Research shows that higher fiber intakes "have resulted in a reduction in the incidence of a surprisingly large number of relevant diseases (heart disease, type 2 diabetes, and colorectal cancer)," a reduction in weight body and total cholesterol and reduced mortality, Reynolds wrote. Similar results have been shown with the increase in whole grain intakes.
The World Health Organization has commissioned the Reynolds team to inform future recommendations on fiber intake.
The researchers analyzed more than 180 observational studies and 50 clinical trials conducted over the last four decades. That's the strength of the analysis, said co-author Jim Mann, professor of nutrition and human medicine at the University of Otago.
"The health benefits of dietary fiber seem to be even greater than we once thought," Mann said of the results.
The analysis revealed a 15% to 30% reduction in the risk of death and chronic disease among those who had the highest fiber intake in their diet compared to those with the lowest intake. .
A high-fiber diet was associated on average with a 22% reduction in risk of stroke, 16% risk of type 2 diabetes and colorectal cancer, and a 30% reduction in risk of death. by coronary heart disease.
Most people consume about 20 grams of dietary fiber a day in the world, said Mann about the results. According to his research, he recommends daily consumption of 25 grams (0.88 ounces) to 29 grams (1.02 ounces) of fiber. Higher amounts are even more beneficial, according to the analysis.
An increase of 15 grams (0.52 oz) of whole grains consumed per day was associated with a 2% to 19% reduction in the total number of deaths and the incidence of coronary heart disease, type 2 diabetes, and colorectal cancer.
The study notes that the relationship between high fiber / whole grain consumption and a reduction in noncommunicable diseases could be causal.
The analysis revealed no danger with a high fiber intake. But he adds that for people with iron deficiency, high levels of whole grains can further reduce iron levels.
The authors note that carbohydrates include sugars, starches and dietary fiber. "However, sugars, starches and fibers are all carbohydrates that play different roles in the body," Reynolds wrote.
The fiber content It turned out to be a better indicator of the ability of a carbohydrate food to prevent a disease than the glycemic index, which measures the degree of increase in blood sugar after eating. A particular food.
The study revealed a small reduction in the risk of Stroke and Type 2 Diabetes in people who adhere to a low glycemic diet, which includes foods like green leafy vegetables, most fruits, kidney beans and breakfast cereals.
The glycemic index is not as good as that of dietary fiber to determine if a food is a good food containing carbohydrates, Mann said. Foods that do not increase blood sugar can still contain a lot of sugars, saturated fats and sodium. Ice cream, for example, has a low glycemic index but contains a lot of sugar.
One of the limitations of the analysis is that the studies focused only on healthy people. Therefore, the results do not apply to people with pre-existing chronic disease. In addition, most studies have been conducted in Western societies. it is not "100% sure" that the results therefore apply to the less favored companies, Mann explained.
Brian Power, dietician and nutrition lecturer at University College London, said the analysis was "very robust" and "powerful". Power, who did not participate in the research, said it was the "best evidence in terms of synthesizing what we know".
"Any increase in dietary fiber consumption is good for your health," he added. small changes in the diet to get a health benefit. A person can add 8 grams of fiber to his diet with a breakfast consisting of flakes of bran, four dried apricots and a handful of almonds.
Reynolds advised, "The practical ways to increase fiber intake is to base meals and snacks around whole grains, vegetables, legumes and whole fruits."
Helen Stokes-Lampard, president of the Royal College of General Practitioners, wrote in an e-mail that "adopting a healthy lifestyle is an obvious way to improve one's health, safety and health outcomes. Feeding a balanced diet, exercising regularly and getting enough sleep, drinking alcohol in moderation and not smoking is essential. "
"We have long known that eating high fiber foods is good for us and helps to ease digestion," wrote Stokes-Lampard, who did not participate in the new analysis, "so it's reassuring to see This high quality product has been researched to show how important these benefits can be to our long-term health and well-being, and why it is so important to include these foods in our diets. . "