High intake of cereal fiber is associated with a reduced risk of type 2 diabetes, independent of risk factors related to age, sex, and lifestyle, reported Dr. Matthias B. Schulze and his associates at the German Institute of Human Nutrition, in Potsdam-Rehbruecke.
In contrast, intake of fruit fiber and vegetable fiber are not significantly associated with diabetes risk, the researchers said.
Dr. Schulze and his associates analyzed data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study to examine the relationship between fiber consumption and diabetes risk. The EPIC study is a multicenter cohort diet study in members of the general European population first recruited in 1994–1998, when they were aged 35–65 years.
A subgroup of subjects in the Potsdam portion of the study was followed every 2–3 years to identify incident cases of diabetes. Dr. Schulze and his associates assessed 25,067 of these subjects. There were 844 incident cases of diabetes identified during a mean of 7 years of follow-up.
The study subjects were divided into quintiles according to their fiber intake. Cereal fiber consumption was inversely associated with diabetes risk. The relative risk for diabetes was 0.73 for subjects in the highest quintile of cereal fiber consumption, compared with those in the lowest quintile, the investigators said (Arch. Intern. Med. 2007;167:956–65).
In contrast, total fiber, fruit fiber, and vegetable fiber intake were not associated, either positively or negatively, with diabetes risk.
Dr. Schulze and his associates also conducted a meta-analysis of nine cohort studies concerning fiber intake and eight concerning magnesium intake and diabetes risk. The meta-analysis “showed an inverse association for cereal fiber and magnesium, but no beneficial effect of other fiber sources,” they noted.