cardiovascular disease but without type 2 diabetes at the beginning of the PREDIMED study. After 4 years of follow-up, the results showed that compared to individuals with a lower consumption of total legumes, those with a high consumption had a 35% lower risk of developing diabetes.
“A higher consumption of total legumes, especially lentils, was associated with a lower risk of type 2 diabetes development,” revealed the authors – led by senior researcher and corresponding author Jordi Salas-Salvadó from Rovira i Virgili University, University Hospital of Sant Joan de Reus, and Institute of Health Carlos III in Spain.
“The substitution of legumes for other protein- or carbohydrate-rich foods is also associated with a lower risk of type 2 diabetes,” added the team. “However, given the mixed results from previous researches, further studies are needed to confirm our findings and elucidate which mechanisms are involved.”
Salas-Salvadó and colleagues looked at data from 3,349 participants involved in the PREvención con DIeta MEDiterránea (PREDIMED). All participants were classed as ‘at risk’ for type 2 diabetes, however none had the condition at study onset.
Dietary information was assessed at baseline and during a yearly during follow-up for four years – and was compared to incidence of type 2 diabetes in the group to attain risk levels for different consumption levels.
The team reported that compared to the lowest intakes of total legumes, at 12.73 grams/day, (approximately equivalent to 1.5 servings per week of 60g of raw legumes), those with a higher consumption of around 28.75 grams/day (equivalent to 3.35 servings per week) had a 35% lower risk of developing type 2 diabetes.
When looking at different subtypes of legume, lentils in particular were seen to associated with a lower risk of type 2 diabetes. Indeed, those participants who had a higher consumption of lentils during the follow-up (nearly 1 serving/week) compared to those individuals with a lower consumption (less than half a serving per week), had a 33% lower risk of developing the disease.
Consumption of chickpeas was borderline significantly associated with a lower risk of type 2 diabetes incidence, said the team – who revealed that when the intake of dry beans and fresh peas alone was looked at, no significant association was found.
“It should be underlined that the theoretical effect of substituting half a serving/day of legumes for half a serving/day of other foods rich in protein or carbohydrates, including eggs, wholemeal and white bread, rice or baked potato, was associated with a significant lower risk of type 2 diabetes incidence,” said the authors.
Source: Clinical Nutrion
Published online ahead of print, doi: 10.1016/j.clnu.2017.03.015
“Legume consumption is inversely associated with type 2 diabetes incidence in adults: a prospective assessment from the PREDIMED study”
Authors: Nerea Becerra-Tomás, et al