While they might sound like healthy choices, a large study in Finland has revealed the detrimental impact of eating most fruits and several grains on diabetes risk. The study also revealed a helpful food ally in fighting off the disease.
The study focused particularly on the way in which the diets of children could impact the development of type 1 diabetes (T1D), a lifelong disease in which the body's immune system mistakenly attacks and kills insulin-producing islet cells in the pancreas. According to the researchers, T1D in children is projected to double in the next 20 years, jumping from 8.4 million cases worldwide in 2021 to 17.4 million by 2024. Finland in particular has the highest rate of the disease in the world; it affects 52.2 children per 100,000 under five years old.
So researchers there followed 5,674 children from the day they were born until they were six years old. During that period, their parents kept meticulous records on everything the children were fed. All of the children in the study were genetically predisposed to developing T1D and, at the end of the six-year period, 94 of them developed the condition and another 206 developed islet autoimmunity, a precursor to T1D.
"To the best of our knowledge, this is the first time a child’s entire diet has been considered at the same time," says Suvi Virtanen, from the Finnish Institute for Health and Welfare in Helsinki, who led the research.
When comparing diets to the development of T1D, the researchers found a definite spike in those who ate more fruit, oats and rye than in those who ate less. They also discovered that eating more bananas, wheat, and fermented dairy products like yogurt increased the risk of islet autoimmunity.
Berry good news
There was some good news in the study as well. The team found that the children who ate more raspberries, blueberries, blackcurrants, lingonberries and other berries lowered the risk of developing T1D. They also found a similar inverse relationship between islet autoimmunity and eating more cruciferous vegetables like cauliflower, broccoli and cabbage.
"Berries are particularly rich in polyphenols, plant compounds which may dampen the inflammation that is associated with the development of type 1 diabetes," says Virtanen. "On the other hand, fruits may contain harmful substances that don’t occur in berries. For example, berries can be free of pesticides that are found on other fruits."
Virtanen says that further research is needed to tease out which compounds in the foods linked to the development of TD1 had either positive or negative impacts. She also says that her team is not making any dietary recommendation based on the findings, as all of the foods linked to negative consequences for T1D have other health benefits.
"Many of the foods that we found to be associated with increased risk of type 1 diabetes and the disease process are considered part of a healthy diet and it is important that our results are replicated in other studies before anyone considers making changes to their child’s diet," she cautions.
The research will be presented this week at the annual meeting of the European Association for the Study of Diabetes (EASD) in Madrid, Spain.
More details needed
Kevin McConway, emeritus professor of applied statistics at the Open University who was not involved in the research, also points out a few other issues in the study. He says that while the findings will be presented at a conference, at this point the hard data backing up the findings in a peer-reviewed paper is lacking, as are hard-and-fast numbers describing the actual increases in T1D risks described. He also says that the population studied might have differences beyond their diets to account for the spike seen in T1D in certain individuals.
"The issue here is that the children who ate different foods would also have differed in many other respects, though we have no detail on exactly which respects," he said. "Maybe the correlations between consumption of different foods and the health outcomes, that the researchers reported, were not caused by the foods but by one or more of the other differences. We just can’t tell."
Source: Diabetologia via EurekAlert
