Food processing could eliminate health benefits from high-fiber foods

Recent studies have highlighted how fiber can lower consumers’ risk of disease. A new study conducted by researchers from the University of Otago has confirmed those findings, particularly when it comes to diabetes; however, the way food is prepared could affect the benefits linked with fiber. 

The researchers learned that fiber can increase life expectancy for those struggling with diabetes, but opting for processed food can reduce the benefits that come from the nutrient. 

“Whole grain foods are now widely believed to be beneficial, but increasingly products available on the supermarket shelves are ultra-processed,” said researcher Jim Mann.  

Moving away from processed foods

To get to these findings, the researchers conducted two complementary studies. The first study evaluated data from over 8,300 participants with type 1 or type 2 diabetes; the second study analyzed the effect processed foods had on participants with type 2 diabetes. 

In the first study, participants reported on their daily dietary intake, giving the researchers a clear picture of how much fiber they were getting each day. The researchers learned that those who ate more than the recommended serving of fiber each day reduced their risk of premature death by over 30 percent. 

“Try a few different ways for you to increase your fibre intake, see what works best for you,” said researcher Dr. Andrew Reynolds. “If you eat white or refined bread or rolls, try changing to whole grain bread or rolls. Try brown rice, try brown pasta, try adding half a tin of legumes to meals you already make.” 

Building off of these findings, the second study had participants experiment with different types of fiber sources to determine how they affected the body. The manipulation to the participants’ diets occurred over two two-week periods; the participants alternated between heavily processed foods for two weeks and lesser-processed foods for another two weeks. 

Based on blood sugar readings, heavily processed foods yielded poorer health outcomes for the participants than the foods that weren’t as heavily processed. 

Fiber from better sources

Though these studies focused on those with diabetes, the researchers explained that all consumers can benefit from adding more fiber into their diets. However, the source of that fiber can ultimately make the biggest difference. 

“...We are now beginning to understand that how foods are processed is also important, and for whole grains when you finely mill them you can remove their benefits,” said Dr. Reynolds.