A new meta-analysis examines 40 years’ worth of research in an attempt to find out the ideal amount of fiber that we should consume to prevent chronic disease and premature mortality.
Researchers and public health organizations have long hailed the benefits of eating fiber, but how much fiber should we consume, exactly? This question has prompted the World Health Organization (WHO) to commission a new study. The results appear in the journal The Lancet.
The new research aimed to help develop new guidelines for dietary fiber consumption, as well as reveal which carbs protect the most against noncommunicable diseases and can stave off weight gain. Noncommunicable diseases are also called chronic diseases. They typically last for a long time and progress slowly. According to WHO, there are “four main types of noncommunicable diseases:” cardiovascular diseases, cancer, chronic respiratory diseases, and diabetes.
Professor Jim Mann, of the University of Otago, in New Zealand, is the corresponding author of the study, and Andrew Reynolds, a postdoctoral research fellow at Otago’s Dunedin School of Medicine, is the first author of the paper. Prof. Mann explains the motivation for the study, saying, “Previous reviews and meta-analyses have usually examined a single indicator of carbohydrate quality and a limited number of diseases, so it has not been possible to establish which foods to recommend for protecting against a range of conditions.”
To find out, the researchers performed a meta-analysis of observational studies and clinical trials.
Reynolds and colleagues examined the data included in 185 observational studies — amounting to 135 million person-years — and 58 clinical trials which recruited over 4,600 people in total. The studies analyzed took place over almost 40 years. The scientists investigated the incidence of certain chronic diseases, as well as the rate of premature deaths resulting from them.
These conditions were: coronary heart disease, cardiovascular disease, stroke, type 2 diabetes, colon cancer, and a range of obesity-related cancers, such as breast cancer, endometrial cancer, esophageal cancer, and prostate cancer. Overall, the research found that people who consume the most fiber in their diet are 15–30 percent less likely to die prematurely from any cause or a cardiovascular condition, compared with those who eat the least fiber.
Consuming foods rich in fiber correlated with a 16–24 percent lower incidence of coronary heart disease, stroke, type 2 diabetes, and colon cancer.
