A diet rich in fiber, particularly from whole grains, may cut risk of death from cardiovascular, infectious and respiratory diseases, according to a report that was published online in the Archives of Internal Medicine this week.

Dr Yikyung Park, of the National Cancer Institute (NCI) in Rockville, Maryland, in the US, and colleagues from NCI and AARP also found that dietary fiber was linked to a reduced risk of death from any cause over a nine-year period.

Using data on 388,000 men and women, they calculated that the 20% who ate the most fiber (29.4 grams per day for men and 25.8 grams for women) were 22% less likely to die than the 20% who ate the least (12.6 grams per day for men and 10.8 grams for women).

Diets rich in fiber, the part of plant foods such as fruits, vegetables and whole grains that resists digestion, are thought to lower risk of heart disease, some cancers, diabetes and obesity, wrote the researchers in their background information.

We also know that fiber reduces inflammation, helps bowel movements, lowers blood pressure, reduces cholesterol and improves glucose levels in the blood, promotes weight loss, and binds to agents that potentially cause cancer so they are more likely to be excreted by the body.

Park and colleagues also found that:

  • Higher dietary fiber intake lowered risk of death from cardiovascular, infectious, and respiratory diseases by 24% to 56% in men and by 34% to 59% in women.
  • For men only, the more fiber they ate, the lower their risk of death from cancer.
  • There was a significant link, for both men and women, between a diet rich in fiber from grains but not other sources, and total and cause-specific death.

“The findings remained robust when we corrected for dietary intake measurement error using calibration study data; in fact, the association was even stronger with measurement error correction,” they wrote.

They also noted that the current dietary guidelines for Americans recommend a diet rich in fiber such as vegetables, fruts and whole grains and that they should consume 14 grams of fiber for every 1,000 calories.

“Dietary fiber may reduce the risk of death from cardiovascular, infectious, and respiratory diseases. Making fiber-rich food choices more often may provide significant health benefits,” they concluded.

Park and colleagues used data from 219,123 men and 168,999 women taking part in the National Institutes of Health-AARP Diet and Health Study who had filled in a food frequency questionnaire at the beginning of the study in 1995 and 1996.

They determined cause of death by matching study records to national registries. Over an average of nine years of follow-up, 20,126 men and 11,330 women died.

Funds from the Intramural Research Program of the National Cancer Institute, National Institutes of Health helped pay for the research.

“Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study.”
Yikyung Park; Amy F. Subar; Albert Hollenbeck; Arthur Schatzkin.
Arch Intern Med, Published online 14 Feb 2011.

Additional source: JAMA Archives.

Written by: Catharine Paddock, PhD