Harvard T.H. Chan School of Public Health
Eating more whole grains may reduce the risk of premature death,
according to a new meta-analysis by researchers from Harvard T.H. Chan School
of Public Health.
The study found that people who ate the most whole grains (70
grams/day, about 4 servings), compared with those who ate little or no whole
grains, had a lower risk of dying during the study period.
"These findings further support current dietary guidelines
that recommend at least 3 daily servings (or 48 grams) of whole grains to
improve long-term health and prevent premature death," said Qi Sun,
assistant professor in the Department of Nutrition and senior author of the
study.
Previous studies have found that whole grains may reduce risk of
cardiovascular disease (CVD), diabetes, and poor gut health, among other
conditions.
The meta-analysis combined results from 12 published studies, in
addition to unpublished results from the National Health and Nutrition
Examination Survey (NHANES) III and NHANES 1999-2004.
The studies were
conducted in the United States, the United Kingdom, or in Scandinavian
countries between 1970 and 2010. Health information from 786,076 participants
was included in the analysis.
The results showed that people who ate 70 grams/day of whole
grains, compared with those who ate little or no whole grains, had a 22% lower
risk of total mortality, a 23% lower risk of CVD mortality, and a 20% lower
risk of cancer mortality.
Mortality rate is a measure of the number of deaths in a
particular population for a specific period of time.
The researchers note that multiple bioactive compounds in whole
grains could contribute to their health benefits, and that high fiber content
may lower cholesterol production and glucose response and increase satiety.
The researchers recommend that people choose foods that are high
in whole grain ingredients--such as bran, oatmeal, and quinoa--that have at
least 16 grams per serving, while reducing consumption of unhealthy refined
carbohydrates.
One limitation of the meta-analysis was that some of the studies
used were carried out before a more consistent definition of whole grains
became available; therefore, lists of whole grain foods varied substantially
among individual studies.
In addition, as most of the studies were from the
U.S. and Scandinavian countries, it is not known whether these findings can be
generalized to other populations.