Written by Marcia J. Egles, MD. This study of 367,442 adults, ages 50 – 71, demonstrated that those with the highest intake of whole grains  had a 17% lower risk of all cause mortality. In the highest grain intake group, those with diabetes showed the greatest mortality reduction rate of 48%.

According to a recent large population study from the U.S. National Institute of Health, a diet rich in whole grains was associated with lower rates of death during a fourteen year study period. The study found consumption of whole grains to be associated with both lessened overall mortality rates, as well as lessened mortality rates specifically from cancer, cardiovascular disease, diabetes, respiratory disease and infections. The data also suggested cereal fiber as one potentially protective component of this effect. (1)

In other studies, evidence has accumulated that consumption of whole grain products, and especially of dietary fiber found within grain, may reduce the risk of chronic disease. (2,3,4) Few studies however approach the magnitude of the present study of 367,442 adults followed for an average of 14 years.

The NIH-AARP Diet and Health Study included 566,399 American Association of Retired Persons members aged 50 to 71 starting in 1995. From this population, the current study selected 367,442 participants who had completed dietary questionnaires and who were without significant known major diseases such as cancer, diabetes or heart disease at baseline. Forty-four per cent of the participants were female. Forty-six thousand and sixty-seven cause-specified deaths were documented from the AARP database until 2009.

Whole grains are the germ, bran and endosperm seed components of the grain together. In the study, a food was counted as “whole grain” if it contained at least 25% whole grain or bran. The sources of whole grain in this study included breakfast cereals, breads, popcorn, rice and pastas. The dietary data was gathered only one time at the start of the study.

When the data was examined, there was a link between lower intakes of whole grains and higher rates of mortality over the 14 years. As compared with individuals with the lowest intake (the lowest fifth) of whole grains, those in the highest intake group (the top fifth) had a 17 % lower risk of all-cause mortality ( p trend less than 0.0001). Depending on the disease, disease-specific mortality ranged from 11 to 48% lower in the top whole grain intake group compared to those in the lowest intake group. Diabetes was the disease showing the 48% mortality rate reduction.

The presence of cereal fiber in whole grain was thought to be one potentially protective component of whole grain.  When the dietary cereal fiber component was statistically evaluated, the results mirrored the results seen with whole grain, but only significantly (p trend less than 0.029) for cancer and diabetes deaths. This study adds to a growing body of evidence of a beneficial effect of whole grain and cereal fiber in the diet.

Source: Huang et al. Consumption of whole grains and cereal fiber and total and cause-specific mortality: prospective analysis of 367,442 individuals. BMC Medicine (2015) 13:59 DOI 10.1186/s12916-015-0294-7. C 2015 Huang et al; Licensee BioMed Central.

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Posted May 11, 2015

References:

  1. Huang, Tao et al.  Consumption of whole grains and cereal fiber and total and cause-specific mortality: prospective analysis of 367,442 individuals.  BMC Medicine (2015) 13:59 DOI 10.1186/ s12916-015-0294-7.
  2. Pak Y, et al. Dietary fiber intake and mortality in the NIH-AARP diet and health study.  Arch Intern Med. 2011; 171;1061-8.
  3. De Munter, JS et al. Whole grain brain, and germ intake and risk of type-2 diabetes, a prospective cohort study and systematic review. PLoS Med 2007:4:e261.
  4. 4. Mellen PBet al.  Whole grain intake and cardiovascular disease: a meta-analysis.  Nutr Metab Cardiovasc. Dis. 2008, 18: 283-90.