The highest intakes of fiber – equivalent to about 30 grams per day for men and 25 grams for women – were associated with a reduction in the risk of dying from cardiovascular, infectious, and respiratory diseases of up to 60 percent, according to findings published in the Archives of Internal Medicine.
“Interestingly, our study found that dietary fiber intake, especially from grains, was inversely associated with the risk of death from infectious and respiratory diseases,” wrote researchers, led by Yikyung Park, ScD.
“Inflammation, a predominant pathphysiologic response in many infectious and respiratory diseases, has been suggested to contribute the progression of these diseases [and] studies have shown that dietary fiber has anti-inflammatory properties:
“The anti-inflammatory properties of dietary fiber could explain, in part, significant inverse associations of dietary fiber intake with infectious and respiratory diseases as well as with CVD death,” they added.
A 2008 International Food Information Council survey found 77 percent of people are proactively trying to consume additional fiber.
Despite such good intentions, however, many Americans only achieve about 50 percent of their recommended amount of 25 to 30 grams of fiber daily.
Packaged Facts estimates that in 2004, 91 percent of all fiber food ingredient sales were of conventional, insoluble-type fibers, which contains cellulose, hemicellulose and lignin and cannot be dissolved in water.
The remaining 9 percent share was split evenly between conventional, soluble-type fibers and emerging, novel fibers. The market researcher projects that insoluble fibers will decrease to 53.3 percent by 2014, while the share for the mostly new or newly refined conventional, soluble-type fibers will decrease slightly to 7.4 percent.
The new study’s findings support the recommendations for intakes, with consumption of between 25 and 30 grams linked to lower risks of dying from a range of diseases.
The National Cancer Institute analyzed data from 219,123 men and 168,999 women participating in the NIH (National Institutes of Health)-AARP Diet and Health Study. Dietary intakes were assessed using food frequency questionnaires.
Over the course of about 9 years of study, 11,330 deaths in women and 20,126 deaths in men were documented.
After crunching the numbers, the researchers found that people with the highest average intakes – between 25 and 30 grams of fiber per day – had a 22 percent lower risk of death from all the causes.
For men, the highest intakes were associated with a reduction in the risk of death from cardiovascular, infectious, and respiratory diseases ranging from 34 to 59 percent in women and 24 to 56 percent in men.
The strongest associations were observed for fiber from grains and no from other sources, added the NCI researchers.
“Our study shows that dietary fiber may reduce the risk of premature death from all causes, especially from CVD and infectious and respiratory diseases,” wrote Dr Park and colleagues.
“The current Dietary Guidelines for Americans recommend choosing fiber-rich fruits, vegetables, and whole grains frequently and consuming 14 g/1000 calories of dietary fiber. A diet rich in dietary fiber from whole plant foods may provide significant health benefits,” they concluded.
Source: Archives of Internal Medicine
Published online ahead of print, doi:10.1001/archinternmed.2011.18
“Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study”
Authors: Y. Park, A.F. Subar, A. Hollenbeck, A. Schatzkin