Eating more whole grains is associated with up to 15% lower mortality, particularly from causes related to cardiovascular disease, according to a large new long-term study from Harvard T.H. Chan School of Public Health (HSPH).
The study, which appeared online January 5 in JAMA Internal Medicine (doi:10.1001/jamainternmed.2014.6283), also found that bran, a component of whole-grain foods, was associated with similar beneficial effects. Bran intake was linked with up to 6% lower overall mortality and up to 20% lower CVD-related mortality. Although eating more whole grains has been previously associated with a lower risk of major chronic diseases, such as type 2 diabetes and CVD, until now there has been limited evidence regarding whole grains’ link with mortality.
- HSPH researchers and colleagues looked at data from more than
74,000 women from the Nurses’ Health Study and more than 43,000 men from the Health Professionals Follow-Up Study who filled out questionnaires about their diet every 2–4 years from the mid-1980s to 2010.
- Adjusting for a variety of factors, such as age, smoking, body mass index, physical activity, and overall diet excluding whole grains, the researchers compared the participants’ whole grain intake with mortality data over an approximately 25-year period.
- Whole-grain intake was associated with up to 9% lower overall mortality and up to 15% lower CVD-related mortality.
- For each serving of whole grains (28 grams/day), overall mortality dropped by 5%; CVD-related mortality fell by 9%.
- In contrast, the researchers found no association between eating whole grains and a lower death rate from cancer.
- They also found no decrease in mortality from eating germ, another essential component of whole grains.
- Replacing refined grains and red meats with whole grains is likely to lower mortality, according to the study.
The Take-Home Message
- Swapping just one serving of refined grains or red meat per day with one serving of whole grains was linked with lower CVD-related mortality: 8% lower mortality for swapping out refined grains, and 20% lower mortality for swapping out red meat.